View Full Version : Single photon self-interference over time.
Patrick Powers
Jun12-04, 07:19 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>I happened across a 1999 thread entitled "Length of wavetrain of a\nsingle photon". The experimental setup is an inferometer with paths\nof unequal length. The questions are, how much may the lengths differ\nbefore the interference pattern disappears? and, what if there is\nonly a single photon present in the system?\n\nIt was stated that the difference in length depends on the coherence\nlength of the light source. The longer the coherence length, the\ngreater the difference in path length may be. It was also stated that\nfor linear optics it is well known that intensity of light makes no\ndifference to interference patterns.\n\nSo it would seem that if we feed light from a coherent source into the\ninferometer at very low intensity then we have a single photon\ninterfering with itself over paths of quite different lengths. So it\nappears that this photon is not traveling at c. This is a problem.\n\nHere is a proposed solution, which is that it is that as the coherence\nlength increases it becomes less likely that a single photon can exist\nalone in the system. In other words, as the coherence length\nincreases the photons are more likely to come in groups. This is an\nif and only if situation, so the condition of the single photon\ninterfering with itself in this way cannot occur.\n\nI\'m told that wavelength and number of photons are conjugate and have\nan inherent uncertainty. As the wavelength is more precisely known\nthe number of photons is more uncertain. (I don\'t know how phase fits\ninto this, so this may not be quite right.) Now consider a laser.\nThis would mean that as the coherence length increases, the number of\nphotons in the laser becomes less certain. The number of the photons\nproduced by the laser in a given unit of time becomes less certain.\nThis means that the photons tend to clump together in time. (I fairly\nsure this can be proved. The basic idea is that the distribution of\nthe photons deviates from Poisson, and autocorrelation is the only way\nthis can occur.)\n\nScorning the firm but tiresome ground of mathematics and moving boldly\ninto the bog of intuition I propose the following. To maintain\ncoherence the photons must travel in a pack. So a light source with\nlong coherence length necessarily emits packets, not single photons.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>I happened across a 1999 thread entitled "Length of wavetrain of a
single photon". The experimental setup is an inferometer with paths
of unequal length. The questions are, how much may the lengths differ
before the interference pattern disappears? and, what if there is
only a single photon present in the system?
It was stated that the difference in length depends on the coherence
length of the light source. The longer the coherence length, the
greater the difference in path length may be. It was also stated that
for linear optics it is well known that intensity of light makes no
difference to interference patterns.
So it would seem that if we feed light from a coherent source into the
inferometer at very low intensity then we have a single photon
interfering with itself over paths of quite different lengths. So it
appears that this photon is not traveling at c. This is a problem.
Here is a proposed solution, which is that it is that as the coherence
length increases it becomes less likely that a single photon can exist
alone in the system. In other words, as the coherence length
increases the photons are more likely to come in groups. This is an
if and only if situation, so the condition of the single photon
interfering with itself in this way cannot occur.
I'm told that wavelength and number of photons are conjugate and have
an inherent uncertainty. As the wavelength is more precisely known
the number of photons is more uncertain. (I don't know how phase fits
into this, so this may not be quite right.) Now consider a laser.
This would mean that as the coherence length increases, the number of
photons in the laser becomes less certain. The number of the photons
produced by the laser in a given unit of time becomes less certain.
This means that the photons tend to clump together in time. (I fairly
sure this can be proved. The basic idea is that the distribution of
the photons deviates from Poisson, and autocorrelation is the only way
this can occur.)
Scorning the firm but tiresome ground of mathematics and moving boldly
into the bog of intuition I propose the following. To maintain
coherence the photons must travel in a pack. So a light source with
long coherence length necessarily emits packets, not single photons.
Rahul Jain
Jun14-04, 03:07 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>frisbieinstein@yahoo.com (Patrick Powers) writes:\n\n> I\'m told that wavelength and number of photons are conjugate and have\n> an inherent uncertainty. As the wavelength is more precisely known\n> the number of photons is more uncertain.\n\nThis is not true. The uncertainty is between position and momenutm.\nMomentum is related to wavelength -- the lower the wavelength, the more\nmomentum. As you constrain the possible momenta, the possible positions\nof the particle become more widely spread. This is a consequence of\napplying wave mechanics to the wavefunctions of particles. It falls out\nrather trivially once you undersand both underlying principles.\n\nWhat you should read is QED by Richard Feynman. It\'s a wonderful\nexplanation of the phenomenon of wavefunction propagation and\ninterference without a single bit of formal math.\n\n--\nRahul Jain\nrjain@nyct.net\nProfessional Software Developer, Amateur Quantum Mechanicist\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>frisbieinstein@yahoo.com (Patrick Powers) writes:
> I'm told that wavelength and number of photons are conjugate and have
> an inherent uncertainty. As the wavelength is more precisely known
> the number of photons is more uncertain.
This is not true. The uncertainty is between position and momenutm.
Momentum is related to wavelength -- the lower the wavelength, the more
momentum. As you constrain the possible momenta, the possible positions
of the particle become more widely spread. This is a consequence of
applying wave mechanics to the wavefunctions of particles. It falls out
rather trivially once you undersand both underlying principles.
What you should read is QED by Richard Feynman. It's a wonderful
explanation of the phenomenon of wavefunction propagation and
interference without a single bit of formal math.
--
Rahul Jain
rjain@nyct.net
Professional Software Developer, Amateur Quantum Mechanicist
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Patrick Powers <frisbieinstein@yahoo.com> writes\n>I happened across a 1999 thread entitled "Length of wavetrain of a\n>single photon". The experimental setup is an inferometer with paths\n>of unequal length. The questions are, how much may the lengths differ\n>before the interference pattern disappears? and, what if there is\n>only a single photon present in the system?\n\nAh, yes, that was mostly me thrashing about trying thought experiments.\nBased largely on a misconception (mine).\n\nIMHO (based on infinite ignorance) it makes (much) more sense to\nconsider the photon beam as a wave. That is entirely a wave, with no\nquantum aspect at all. The clincher was an experiment where two\n*different* (but highly stable) lasers sent a lightbeam each through\n*one* slit of a two slit interferometer. No matter how much you\nattenuate the beams you always get a diffraction pattern. Even if,\nnaively, there is never more than one photon from one of the lasers in\nthe apparatus at any one time.\n\nObviously if you consider light as a maxwellian wave, then there is no\nlimit to the level of attenuation of the field you can have and it still\nbe a continuous wave, and the result found is absolutely as expected.\n\nThe descriptions where a photon is considered particulate obtain the\nsame result (I am assured, and do not disbelieve). This is because (as\nfar as I can grasp) these descriptions are most cleverly and subtly\ndrawn up. For example there can be no knowledge of the number of photons\nin either laser beam, adding or subtraction one does *not* alter the\ndescription. I also suspect time-averaging is also (for a laser) hidden\nin the description. The net result seems to be that it effectively works\nout that the probability is high of being either no photons in the\napparatus, or two (one from each), at any given time. This shows what a\nneat formulation it is, and for more particulate particles (like\nelectrons) I imagine it is a most powerful tool to use.\n\nIMHO (which is probably considered by most here to be a cranky one), the\nquantum nature of light is a consequence of the quantum nature of the\ndetector. The particle formulation (qed/dirac) is one where one can in\neffect brilliantly cancel nasty integrations to obtain a result very\nsimply or is a brilliant technique to visualise (and obtain a numerical\nresult) a complex and nasty analytical function. I am not sure if there\nis any other way known to obtain results without using these techniques.\nWhich doesn\'t mean that a particle is in fact an infinitesimal point,\nany more than an integrated curve is a collection of infinitesimal line\nsegments.\n\nThe net result is to note that neither the particulate description, nor\nthe wavelike description, actually describe a laser beam as a stream of\nindividual photon bullets. In particular the particulate description\ndoesn\'t really describe the laserbeam-in-flight at all, but does\ndescribe (accurately) its generation and interaction with any targets.\nSince both generation and interaction with (most) targets are with\nquantised systems (typically atoms changing energy state), one obtains a\nquantised result.\n\nWell, my 2c worth, anyway.\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com (whitelist check on first posting)<<\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Patrick Powers <frisbieinstein@yahoo.com> writes
>I happened across a 1999 thread entitled "Length of wavetrain of a
>single photon". The experimental setup is an inferometer with paths
>of unequal length. The questions are, how much may the lengths differ
>before the interference pattern disappears? and, what if there is
>only a single photon present in the system?
Ah, yes, that was mostly me thrashing about trying thought experiments.
Based largely on a misconception (mine).
IMHO (based on infinite ignorance) it makes (much) more sense to
consider the photon beam as a wave. That is entirely a wave, with no
quantum aspect at all. The clincher was an experiment where two
*different* (but highly stable) lasers sent a lightbeam each through
*one* slit of a two slit interferometer. No matter how much you
attenuate the beams you always get a diffraction pattern. Even if,
naively, there is never more than one photon from one of the lasers in
the apparatus at any one time.
Obviously if you consider light as a maxwellian wave, then there is no
limit to the level of attenuation of the field you can have and it still
be a continuous wave, and the result found is absolutely as expected.
The descriptions where a photon is considered particulate obtain the
same result (I am assured, and do not disbelieve). This is because (as
far as I can grasp) these descriptions are most cleverly and subtly
drawn up. For example there can be no knowledge of the number of photons
in either laser beam, adding or subtraction one does *not* alter the
description. I also suspect time-averaging is also (for a laser) hidden
in the description. The net result seems to be that it effectively works
out that the probability is high of being either no photons in the
apparatus, or two (one from each), at any given time. This shows what a
neat formulation it is, and for more particulate particles (like
electrons) I imagine it is a most powerful tool to use.
IMHO (which is probably considered by most here to be a cranky one), the
quantum nature of light is a consequence of the quantum nature of the
detector. The particle formulation (qed/dirac) is one where one can in
effect brilliantly cancel nasty integrations to obtain a result very
simply or is a brilliant technique to visualise (and obtain a numerical
result) a complex and nasty analytical function. I am not sure if there
is any other way known to obtain results without using these techniques.
Which doesn't mean that a particle is in fact an infinitesimal point,
any more than an integrated curve is a collection of infinitesimal line
segments.
The net result is to note that neither the particulate description, nor
the wavelike description, actually describe a laser beam as a stream of
individual photon bullets. In particular the particulate description
doesn't really describe the laserbeam-in-flight at all, but does
describe (accurately) its generation and interaction with any targets.
Since both generation and interaction with (most) targets are with
quantised systems (typically atoms changing energy state), one obtains a
quantised result.
Well, my 2c worth, anyway.
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com (whitelist check on first posting)<<
Charles Francis
Jun27-04, 05:56 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>In message <kLv2awG7KpzAFw3u@farmeroz.port995.com>, Oz\n<oz@farmeroz.port995.com> writes\n>Patrick Powers <frisbieinstein@yahoo.com> writes\n>>I happened across a 1999 thread entitled "Length of wavetrain of a\n>>single photon". The experimental setup is an inferometer with paths\n>>of unequal length. The questions are, how much may the lengths differ\n>>before the interference pattern disappears? and, what if there is\n>>only a single photon present in the system?\n>\n>Ah, yes, that was mostly me thrashing about trying thought experiments.\n>Based largely on a misconception (mine).\n>\n>IMHO (based on infinite ignorance)\n\n[Grrrr. Haven\'t I taught you anything of the mathematical structure of\nqm by now? I shall assume you mean this as a deliberate slight on my\nabilities as teacher, and start getting the fireballs ready.]\n\n> it makes (much) more sense to\n>consider the photon beam as a wave.\n\nThis is becoming something of a long standing argument between myself\nand Oz. I have been seeking to persuade him that this view is not\nconsistent with the mathematical structure and experimental results of\nquantum mechanics. So far, it seems, without success.\n\n>That is entirely a wave, with no\n>quantum aspect at all. The clincher was an experiment where two\n>*different* (but highly stable) lasers sent a lightbeam each through\n>*one* slit of a two slit interferometer. No matter how much you\n>attenuate the beams you always get a diffraction pattern. Even if,\n>naively, there is never more than one photon from one of the lasers in\n>the apparatus at any one time.\n\nActually this is not strictly true. When the intensity is low enough to\ndetect single photons you do not detect a diffraction pattern from a\nsingle photon. You get a photon detected at a point. When you collate\nthe results of many photon detections, then you get a diffraction\npattern.\n\n>Obviously if you consider light as a maxwellian wave, then there is no\n>limit to the level of attenuation of the field you can have and it still\n>be a continuous wave, and the result found is absolutely as expected.\n\nNo it is not. It does not predict that photons will be found at points.\n\n>The descriptions where a photon is considered particulate obtain the\n>same result (I am assured, and do not disbelieve). This is because (as\n>far as I can grasp) these descriptions are most cleverly and subtly\n>drawn up. For example there can be no knowledge of the number of photons\n>in either laser beam, adding or subtraction one does *not* alter the\n>description.\n\nWeird isn\'t it.\n\n>I also suspect time-averaging is also (for a laser) hidden\n>in the description.\n\nCertainly. You cannot say when any photon is emitted, so you have to\nmodel the emissions as smeared in time.\n\n>\n>IMHO (which is probably considered by most here to be a cranky one), the\n>quantum nature of light is a consequence of the quantum nature of the\n>detector.\n\nCertainly considered cranky by me.\n\n>\n>The net result is to note that neither the particulate description, nor\n>the wavelike description, actually describe a laser beam as a stream of\n>individual photon bullets. In particular the particulate description\n>doesn\'t really describe the laserbeam-in-flight at all, but does\n>describe (accurately) its generation and interaction with any targets.\n\nActually that\'s quite good.\n\n>Since both generation and interaction with (most) targets are with\n>quantised systems (typically atoms changing energy state), one obtains a\n>quantised result.\n\nThat is quantisation of the photon by the source, not quantisation by\nthe detector. So your model would have it that the structure of a\ndetector is dictated by the structure of the source, some distance away.\n\n>Well, my 2c worth, anyway.\n>\nI didn\'t know the dollar had collapsed!\n--\nCharles Francis\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>In message <kLv2awG7KpzAFw3u@farmeroz.port995.com>, Oz
<oz@farmeroz.port995.com> writes
>Patrick Powers <frisbieinstein@yahoo.com> writes
>>I happened across a 1999 thread entitled "Length of wavetrain of a
>>single photon". The experimental setup is an inferometer with paths
>>of unequal length. The questions are, how much may the lengths differ
>>before the interference pattern disappears? and, what if there is
>>only a single photon present in the system?
>
>Ah, yes, that was mostly me thrashing about trying thought experiments.
>Based largely on a misconception (mine).
>
>IMHO (based on infinite ignorance)
[Grrrr. Haven't I taught you anything of the mathematical structure of
qm by now? I shall assume you mean this as a deliberate slight on my
abilities as teacher, and start getting the fireballs ready.]
> it makes (much) more sense to
>consider the photon beam as a wave.
This is becoming something of a long standing argument between myself
and Oz. I have been seeking to persuade him that this view is not
consistent with the mathematical structure and experimental results of
quantum mechanics. So far, it seems, without success.
>That is entirely a wave, with no
>quantum aspect at all. The clincher was an experiment where two
>*different* (but highly stable) lasers sent a lightbeam each through
>*one* slit of a two slit interferometer. No matter how much you
>attenuate the beams you always get a diffraction pattern. Even if,
>naively, there is never more than one photon from one of the lasers in
>the apparatus at any one time.
Actually this is not strictly true. When the intensity is low enough to
detect single photons you do not detect a diffraction pattern from a
single photon. You get a photon detected at a point. When you collate
the results of many photon detections, then you get a diffraction
pattern.
>Obviously if you consider light as a maxwellian wave, then there is no
>limit to the level of attenuation of the field you can have and it still
>be a continuous wave, and the result found is absolutely as expected.
No it is not. It does not predict that photons will be found at points.
>The descriptions where a photon is considered particulate obtain the
>same result (I am assured, and do not disbelieve). This is because (as
>far as I can grasp) these descriptions are most cleverly and subtly
>drawn up. For example there can be no knowledge of the number of photons
>in either laser beam, adding or subtraction one does *not* alter the
>description.
Weird isn't it.
>I also suspect time-averaging is also (for a laser) hidden
>in the description.
Certainly. You cannot say when any photon is emitted, so you have to
model the emissions as smeared in time.
>
>IMHO (which is probably considered by most here to be a cranky one), the
>quantum nature of light is a consequence of the quantum nature of the
>detector.
Certainly considered cranky by me.
>
>The net result is to note that neither the particulate description, nor
>the wavelike description, actually describe a laser beam as a stream of
>individual photon bullets. In particular the particulate description
>doesn't really describe the laserbeam-in-flight at all, but does
>describe (accurately) its generation and interaction with any targets.
Actually that's quite good.
>Since both generation and interaction with (most) targets are with
>quantised systems (typically atoms changing energy state), one obtains a
>quantised result.
That is quantisation of the photon by the source, not quantisation by
the detector. So your model would have it that the structure of a
detector is dictated by the structure of the source, some distance away.
>Well, my 2c worth, anyway.
>
I didn't know the dollar had collapsed!
--
Charles Francis
Rahul Jain
Jun29-04, 05:40 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Oz <oz@farmeroz.port995.com> writes:\n\n> IMHO (based on infinite ignorance) it makes (much) more sense to\n> consider the photon beam as a wave. That is entirely a wave, with no\n> quantum aspect at all. The clincher was an experiment where two\n> *different* (but highly stable) lasers sent a lightbeam each through\n> *one* slit of a two slit interferometer. No matter how much you\n> attenuate the beams you always get a diffraction pattern. Even if,\n> naively, there is never more than one photon from one of the lasers in\n> the apparatus at any one time.\n\nBut if you send a single photon at a time through the slits and plot\nwhere they are detected, you will eventually get a diffraction pattern.\nEach individual photon will be detected at a specific location. I\nbelieve QED by Feynman discusses this phenomenon.\n\n--\nRahul Jain\nrjain@nyct.net\nProfessional Software Developer, Amateur Quantum Mechanicist\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Oz <oz@farmeroz.port995.com> writes:
> IMHO (based on infinite ignorance) it makes (much) more sense to
> consider the photon beam as a wave. That is entirely a wave, with no
> quantum aspect at all. The clincher was an experiment where two
> *different* (but highly stable) lasers sent a lightbeam each through
> *one* slit of a two slit interferometer. No matter how much you
> attenuate the beams you always get a diffraction pattern. Even if,
> naively, there is never more than one photon from one of the lasers in
> the apparatus at any one time.
But if you send a single photon at a time through the slits and plot
where they are detected, you will eventually get a diffraction pattern.
Each individual photon will be detected at a specific location. I
believe QED by Feynman discusses this phenomenon.
--
Rahul Jain
rjain@nyct.net
Professional Software Developer, Amateur Quantum Mechanicist
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Charles Francis <charles@lluestfarmpoultry.co.uk> writes\n>In message <kLv2awG7KpzAFw3u@farmeroz.port995.com>, Oz\n><oz@farmeroz.port995.com> writes\n>>\n>>Ah, yes, that was mostly me thrashing about trying thought experiments.\n>>Based largely on a misconception (mine).\n>>\n>>IMHO (based on infinite ignorance)\n>\n>[Grrrr. Haven\'t I taught you anything of the mathematical structure of\n>qm by now? I shall assume you mean this as a deliberate slight on my\n>abilities as teacher, and start getting the fireballs ready.]\n\nI am only too well aware that an informal internet course, no matter how\ngood the teacher and how willing but idle the student, will ever\napproach the depth of knowledge of those who have spent a lifetime\nstudying a topic. Ergo I will forever be infinitely ignorant.\n\n>> it makes (much) more sense to\n>>consider the photon beam as a wave.\n>\n>This is becoming something of a long standing argument between myself\n>and Oz. I have been seeking to persuade him that this view is not\n>consistent with the mathematical structure and experimental results of\n>quantum mechanics. So far, it seems, without success.\n\nIts certainly not the model of choice for the most effective\nmathematical structure describing QM. Most physicists seem to prefer the\ndirac representation and eschew the wavelike schroedinger formulation. I\nsuspect that this is to some extent horses for courses as I suspect that\nschroedinger is still used by chemists and material scientists.\n\n>>That is entirely a wave, with no\n>>quantum aspect at all. The clincher was an experiment where two\n>>*different* (but highly stable) lasers sent a lightbeam each through\n>>*one* slit of a two slit interferometer. No matter how much you\n>>attenuate the beams you always get a diffraction pattern. Even if,\n>>naively, there is never more than one photon from one of the lasers in\n>>the apparatus at any one time.\n>\n>Actually this is not strictly true. When the intensity is low enough to\n>detect single photons you do not detect a diffraction pattern from a\n>single photon. You get a photon detected at a point. When you collate\n>the results of many photon detections, then you get a diffraction\n>pattern.\n\nI know. I have no problem with that using the mechanisms I have\npreviously described.\n\n>>Obviously if you consider light as a maxwellian wave, then there is no\n>>limit to the level of attenuation of the field you can have and it still\n>>be a continuous wave, and the result found is absolutely as expected.\n>\n>No it is not. It does not predict that photons will be found at points.\n\nIt does *if you include the details of the detector*.\nALL detectors ONLY detect whole photons because they require a whole\nphoton energy jump to change state.\n\n>>The descriptions where a photon is considered particulate obtain the\n>>same result (I am assured, and do not disbelieve). This is because (as\n>>far as I can grasp) these descriptions are most cleverly and subtly\n>>drawn up. For example there can be no knowledge of the number of photons\n>>in either laser beam, adding or subtraction one does *not* alter the\n>>description.\n>\n>Weird isn\'t it.\n\nNo, its just clever mathematical structure set up to match what is\nobserved. There wouldn\'t be much point setting up a mathematical\nstructure that predicted what wasn\'t observed.\n\nI have no problem with that.\nA methodology that gives the right answers and has a good toolbag of\nuseful and well understood tools is a powerful and useful animal. Often\nthe most useful descriptions are the ones that simply avoid the\ndifficult questions and difficult explanations. I have no problem with\nthat.\n\n>>I also suspect time-averaging is also (for a laser) hidden\n>>in the description.\n>\n>Certainly. You cannot say when any photon is emitted, so you have to\n>model the emissions as smeared in time.\n\nAs I suspected.\n\n>>IMHO (which is probably considered by most here to be a cranky one), the\n>>quantum nature of light is a consequence of the quantum nature of the\n>>detector.\n>\n>Certainly considered cranky by me.\n\nI rather doubt you would consider it so for *emission*.\nWhy do you consider it so for *detection*?\n\n>>The net result is to note that neither the particulate description, nor\n>>the wavelike description, actually describe a laser beam as a stream of\n>>individual photon bullets. In particular the particulate description\n>>doesn\'t really describe the laserbeam-in-flight at all, but does\n>>describe (accurately) its generation and interaction with any targets.\n>\n>Actually that\'s quite good.\n\n<Oz faints...>\n\n>>Since both generation and interaction with (most) targets are with\n>>quantised systems (typically atoms changing energy state), one obtains a\n>>quantised result.\n>\n>That is quantisation of the photon by the source, not quantisation by\n>the detector. So your model would have it that the structure of a\n>detector is dictated by the structure of the source, some distance away.\n\nEmission is (as far as I can tell) *always* quantised.\nWhy would you think that shouldn\'t be so for detection,\nadmittedly in a more complex setup (since we require irreversibility)?\n\n>>Well, my 2c worth, anyway.\n>>\n>I didn\'t know the dollar had collapsed!\n\nI doubt an international audience would understand 2p\'s worth.\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com (whitelist check on first posting)<<\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Charles Francis <charles@lluestfarmpoultry.co.uk> writes
>In message <kLv2awG7KpzAFw3u@farmeroz.port995.com>, Oz
><oz@farmeroz.port995.com> writes
>>
>>Ah, yes, that was mostly me thrashing about trying thought experiments.
>>Based largely on a misconception (mine).
>>
>>IMHO (based on infinite ignorance)
>
>[Grrrr. Haven't I taught you anything of the mathematical structure of
>qm by now? I shall assume you mean this as a deliberate slight on my
>abilities as teacher, and start getting the fireballs ready.]
I am only too well aware that an informal internet course, no matter how
good the teacher and how willing but idle the student, will ever
approach the depth of knowledge of those who have spent a lifetime
studying a topic. Ergo I will forever be infinitely ignorant.
>> it makes (much) more sense to
>>consider the photon beam as a wave.
>
>This is becoming something of a long standing argument between myself
>and Oz. I have been seeking to persuade him that this view is not
>consistent with the mathematical structure and experimental results of
>quantum mechanics. So far, it seems, without success.
Its certainly not the model of choice for the most effective
mathematical structure describing QM. Most physicists seem to prefer the
dirac representation and eschew the wavelike schroedinger formulation. I
suspect that this is to some extent horses for courses as I suspect that
schroedinger is still used by chemists and material scientists.
>>That is entirely a wave, with no
>>quantum aspect at all. The clincher was an experiment where two
>>*different* (but highly stable) lasers sent a lightbeam each through
>>*one* slit of a two slit interferometer. No matter how much you
>>attenuate the beams you always get a diffraction pattern. Even if,
>>naively, there is never more than one photon from one of the lasers in
>>the apparatus at any one time.
>
>Actually this is not strictly true. When the intensity is low enough to
>detect single photons you do not detect a diffraction pattern from a
>single photon. You get a photon detected at a point. When you collate
>the results of many photon detections, then you get a diffraction
>pattern.
I know. I have no problem with that using the mechanisms I have
previously described.
>>Obviously if you consider light as a maxwellian wave, then there is no
>>limit to the level of attenuation of the field you can have and it still
>>be a continuous wave, and the result found is absolutely as expected.
>
>No it is not. It does not predict that photons will be found at points.
It does *if you include the details of the detector*.
ALL detectors ONLY detect whole photons because they require a whole
photon energy jump to change state.
>>The descriptions where a photon is considered particulate obtain the
>>same result (I am assured, and do not disbelieve). This is because (as
>>far as I can grasp) these descriptions are most cleverly and subtly
>>drawn up. For example there can be no knowledge of the number of photons
>>in either laser beam, adding or subtraction one does *not* alter the
>>description.
>
>Weird isn't it.
No, its just clever mathematical structure set up to match what is
observed. There wouldn't be much point setting up a mathematical
structure that predicted what wasn't observed.
I have no problem with that.
A methodology that gives the right answers and has a good toolbag of
useful and well understood tools is a powerful and useful animal. Often
the most useful descriptions are the ones that simply avoid the
difficult questions and difficult explanations. I have no problem with
that.
>>I also suspect time-averaging is also (for a laser) hidden
>>in the description.
>
>Certainly. You cannot say when any photon is emitted, so you have to
>model the emissions as smeared in time.
As I suspected.
>>IMHO (which is probably considered by most here to be a cranky one), the
>>quantum nature of light is a consequence of the quantum nature of the
>>detector.
>
>Certainly considered cranky by me.
I rather doubt you would consider it so for *emission*.
Why do you consider it so for *detection*?
>>The net result is to note that neither the particulate description, nor
>>the wavelike description, actually describe a laser beam as a stream of
>>individual photon bullets. In particular the particulate description
>>doesn't really describe the laserbeam-in-flight at all, but does
>>describe (accurately) its generation and interaction with any targets.
>
>Actually that's quite good.
<Oz faints...>
>>Since both generation and interaction with (most) targets are with
>>quantised systems (typically atoms changing energy state), one obtains a
>>quantised result.
>
>That is quantisation of the photon by the source, not quantisation by
>the detector. So your model would have it that the structure of a
>detector is dictated by the structure of the source, some distance away.
Emission is (as far as I can tell) *always* quantised.
Why would you think that shouldn't be so for detection,
admittedly in a more complex setup (since we require irreversibility)?
>>Well, my 2c worth, anyway.
>>
>I didn't know the dollar had collapsed!
I doubt an international audience would understand 2p's worth.
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com (whitelist check on first posting)<<
Charles Francis
Jun30-04, 05:41 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>In message <cbsre1\\$dkd\\$1@lfa222122.richmond.edu>, Oz\n<oz@farmeroz.port995.com> writes\n>Charles Francis <charles@lluestfarmpoultry.co.uk> writes\n>>In message <kLv2awG7KpzAFw3u@farmeroz.port995.com>, Oz\n>><oz@farmeroz.port995.com> writes\n>>>\n>>>Ah, yes, that was mostly me thrashing about trying thought experiments.\n>>>Based largely on a misconception (mine).\n>>>\n>>>IMHO (based on infinite ignorance)\n>>\n>>[Grrrr. Haven\'t I taught you anything of the mathematical structure of\n>>qm by now? I shall assume you mean this as a deliberate slight on my\n>>abilities as teacher, and start getting the fireballs ready.]\n>\n>I am only too well aware that an informal internet course, no matter how\n>good the teacher and how willing but idle the student, will ever\n>approach the depth of knowledge of those who have spent a lifetime\n>studying a topic. Ergo I will forever be infinitely ignorant.\n\nThen lines are in order. Write out an infinite number of times "there is\nno such thing as infinity"\n\n>>> it makes (much) more sense to\n>>>consider the photon beam as a wave.\n>>\n>>This is becoming something of a long standing argument between myself\n>>and Oz. I have been seeking to persuade him that this view is not\n>>consistent with the mathematical structure and experimental results of\n>>quantum mechanics. So far, it seems, without success.\n>\n>Its certainly not the model of choice for the most effective\n>mathematical structure describing QM. Most physicists seem to prefer the\n>dirac representation and eschew the wavelike schroedinger formulation.\n\nThat makes no difference to the maths, since given ket |f> is in direct\ncorrespondence to the wavefunction f(x). The real difference is that the\nket can be given some sort of physical meaning, as the result of an\nexperiment, whereas the wave function has all these weird, seemingly\nimpossible, properties. At least impossible if it somehow represents a\nphysical thing.\n\n> I\n>suspect that this is to some extent horses for courses as I suspect that\n>schroedinger is still used by chemists and material scientists.\n\nOf course. As I say it makes no difference to the predictions. And since\nthey have not been trained to think in terms of abstract vector spaces\nit is easier for them to work using wavefunctions. However that is a\nlimitation in training which a mathematician will not have, so a\nmathematician is actually free to choose whichever is the better, more\naccurate or more sensible representation, whereas the chemist or\nmaterial scientist only has that which he knows.\n\n>>>That is entirely a wave, with no\n>>>quantum aspect at all. The clincher was an experiment where two\n>>>*different* (but highly stable) lasers sent a lightbeam each through\n>>>*one* slit of a two slit interferometer. No matter how much you\n>>>attenuate the beams you always get a diffraction pattern. Even if,\n>>>naively, there is never more than one photon from one of the lasers in\n>>>the apparatus at any one time.\n>>\n>>Actually this is not strictly true. When the intensity is low enough to\n>>detect single photons you do not detect a diffraction pattern from a\n>>single photon. You get a photon detected at a point. When you collate\n>>the results of many photon detections, then you get a diffraction\n>>pattern.\n>\n>I know. I have no problem with that using the mechanisms I have\n>previously described.\n\nExcept that there is no indication that such mechanisms exist in nature,\nand the exploration of every mathematician and physicist who has studied\nit, from Von Neumann and Dirac onwards indicates that such a mechanism\nis not even consistent with standard quantum mechanics.\n\n>>>Obviously if you consider light as a maxwellian wave, then there is no\n>>>limit to the level of attenuation of the field you can have and it still\n>>>be a continuous wave, and the result found is absolutely as expected.\n>>\n>>No it is not. It does not predict that photons will be found at points.\n>\n>It does *if you include the details of the detector*.\n\nThat makes no difference.\n\n>ALL detectors ONLY detect whole photons because they require a whole\n>photon energy jump to change state.\n\nThis isn\'t true either. If you take a simple detector based on the\nphotoelectric effect then you only require that the photons have a\ncertain minimum energy. Any energy above that will cause the effect. If\nyou could build up the required energy level gradually you would have\nclassical physics and no photoelectric effect.\n\n>>>The descriptions where a photon is considered particulate obtain the\n>>>same result (I am assured, and do not disbelieve). This is because (as\n>>>far as I can grasp) these descriptions are most cleverly and subtly\n>>>drawn up. For example there can be no knowledge of the number of photons\n>>>in either laser beam, adding or subtraction one does *not* alter the\n>>>description.\n>>\n>>Weird isn\'t it.\n>\n>No, its just clever mathematical structure set up to match what is\n>observed. There wouldn\'t be much point setting up a mathematical\n>structure that predicted what wasn\'t observed.\n>\n>I have no problem with that.\n>A methodology that gives the right answers and has a good toolbag of\n>useful and well understood tools is a powerful and useful animal. Often\n>the most useful descriptions are the ones that simply avoid the\n>difficult questions and difficult explanations. I have no problem with\n>that.\n\nPerhaps if we can continue with studying qed I will be able to show that\nthere is bit more to this than methodology.\n\n>>>I also suspect time-averaging is also (for a laser) hidden\n>>>in the description.\n>>\n>>Certainly. You cannot say when any photon is emitted, so you have to\n>>model the emissions as smeared in time.\n>\n>As I suspected.\n>\n>>>IMHO (which is probably considered by most here to be a cranky one), the\n>>>quantum nature of light is a consequence of the quantum nature of the\n>>>detector.\n>>\n>>Certainly considered cranky by me.\n>\n>I rather doubt you would consider it so for *emission*.\n>Why do you consider it so for *detection*?\n\nThe emission creates a photon of particular energy. That is the quantum\nnature of light. If the quantum nature is consequent on emission you\ncannot then have it that the quantum nature is consequent on detection.\n\n>>>Since both generation and interaction with (most) targets are with\n>>>quantised systems (typically atoms changing energy state), one obtains a\n>>>quantised result.\n>>\n>>That is quantisation of the photon by the source, not quantisation by\n>>the detector. So your model would have it that the structure of a\n>>detector is dictated by the structure of the source, some distance away.\n>\n>Emission is (as far as I can tell) *always* quantised.\n>Why would you think that shouldn\'t be so for detection,\n>admittedly in a more complex setup (since we require irreversibility)?\n\nWe generally also require some form of causality, that a future event\n(detection) does not affect present or past ones.\n\n--\nCharles Francis\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>In message <cbsre1$dkd$1@lfa222122.richmond.edu>, Oz
<oz@farmeroz.port995.com> writes
>Charles Francis <charles@lluestfarmpoultry.co.uk> writes
>>In message <kLv2awG7KpzAFw3u@farmeroz.port995.com>, Oz
>><oz@farmeroz.port995.com> writes
>>>
>>>Ah, yes, that was mostly me thrashing about trying thought experiments.
>>>Based largely on a misconception (mine).
>>>
>>>IMHO (based on infinite ignorance)
>>
>>[Grrrr. Haven't I taught you anything of the mathematical structure of
>>qm by now? I shall assume you mean this as a deliberate slight on my
>>abilities as teacher, and start getting the fireballs ready.]
>
>I am only too well aware that an informal internet course, no matter how
>good the teacher and how willing but idle the student, will ever
>approach the depth of knowledge of those who have spent a lifetime
>studying a topic. Ergo I will forever be infinitely ignorant.
Then lines are in order. Write out an infinite number of times "there is
no such thing as infinity"
>>> it makes (much) more sense to
>>>consider the photon beam as a wave.
>>
>>This is becoming something of a long standing argument between myself
>>and Oz. I have been seeking to persuade him that this view is not
>>consistent with the mathematical structure and experimental results of
>>quantum mechanics. So far, it seems, without success.
>
>Its certainly not the model of choice for the most effective
>mathematical structure describing QM. Most physicists seem to prefer the
>dirac representation and eschew the wavelike schroedinger formulation.
That makes no difference to the maths, since given ket |f> is in direct
correspondence to the wavefunction f(x). The real difference is that the
ket can be given some sort of physical meaning, as the result of an
experiment, whereas the wave function has all these weird, seemingly
impossible, properties. At least impossible if it somehow represents a
physical thing.
> I
>suspect that this is to some extent horses for courses as I suspect that
>schroedinger is still used by chemists and material scientists.
Of course. As I say it makes no difference to the predictions. And since
they have not been trained to think in terms of abstract vector spaces
it is easier for them to work using wavefunctions. However that is a
limitation in training which a mathematician will not have, so a
mathematician is actually free to choose whichever is the better, more
accurate or more sensible representation, whereas the chemist or
material scientist only has that which he knows.
>>>That is entirely a wave, with no
>>>quantum aspect at all. The clincher was an experiment where two
>>>*different* (but highly stable) lasers sent a lightbeam each through
>>>*one* slit of a two slit interferometer. No matter how much you
>>>attenuate the beams you always get a diffraction pattern. Even if,
>>>naively, there is never more than one photon from one of the lasers in
>>>the apparatus at any one time.
>>
>>Actually this is not strictly true. When the intensity is low enough to
>>detect single photons you do not detect a diffraction pattern from a
>>single photon. You get a photon detected at a point. When you collate
>>the results of many photon detections, then you get a diffraction
>>pattern.
>
>I know. I have no problem with that using the mechanisms I have
>previously described.
Except that there is no indication that such mechanisms exist in nature,
and the exploration of every mathematician and physicist who has studied
it, from Von Neumann and Dirac onwards indicates that such a mechanism
is not even consistent with standard quantum mechanics.
>>>Obviously if you consider light as a maxwellian wave, then there is no
>>>limit to the level of attenuation of the field you can have and it still
>>>be a continuous wave, and the result found is absolutely as expected.
>>
>>No it is not. It does not predict that photons will be found at points.
>
>It does *if you include the details of the detector*.
That makes no difference.
>ALL detectors ONLY detect whole photons because they require a whole
>photon energy jump to change state.
This isn't true either. If you take a simple detector based on the
photoelectric effect then you only require that the photons have a
certain minimum energy. Any energy above that will cause the effect. If
you could build up the required energy level gradually you would have
classical physics and no photoelectric effect.
>>>The descriptions where a photon is considered particulate obtain the
>>>same result (I am assured, and do not disbelieve). This is because (as
>>>far as I can grasp) these descriptions are most cleverly and subtly
>>>drawn up. For example there can be no knowledge of the number of photons
>>>in either laser beam, adding or subtraction one does *not* alter the
>>>description.
>>
>>Weird isn't it.
>
>No, its just clever mathematical structure set up to match what is
>observed. There wouldn't be much point setting up a mathematical
>structure that predicted what wasn't observed.
>
>I have no problem with that.
>A methodology that gives the right answers and has a good toolbag of
>useful and well understood tools is a powerful and useful animal. Often
>the most useful descriptions are the ones that simply avoid the
>difficult questions and difficult explanations. I have no problem with
>that.
Perhaps if we can continue with studying qed I will be able to show that
there is bit more to this than methodology.
>>>I also suspect time-averaging is also (for a laser) hidden
>>>in the description.
>>
>>Certainly. You cannot say when any photon is emitted, so you have to
>>model the emissions as smeared in time.
>
>As I suspected.
>
>>>IMHO (which is probably considered by most here to be a cranky one), the
>>>quantum nature of light is a consequence of the quantum nature of the
>>>detector.
>>
>>Certainly considered cranky by me.
>
>I rather doubt you would consider it so for *emission*.
>Why do you consider it so for *detection*?
The emission creates a photon of particular energy. That is the quantum
nature of light. If the quantum nature is consequent on emission you
cannot then have it that the quantum nature is consequent on detection.
>>>Since both generation and interaction with (most) targets are with
>>>quantised systems (typically atoms changing energy state), one obtains a
>>>quantised result.
>>
>>That is quantisation of the photon by the source, not quantisation by
>>the detector. So your model would have it that the structure of a
>>detector is dictated by the structure of the source, some distance away.
>
>Emission is (as far as I can tell) *always* quantised.
>Why would you think that shouldn't be so for detection,
>admittedly in a more complex setup (since we require irreversibility)?
We generally also require some form of causality, that a future event
(detection) does not affect present or past ones.
--
Charles Francis
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Charles Francis <charles@lluestfarmpoultry.co.uk> writes\n>In message <cbsre1\\$dkd\\$1@lfa222122.richmond.edu>, Oz\n>>\n>>I am only too well aware that an informal internet course, no matter how\n>>good the teacher and how willing but idle the student, will ever\n>>approach the depth of knowledge of those who have spent a lifetime\n>>studying a topic. Ergo I will forever be infinitely ignorant.\n>\n>Then lines are in order. Write out an infinite number of times "there is\n>no such thing as infinity"\n\nI\'ll do this after this post.\nI may be some time .....\n\n>>>> it makes (much) more sense to\n>>>>consider the photon beam as a wave.\n>>>\n>That makes no difference to the maths, since given ket |f> is in direct\n>correspondence to the wavefunction f(x). The real difference is that the\n>ket can be given some sort of physical meaning, as the result of an\n>experiment, whereas the wave function has all these weird, seemingly\n>impossible, properties. At least impossible if it somehow represents a\n>physical thing.\n\nThat depends, of course, on what you mean by a \'physical thing\'.\n\n>>>Actually this is not strictly true. When the intensity is low enough to\n>>>detect single photons you do not detect a diffraction pattern from a\n>>>single photon. You get a photon detected at a point. When you collate\n>>>the results of many photon detections, then you get a diffraction\n>>>pattern.\n>>\n>>I know. I have no problem with that using the mechanisms I have\n>>previously described.\n>\n>Except that there is no indication that such mechanisms exist in nature,\n\nOf course I would beg to differ. You should look at some of the work on\nchlorophyll absorption of photons as an example.\n\n>and the exploration of every mathematician and physicist who has studied\n>it, from Von Neumann and Dirac onwards indicates that such a mechanism\n>is not even consistent with standard quantum mechanics.\n\nI am happy, as ever, to be shot down.\nA single good counterexample will suffice.\n\n>>ALL detectors ONLY detect whole photons because they require a whole\n>>photon energy jump to change state.\n>\n>This isn\'t true either. If you take a simple detector based on the\n>photoelectric effect then you only require that the photons have a\n>certain minimum energy.\n>Any energy above that will cause the effect. If\n>you could build up the required energy level gradually you would have\n>classical physics and no photoelectric effect.\n\nThat\'s a naive viewpoint.\n\nA mechanical analogy would be a soundwave incident on a field of coupled\n(to a greater or lesser degree) tuning forks (the absorbing atoms). Each\ntuning fork has a trigger that temporarily damps the fork when a certain\n(largish) amplitude is reached on any given fork (corresponding to\nenergy being dumped into an emitted electron). At low or modest incident\nenergies you will get transmission, scattering or individual forks being\n\'triggered\' at a precise amplitude, but ONLY if the sound is close to\nthe resonant frequency of the fork in question. This is because it\nrequires many oscillations for the energy in the fork to build up to the\ntriggering amplitude and off-resonant sound cannot achieve this.\n\nIts also untrue to say that a lower energy of photon, or even a static\napplied field, will never cause photoemission no matter what the\namplitude. Ionisation, even of gasses, can be achieved with a static or\nvery low photon energy at high enough energies. Sparks and tunnelling\nelectron sources do precisely this.\n\nNote that the energy levels required (or should I say energy densities)\nfor the static \'photoemission\' are orders higher than the \'normal\'\nresonant absorption modes. It should not be surprising that the resonant\nmodes are finely tuned.\n\n>>I have no problem with that.\n>>A methodology that gives the right answers and has a good toolbag of\n>>useful and well understood tools is a powerful and useful animal. Often\n>>the most useful descriptions are the ones that simply avoid the\n>>difficult questions and difficult explanations. I have no problem with\n>>that.\n>\n>Perhaps if we can continue with studying qed I will be able to show that\n>there is bit more to this than methodology.\n\nGive me time. This sort of thing requires me to make significant effort,\nferchristsake.\n\n>>>Certainly considered cranky by me.\n>>\n>>I rather doubt you would consider it so for *emission*.\n>>Why do you consider it so for *detection*?\n>\n>The emission creates a photon of particular energy. That is the quantum\n>nature of light. If the quantum nature is consequent on emission you\n>cannot then have it that the quantum nature is consequent on detection.\n\nOne can have nothing else given that absorption is the inverse of\nemission and is time-reversible. If a system absorbs at a given\nfrequency then it must emit at a given frequency. Quantum mechanical\nbalancing is thus inevitable, a (physical) equivalent of an identity.\n\n>>Emission is (as far as I can tell) *always* quantised.\n>>Why would you think that shouldn\'t be so for detection,\n>>admittedly in a more complex setup (since we require irreversibility)?\n>\n>We generally also require some form of causality, that a future event\n>(detection) does not affect present or past ones.\n\nI\'m not sure what your point is here. Perhaps you could expand on it?\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com (whitelist check on first posting)<<\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Charles Francis <charles@lluestfarmpoultry.co.uk> writes
>In message <cbsre1$dkd$1@lfa222122.richmond.edu>, Oz
>>
>>I am only too well aware that an informal internet course, no matter how
>>good the teacher and how willing but idle the student, will ever
>>approach the depth of knowledge of those who have spent a lifetime
>>studying a topic. Ergo I will forever be infinitely ignorant.
>
>Then lines are in order. Write out an infinite number of times "there is
>no such thing as infinity"
I'll do this after this post.
I may be some time .....
>>>> it makes (much) more sense to
>>>>consider the photon beam as a wave.
>>>
>That makes no difference to the maths, since given ket |f> is in direct
>correspondence to the wavefunction f(x). The real difference is that the
>ket can be given some sort of physical meaning, as the result of an
>experiment, whereas the wave function has all these weird, seemingly
>impossible, properties. At least impossible if it somehow represents a
>physical thing.
That depends, of course, on what you mean by a 'physical thing'.
>>>Actually this is not strictly true. When the intensity is low enough to
>>>detect single photons you do not detect a diffraction pattern from a
>>>single photon. You get a photon detected at a point. When you collate
>>>the results of many photon detections, then you get a diffraction
>>>pattern.
>>
>>I know. I have no problem with that using the mechanisms I have
>>previously described.
>
>Except that there is no indication that such mechanisms exist in nature,
Of course I would beg to differ. You should look at some of the work on
chlorophyll absorption of photons as an example.
>and the exploration of every mathematician and physicist who has studied
>it, from Von Neumann and Dirac onwards indicates that such a mechanism
>is not even consistent with standard quantum mechanics.
I am happy, as ever, to be shot down.
A single good counterexample will suffice.
>>ALL detectors ONLY detect whole photons because they require a whole
>>photon energy jump to change state.
>
>This isn't true either. If you take a simple detector based on the
>photoelectric effect then you only require that the photons have a
>certain minimum energy.
>Any energy above that will cause the effect. If
>you could build up the required energy level gradually you would have
>classical physics and no photoelectric effect.
That's a naive viewpoint.
A mechanical analogy would be a soundwave incident on a field of coupled
(to a greater or lesser degree) tuning forks (the absorbing atoms). Each
tuning fork has a trigger that temporarily damps the fork when a certain
(largish) amplitude is reached on any given fork (corresponding to
energy being dumped into an emitted electron). At low or modest incident
energies you will get transmission, scattering or individual forks being
'triggered' at a precise amplitude, but ONLY if the sound is close to
the resonant frequency of the fork in question. This is because it
requires many oscillations for the energy in the fork to build up to the
triggering amplitude and off-resonant sound cannot achieve this.
Its also untrue to say that a lower energy of photon, or even a static
applied field, will never cause photoemission no matter what the
amplitude. Ionisation, even of gasses, can be achieved with a static or
very low photon energy at high enough energies. Sparks and tunnelling
electron sources do precisely this.
Note that the energy levels required (or should I say energy densities)
for the static 'photoemission' are orders higher than the 'normal'
resonant absorption modes. It should not be surprising that the resonant
modes are finely tuned.
>>I have no problem with that.
>>A methodology that gives the right answers and has a good toolbag of
>>useful and well understood tools is a powerful and useful animal. Often
>>the most useful descriptions are the ones that simply avoid the
>>difficult questions and difficult explanations. I have no problem with
>>that.
>
>Perhaps if we can continue with studying qed I will be able to show that
>there is bit more to this than methodology.
Give me time. This sort of thing requires me to make significant effort,
ferchristsake.
>>>Certainly considered cranky by me.
>>
>>I rather doubt you would consider it so for *emission*.
>>Why do you consider it so for *detection*?
>
>The emission creates a photon of particular energy. That is the quantum
>nature of light. If the quantum nature is consequent on emission you
>cannot then have it that the quantum nature is consequent on detection.
One can have nothing else given that absorption is the inverse of
emission and is time-reversible. If a system absorbs at a given
frequency then it must emit at a given frequency. Quantum mechanical
balancing is thus inevitable, a (physical) equivalent of an identity.
>>Emission is (as far as I can tell) *always* quantised.
>>Why would you think that shouldn't be so for detection,
>>admittedly in a more complex setup (since we require irreversibility)?
>
>We generally also require some form of causality, that a future event
>(detection) does not affect present or past ones.
I'm not sure what your point is here. Perhaps you could expand on it?
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com (whitelist check on first posting)<<
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nRahul Jain <rjain@nyct.net> writes\n>Oz <oz@farmeroz.port995.com> writes:\n>\n>> IMHO (based on infinite ignorance) it makes (much) more sense to\n>> consider the photon beam as a wave. That is entirely a wave, with no\n>> quantum aspect at all. The clincher was an experiment where two\n>> *different* (but highly stable) lasers sent a lightbeam each through\n>> *one* slit of a two slit interferometer. No matter how much you\n>> attenuate the beams you always get a diffraction pattern. Even if,\n>> naively, there is never more than one photon from one of the lasers in\n>> the apparatus at any one time.\n>\n>But if you send a single photon at a time through the slits and plot\n>where they are detected, you will eventually get a diffraction pattern.\n\nIndeed so, which is as expected.\nIts less obvious (for a particulate model) that sending one photon\nthrough *one* slit from one laser, then (later) sending another photon\nfrom a different laser through the *other* slit, will also produce a\ndiffraction pattern.\n\nThe (particulate) maths is cleverly set up so that the probability of\nfinding one electron in the apparatus is zero, but the probability of\nfinding either no photons or two (one from each beam/slit) photons is\nunity.\n\nI consider this a tour de force of the particulate methodology and I Am\nImpressed. It confirms it as a brilliant model for \'shut up and\ncalculate\' which I would use if I needed to calculate and knew how to.\n\nHowever I have my doubts of the physicality of this, hence my\nalternative viewpoint. That is the particle (and I would include massive\nones too) travels as a wave (non-particulate) but the detector (and\nemitter) must of necessity be an energy-jump - that is quantised.\n\n>Each individual photon will be detected at a specific location. I\n>believe QED by Feynman discusses this phenomenon.\n\nOf course.\nThis must be inevitable for detectors using the model I suggest.\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com (whitelist check on first posting)<<\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Rahul Jain <rjain@nyct.net> writes
>Oz <oz@farmeroz.port995.com> writes:
>
>> IMHO (based on infinite ignorance) it makes (much) more sense to
>> consider the photon beam as a wave. That is entirely a wave, with no
>> quantum aspect at all. The clincher was an experiment where two
>> *different* (but highly stable) lasers sent a lightbeam each through
>> *one* slit of a two slit interferometer. No matter how much you
>> attenuate the beams you always get a diffraction pattern. Even if,
>> naively, there is never more than one photon from one of the lasers in
>> the apparatus at any one time.
>
>But if you send a single photon at a time through the slits and plot
>where they are detected, you will eventually get a diffraction pattern.
Indeed so, which is as expected.
Its less obvious (for a particulate model) that sending one photon
through *one* slit from one laser, then (later) sending another photon
from a different laser through the *other* slit, will also produce a
diffraction pattern.
The (particulate) maths is cleverly set up so that the probability of
finding one electron in the apparatus is zero, but the probability of
finding either no photons or two (one from each beam/slit) photons is
unity.
I consider this a tour de force of the particulate methodology and I Am
Impressed. It confirms it as a brilliant model for 'shut up and
calculate' which I would use if I needed to calculate and knew how to.
However I have my doubts of the physicality of this, hence my
alternative viewpoint. That is the particle (and I would include massive
ones too) travels as a wave (non-particulate) but the detector (and
emitter) must of necessity be an energy-jump - that is quantised.
>Each individual photon will be detected at a specific location. I
>believe QED by Feynman discusses this phenomenon.
Of course.
This must be inevitable for detectors using the model I suggest.
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com (whitelist check on first posting)<<
Patrick Powers
Jul6-04, 01:47 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nOz <oz@farmeroz.port995.com> wrote in message news:<kLv2awG7KpzAFw3u@farmeroz.port995.com>...\n> Patrick Powers <frisbieinstein@yahoo.com> writes\n> >I happened across a 1999 thread entitled "Length of wavetrain of a\n> >single photon". The experimental setup is an inferometer with paths\n> >of unequal length. The questions are, how much may the lengths differ\n> >before the interference pattern disappears? and, what if there is\n> >only a single photon present in the system?\n>\n> Ah, yes, that was mostly me thrashing about trying thought experiments.\n> Based largely on a misconception (mine).\n>\n> IMHO (based on infinite ignorance) it makes (much) more sense to\n> consider the photon beam as a wave. That is entirely a wave, with no\n> quantum aspect at all. The clincher was an experiment where two\n> *different* (but highly stable) lasers sent a lightbeam each through\n> *one* slit of a two slit interferometer. No matter how much you\n> attenuate the beams you always get a diffraction pattern. Even if,\n> naively, there is never more than one photon from one of the lasers in\n> the apparatus at any one time.\n>\n\nHmm. What happens if the lasers produce light of different\nwavelengths? Does the phase of the two light sources need to be\nsynchronized in any way?\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Oz <oz@farmeroz.port995.com> wrote in message news:<kLv2awG7KpzAFw3u@farmeroz.port995.com>...
> Patrick Powers <frisbieinstein@yahoo.com> writes
> >I happened across a 1999 thread entitled "Length of wavetrain of a
> >single photon". The experimental setup is an inferometer with paths
> >of unequal length. The questions are, how much may the lengths differ
> >before the interference pattern disappears? and, what if there is
> >only a single photon present in the system?
>
> Ah, yes, that was mostly me thrashing about trying thought experiments.
> Based largely on a misconception (mine).
>
> IMHO (based on infinite ignorance) it makes (much) more sense to
> consider the photon beam as a wave. That is entirely a wave, with no
> quantum aspect at all. The clincher was an experiment where two
> *different* (but highly stable) lasers sent a lightbeam each through
> *one* slit of a two slit interferometer. No matter how much you
> attenuate the beams you always get a diffraction pattern. Even if,
> naively, there is never more than one photon from one of the lasers in
> the apparatus at any one time.
>
Hmm. What happens if the lasers produce light of different
wavelengths? Does the phase of the two light sources need to be
synchronized in any way?
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\nPatrick Powers <frisbieinstein@yahoo.com> writes\n>\n>Oz <oz@farmeroz.port995.com> wrote\n\n>>\n>> IMHO (based on infinite ignorance) it makes (much) more sense to\n>> consider the photon beam as a wave. That is entirely a wave, with no\n>> quantum aspect at all. The clincher was an experiment where two\n>> *different* (but highly stable) lasers sent a lightbeam each through\n>> *one* slit of a two slit interferometer. No matter how much you\n>> attenuate the beams you always get a diffraction pattern. Even if,\n>> naively, there is never more than one photon from one of the lasers in\n>> the apparatus at any one time.\n>>\n>\n>Hmm. What happens if the lasers produce light of different\n>wavelengths?\n\nThen you will get beats, this effect is the light version of\ninterference between (radio) transmitters. Old people who used to listen\nto the radio on medium wave will be quite familiar with the effect and\nthe problem.\n\n>Does the phase of the two light sources need to be\n>synchronized in any way?\n\n>From what I remember of the details of the experiment posted here, the\nlasers are particularly stable. I hope they didn\'t synchronise them in\nany way, because that would have affected the interpretation of the\nexperiment. I imagine that the particular pattern would depend on the\nphase differences between the lasers.\n\nNote that its trivially easy to do this for low frequency radio waves\nbecause (for example using quartz crystals) extraordinarily high\naccuracies and stabilities are readily achievable.\n\nHmmm, a thought.\nAt 1MHz a photon has energy of 7x10^(-28) J.\nIf we were to use a 50 ohm aerial then one photon a second would\ngenerate about 0.2 uV. Hmm, that ought to be detectable....\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com (whitelist check on first posting)<<\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Patrick Powers <frisbieinstein@yahoo.com> writes
>
>Oz <oz@farmeroz.port995.com> wrote
>>
>> IMHO (based on infinite ignorance) it makes (much) more sense to
>> consider the photon beam as a wave. That is entirely a wave, with no
>> quantum aspect at all. The clincher was an experiment where two
>> *different* (but highly stable) lasers sent a lightbeam each through
>> *one* slit of a two slit interferometer. No matter how much you
>> attenuate the beams you always get a diffraction pattern. Even if,
>> naively, there is never more than one photon from one of the lasers in
>> the apparatus at any one time.
>>
>
>Hmm. What happens if the lasers produce light of different
>wavelengths?
Then you will get beats, this effect is the light version of
interference between (radio) transmitters. Old people who used to listen
to the radio on medium wave will be quite familiar with the effect and
the problem.
>Does the phase of the two light sources need to be
>synchronized in any way?
>From what I remember of the details of the experiment posted here, the
lasers are particularly stable. I hope they didn't synchronise them in
any way, because that would have affected the interpretation of the
experiment. I imagine that the particular pattern would depend on the
phase differences between the lasers.
Note that its trivially easy to do this for low frequency radio waves
because (for example using quartz crystals) extraordinarily high
accuracies and stabilities are readily achievable.
Hmmm, a thought.
At 1MHz a photon has energy of 7x10^(-28) J.
If we were to use a 50 ohm aerial then one photon a second would
generate about .2 uV. Hmm, that ought to be detectable....
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com (whitelist check on first posting)<<
Rahul Jain
Jul13-04, 02:37 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nOz <oz@farmeroz.port995.com> writes:\n\n> Hmmm, a thought.\n> At 1MHz a photon has energy of 7x10^(-28) J.\n> If we were to use a 50 ohm aerial then one photon a second would\n> generate about 0.2 uV. Hmm, that ought to be detectable....\n\nA device called a "photomultiplier" is often used as a single-photon\ndetector. Feynman referred to them in his excellent book, QED.\n\n--\nRahul Jain\nrjain@nyct.net\nProfessional Software Developer, Amateur Quantum Mechanicist\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Oz <oz@farmeroz.port995.com> writes:
> Hmmm, a thought.
> At 1MHz a photon has energy of 7x10^(-28) J.
> If we were to use a 50 ohm aerial then one photon a second would
> generate about .2 uV. Hmm, that ought to be detectable....
A device called a "photomultiplier" is often used as a single-photon
detector. Feynman referred to them in his excellent book, QED.
--
Rahul Jain
rjain@nyct.net
Professional Software Developer, Amateur Quantum Mechanicist
Rahul Jain
Jul13-04, 02:37 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nOz <oz@farmeroz.port995.com> writes:\n\n> However I have my doubts of the physicality of this, hence my\n> alternative viewpoint. That is the particle (and I would include massive\n> ones too) travels as a wave (non-particulate) but the detector (and\n> emitter) must of necessity be an energy-jump - that is quantised.\n\nYes, this is the Copenhagen interpretation. There are efforts under way\nto characterize exactly how the wave collapses (seemingly randomly) to a\nspecific point when it interacts with some "detector". Observing the\nbehavior of fullerenes sent through a diffraction grating with enough\nheat to cause radiation of a photon at times shows that decoherence\nseems to occur whenever the wave function of the system spreads out\nenough that some parts of it span paths that can not be chosen\nindependently without violating the basic conservation laws (a.k.a.\nsymmetries) of the universe, similarly to Penrose\'s conjecture.\n\n--\nRahul Jain\nrjain@nyct.net\nProfessional Software Developer, Amateur Quantum Mechanicist\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Oz <oz@farmeroz.port995.com> writes:
> However I have my doubts of the physicality of this, hence my
> alternative viewpoint. That is the particle (and I would include massive
> ones too) travels as a wave (non-particulate) but the detector (and
> emitter) must of necessity be an energy-jump - that is quantised.
Yes, this is the Copenhagen interpretation. There are efforts under way
to characterize exactly how the wave collapses (seemingly randomly) to a
specific point when it interacts with some "detector". Observing the
behavior of fullerenes sent through a diffraction grating with enough
heat to cause radiation of a photon at times shows that decoherence
seems to occur whenever the wave function of the system spreads out
enough that some parts of it span paths that can not be chosen
independently without violating the basic conservation laws (a.k.a.
symmetries) of the universe, similarly to Penrose's conjecture.
--
Rahul Jain
rjain@nyct.net
Professional Software Developer, Amateur Quantum Mechanicist
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nRahul Jain <rjain@nyct.net> writes\n>Oz <oz@farmeroz.port995.com> writes:\n>\n>> Hmmm, a thought.\n>> At 1MHz a photon has energy of 7x10^(-28) J.\n>> If we were to use a 50 ohm aerial then one photon a second would\n>> generate about 0.2 uV. Hmm, that ought to be detectable....\n>\n>A device called a "photomultiplier" is often used as a single-photon\n>detector. Feynman referred to them in his excellent book, QED.\n\nIndeed. Coming from the days of valves, this isn\'t new to me.\nI handled them at school.\n\nBut that wasn\'t really where I was coming from. I just idly wondered if\nyou could detect \'less than a photon\' from a radio wave by measuring the\nfield. On the face of it this doesn\'t seem impossible. I could measure\n0.2uV for say 1/100 sec (which is some 10,000 oscillations) and by\nimplication measure 1/100th of a photon. Now, I\'m not quite sure if this\nis possible or not (or that I have slipped a few orders of magnitude),\nbut offhand 0.2uV sounds a large enough amplitude to get quite a nice\nsignal. The only slight worry I have is that the required tuned circuits\nwould have a Q of several hundred thus invalidating the result by the\nvery mechanism I suggest for \'collapse\'\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com<<\nozacoohdb@despammed.com still functions.\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Rahul Jain <rjain@nyct.net> writes
>Oz <oz@farmeroz.port995.com> writes:
>
>> Hmmm, a thought.
>> At 1MHz a photon has energy of 7x10^(-28) J.
>> If we were to use a 50 ohm aerial then one photon a second would
>> generate about .2 uV. Hmm, that ought to be detectable....
>
>A device called a "photomultiplier" is often used as a single-photon
>detector. Feynman referred to them in his excellent book, QED.
Indeed. Coming from the days of valves, this isn't new to me.
I handled them at school.
But that wasn't really where I was coming from. I just idly wondered if
you could detect 'less than a photon' from a radio wave by measuring the
field. On the face of it this doesn't seem impossible. I could measure
.2uV for say 1/100 sec (which is some 10,000 oscillations) and by
implication measure 1/100th of a photon. Now, I'm not quite sure if this
is possible or not (or that I have slipped a few orders of magnitude),
but offhand .2uV sounds a large enough amplitude to get quite a nice
signal. The only slight worry I have is that the required tuned circuits
would have a Q of several hundred thus invalidating the result by the
very mechanism I suggest for 'collapse'
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com<<
ozacoohdb@despammed.com still functions.
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nRahul Jain <rjain@nyct.net> writes\n\n>Observing the\n>behavior of fullerenes sent through a diffraction grating with enough\n>heat to cause radiation of a photon at times shows that decoherence\n>seems to occur whenever the wave function of the system spreads out\n>enough that some parts of it span paths that can not be chosen\n>independently without violating the basic conservation laws (a.k.a.\n>symmetries) of the universe, similarly to Penrose\'s conjecture.\n\nHmmm. Ok lets get this right.\n\n\'Hot\' fullerene (particle) is sent through a pair of slits.\nThey are hot because of internal vibrations within their lattice.\nSo they emit low energy photons and by triangulation you locate the\nparticle to some rough path.\n\nNow, wouldn\'t it be true to say that just by emitting photons, and\ncertainly by detecting them in this manner, you inherently disturb the\nsuperposition?\n\nPerhaps you could give some examples of how the conservation laws are\n(not) violated.\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com<<\nozacoohdb@despammed.com still functions.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Rahul Jain <rjain@nyct.net> writes
>Observing the
>behavior of fullerenes sent through a diffraction grating with enough
>heat to cause radiation of a photon at times shows that decoherence
>seems to occur whenever the wave function of the system spreads out
>enough that some parts of it span paths that can not be chosen
>independently without violating the basic conservation laws (a.k.a.
>symmetries) of the universe, similarly to Penrose's conjecture.
Hmmm. Ok lets get this right.
'Hot' fullerene (particle) is sent through a pair of slits.
They are hot because of internal vibrations within their lattice.
So they emit low energy photons and by triangulation you locate the
particle to some rough path.
Now, wouldn't it be true to say that just by emitting photons, and
certainly by detecting them in this manner, you inherently disturb the
superposition?
Perhaps you could give some examples of how the conservation laws are
(not) violated.
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com<<
ozacoohdb@despammed.com still functions.
Patrick Powers
Jul16-04, 08:20 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\n\nRahul Jain <rjain@nyct.net> wrote in message news:<87n024ik7b.fsf@nyct.net>...\n> Oz <oz@farmeroz.port995.com> writes:\n>\n> > However I have my doubts of the physicality of this, hence my\n> > alternative viewpoint. That is the particle (and I would include massive\n> > ones too) travels as a wave (non-particulate) but the detector (and\n> > emitter) must of necessity be an energy-jump - that is quantised.\n>\n> Yes, this is the Copenhagen interpretation. There are efforts under way\n> to characterize exactly how the wave collapses (seemingly randomly) to a\n> specific point when it interacts with some "detector". Observing the\n> behavior of fullerenes sent through a diffraction grating with enough\n> heat to cause radiation of a photon at times shows that decoherence\n> seems to occur whenever the wave function of the system spreads out\n> enough that some parts of it span paths that can not be chosen\n> independently without violating the basic conservation laws (a.k.a.\n> symmetries) of the universe, similarly to Penrose\'s conjecture.\n\nHmm. Usually the invariance of c is taken as an observation and then\nE=mc^2 derived. I wonder if it would be possible to take the\nequivalence of energy and matter, observed as electron-proton\nannihilation, then derive the invariance of c in all frames. The idea\nis that if c is not invariant then it would be possible to distinguish\npaths that can be chosen independently without violating the basic\nconservation laws.\n\nOr something like that.\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Rahul Jain <rjain@nyct.net> wrote in message news:<87n024ik7b.fsf@nyct.net>...
> Oz <oz@farmeroz.port995.com> writes:
>
> > However I have my doubts of the physicality of this, hence my
> > alternative viewpoint. That is the particle (and I would include massive
> > ones too) travels as a wave (non-particulate) but the detector (and
> > emitter) must of necessity be an energy-jump - that is quantised.
>
> Yes, this is the Copenhagen interpretation. There are efforts under way
> to characterize exactly how the wave collapses (seemingly randomly) to a
> specific point when it interacts with some "detector". Observing the
> behavior of fullerenes sent through a diffraction grating with enough
> heat to cause radiation of a photon at times shows that decoherence
> seems to occur whenever the wave function of the system spreads out
> enough that some parts of it span paths that can not be chosen
> independently without violating the basic conservation laws (a.k.a.
> symmetries) of the universe, similarly to Penrose's conjecture.
Hmm. Usually the invariance of c is taken as an observation and then
E=mc^2 derived. I wonder if it would be possible to take the
equivalence of energy and matter, observed as electron-proton
annihilation, then derive the invariance of c in all frames. The idea
is that if c is not invariant then it would be possible to distinguish
paths that can be chosen independently without violating the basic
conservation laws.
Or something like that.
Rahul Jain
Jul19-04, 03:09 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\nOz <oz@farmeroz.port995.com> writes:\n\n> \'Hot\' fullerene (particle) is sent through a pair of slits.\n> They are hot because of internal vibrations within their lattice.\n> So they emit low energy photons\n\nThat\'s how the experiment went... but...\n\n> and by triangulation you locate the particle to some rough path.\n\nThey never even tried to detect the photon emissions. They merely\nmodeled the probability of emission at varying temperatures and figured\nout the probability for the photon itself to carry "which-path"\ninformation.\n\n> Now, wouldn\'t it be true to say that just by emitting photons, and\n> certainly by detecting them in this manner, you inherently disturb the\n> superposition?\n\nExactly, that\'s what the theory of decoherence is all about. Instead of\nsome arbitrary "measurement" action, the condition for decoherence is\nmore precisely defined in terms of QM instead of in terms of some\nmystical force that only the human brain (or maybe the vertebrate brain)\npossesses.\n\n> Perhaps you could give some examples of how the conservation laws are\n> (not) violated.\n\nThe typical one in EPR-type experiments is conservation of angular\nmomentum. As far as I understand, the polarizations of the particles\nends up in such a way that the angular momentum the particle source\nlost/gained constrains the net angular momentum of the emitted entangled\nphotons.\n\n--\nRahul Jain\nrjain@nyct.net\nProfessional Software Developer, Amateur Quantum Mechanicist\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Oz <oz@farmeroz.port995.com> writes:
> 'Hot' fullerene (particle) is sent through a pair of slits.
> They are hot because of internal vibrations within their lattice.
> So they emit low energy photons
That's how the experiment went... but...
> and by triangulation you locate the particle to some rough path.
They never even tried to detect the photon emissions. They merely
modeled the probability of emission at varying temperatures and figured
out the probability for the photon itself to carry "which-path"
information.
> Now, wouldn't it be true to say that just by emitting photons, and
> certainly by detecting them in this manner, you inherently disturb the
> superposition?
Exactly, that's what the theory of decoherence is all about. Instead of
some arbitrary "measurement" action, the condition for decoherence is
more precisely defined in terms of QM instead of in terms of some
mystical force that only the human brain (or maybe the vertebrate brain)
possesses.
> Perhaps you could give some examples of how the conservation laws are
> (not) violated.
The typical one in EPR-type experiments is conservation of angular
momentum. As far as I understand, the polarizations of the particles
ends up in such a way that the angular momentum the particle source
lost/gained constrains the net angular momentum of the emitted entangled
photons.
--
Rahul Jain
rjain@nyct.net
Professional Software Developer, Amateur Quantum Mechanicist
Rahul Jain
Jul19-04, 03:09 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\nOz <oz@farmeroz.port995.com> writes:\n\n> But that wasn\'t really where I was coming from. I just idly wondered if\n> you could detect \'less than a photon\' from a radio wave by measuring the\n> field. On the face of it this doesn\'t seem impossible.\n\nIt shouldn\'t be, according to classical EM. Of course, we know that this\nis where classical EM breaks down...\n\n> I could measure 0.2uV for say 1/100 sec (which is some 10,000\n> oscillations) and by implication measure 1/100th of a photon.\n\nBut you wouldn\'t, due to the quantization of the EM field.\n\n> Now, I\'m not quite sure if this is possible or not (or that I have\n> slipped a few orders of magnitude), but offhand 0.2uV sounds a large\n> enough amplitude to get quite a nice signal.\n\nSure, as long as you can manage to get a whole photon to induce that\nchange.\n\n\n--\nRahul Jain\nrjain@nyct.net\nProfessional Software Developer, Amateur Quantum Mechanicist\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Oz <oz@farmeroz.port995.com> writes:
> But that wasn't really where I was coming from. I just idly wondered if
> you could detect 'less than a photon' from a radio wave by measuring the
> field. On the face of it this doesn't seem impossible.
It shouldn't be, according to classical EM. Of course, we know that this
is where classical EM breaks down...
> I could measure .2uV for say 1/100 sec (which is some 10,000
> oscillations) and by implication measure 1/100th of a photon.
But you wouldn't, due to the quantization of the EM field.
> Now, I'm not quite sure if this is possible or not (or that I have
> slipped a few orders of magnitude), but offhand .2uV sounds a large
> enough amplitude to get quite a nice signal.
Sure, as long as you can manage to get a whole photon to induce that
change.
--
Rahul Jain
rjain@nyct.net
Professional Software Developer, Amateur Quantum Mechanicist
p.kinsler@imperial.ac.uk
Jul27-04, 07:51 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\nRahul Jain <rjain@nyct.net> wrote:\n> Oz <oz@farmeroz.port995.com> writes:\n[...]\n> > Now, I\'m not quite sure if this is possible or not (or that I have\n> > slipped a few orders of magnitude), but offhand 0.2uV sounds a large\n> > enough amplitude to get quite a nice signal.\n\n> Sure, as long as you can manage to get a whole photon to induce that\n> change.\n\nBut what if the field was in a coherent state with an average occupation\nnumber of less than one? Are such states guaranteed to never interact\nwith anything, because they don\'t contain enough photons? [1]\n\n[1] This is sort of a trick question.\n--\n---------------------------------+---------------------------------\nDr. Paul Kinsler\nBlackett Laboratory (QOLS) (ph) +44-20-759-47520 (fax) 47714\nImperial College London, Dr.Paul.Kinsler@physics.org\nSW7 2BW, United Kingdom. http://www.qols.ph.ic.ac.uk/~kinsle/\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Rahul Jain <rjain@nyct.net> wrote:
> Oz <oz@farmeroz.port995.com> writes:
[...]
> > Now, I'm not quite sure if this is possible or not (or that I have
> > slipped a few orders of magnitude), but offhand .2uV sounds a large
> > enough amplitude to get quite a nice signal.
> Sure, as long as you can manage to get a whole photon to induce that
> change.
But what if the field was in a coherent state with an average occupation
number of less than one? Are such states guaranteed to never interact
with anything, because they don't contain enough photons? [1]
[1] This is sort of a trick question.
--
---------------------------------+---------------------------------
Dr. Paul Kinsler
Blackett Laboratory (QOLS) (ph) +44-20-759-47520 (fax) 47714
Imperial College London, Dr.Paul.Kinsler@physics.org
SW7 2BW, United Kingdom. http://www.qols.ph.ic.ac.uk/~kinsle/
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\np.kinsler@imperial.ac.uk writes\n\n>But what if the field was in a coherent state with an average occupation\n>number of less than one? Are such states guaranteed to never interact\n>with anything, because they don\'t contain enough photons? [1]\n>\n>[1] This is sort of a trick question.\n\nAn average occupation number of <1 doesn\'t imply to me that the beam\nwon\'t send a photonsworth of energy given enough time.\n\nIn the aerial example I gave this would be roughly equivalent to having\nto look for a very long time to see the signal through the noise.\n\nI\'m still not convinced (but far from confident) that its impossible to\nsee less than a photonsworth of em field. Go to audio frequencies and\nmicrophone outputs are measured in microvolts, the EM wave we get from\nthem (down the coax) being what we measure. There should be a noise\nlevel limiting detection but this is normally thermal and can be reduced\nby cooling.\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com<<\nozacoohdb@despammed.com still functions.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>p.kinsler@imperial.ac.uk writes
>But what if the field was in a coherent state with an average occupation
>number of less than one? Are such states guaranteed to never interact
>with anything, because they don't contain enough photons? [1]
>
>[1] This is sort of a trick question.
An average occupation number of <1 doesn't imply to me that the beam
won't send a photonsworth of energy given enough time.
In the aerial example I gave this would be roughly equivalent to having
to look for a very long time to see the signal through the noise.
I'm still not convinced (but far from confident) that its impossible to
see less than a photonsworth of em field. Go to audio frequencies and
microphone outputs are measured in microvolts, the EM wave we get from
them (down the coax) being what we measure. There should be a noise
level limiting detection but this is normally thermal and can be reduced
by cooling.
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com<<
ozacoohdb@despammed.com still functions.
Rahul Jain
Jul29-04, 04:59 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\np.kinsler@imperial.ac.uk writes:\n\n> But what if the field was in a coherent state with an average occupation\n> number of less than one? Are such states guaranteed to never interact\n> with anything, because they don\'t contain enough photons? [1]\n>\n> [1] This is sort of a trick question.\n\nDepends whether you\'re interacting with a "measurement tool" or with a\n"quantum system". Defining the difference between the two is left as an\nexercise for the reader. :)\n\n..... Of course, from another thread, you might be able to tell that I\nthink that decoherence has something to do with this. The results of a\ndecoherence-forcing system and those of a measurement seem to be\nidentical as far as I can tell. They prevent alternate possibilities\nfrom interfering with that state. Either a double-slit with measurement\ndevices on the slits or a spontaneously-photon-emitting particle seem to\nhave similar results, i.e., the loss of an interference pattern.\n\n--\nRahul Jain\nrjain@nyct.net\nProfessional Software Developer, Amateur Quantum Mechanicist\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>p.kinsler@imperial.ac.uk writes:
> But what if the field was in a coherent state with an average occupation
> number of less than one? Are such states guaranteed to never interact
> with anything, because they don't contain enough photons? [1]
>
> [1] This is sort of a trick question.
Depends whether you're interacting with a "measurement tool" or with a
"quantum system". Defining the difference between the two is left as an
exercise for the reader. :)
..... Of course, from another thread, you might be able to tell that I
think that decoherence has something to do with this. The results of a
decoherence-forcing system and those of a measurement seem to be
identical as far as I can tell. They prevent alternate possibilities
from interfering with that state. Either a double-slit with measurement
devices on the slits or a spontaneously-photon-emitting particle seem to
have similar results, i.e., the loss of an interference pattern.
--
Rahul Jain
rjain@nyct.net
Professional Software Developer, Amateur Quantum Mechanicist
Rahul Jain
Aug4-04, 01:25 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Oz <oz@farmeroz.port995.com> writes:\n\n> I\'m still not convinced (but far from confident) that its impossible to\n> see less than a photonsworth of em field. Go to audio frequencies and\n> microphone outputs are measured in microvolts, the EM wave we get from\n> them (down the coax) being what we measure. There should be a noise\n> level limiting detection but this is normally thermal and can be reduced\n> by cooling.\n\nA photon can have any frequency (as far as we know), so it can have any\namount of energy. E = hf. Fix the frequency, and you see the\nquantization. Also, compare Planck\'s constant to the systems you are\nconsidering.\n\n--\nRahul Jain\nrjain@nyct.net\nProfessional Software Developer, Amateur Quantum Mechanicist\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Oz <oz@farmeroz.port995.com> writes:
> I'm still not convinced (but far from confident) that its impossible to
> see less than a photonsworth of em field. Go to audio frequencies and
> microphone outputs are measured in microvolts, the EM wave we get from
> them (down the coax) being what we measure. There should be a noise
> level limiting detection but this is normally thermal and can be reduced
> by cooling.
A photon can have any frequency (as far as we know), so it can have any
amount of energy. E = hf. Fix the frequency, and you see the
quantization. Also, compare Planck's constant to the systems you are
considering.
--
Rahul Jain
rjain@nyct.net
Professional Software Developer, Amateur Quantum Mechanicist
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Rahul Jain <rjain@nyct.net> writes\n>Oz <oz@farmeroz.port995.com> writes:\n>\n>> I\'m still not convinced (but far from confident) that its impossible to\n>> see less than a photonsworth of em field. Go to audio frequencies and\n>> microphone outputs are measured in microvolts, the EM wave we get from\n>> them (down the coax) being what we measure. There should be a noise\n>> level limiting detection but this is normally thermal and can be reduced\n>> by cooling.\n>\n>A photon can have any frequency (as far as we know), so it can have any\n>amount of energy. E = hf.\n\nOf course. Not that this has much relevance to my statement.\nNow find me a single atom detector that can detect *any* energy.\nYou can\'t.\n\n>Fix the frequency, and you see the\n>quantization.\n\nActually, I don\'t.\nI see quantisation in emitters and detectors, but that is another thing.\n\n>Also, compare Planck\'s constant to the systems you are\n>considering.\n\nI did, in an earlier post. At 1MHz a photon corresponded to something in\nthe microvolts over 50 ohms for 1 second, from memory.\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com<<\nozacoohdb@despammed.com still functions.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Rahul Jain <rjain@nyct.net> writes
>Oz <oz@farmeroz.port995.com> writes:
>
>> I'm still not convinced (but far from confident) that its impossible to
>> see less than a photonsworth of em field. Go to audio frequencies and
>> microphone outputs are measured in microvolts, the EM wave we get from
>> them (down the coax) being what we measure. There should be a noise
>> level limiting detection but this is normally thermal and can be reduced
>> by cooling.
>
>A photon can have any frequency (as far as we know), so it can have any
>amount of energy. E = hf.
Of course. Not that this has much relevance to my statement.
Now find me a single atom detector that can detect *any* energy.
You can't.
>Fix the frequency, and you see the
>quantization.
Actually, I don't.
I see quantisation in emitters and detectors, but that is another thing.
>Also, compare Planck's constant to the systems you are
>considering.
I did, in an earlier post. At 1MHz a photon corresponded to something in
the microvolts over 50 ohms for 1 second, from memory.
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com<<
ozacoohdb@despammed.com still functions.
p.kinsler@imperial.ac.uk
Aug12-04, 08:29 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\nOz <oz@farmeroz.port995.com> wrote:\n> p.kinsler@imperial.ac.uk writes\n\n> >But what if the field was in a coherent state with an average occupation\n> >number of less than one? Are such states guaranteed to never interact\n> >with anything, because they don\'t contain enough photons? [1]\n> >\n> >[1] This is sort of a trick question.\n\n> An average occupation number of <1 doesn\'t imply to me that the beam\n> won\'t send a photonsworth of energy given enough time.\n\nWell now, that would depend on what field mode my photon is\nin. If it was a plane wave, I might well have box-normalised\nit into photons per unit length, and you\'d be right. If I hadn\'t\nnormalised that sort of way, you\'d be wrong.\n\n> I\'m still not convinced (but far from confident) that its\n> impossible to see less than a photonsworth of em field.\n\nYou can. With a crude (but perfect) photon-eating detector,\nyou\'d see a yes/no signal according to the fractional occupation\nof the mode(s) containing the incoming signal. If it\'s a\nrepeatable measurement, you are pretty much guaranteed a\nsignal on average; assuming sufficiently perfect conditions.\n\n--\n---------------------------------+---------------------------------\nDr. Paul Kinsler\nBlackett Laboratory (QOLS) (ph) +44-20-759-47520 (fax) 47714\nImperial College London, Dr.Paul.Kinsler@physics.org\nSW7 2BW, United Kingdom. http://www.qols.ph.ic.ac.uk/~kinsle/\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Oz <oz@farmeroz.port995.com> wrote:
> p.kinsler@imperial.ac.uk writes
> >But what if the field was in a coherent state with an average occupation
> >number of less than one? Are such states guaranteed to never interact
> >with anything, because they don't contain enough photons? [1]
> >
> >[1] This is sort of a trick question.
> An average occupation number of <1 doesn't imply to me that the beam
> won't send a photonsworth of energy given enough time.
Well now, that would depend on what field mode my photon is
in. If it was a plane wave, I might well have box-normalised
it into photons per unit length, and you'd be right. If I hadn't
normalised that sort of way, you'd be wrong.
> I'm still not convinced (but far from confident) that its
> impossible to see less than a photonsworth of em field.
You can. With a crude (but perfect) photon-eating detector,
you'd see a yes/no signal according to the fractional occupation
of the mode(s) containing the incoming signal. If it's a
repeatable measurement, you are pretty much guaranteed a
signal on average; assuming sufficiently perfect conditions.
--
---------------------------------+---------------------------------
Dr. Paul Kinsler
Blackett Laboratory (QOLS) (ph) +44-20-759-47520 (fax) 47714
Imperial College London, Dr.Paul.Kinsler@physics.org
SW7 2BW, United Kingdom. http://www.qols.ph.ic.ac.uk/~kinsle/
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\np.kinsler@imperial.ac.uk writes\n>\n>\n>\n>Oz <oz@farmeroz.port995.com> wrote:\n>> p.kinsler@imperial.ac.uk writes\n>\n>> >But what if the field was in a coherent state with an average occupation\n>> >number of less than one? Are such states guaranteed to never interact\n>> >with anything, because they don\'t contain enough photons? [1]\n>> >\n>> >[1] This is sort of a trick question.\n>\n>> An average occupation number of <1 doesn\'t imply to me that the beam\n>> won\'t send a photonsworth of energy given enough time.\n>\n>Well now, that would depend on what field mode my photon is\n>in.\n\nDamn but you always baffle me with knowledge.....\n\n>If it was a plane wave, I might well have box-normalised\n>it into photons per unit length, and you\'d be right. If I hadn\'t\n>normalised that sort of way, you\'d be wrong.\n\nhang on. The result cannot depend on how YOU chose to normalise it.\nI\'m going to renormalise it to suit me, and I (eventually) detect a\nphoton.\n\nPlease bear in mind I speak from a well of infinite ignorance.\n\n>> I\'m still not convinced (but far from confident) that its\n>> impossible to see less than a photonsworth of em field.\n>\n>You can. With a crude (but perfect) photon-eating detector,\n>you\'d see a yes/no signal according to the fractional occupation\n>of the mode(s) containing the incoming signal. If it\'s a\n>repeatable measurement, you are pretty much guaranteed a\n>signal on average; assuming sufficiently perfect conditions.\n\nHmmm. That sounds like a \'yes\', but I think its really a \'no\'.\n\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com<<\nozacoohdb@despammed.com still functions.\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>p.kinsler@imperial.ac.uk writes
>
>
>
>Oz <oz@farmeroz.port995.com> wrote:
>> p.kinsler@imperial.ac.uk writes
>
>> >But what if the field was in a coherent state with an average occupation
>> >number of less than one? Are such states guaranteed to never interact
>> >with anything, because they don't contain enough photons? [1]
>> >
>> >[1] This is sort of a trick question.
>
>> An average occupation number of <1 doesn't imply to me that the beam
>> won't send a photonsworth of energy given enough time.
>
>Well now, that would depend on what field mode my photon is
>in.
Damn but you always baffle me with knowledge.....
>If it was a plane wave, I might well have box-normalised
>it into photons per unit length, and you'd be right. If I hadn't
>normalised that sort of way, you'd be wrong.
hang on. The result cannot depend on how YOU chose to normalise it.
I'm going to renormalise it to suit me, and I (eventually) detect a
photon.
Please bear in mind I speak from a well of infinite ignorance.
>> I'm still not convinced (but far from confident) that its
>> impossible to see less than a photonsworth of em field.
>
>You can. With a crude (but perfect) photon-eating detector,
>you'd see a yes/no signal according to the fractional occupation
>of the mode(s) containing the incoming signal. If it's a
>repeatable measurement, you are pretty much guaranteed a
>signal on average; assuming sufficiently perfect conditions.
Hmmm. That sounds like a 'yes', but I think its really a 'no'.
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com<<
ozacoohdb@despammed.com still functions.
p.kinsler@imperial.ac.uk
Aug17-04, 11:26 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\nOz <oz@farmeroz.port995.com> wrote:\n> >> An average occupation number of <1 doesn\'t imply to me that the beam\n> >> won\'t send a photonsworth of energy given enough time.\n> [...]\n> hang on. The result cannot depend on how YOU chose to normalise it.\n\nYes it can: the originally stated initial condition was rather\nvague, and did not specify whether an "average occupation number\nof n<1" was "n<1 over all space" or "n<1 per volume" -- consequently\nI might chose to start with either.\n\n> I\'m going to renormalise it to suit me, and I (eventually) detect a\n> photon.\n\nWell then, you should have made it clear it was "n<1 per volume",\nnot "n<1 over all space".\n\n> [...]\n> Please bear in mind I speak from a well of infinite ignorance.\n> >You can. With a [crude (but perfect) photon-eating detector,\n> >you\'d see a yes/no signal according to the fractional occupation\n> >of the mode(s) containing the incoming signal. If it\'s a\n> >repeatable measurement, you are pretty much guaranteed a\n> >signal on average; assuming sufficiently perfect conditions.\n\n> Hmmm. That sounds like a \'yes\', but I think its really a \'no\'.\n\nI don\'t think it\'s all that much of a "no". I just put in a\nfew ifs and maybes to cover the fact I can\'t be bothered to\ncheck how practical it might be.\n\n\n--\n---------------------------------+---------------------------------\nDr. Paul Kinsler\nBlackett Laboratory (QOLS) (ph) +44-20-759-47520 (fax) 47714\nImperial College London, Dr.Paul.Kinsler@physics.org\nSW7 2BW, United Kingdom. http://www.qols.ph.ic.ac.uk/~kinsle/\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Oz <oz@farmeroz.port995.com> wrote:
> >> An average occupation number of <1 doesn't imply to me that the beam
> >> won't send a photonsworth of energy given enough time.
> [...]
> hang on. The result cannot depend on how YOU chose to normalise it.
Yes it can: the originally stated initial condition was rather
vague, and did not specify whether an "average occupation number
of n<1" was "n<1 over all space" or "n<1 per volume" -- consequently
I might chose to start with either.
> I'm going to renormalise it to suit me, and I (eventually) detect a
> photon.
Well then, you should have made it clear it was "n<1 per volume",
not "n<1 over all space".
> [...]
> Please bear in mind I speak from a well of infinite ignorance.
> >You can. With a [crude (but perfect) photon-eating detector,
> >you'd see a yes/no signal according to the fractional occupation
> >of the mode(s) containing the incoming signal. If it's a
> >repeatable measurement, you are pretty much guaranteed a
> >signal on average; assuming sufficiently perfect conditions.
> Hmmm. That sounds like a 'yes', but I think its really a 'no'.
I don't think it's all that much of a "no". I just put in a
few ifs and maybes to cover the fact I can't be bothered to
check how practical it might be.
--
---------------------------------+---------------------------------
Dr. Paul Kinsler
Blackett Laboratory (QOLS) (ph) +44-20-759-47520 (fax) 47714
Imperial College London, Dr.Paul.Kinsler@physics.org
SW7 2BW, United Kingdom. http://www.qols.ph.ic.ac.uk/~kinsle/
gptejms
Aug17-04, 01:31 PM
I happened across a 1999 thread entitled "Length of wavetrain of a
single photon". The experimental setup is an inferometer with paths
of unequal length. The questions are, how much may the lengths differ
before the interference pattern disappears? and, what if there is
only a single photon present in the system?
It was stated that the difference in length depends on the coherence
length of the light source. The longer the coherence length, the
greater the difference in path length may be. It was also stated that
for linear optics it is well known that intensity of light makes no
difference to interference patterns.
So it would seem that if we feed light from a coherent source into the
inferometer at very low intensity then we have a single photon
interfering with itself over paths of quite different lengths. So it
appears that this photon is not traveling at c. This is a problem.
As you have yourself said intensity of light makes no difference to the interference
pattern--it's just that it takes longer to build up.Now regarding coherence length ,at
least in this particular case it seems it's independent of intensity or the rate of photon
ejection by the source.What governs the coherence length is the kind of source--more
specifically the bandwidth.Given the narrow bandwidth of laser sources,the coherence
length can run into kms. i.e. much higher than the dimensions of our laboratory
experiments.
The valid question is 'can we ensure such low intensity (low photon no.) ejection from
a laser source/cavity?'
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>p.kinsler@imperial.ac.uk writes\n>\n>\n>\n>Oz <oz@farmeroz.port995.com> wrote:\n>> >> An average occupation number of <1 doesn\'t imply to me that the beam\n>> >> won\'t send a photonsworth of energy given enough time.\n>> [...]\n>> hang on. The result cannot depend on how YOU chose to normalise it.\n>\n>Yes it can: the originally stated initial condition was rather\n>vague, and did not specify whether an "average occupation number\n>of n<1" was "n<1 over all space" or "n<1 per volume" -- consequently\n>I might chose to start with either.\n\nOh.....\n\n>> I\'m going to renormalise it to suit me, and I (eventually) detect a\n>> photon.\n>\n>Well then, you should have made it clear it was "n<1 per volume",\n>not "n<1 over all space".\n\nOh....\n\nYou meant n<1 over all space then?\n\nThat must surely mean I might, or might not, detect a photon....\n\n>> [...]\n>> Please bear in mind I speak from a well of infinite ignorance.\n>> >You can. With a [crude (but perfect) photon-eating detector,\n>> >you\'d see a yes/no signal according to the fractional occupation\n>> >of the mode(s) containing the incoming signal. If it\'s a\n>> >repeatable measurement, you are pretty much guaranteed a\n>> >signal on average; assuming sufficiently perfect conditions.\n>\n>> Hmmm. That sounds like a \'yes\', but I think its really a \'no\'.\n>\n>I don\'t think it\'s all that much of a "no". I just put in a\n>few ifs and maybes to cover the fact I can\'t be bothered to\n>check how practical it might be.\n\nThe problem is noise. You might detect a fractional photon, but there\nagain it might just be a particularly noisy bit of noise. Of course,\ngiven enough observations you might be able to say with some certainty\nthat you had detected photons, but you would probably be very unsure how\nmany you had actually detected.\n\nI did once work out (well, sort of) the envelope for a 1MHz photon.\nObviously it could be short, of high amplitude or long of low amplitude.\nReally its just a trade-off between detecting a small but long-lived\nperiodic variation buried in noise or a high but short one rather less\nburied in noise. I\'m still not convinced a low-noise detector\n(amplified, naturally) and an appropriate aerial wouldn\'t be able to\ndetect a fractional photonsworth of 1MHz EM wave to an adequately high\nprobability. One assumes in an environment with zero \'environmental\'\nnoise.\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com<<\nozacoohdb@despammed.com still functions.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>p.kinsler@imperial.ac.uk writes
>
>
>
>Oz <oz@farmeroz.port995.com> wrote:
>> >> An average occupation number of <1 doesn't imply to me that the beam
>> >> won't send a photonsworth of energy given enough time.
>> [...]
>> hang on. The result cannot depend on how YOU chose to normalise it.
>
>Yes it can: the originally stated initial condition was rather
>vague, and did not specify whether an "average occupation number
>of n<1" was "n<1 over all space" or "n<1 per volume" -- consequently
>I might chose to start with either.
Oh.....
>> I'm going to renormalise it to suit me, and I (eventually) detect a
>> photon.
>
>Well then, you should have made it clear it was "n<1 per volume",
>not "n<1 over all space".
Oh....
You meant n<1 over all space then?
That must surely mean I might, or might not, detect a photon....
>> [...]
>> Please bear in mind I speak from a well of infinite ignorance.
>> >You can. With a [crude (but perfect) photon-eating detector,
>> >you'd see a yes/no signal according to the fractional occupation
>> >of the mode(s) containing the incoming signal. If it's a
>> >repeatable measurement, you are pretty much guaranteed a
>> >signal on average; assuming sufficiently perfect conditions.
>
>> Hmmm. That sounds like a 'yes', but I think its really a 'no'.
>
>I don't think it's all that much of a "no". I just put in a
>few ifs and maybes to cover the fact I can't be bothered to
>check how practical it might be.
The problem is noise. You might detect a fractional photon, but there
again it might just be a particularly noisy bit of noise. Of course,
given enough observations you might be able to say with some certainty
that you had detected photons, but you would probably be very unsure how
many you had actually detected.
I did once work out (well, sort of) the envelope for a 1MHz photon.
Obviously it could be short, of high amplitude or long of low amplitude.
Really its just a trade-off between detecting a small but long-lived
periodic variation buried in noise or a high but short one rather less
buried in noise. I'm still not convinced a low-noise detector
(amplified, naturally) and an appropriate aerial wouldn't be able to
detect a fractional photonsworth of 1MHz EM wave to an adequately high
probability. One assumes in an environment with zero 'environmental'
noise.
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com<<
ozacoohdb@despammed.com still functions.
John Baez
Aug25-04, 02:44 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>In article <87smd0k0qz.fsf@nyct.net>, Rahul Jain <rjain@nyct.net> wrote:\n\n>frisbieinstein@yahoo.com (Patrick Powers) writes:\n\n>> I\'m told that wavelength and number of photons are conjugate and have\n>> an inherent uncertainty. As the wavelength is more precisely known\n>> the number of photons is more uncertain.\n\n>This is not true.\n\nNo, but it\'s close: Patrick Powers is probably thinking about an\nuncertainty principle that limits how accurately you can simultaneously\nmeasure the *phase* of a given mode of the electromagnetic field\nand the *number of photons* in this mode.\n\n>The uncertainty is between position and momenutm.\n\nThis is an uncertainty principle that holds for the state of a single\nparticle in quantum mechanics. Patrick Powers is probably thinking\nabout another uncertainty principle, one which holds for the state of\na collection of photons in quantum electromagnetism.\n\nPeople usually learn about this other uncertainty principle only when\nthey study quantum optics - which is a very practical special case of\nquantum field theory.\n\nFor details try this:\n\nhttp://people.deas.harvard.edu/~jones/ap216/lectures/ls_3/ls3_u3/ls3_unit_3.html\n\nEquation III-5 defines the "phase operator" Phi and relates it\nto the "number operator". Equation III-64c gives a commutation\nrelation between the phase operator and its canonically conjugate\nmomentum, which is used to obtain an uncertainty principle in\nequation III-64d. They don\'t seem to work out the commutation relation\nand uncertainty principle relating phase and number operators, but\nI think all the necessary equations are there to do this calculation.\n\nThere must be some book that explains the phase/number uncertainty\nrelation a bit better than this website. There\'s a simple version\nof this relation which applies to the quantum harmonic oscillator!\nLike I said, people usually learn this stuff only when they study\nquantum optics, but each mode of light is an independent harmonic\noscillator, so you just need to understand the harmonic oscillator\nto get a glimpse of this stuff.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>In article <87smd0k0qz.fsf@nyct.net>, Rahul Jain <rjain@nyct.net> wrote:
>frisbieinstein@yahoo.com (Patrick Powers) writes:
>> I'm told that wavelength and number of photons are conjugate and have
>> an inherent uncertainty. As the wavelength is more precisely known
>> the number of photons is more uncertain.
>This is not true.
No, but it's close: Patrick Powers is probably thinking about an
uncertainty principle that limits how accurately you can simultaneously
measure the *phase* of a given mode of the electromagnetic field
and the *number of photons* in this mode.
>The uncertainty is between position and momenutm.
This is an uncertainty principle that holds for the state of a single
particle in quantum mechanics. Patrick Powers is probably thinking
about another uncertainty principle, one which holds for the state of
a collection of photons in quantum electromagnetism.
People usually learn about this other uncertainty principle only when
they study quantum optics - which is a very practical special case of
quantum field theory.
For details try this:
http://people.deas.harvard.edu/~jones/ap216/lectures/ls_3/ls3_u3/ls3_unit_3.html
Equation III-5 defines the "phase operator" \Phi and relates it
to the "number operator". Equation III-64c gives a commutation
relation between the phase operator and its canonically conjugate
momentum, which is used to obtain an uncertainty principle in
equation III-64d. They don't seem to work out the commutation relation
and uncertainty principle relating phase and number operators, but
I think all the necessary equations are there to do this calculation.
There must be some book that explains the phase/number uncertainty
relation a bit better than this website. There's a simple version
of this relation which applies to the quantum harmonic oscillator!
Like I said, people usually learn this stuff only when they study
quantum optics, but each mode of light is an independent harmonic
oscillator, so you just need to understand the harmonic oscillator
to get a glimpse of this stuff.
p.kinsler@imperial.ac.uk
Sep2-04, 03:44 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\nJohn Baez <baez@galaxy.ucr.edu> wrote:\n> For details try this:\n\n> http://people.deas.harvard.edu/~jones/ap216/lectures/ls_3/ls3_u3/ls3_unit_3.html\n\n.... which doesn\'t mention the rather nice phase operator\nof Pegg & Barnett -\n\nD.T. Pegg, S.M. Barnett\nPhys. Rev. A39, (n4), 1665 (1989).\nPhase properties of the quantised single mode electromagnetic field.\n\n\n--\n---------------------------------+---------------------------------\nDr. Paul Kinsler\nBlackett Laboratory (QOLS) (ph) +44-20-759-47520 (fax) 47714\nImperial College London, Dr.Paul.Kinsler@physics.org\nSW7 2BW, United Kingdom. http://www.qols.ph.ic.ac.uk/~kinsle/\n\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>John Baez <baez@galaxy.ucr.edu> wrote:
> For details try this:
> http://people.deas.harvard.edu/~jones/ap216/lectures/ls_3/ls3_u3/ls3_unit_3.html
.... which doesn't mention the rather nice phase operator
of Pegg & Barnett -
D.T. Pegg, S.M. Barnett
Phys. Rev. A39, (n4), 1665 (1989).
Phase properties of the quantised single mode electromagnetic field.
--
---------------------------------+---------------------------------
Dr. Paul Kinsler
Blackett Laboratory (QOLS) (ph) +44-20-759-47520 (fax) 47714
Imperial College London, Dr.Paul.Kinsler@physics.org
SW7 2BW, United Kingdom. http://www.qols.ph.ic.ac.uk/~kinsle/
Patrick Powers
Sep9-04, 02:55 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>baez@galaxy.ucr.edu (John Baez) wrote in message news:<cgg1es\\$2e0\\$1@glue.ucr.edu>...\n>\n> No, but it\'s close: Patrick Powers is probably thinking about an\n> uncertainty principle that limits how accurately you can simultaneously\n> measure the *phase* of a given mode of the electromagnetic field\n> and the *number of photons* in this mode.\n>\n\nYou are too kind.\n\nAs far as I can tell, many think of this situation (Single photon\nself-interference over time.) as a classical field, with somehow\nenergy able to enter and exit only in quanta. This is mathematically\nsatisfactory and allows for calculation.\n\nI assume that if the emission of the photons were observed then the\ninterference effects would disappear.\n\nI can think of two ways of explaining the observations without\nresorting to classical fields. One is to have an infinite number of\nphotons with probability zero (or very large number with very small\nprobability). The other is to allow future events to influence the\npast, a favorite assumption of Dr. Feynman. But there is not much\npoint in developing such theories, as they have no predictive\nproperties. This is just amusement for amateurs like me.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>baez@galaxy.ucr.edu (John Baez) wrote in message news:<cgg1es$2e0$1@glue.ucr.edu>...
>
> No, but it's close: Patrick Powers is probably thinking about an
> uncertainty principle that limits how accurately you can simultaneously
> measure the *phase* of a given mode of the electromagnetic field
> and the *number of photons* in this mode.
>
You are too kind.
As far as I can tell, many think of this situation (Single photon
self-interference over time.) as a classical field, with somehow
energy able to enter and exit only in quanta. This is mathematically
satisfactory and allows for calculation.
I assume that if the emission of the photons were observed then the
interference effects would disappear.
I can think of two ways of explaining the observations without
resorting to classical fields. One is to have an infinite number of
photons with probability zero (or very large number with very small
probability). The other is to allow future events to influence the
past, a favorite assumption of Dr. Feynman. But there is not much
point in developing such theories, as they have no predictive
properties. This is just amusement for amateurs like me.
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Patrick Powers <frisbieinstein@yahoo.com> writes\n\n\n>The other is to allow future events to influence the\n>past, a favorite assumption of Dr. Feynman.\n\nWas it? Gosh.\n\nIn that case he is bound to have put some equations to work.\nAnyone any idea of the general gist and why it fell from favour?\n\n>But there is not much\n>point in developing such theories, as they have no predictive\n>properties.\n\nI\'m not so sure about that though.\nPredicting (some level of) unpredictability would be predictive.\n\n>This is just amusement for amateurs like me.\n\nYes, I know what you mean ...\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com<<\nozacoohdb@despammed.com still functions.\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Patrick Powers <frisbieinstein@yahoo.com> writes
>The other is to allow future events to influence the
>past, a favorite assumption of Dr. Feynman.
Was it? Gosh.
In that case he is bound to have put some equations to work.
Anyone any idea of the general gist and why it fell from favour?
>But there is not much
>point in developing such theories, as they have no predictive
>properties.
I'm not so sure about that though.
Predicting (some level of) unpredictability would be predictive.
>This is just amusement for amateurs like me.
Yes, I know what you mean ...
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com<<
ozacoohdb@despammed.com still functions.
Fred Chen
Sep14-04, 12:12 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\nfrisbieinstein@yahoo.com (Patrick Powers) wrote in message news:<9511688f.0409042300.46a57d3d@posting.google. com>...\n> baez@galaxy.ucr.edu (John Baez) wrote in message news:<cgg1es\\$2e0\\$1@glue.ucr.edu>...\n> >\n> > No, but it\'s close: Patrick Powers is probably thinking about an\n> > uncertainty principle that limits how accurately you can simultaneously\n> > measure the *phase* of a given mode of the electromagnetic field\n> > and the *number of photons* in this mode.\n> >\n>\n> You are too kind.\n>\n> As far as I can tell, many think of this situation (Single photon\n> self-interference over time.) as a classical field, with somehow\n> energy able to enter and exit only in quanta. This is mathematically\n> satisfactory and allows for calculation.\n>\n> I assume that if the emission of the photons were observed then the\n> interference effects would disappear.\n>\n> I can think of two ways of explaining the observations without\n> resorting to classical fields. One is to have an infinite number of\n> photons with probability zero (or very large number with very small\n> probability). The other is to allow future events to influence the\n> past, a favorite assumption of Dr. Feynman. But there is not much\n> point in developing such theories, as they have no predictive\n> properties. This is just amusement for amateurs like me.\n\nI had a related debate in another forum (Everything-list). Did you\nread of the Ashfar experiment? You may find it interesting.\n\nAnyway, wave behavior (such as interference and diffraction) results\nfrom the statistics of many, many photons. A single photon is merely a\nparticle description. The probability of detecting it at a given\nlocation is proportional to the corresponding wave intensity.\n\nSelf-interference or self-interaction seems to me a dangerous concept\ntheoretically, mainly because it can lead to an infinite regress or\nsequence of self-interference in the mathematical formalism.\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>frisbieinstein@yahoo.com (Patrick Powers) wrote in message news:<9511688f.0409042300.46a57d3d@posting.google.com>...
> baez@galaxy.ucr.edu (John Baez) wrote in message news:<cgg1es$2e0$1@glue.ucr.edu>...
> >
> > No, but it's close: Patrick Powers is probably thinking about an
> > uncertainty principle that limits how accurately you can simultaneously
> > measure the *phase* of a given mode of the electromagnetic field
> > and the *number of photons* in this mode.
> >
>
> You are too kind.
>
> As far as I can tell, many think of this situation (Single photon
> self-interference over time.) as a classical field, with somehow
> energy able to enter and exit only in quanta. This is mathematically
> satisfactory and allows for calculation.
>
> I assume that if the emission of the photons were observed then the
> interference effects would disappear.
>
> I can think of two ways of explaining the observations without
> resorting to classical fields. One is to have an infinite number of
> photons with probability zero (or very large number with very small
> probability). The other is to allow future events to influence the
> past, a favorite assumption of Dr. Feynman. But there is not much
> point in developing such theories, as they have no predictive
> properties. This is just amusement for amateurs like me.
I had a related debate in another forum (Everything-list). Did you
read of the Ashfar experiment? You may find it interesting.
Anyway, wave behavior (such as interference and diffraction) results
from the statistics of many, many photons. A single photon is merely a
particle description. The probability of detecting it at a given
location is proportional to the corresponding wave intensity.
Self-interference or self-interaction seems to me a dangerous concept
theoretically, mainly because it can lead to an infinite regress or
sequence of self-interference in the mathematical formalism.
Patrick Powers
Sep14-04, 12:21 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Oz <oz@farmeroz.port995.com> wrote in message news:<h\\$63HZCgFsQBFwYD@farmeroz.port995.com>...\ n> Patrick Powers <frisbieinstein@yahoo.com> writes\n>\n>\n> >The other is to allow future events to influence the\n> >past, a favorite assumption of Dr. Feynman.\n>\n> Was it? Gosh.\n>\n> In that case he is bound to have put some equations to work.\n> Anyone any idea of the general gist and why it fell from favour?\n>\n\nRichard Feynman\'s PhD thesis, supervised by Wheeler, had to do with\nwaves coming out of the future and past. I think it might have been a\nMachian theory of inertia. He once remarked that a positron is an\nelectron going back in time, an idea which has failed to find favor\nwith physicists in general.\n\nTo me the whole concept seems unfalsifiable. How could one prove that\nan event in the past was not caused by one from the future? A theory\nthat uses past events to predict the future is also more useful than\none that uses future events to predict the past, so you might as well\nstick with that.\n\nThat idea that there are an infinite number of photons with zero\nprobability should be somewhat testable. I\'d guess the number of\nphotons observed using a perfect detector would always have a Poisson\ndistribution.\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Oz <oz@farmeroz.port995.com> wrote in message news:<h$63HZCgFsQBFwYD@farmeroz.port995.com>...
> Patrick Powers <frisbieinstein@yahoo.com> writes
>
>
> >The other is to allow future events to influence the
> >past, a favorite assumption of Dr. Feynman.
>
> Was it? Gosh.
>
> In that case he is bound to have put some equations to work.
> Anyone any idea of the general gist and why it fell from favour?
>
Richard Feynman's PhD thesis, supervised by Wheeler, had to do with
waves coming out of the future and past. I think it might have been a
Machian theory of inertia. He once remarked that a positron is an
electron going back in time, an idea which has failed to find favor
with physicists in general.
To me the whole concept seems unfalsifiable. How could one prove that
an event in the past was not caused by one from the future? A theory
that uses past events to predict the future is also more useful than
one that uses future events to predict the past, so you might as well
stick with that.
That idea that there are an infinite number of photons with zero
probability should be somewhat testable. I'd guess the number of
photons observed using a perfect detector would always have a Poisson
distribution.
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\n\nPatrick Powers <frisbieinstein@yahoo.com> writes\n>To me the whole concept seems unfalsifiable. How could one prove that\n>\n>an event in the past was not caused by one from the future? A theory\n>\n>that uses past events to predict the future is also more useful than\n>\n>one that uses future events to predict the past, so you might as well\n>\n>stick with that.\n\nIndeed. However if an antiparticle can be seen as a particle coming from\nthe future, then its likely that this will have an effect. Given that\nthe overwhelming majority of particles are not antiparticles then one\nwould still have a macroscopic defined flow of time but in the time\nperiod where antiparticles are important, you wouldn\'t. You would get\nsome strange effects, maybe something not dissimilar to QM.\n\nTo be consistent you would want antiparticles not to be able to alter\nthings in their past (ie outside a reverse lightcone) just as particles\ncannot alter things in their lightcone. A photon is its own\nantiparticle, which is itself intriguing given this (rather strange)\nviewpoint.\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com<<\nozacoohdb@despammed.com still functions.\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Patrick Powers <frisbieinstein@yahoo.com> writes
>To me the whole concept seems unfalsifiable. How could one prove that
>
>an event in the past was not caused by one from the future? A theory
>
>that uses past events to predict the future is also more useful than
>
>one that uses future events to predict the past, so you might as well
>
>stick with that.
Indeed. However if an antiparticle can be seen as a particle coming from
the future, then its likely that this will have an effect. Given that
the overwhelming majority of particles are not antiparticles then one
would still have a macroscopic defined flow of time but in the time
period where antiparticles are important, you wouldn't. You would get
some strange effects, maybe something not dissimilar to QM.
To be consistent you would want antiparticles not to be able to alter
things in their past (ie outside a reverse lightcone) just as particles
cannot alter things in their lightcone. A photon is its own
antiparticle, which is itself intriguing given this (rather strange)
viewpoint.
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com<<
ozacoohdb@despammed.com still functions.
Patrick Powers
Sep16-04, 07:09 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nOz <oz@farmeroz.port995.com> wrote in message news:<MEkMpSQeKzRBFwG1@farmeroz.port995.com>...\n> Patrick Powers <frisbieinstein@yahoo.com> writes\n> >To me the whole concept seems unfalsifiable. How could one prove that\n> >\n> >an event in the past was not caused by one from the future? A theory\n> >\n> >that uses past events to predict the future is also more useful than\n> >\n> >one that uses future events to predict the past, so you might as well\n> >\n> >stick with that.\n>\n> Indeed. However if an antiparticle can be seen as a particle coming from\n> the future, then its likely that this will have an effect. Given that\n> the overwhelming majority of particles are not antiparticles then one\n> would still have a macroscopic defined flow of time but in the time\n> period where antiparticles are important, you wouldn\'t. You would get\n> some strange effects, maybe something not dissimilar to QM.\n>\n> To be consistent you would want antiparticles not to be able to alter\n> things in their past (ie outside a reverse lightcone) just as particles\n> cannot alter things in their lightcone. A photon is its own\n> antiparticle, which is itself intriguing given this (rather strange)\n> viewpoint.\n\nYou can see what he meant at\nhttp://www.quantummatter.com/body_feyn.html\n\nThey claim that if you plug negative time into the electron equation\nyou get the positron equation. I don\'t think there is any meaning\nbeyond this.\n\nWhat interests me is the infinite photons with zero probability but\nwell-defined mean. Suppose each of these photons has numbers for\n"phase" and "polarity" when created. It could be that this forms a\n"field" without nagging doubts about the absence of a medium, and that\nwith such an interpretation the "photon self-interference over time"\nis no longer a mystery.\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Oz <oz@farmeroz.port995.com> wrote in message news:<MEkMpSQeKzRBFwG1@farmeroz.port995.com>...
> Patrick Powers <frisbieinstein@yahoo.com> writes
> >To me the whole concept seems unfalsifiable. How could one prove that
> >
> >an event in the past was not caused by one from the future? A theory
> >
> >that uses past events to predict the future is also more useful than
> >
> >one that uses future events to predict the past, so you might as well
> >
> >stick with that.
>
> Indeed. However if an antiparticle can be seen as a particle coming from
> the future, then its likely that this will have an effect. Given that
> the overwhelming majority of particles are not antiparticles then one
> would still have a macroscopic defined flow of time but in the time
> period where antiparticles are important, you wouldn't. You would get
> some strange effects, maybe something not dissimilar to QM.
>
> To be consistent you would want antiparticles not to be able to alter
> things in their past (ie outside a reverse lightcone) just as particles
> cannot alter things in their lightcone. A photon is its own
> antiparticle, which is itself intriguing given this (rather strange)
> viewpoint.
You can see what he meant at
http://www.quantummatter.com/body_feyn.html
They claim that if you plug negative time into the electron equation
you get the positron equation. I don't think there is any meaning
beyond this.
What interests me is the infinite photons with zero probability but
well-defined mean. Suppose each of these photons has numbers for
"phase" and "polarity" when created. It could be that this forms a
"field" without nagging doubts about the absence of a medium, and that
with such an interpretation the "photon self-interference over time"
is no longer a mystery.
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\nPatrick Powers\n\n> How could one prove that\n> an event in the past\n> was not caused by one\n> from the future?\n\n..... alternately exposing an antenna to the sky, at night,\nthen shielding it. Figuring that the radiation reaction\nshould be affected, causing variations in the power or in\nthe current in the antenna. But experiments were not\nconclusive!!\n\n- R.B. Partridge, Absorber Theory of Radiation and the Future of\nthe Universe, 1973, Nature, 244, p. 263\n- D.T. Pegg, On a Recent Experiment to Detect Advanced Radiation,\n1975, J.Physics, A8-L60\n- D.T. Pegg, Absorber Theory of Radiation, 1975, Rep.Progr.Physics,\n38, p.1339\n- L.S. Schulman, Formulation and Justification of the Wheeler-\nFeynman Absorber Theory, 1980, Found. Physics, 10, p.841\n- J.E. Hogart, Cosmological Considerations of the Absorber Theory\nof Radiation, 1962, Proc.RoyalSoc. London, A267, p.365\n- Fred Hoyle and J.Narlikar "Lectures on Cosmology and Action\nat a Distance Electrodynamics",(World Scientific 1996)\n- Fred Hoyle and J.Narlikar in Rev. Mod. Physics, 67 (1995) 113\n- David Pegg, a review article about "advanced vs.retarded" actions\nhttp://www.physica.org/asp/archivedocument.asp?article=T070p01a00106.pdf\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Patrick Powers
> How could one prove that
> an event in the past
> was not caused by one
> from the future?
..... alternately exposing an antenna to the sky, at night,
then shielding it. Figuring that the radiation reaction
should be affected, causing variations in the power or in
the current in the antenna. But experiments were not
conclusive!!
- R.B. Partridge, Absorber Theory of Radiation and the Future of
the Universe, 1973, Nature, 244, p. 263
- D.T. Pegg, On a Recent Experiment to Detect Advanced Radiation,
1975, J.Physics, A8-L60- D.T. Pegg, Absorber Theory of Radiation, 1975, Rep.Progr.Physics,
38, p.1339
- L.S. Schulman, Formulation and Justification of the Wheeler-
Feynman Absorber Theory, 1980, Found. Physics, 10, p.841
- J.E. Hogart, Cosmological Considerations of the Absorber Theory
of Radiation, 1962, Proc.RoyalSoc. London, A267, p.365
- Fred Hoyle and J.Narlikar "Lectures on Cosmology and Action
at a Distance Electrodynamics",(World Scientific 1996)
- Fred Hoyle and J.Narlikar in Rev. Mod. Physics, 67 (1995) 113
- David Pegg, a review article about "advanced vs.retarded" actions
http://www.physica.org/asp/archivedocument.asp?article=T070p01a00106.pdf
Patrick Powers
Sep17-04, 05:32 AM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\nfrisbieinstein@yahoo.com (Patrick Powers) wrote in message news:<9511688f.0409152348.390e0047@posting.google. com>...\n>\n> What interests me is the infinite photons with zero probability but\n> well-defined mean. Suppose each of these photons has numbers for\n> "phase" and "polarity" when created. It could be that this forms a\n> "field" without nagging doubts about the absence of a medium, and that\n> with such an interpretation the "photon self-interference over time"\n> is no longer a mystery.\n\nThe JJ Thorne beam splitter experiment blows this idea away. So\nsuppose that the "probability photons" are little solitons containing\nwaves, and are produced with a frequency roughly corresponding to the\nfrequency of the wave. Then we have these ghost photons lined up like\nbeads on a string. It should look just like a field most of the time,\nbut the Thorne experiment results would be just as observed.\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>frisbieinstein@yahoo.com (Patrick Powers) wrote in message news:<9511688f.0409152348.390e0047@posting.google.com>...
>
> What interests me is the infinite photons with zero probability but
> well-defined mean. Suppose each of these photons has numbers for
> "phase" and "polarity" when created. It could be that this forms a
> "field" without nagging doubts about the absence of a medium, and that
> with such an interpretation the "photon self-interference over time"
> is no longer a mystery.
The JJ Thorne beam splitter experiment blows this idea away. So
suppose that the "probability photons" are little solitons containing
waves, and are produced with a frequency roughly corresponding to the
frequency of the wave. Then we have these ghost photons lined up like
beads on a string. It should look just like a field most of the time,
but the Thorne experiment results would be just as observed.
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