View Full Version : [SOLVED] Double slit experiment in time
David Rutherford
Apr28-04, 01:47 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>Has there ever been a double slit experiment done in time rather than\nspace? In other words, take the usual double slit setup where the slits\nare separated in space, and rotate the whole thing so that the slits are\nseparated in time, rather than space. This would amount to having only\none slit opening and closing successively.\n\nMaybe it would be a little clearer if I draw a picture. A\ntwo-dimensional slice of the usual double slit setup would look like this,\n\n_________________________ detection screen\nA\n\n\n_______ ________ ________ x\n|\n|\n[] source |_______y\n\nNote the coordinate axes to the right. Sorry, I can\'t draw the\ninterference pattern in ascii, but you can check Feynman\'s "Lectures on\nPhysics", Vol. 3, Pg. III-1-4, Fig. 1-3, or any introductory quantum\nmechanics text, to see what it looks like. It has a maximum intensity in\nthe region of A.\n\nNow rotate the setup, above (including the interference pattern), in\nspacetime so that it looks like this,\n\n_________________________ detection screen\nA\n\n\n_______ ________ ________ x\n|\n|\n[] source |_______t\n\nNote the change in coordinate axes on the right. This setup amounts to a\nscreen with only _one_ slit. That slit starts out closed, then it opens\nfor a short time, closes again, then opens, then closes. You can see\nthis if you follow the time line from left to right on the diagram.\n\nIf you follow the time line from left to right on the interference\npattern, you\'ll see that it amounts to a flashing spot of light (if the\nslit is a round hole) with maximum intensity occurring midway in the\ntime period between the openings of the slit (in the region of A).\n\nMy question is, has this experiment (the second one) been done and, if\nso, what sort of pattern was detected?\n\n--\nDave Rutherford\n"New Transformation Equations and the Electric Field Four-vector"\nhttp://www.softcom.net/users/der555/newtransform.pdf\n\nApplications:\n"4/3 Problem Resolution"\nhttp://www.softcom.net/users/der555/elecmass.pdf\n"Action-reaction Paradox Resolution"\nhttp://www.softcom.net/users/der555/actreact.pdf\n"Energy Density Correction"\nhttp://www.softcom.net/users/der555/enerdens.pdf\n"Proposed Quantum Mechanical Connection"\nhttp://www.softcom.net/users/der555/quantum.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>Has there ever been a double slit experiment done in time rather than
space? In other words, take the usual double slit setup where the slits
are separated in space, and rotate the whole thing so that the slits are
separated in time, rather than space. This would amount to having only
one slit opening and closing successively.
Maybe it would be a little clearer if I draw a picture. A
two-dimensional slice of the usual double slit setup would look like this,
__{_______________________} detection screen
A
__{_____} __{______} __{______} x
|
|
[] source |__{_____y}
Note the coordinate axes to the right. Sorry, I can't draw the
interference pattern in ascii, but you can check Feynman's "Lectures on
Physics", Vol. 3, Pg. III-1-4, Fig. 1-3, or any introductory quantum
mechanics text, to see what it looks like. It has a maximum intensity in
the region of A.
Now rotate the setup, above (including the interference pattern), in
spacetime so that it looks like this,
__{_______________________} detection screen
A
__{_____} __{______} __{______} x
|
|
[] source |__{_____t}
Note the change in coordinate axes on the right. This setup amounts to a
screen with only _one_ slit. That slit starts out closed, then it opens
for a short time, closes again, then opens, then closes. You can see
this if you follow the time line from left to right on the diagram.
If you follow the time line from left to right on the interference
pattern, you'll see that it amounts to a flashing spot of light (if the
slit is a round hole) with maximum intensity occurring midway in the
time period between the openings of the slit (in the region of A).
My question is, has this experiment (the second one) been done and, if
so, what sort of pattern was detected?
--
Dave Rutherford
"New Transformation Equations and the Electric Field Four-vector"
http://www.softcom.net/users/der555/newtransform.pdf
Applications:
"4/3 Problem Resolution"
http://www.softcom.net/users/der555/elecmass.pdf
"Action-reaction Paradox Resolution"
http://www.softcom.net/users/der555/actreact.pdf
"Energy Density Correction"
http://www.softcom.net/users/der555/enerdens.pdf
"Proposed Quantum Mechanical Connection"
http://www.softcom.net/users/der555/quantum.pdf
<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>David Rutherford asked:\n\n> Has there ever been a double slit experiment done\n> in time rather than space?\n\nConsider a diaphragm, with two slits, slit 1 and\nslit 2. Each of these slits can be opened, or closed,\nby a shutter connected with a separate counter.\nA weak alpha-particle emitter is placed between\nthe two counters. Imagine that, in the beginning\nof the experiment, both slits are closed.\nIf an alpha-particle strikes one of the counters,\nthe slit connected with this counter is opened,\nand the counters cease to operate, and a light source\nis turned on, in front of the diaphragm, and this\nlight source illuminate a photographic plate placed\nbehind the diaphragm. Following QM rules, we can write\npsi = 1/sqrt2 (psi_1 + psi_2)\nwhere psi_1 is the wavefunction describing the system\nwhen the slit 1 is open (psi_2 when the slit 2 is open).\nThus, from the theory, we should get an interference\npattern, on the photographic plate behind the diaphragm.\nBut if we keep our eyes opened, and we observe which slit\nis open (slit 1, or slit 2) then, in accordance with the\n\'complementarity\' principle, a reduction takes place,\nand no interference pattern appears on the plate.\n\nThe above interesting \'gedanken\' experiment is due to\nL. Janossy, and K. Nagy, [\'Uber eine Form des Einsteinschen\nParadoxes der Quantentheorie\', Annalen der Physik, 17, (1956),\n115-121]. Btw, Janossy and Nagy thought it was possible\nto perform such an experiment, but they also thought\nit was impossible to get that interference.\n\nAfter useful considerations by Leonard Mandel [\'On the\nPossibility of Observing Interference Effects with Light\nBeams Divided by a Shutter\', J. Opt. Soc. Amer., 49, (1959),\n931] at last R.M. Sillitto and Catherine Wykes [\'An Interference\nExperiment With Light Beams Modulated In Anti-Phase By An\nElectro-Optic Shutter\', Physics Letters, 39-A-4, (1972), 333-334]\nperformed an experiment \'similar\' to the Janossy and Nagy\nexperiment and found a clean interference pattern when just\none photon was present in their interferometer, at a time.\nThey used an electro-optic (very fast, but not random) shutter,\nwhich was switched several times during the time-travel of each\nphoton.\n\nIn terms of photons the condition for interference is that\nthe two paths (from the two slits on which the shutter is\ndoing its job) lead to the same cell of phase space, so that\nthe path of each photon is intrinsically indeterminate.\nMore or less, the usual \'welcher weg\' or \'indistinguishability\'\nissue.\n\nOf course, the shutter (random or not that it is) must switch\nin a time which is less than the uncertainty in the time arrival\nof the photon.\n\nA quantum-theoretical treatment of that, via time-dependent\nSchroedinger equation, was given by Marcos Moshinshy [\'Diffraction\nin Time\', Physical Review, vol. 88, n. 3, (1952), pages 625-631]\n\nSaluti,\n\ns.\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>David Rutherford asked:
> Has there ever been a double slit experiment done
> in time rather than space?
Consider a diaphragm, with two slits, slit 1 and
slit 2. Each of these slits can be opened, or closed,
by a shutter connected with a separate counter.
A weak \alpha-particle emitter is placed between
the two counters. Imagine that, in the beginning
of the experiment, both slits are closed.
If an \alpha-particle strikes one of the counters,
the slit connected with this counter is opened,
and the counters cease to operate, and a light source
is turned on, in front of the diaphragm, and this
light source illuminate a photographic plate placed
behind the diaphragm. Following QM rules, we can write
\psi = 1/sqrt2 (\psi_1 + \psi_2)
where \psi_1 is the wavefunction describing the system
when the slit 1 is open (\psi_2 when the slit 2 is open).
Thus, from the theory, we should get an interference
pattern, on the photographic plate behind the diaphragm.
But if we keep our eyes opened, and we observe which slit
is open (slit 1, or slit 2) then, in accordance with the
'complementarity' principle, a reduction takes place,
and no interference pattern appears on the plate.
The above interesting 'gedanken' experiment is due to
L. Janossy, and K. Nagy, ['Uber eine Form des Einsteinschen
Paradoxes der Quantentheorie', Annalen der Physik, 17, (1956),
115-121]. Btw, Janossy and Nagy thought it was possible
to perform such an experiment, but they also thought
it was impossible to get that interference.
After useful considerations by Leonard Mandel ['On the
Possibility of Observing Interference Effects with Light
Beams Divided by a Shutter', J. Opt. Soc. Amer., 49, (1959),
931] at last R.M. Sillitto and Catherine Wykes ['An Interference
Experiment With Light Beams Modulated In Anti-Phase By An
Electro-Optic Shutter', Physics Letters, 39-A-4, (1972), 333-334]
performed an experiment 'similar' to the Janossy and Nagy
experiment and found a clean interference pattern when just
one photon was present in their interferometer, at a time.
They used an electro-optic (very fast, but not random) shutter,
which was switched several times during the time-travel of each
photon.
In terms of photons the condition for interference is that
the two paths (from the two slits on which the shutter is
doing its job) lead to the same cell of phase space, so that
the path of each photon is intrinsically indeterminate.
More or less, the usual 'welcher weg' or 'indistinguishability'
issue.
Of course, the shutter (random or not that it is) must switch
in a time which is less than the uncertainty in the time arrival
of the photon.
A quantum-theoretical treatment of that, via time-dependent
Schroedinger equation, was given by Marcos Moshinshy ['Diffraction
in Time', Physical Review, vol. 88, n. 3, (1952), pages 625-631]
Saluti,
s.
David Rutherford
Apr30-04, 10:30 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\nscerir wrote:\n> David Rutherford asked:\n>\n>>Has there ever been a double slit experiment done\n>>in time rather than space?\n>\n> Consider a diaphragm, with two slits, slit 1 and\n> slit 2.\n\nI think you are misunderstanding me. The screen in the second experiment\nI described in my OP (which is the one I\'m asking about), has only _one_\nslit, _not_ two. The opening of the slit twice in succession is what\ncauses it to be a two slit experiment in time, rather than space.\n\nLook again at the screen and the coordinate axes,\n\nx\n|\n|\n_______1_______2_______ |______ t\n\nTake a piece of paper and cover the diagram. Now slowly move the paper\nto the right (as if moving forward though time). At first, the slit is\nclosed (solid line), then it opens at 1 (gap at 1), closes between 1 and\n2, opens at 2 (gap at 2), then closes after 2. There is only one slit in\nthe screen. That slit is opening and closing, but when the whole\nsequence is viewed at once, as above, it \'looks like\' there are two open\nslits along the t-axis. It\'s as if the usual double slit setup has been\nrotated in spacetime.\n\n--\nDave Rutherford\n"New Transformation Equations and the Electric Field Four-vector"\nhttp://www.softcom.net/users/der555/newtransform.pdf\n\nApplications:\n"4/3 Problem Resolution"\nhttp://www.softcom.net/users/der555/elecmass.pdf\n"Action-reaction Paradox Resolution"\nhttp://www.softcom.net/users/der555/actreact.pdf\n"Energy Density Correction"\nhttp://www.softcom.net/users/der555/enerdens.pdf\n"Proposed Quantum Mechanical Connection"\nhttp://www.softcom.net/users/der555/quantum.pdf\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>scerir wrote:
> David Rutherford asked:
>
>>Has there ever been a double slit experiment done
>>in time rather than space?
>
> Consider a diaphragm, with two slits, slit 1 and
> slit 2.
I think you are misunderstanding me. The screen in the second experiment
I described in my OP (which is the one I'm asking about), has only _one_
slit, _not_ two. The opening of the slit twice in succession is what
causes it to be a two slit experiment in time, rather than space.
Look again at the screen and the coordinate axes,
x
|
|
__{_____1_______2_______} |__{____} t
Take a piece of paper and cover the diagram. Now slowly move the paper
to the right (as if moving forward though time). At first, the slit is
closed (solid line), then it opens at 1 (gap at 1), closes between 1 and
2, opens at 2 (gap at 2), then closes after 2. There is only one slit in
the screen. That slit is opening and closing, but when the whole
sequence is viewed at once, as above, it 'looks like' there are two open
slits along the t-axis. It's as if the usual double slit setup has been
rotated in spacetime.
--
Dave Rutherford
"New Transformation Equations and the Electric Field Four-vector"
http://www.softcom.net/users/der555/newtransform.pdf
Applications:
"4/3 Problem Resolution"
http://www.softcom.net/users/der555/elecmass.pdf
"Action-reaction Paradox Resolution"
http://www.softcom.net/users/der555/actreact.pdf
"Energy Density Correction"
http://www.softcom.net/users/der555/enerdens.pdf
"Proposed Quantum Mechanical Connection"
http://www.softcom.net/users/der555/quantum.pdf
Joe Rongen
May1-04, 07:52 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>"David Rutherford" <drutherford@softcom.net> wrote in message\nnews:Lsqdne1MPLLyyQ3dRVn-vA@softcom.net...\n>\n> Look again at the screen and the coordinate axes,\n>\n> x\n> |\n> |\n> _______1_______2_______ |______ t\n>\n> Take a piece of paper and cover the diagram. Now slowly move the paper\n> to the right (as if moving forward though time). At first, the slit is\n> closed (solid line), then it opens at 1 (gap at 1), closes between 1 and\n> 2, opens at 2 (gap at 2), then closes after 2. There is only one slit in\n> the screen. That slit is opening and closing, but when the whole\n> sequence is viewed at once, as above, it \'looks like\' there are two open\n> slits along the t-axis. It\'s as if the usual double slit setup has been\n> rotated in spacetime.\n\nIn principle that idea was used in older double beam spectrophotometers.\nThere they employed a four segmented optical chopper wheel. Segments one\nand three of the chopper were optically sealed and the other two segments\nwere used for sample and reference beam. As for the "double slit experiment\nin time", I think, it only cuts down the exposure time by what ever time the\ngaps are closed.\n\nRegards Joe\n\n"You cannot move mountains if you believe them to be mountains.\nYou must think of them as collections of small stones,\nWhich can be moved one at a time, and then reassembled."\n-- The Tao of Meow\n\n\n---\nOutgoing mail is certified Virus Free.\nChecked by AVG anti-virus system (http://www.grisoft.com).\nVersion: 6.0.670 / Virus Database: 432 - Release Date: 4/27/04\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>"David Rutherford" <drutherford@softcom.net> wrote in message
news:Lsqdne1MPLLyyQ3dRVn-vA@softcom.net...
>
> Look again at the screen and the coordinate axes,
>
> x
> |
> |
> __{_____1_______2_______} |__{____} t
>
> Take a piece of paper and cover the diagram. Now slowly move the paper
> to the right (as if moving forward though time). At first, the slit is
> closed (solid line), then it opens at 1 (gap at 1), closes between 1 and
> 2, opens at 2 (gap at 2), then closes after 2. There is only one slit in
> the screen. That slit is opening and closing, but when the whole
> sequence is viewed at once, as above, it 'looks like' there are two open
> slits along the t-axis. It's as if the usual double slit setup has been
> rotated in spacetime.
In principle that idea was used in older double beam spectrophotometers.
There they employed a four segmented optical chopper wheel. Segments one
and three of the chopper were optically sealed and the other two segments
were used for sample and reference beam. As for the "double slit experiment
in time", I think, it only cuts down the exposure time by what ever time the
gaps are closed.
Regards Joe
"You cannot move mountains if you believe them to be mountains.
You must think of them as collections of small stones,
Which can be moved one at a time, and then reassembled."
-- The Tao of Meow
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6..670 / Virus Database: 432 - Release Date: 4/27/04
<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\nDavid Rutherford <drutherford@softcom.net> writes\n>I think you are misunderstanding me. The screen in the second experiment I\n>described in my OP (which is the one I\'m asking about), has only _one_ slit,\n>_not_ two. The opening of the slit twice in succession is what causes it to be a\n>two slit experiment in time, rather than space.\n\nOK.\n\nHow are you to get a diffraction pattern with one slit?\n\nYou won\'t.\n\nYou *would* get a *time-varying* diffraction pattern if the two sources\nwere of different frequencies.\n\nBut you don\'t need a shutter for that, time-varying diffraction (beats)\nare well known in radio transmission between two transmitters of\nslightly different frequency.\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>David Rutherford <drutherford@softcom.net> writes
>I think you are misunderstanding me. The screen in the second experiment I
>described in my OP (which is the one I'm asking about), has only _one_ slit,
>_not_ two. The opening of the slit twice in succession is what causes it to be a
>two slit experiment in time, rather than space.
OK.
How are you to get a diffraction pattern with one slit?
You won't.
You *would* get a *time-varying* diffraction pattern if the two sources
were of different frequencies.
But you don't need a shutter for that, time-varying diffraction (beats)
are well known in radio transmission between two transmitters of
slightly different frequency.
--
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)<<
David Rutherford
May3-04, 04:52 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\nJoe Rongen wrote:\n> "David Rutherford" <drutherford@softcom.net> wrote in message\n> news:Lsqdne1MPLLyyQ3dRVn-vA@softcom.net...\n>\n>>Look again at the screen and the coordinate axes,\n>>\n>> x\n>> |\n>> |\n>>_______1_______2_______ |______ t\n>>\n>>Take a piece of paper and cover the diagram. Now slowly move the paper\n>>to the right (as if moving forward though time). At first, the slit is\n>>closed (solid line), then it opens at 1 (gap at 1), closes between 1 and\n>>2, opens at 2 (gap at 2), then closes after 2. There is only one slit in\n>>the screen. That slit is opening and closing, but when the whole\n>>sequence is viewed at once, as above, it \'looks like\' there are two open\n>>slits along the t-axis. It\'s as if the usual double slit setup has been\n>>rotated in spacetime.\n>\n>\n> In principle that idea was used in older double beam spectrophotometers.\n> There they employed a four segmented optical chopper wheel. Segments one\n> and three of the chopper were optically sealed and the other two segments\n> were used for sample and reference beam. As for the "double slit experiment\n> in time", I think, it only cuts down the exposure time by what ever time the\n> gaps are closed.\n\nMaybe I\'m not making myself clear. In my second setup (the one I\'m\nasking about), there is a _single_ beam (or single particle at a time\nemission), a screen with _one_ slit in it, and a detection screen, like\nthis,\n\n________________________ detection screen\n\n\n___________ ____________ x\n|\n|\n[] source |______ y\n\nThe slit starts out closed, then it opens briefly, closes, opens\nbriefly, then closes again. The sequence looks like this when viewed in\nspacetime,\n\n________________________ detection screen\nA\n\n_______ _______ ________ x\n|\n|\n[] source |______ t\n\nNotice that the source is firing midway in time between the openings of\nthe slit. In principle, if the results of this experiment are analogous\nto the usual _double_ slit experiment, then there should be a maximum\nintensity detected in the region of A on the detection screen.\n\nThis result would have several interesting implications. First, it would\nindicate that the maximum intensity at A occurs _simultaneously_ with\nthe emission from the source. Also, no matter how far the source is from\nthe slit, there should still be a pattern detected on the detection\nscreen, even if the source is at a distance that is not conducive to the\nparticle(s) reaching the slit when it is open.\n\n--\nDave Rutherford\n"New Transformation Equations and the Electric Field Four-vector"\nhttp://www.softcom.net/users/der555/newtransform.pdf\n\nApplications:\n"4/3 Problem Resolution"\nhttp://www.softcom.net/users/der555/elecmass.pdf\n"Action-reaction Paradox Resolution"\nhttp://www.softcom.net/users/der555/actreact.pdf\n"Energy Density Correction"\nhttp://www.softcom.net/users/der555/enerdens.pdf\n"Proposed Quantum Mechanical Connection"\nhttp://www.softcom.net/users/der555/quantum.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>Joe Rongen wrote:
> "David Rutherford" <drutherford@softcom.net> wrote in message
> news:Lsqdne1MPLLyyQ3dRVn-vA@softcom.net...
>
>>Look again at the screen and the coordinate axes,
>>
>> x
>> |
>> |
>>__{_____1_______2_______} |__{____} t
>>
>>Take a piece of paper and cover the diagram. Now slowly move the paper
>>to the right (as if moving forward though time). At first, the slit is
>>closed (solid line), then it opens at 1 (gap at 1), closes between 1 and
>>2, opens at 2 (gap at 2), then closes after 2. There is only one slit in
>>the screen. That slit is opening and closing, but when the whole
>>sequence is viewed at once, as above, it 'looks like' there are two open
>>slits along the t-axis. It's as if the usual double slit setup has been
>>rotated in spacetime.
>
>
> In principle that idea was used in older double beam spectrophotometers.
> There they employed a four segmented optical chopper wheel. Segments one
> and three of the chopper were optically sealed and the other two segments
> were used for sample and reference beam. As for the "double slit experiment
> in time", I think, it only cuts down the exposure time by what ever time the
> gaps are closed.
Maybe I'm not making myself clear. In my second setup (the one I'm
asking about), there is a _single_ beam (or single particle at a time
emission), a screen with _one_ slit in it, and a detection screen, like
this,
__{______________________} detection screen
__{_________} __{__________} x
|
|
[] source |__{____} y
The slit starts out closed, then it opens briefly, closes, opens
briefly, then closes again. The sequence looks like this when viewed in
spacetime,
__{______________________} detection screen
A
__{_____} __{_____} __{______} x
|
|
[] source |__{____} t
Notice that the source is firing midway in time between the openings of
the slit. In principle, if the results of this experiment are analogous
to the usual _double_ slit experiment, then there should be a maximum
intensity detected in the region of A on the detection screen.
This result would have several interesting implications. First, it would
indicate that the maximum intensity at A occurs _simultaneously_ with
the emission from the source. Also, no matter how far the source is from
the slit, there should still be a pattern detected on the detection
screen, even if the source is at a distance that is not conducive to the
particle(s) reaching the slit when it is open.
--
Dave Rutherford
"New Transformation Equations and the Electric Field Four-vector"
http://www.softcom.net/users/der555/newtransform.pdf
Applications:
"4/3 Problem Resolution"
http://www.softcom.net/users/der555/elecmass.pdf
"Action-reaction Paradox Resolution"
http://www.softcom.net/users/der555/actreact.pdf
"Energy Density Correction"
http://www.softcom.net/users/der555/enerdens.pdf
"Proposed Quantum Mechanical Connection"
http://www.softcom.net/users/der555/quantum.pdf
<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\nDavid Rutherford <drutherford@softcom.net> wrote in message news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...\n> Has there ever been a double slit experiment done in time rather than\n> space? In other words, take the usual double slit setup where the slits\n> are separated in space, and rotate the whole thing so that the slits are\n> separated in time, rather than space. This would amount to having only\n> one slit opening and closing successively.\n>\n> Maybe it would be a little clearer if I draw a picture. A\n> two-dimensional slice of the usual double slit setup would look like this,\n>\n> _________________________ detection screen\n> A\n>\n>\n> _______ ________ ________ x\n> |\n> |\n> [] source |_______y\n>\n\nThe double slit experiment relies on diffraction in space. In this\nsetup you would need diffraction in time, and its difficult to see how\nthat would come about - it would require that a slit opened for a\nshort time affected the speed of what was going through it so the\nfaster stuff from the first opening caught up with the slower stuff\nfrom the second.\n\nStephen Lee\nwww.chronon.org\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>David Rutherford <drutherford@softcom.net> wrote in message news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...
> Has there ever been a double slit experiment done in time rather than
> space? In other words, take the usual double slit setup where the slits
> are separated in space, and rotate the whole thing so that the slits are
> separated in time, rather than space. This would amount to having only
> one slit opening and closing successively.
>
> Maybe it would be a little clearer if I draw a picture. A
> two-dimensional slice of the usual double slit setup would look like this,
>
> __{_______________________} detection screen
> A
>
>
> __{_____} __{______} __{______} x
> |
> |
> [] source |__{_____y}
>
The double slit experiment relies on diffraction in space. In this
setup you would need diffraction in time, and its difficult to see how
that would come about - it would require that a slit opened for a
short time affected the speed of what was going through it so the
faster stuff from the first opening caught up with the slower stuff
from the second.
Stephen Lee
www.chronon.org
Joe Rongen
May3-04, 01:32 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"David Rutherford" <drutherford@softcom.net> wrote in\nmessage news:bcidnctf14FZVQ7dRVn-iQ@softcom.net...\n\n[snip]\n\n> Maybe I\'m not making myself clear. In my second setup (the one I\'m\n> asking about), there is a _single_ beam (or single particle at a time\n> emission), a screen with _one_ slit in it, and a detection screen, like\n> this,\n>\n> ________________________ detection screen\n>\n>\n> ___________ ____________ x\n> |\n> |\n> [] source |______ y\n>\n> The slit starts out closed, then it opens briefly, closes, opens\n> briefly, then closes again.\n\n\nHaving two slits open simultaneously is\nessential to the interference phenomena.\n\nSee experiments by:\nG. I. Taylor, Proc. Camb. Phil. Soc.15, 114 (1909)\nand J. G. King "Interference of Photons" (1959)\n\n> The sequence looks like this when viewed in spacetime,\n>\n> ________________________ detection screen\n> A\n>\n> _______ _______ ________ x\n> |\n> |\n> [] source |______ t\n>\n> Notice that the source is firing midway in time between the openings of\n> the slit. In principle, if the results of this experiment are analogous\n> to the usual _double_ slit experiment, then there should be a maximum\n> intensity detected in the region of A on the detection screen.\n>\n> This result would have several interesting implications.\n\n\nI think, if one slit is open while the other is closed than one would not\nsee a fringe pattern but instead a diffraction pattern of an individual\nslit.\n\nRegards Joe\n\n"Each of us visits that Earth involuntarily and without an\ninvitation. For me, it is enough to wonder at its secrets."\nQuoted in Des MacHale, Wisdom (London, 2002).\n\n\n---\nOutgoing mail is certified Virus Free.\nChecked by AVG anti-virus system (http://www.grisoft.com).\nVersion: 6.0.675 / Virus Database: 437 - Release Date: 5/2/04\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>"David Rutherford" <drutherford@softcom.net> wrote in
message news:bcidnctf14FZVQ7dRVn-iQ@softcom.net...
[snip]
> Maybe I'm not making myself clear. In my second setup (the one I'm
> asking about), there is a _single_ beam (or single particle at a time
> emission), a screen with _one_ slit in it, and a detection screen, like
> this,
>
> __{______________________} detection screen
>
>
> __{_________} __{__________} x
> |
> |
> [] source |__{____} y
>
> The slit starts out closed, then it opens briefly, closes, opens
> briefly, then closes again.
Having two slits open simultaneously is
essential to the interference phenomena.
See experiments by:
G. I. Taylor, Proc. Camb. Phil. Soc.15, 114 (1909)
and J. G. King "Interference of Photons" (1959)
> The sequence looks like this when viewed in spacetime,
>
> __{______________________} detection screen
> A
>
> __{_____} __{_____} __{______} x
> |
> |
> [] source |__{____} t
>
> Notice that the source is firing midway in time between the openings of
> the slit. In principle, if the results of this experiment are analogous
> to the usual _double_ slit experiment, then there should be a maximum
> intensity detected in the region of A on the detection screen.
>
> This result would have several interesting implications.
I think, if one slit is open while the other is closed than one would not
see a fringe pattern but instead a diffraction pattern of an individual
slit.
Regards Joe
"Each of us visits that Earth involuntarily and without an
invitation. For me, it is enough to wonder at its secrets."
Quoted in Des MacHale, Wisdom (London, 2002).
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6..675 / Virus Database: 437 - Release Date: 5/2/04
David Rutherford
May4-04, 03:04 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 wrote:\n> David Rutherford <drutherford@softcom.net> writes\n>\n>>I think you are misunderstanding me. The screen in the second experiment I\n>>described in my OP (which is the one I\'m asking about), has only _one_ slit,\n>>_not_ two. The opening of the slit twice in succession is what causes it to be a\n>>two slit experiment in time, rather than space.\n>\n>\n> OK.\n>\n> How are you to get a diffraction pattern with one slit?\n>\n> You won\'t.\n\nAll I\'m doing is rotating the diagram of the usual double slit\nexperiment (along with the diffraction pattern) in spacetime and\nanalyzing what that would mean (if a correspondence can be made between\nthe two) by looking at the resulting rotated diagram. There would\nactually be no diffraction pattern on the detection screen at the end of\nthe test. There would only be a round spot (for a round slit), if I\'m\nanalyzing it correctly. But that spot would have been pulsing over the\ncourse of the detection.\n\nThe pulsing would start out faint, then increase in intensity until the\nregion A (in time), then it would fade out again. You can see this if\nyou follow the diffraction pattern (check out the Feynman reference I\ngave in an earlier post) from one end of the pattern to the other.\nImagine each peak in the pattern\'s intensity is a pulse. Each pulse\noccurs on the detection screen at a point directly opposite the slit, so\nall the pulses occur at the same place, but at different times.\nRemember, the slit exists all along the line with the gaps in it, but is\nopen only at gaps "1" and "2". The maximum intensity pulse occurs midway\nin time between the two openings of the slit, and _simultaneously_ with\nthe emission of the particle. Remember, the source "[]" only \'exists\' at\ntime "A" in the rotated diagram. In other words, that\'s when the\nparticle(s) is emitted.\n\nThe diffraction pattern is only apparent if you look at the pattern of\nthe pulses along the t-axis. The pulses all occur at the same place\n(same x-coordinate), but at different times.\n\nThe best way for you to get an idea for what\'s happening is to draw the\nusual double slit diagram on a piece of paper with the usual\ninterference pattern and imagine the screens (slit and detection) are\nalong the t-axis. Take a pen or a piece of clear acetate with a straight\nline on it to act as a line of constant t. Now run the line\nperpendicular to the screens from one end of the screens to the other\nand analyze what happens when, and what the implications are.\n\n> You *would* get a *time-varying* diffraction pattern if the two sources\n> were of different frequencies.\n\nThere\'s only one source and there would be a time-varying spot directly\nacross from the slit, if I\'m analyzing the rotated diagram correctly.\n\n--\nDave Rutherford\n"New Transformation Equations and the Electric Field Four-vector"\nhttp://www.softcom.net/users/der555/newtransform.pdf\n\nApplications:\n"4/3 Problem Resolution"\nhttp://www.softcom.net/users/der555/elecmass.pdf\n"Action-reaction Paradox Resolution"\nhttp://www.softcom.net/users/der555/actreact.pdf\n"Energy Density Correction"\nhttp://www.softcom.net/users/der555/enerdens.pdf\n"Proposed Quantum Mechanical Connection"\nhttp://www.softcom.net/users/der555/quantum.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>Oz wrote:
> David Rutherford <drutherford@softcom.net> writes
>
>>I think you are misunderstanding me. The screen in the second experiment I
>>described in my OP (which is the one I'm asking about), has only _one_ slit,
>>_not_ two. The opening of the slit twice in succession is what causes it to be a
>>two slit experiment in time, rather than space.
>
>
> OK.
>
> How are you to get a diffraction pattern with one slit?
>
> You won't.
All I'm doing is rotating the diagram of the usual double slit
experiment (along with the diffraction pattern) in spacetime and
analyzing what that would mean (if a correspondence can be made between
the two) by looking at the resulting rotated diagram. There would
actually be no diffraction pattern on the detection screen at the end of
the test. There would only be a round spot (for a round slit), if I'm
analyzing it correctly. But that spot would have been pulsing over the
course of the detection.
The pulsing would start out faint, then increase in intensity until the
region A (in time), then it would fade out again. You can see this if
you follow the diffraction pattern (check out the Feynman reference I
gave in an earlier post) from one end of the pattern to the other.
Imagine each peak in the pattern's intensity is a pulse. Each pulse
occurs on the detection screen at a point directly opposite the slit, so
all the pulses occur at the same place, but at different times.
Remember, the slit exists all along the line with the gaps in it, but is
open only at gaps "1" and "2". The maximum intensity pulse occurs midway
in time between the two openings of the slit, and _simultaneously_ with
the emission of the particle. Remember, the source "[]" only 'exists' at
time "A" in the rotated diagram. In other words, that's when the
particle(s) is emitted.
The diffraction pattern is only apparent if you look at the pattern of
the pulses along the t-axis. The pulses all occur at the same place
(same x-coordinate), but at different times.
The best way for you to get an idea for what's happening is to draw the
usual double slit diagram on a piece of paper with the usual
interference pattern and imagine the screens (slit and detection) are
along the t-axis. Take a pen or a piece of clear acetate with a straight
line on it to act as a line of constant t. Now run the line
perpendicular to the screens from one end of the screens to the other
and analyze what happens when, and what the implications are.
> You *would* get a *time-varying* diffraction pattern if the two sources
> were of different frequencies.
There's only one source and there would be a time-varying spot directly
across from the slit, if I'm analyzing the rotated diagram correctly.
--
Dave Rutherford
"New Transformation Equations and the Electric Field Four-vector"
http://www.softcom.net/users/der555/newtransform.pdf
Applications:
"4/3 Problem Resolution"
http://www.softcom.net/users/der555/elecmass.pdf
"Action-reaction Paradox Resolution"
http://www.softcom.net/users/der555/actreact.pdf
"Energy Density Correction"
http://www.softcom.net/users/der555/enerdens.pdf
"Proposed Quantum Mechanical Connection"
http://www.softcom.net/users/der555/quantum.pdf
p.kinsler@imperial.ac.uk
May6-04, 07:52 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>\nDavid Rutherford <drutherford@softcom.net> wrote:\n> [...]\n> ________________________ detection screen\n> A\n\n> _______ _______ ________ x\n> |\n> |\n> [] source |______ t\n\n> Notice that the source is firing midway in time between the openings of\n> the slit. In principle, if the results of this experiment are analogous\n> to the usual _double_ slit experiment, then there should be a maximum\n> intensity detected in the region of A on the detection screen.\n\nThe only way I can see you getting interference out of this is\nif the your detection screen (actually at a single point)\nretained its coherence between pulses; so what you have is like\ntwo pulses of light arriving at an atom at different times.\nDepending on the time interval between pulses, and the\nevolution of the detector atom in the meantime, the final\nstate of the atom would differ. After both pulses, you could\nthen read-out the state of the atom.\n\nYou _could_ see some kind of interference-like effect if you\nrepeated the experiment with many different time intervals,\nplotting (say) the atomic inversion as a function of time\ninterval.\n\nI recall calculations rather like this have been done, with two\ntime separated pulses impinging on a single two-level atom;\nalthough I do not recall any specific references.\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>David Rutherford <drutherford@softcom.net> wrote:
> [...]
> __{______________________} detection screen
> A
> __{_____} __{_____} __{______} x
> |
> |
> [] source |__{____} t
> Notice that the source is firing midway in time between the openings of
> the slit. In principle, if the results of this experiment are analogous
> to the usual _double_ slit experiment, then there should be a maximum
> intensity detected in the region of A on the detection screen.
The only way I can see you getting interference out of this is
if the your detection screen (actually at a single point)
retained its coherence between pulses; so what you have is like
two pulses of light arriving at an atom at different times.
Depending on the time interval between pulses, and the
evolution of the detector atom in the meantime, the final
state of the atom would differ. After both pulses, you could
then read-out the state of the atom.
You _could_ see some kind of interference-like effect if you
repeated the experiment with many different time intervals,
plotting (say) the atomic inversion as a function of time
interval.
I recall calculations rather like this have been done, with two
time separated pulses impinging on a single two-level atom;
although I do not recall any specific references.
--
---------------------------------+---------------------------------
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/
David Rutherford
May6-04, 07:52 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>\nJoe Rongen wrote:\n\n> "David Rutherford" <drutherford@softcom.net> wrote in\n> message news:bcidnctf14FZVQ7dRVn-iQ@softcom.net...\n>\n> [snip]\n>\n>\n>>Maybe I\'m not making myself clear. In my second setup (the one I\'m\n>>asking about), there is a _single_ beam (or single particle at a time\n>>emission), a screen with _one_ slit in it, and a detection screen, like\n>>this,\n>>\n>>________________________ detection screen\n>>\n>>\n>>___________ ____________ x\n>> |\n>> |\n>> [] source |______ y\n>>\n>>The slit starts out closed, then it opens briefly, closes, opens\n>>briefly, then closes again.\n>\n>\n>\n> Having two slits open simultaneously is\n> essential to the interference phenomena.\n\nThat\'s true for the usual double slit experiment. But for the spacetime\nrotated experiment (below), if I\'m interpreting it correctly, the\ninterference would be in time, not space. Another possiblitiy is that\nthe pattern might manifest on the detection screen as the concentric\nrings of an Airy pattern, moving inward over time, from the outermost\nring toward the center, then back outward again. That\'s just a guess,\nthough, it\'s not based on analyzing the diagram.\n\n> See experiments by:\n> G. I. Taylor, Proc. Camb. Phil. Soc.15, 114 (1909)\n> and J. G. King "Interference of Photons" (1959)\n>\n>\n>>The sequence looks like this when viewed in spacetime,\n>>\n>>________________________ detection screen\n>> A\n>>\n>>_______ _______ ________ x\n>> |\n>> |\n>> [] source |______ t\n>>\n>>Notice that the source is firing midway in time between the openings of\n>>the slit. In principle, if the results of this experiment are analogous\n>>to the usual _double_ slit experiment, then there should be a maximum\n>>intensity detected in the region of A on the detection screen.\n>>\n>>This result would have several interesting implications.\n>\n>\n>\n> I think, if one slit is open while the other is closed\n\nThere\'s only _one_ slit. Are you implying that the slit might be open\nonly once, instead of twice? That would be analogous to the usual single\nslit experiment.\n\n--\nDave Rutherford\n"New Transformation Equations and the Electric Field Four-vector"\nhttp://www.softcom.net/users/der555/newtransform.pdf\n\nApplications:\n"4/3 Problem Resolution"\nhttp://www.softcom.net/users/der555/elecmass.pdf\n"Action-reaction Paradox Resolution"\nhttp://www.softcom.net/users/der555/actreact.pdf\n"Energy Density Correction"\nhttp://www.softcom.net/users/der555/enerdens.pdf\n"Proposed Quantum Mechanical Connection"\nhttp://www.softcom.net/users/der555/quantum.pdf\n\n\n\n\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>Joe Rongen wrote:
> "David Rutherford" <drutherford@softcom.net> wrote in
> message news:bcidnctf14FZVQ7dRVn-iQ@softcom.net...
>
> [snip]
>
>
>>Maybe I'm not making myself clear. In my second setup (the one I'm
>>asking about), there is a _single_ beam (or single particle at a time
>>emission), a screen with _one_ slit in it, and a detection screen, like
>>this,
>>
>>__{______________________} detection screen
>>
>>
>>__{_________} __{__________} x
>> |
>> |
>> [] source |__{____} y
>>
>>The slit starts out closed, then it opens briefly, closes, opens
>>briefly, then closes again.
>
>
>
> Having two slits open simultaneously is
> essential to the interference phenomena.
That's true for the usual double slit experiment. But for the spacetime
rotated experiment (below), if I'm interpreting it correctly, the
interference would be in time, not space. Another possiblitiy is that
the pattern might manifest on the detection screen as the concentric
rings of an Airy pattern, moving inward over time, from the outermost
ring toward the center, then back outward again. That's just a guess,
though, it's not based on analyzing the diagram.
> See experiments by:
> G. I. Taylor, Proc. Camb. Phil. Soc.15, 114 (1909)
> and J. G. King "Interference of Photons" (1959)
>
>
>>The sequence looks like this when viewed in spacetime,
>>
>>__{______________________} detection screen
>> A
>>
>>__{_____} __{_____} __{______} x
>> |
>> |
>> [] source |__{____} t
>>
>>Notice that the source is firing midway in time between the openings of
>>the slit. In principle, if the results of this experiment are analogous
>>to the usual _double_ slit experiment, then there should be a maximum
>>intensity detected in the region of A on the detection screen.
>>
>>This result would have several interesting implications.
>
>
>
> I think, if one slit is open while the other is closed
There's only _one_ slit. Are you implying that the slit might be open
only once, instead of twice? That would be analogous to the usual single
slit experiment.
--
Dave Rutherford
"New Transformation Equations and the Electric Field Four-vector"
http://www.softcom.net/users/der555/newtransform.pdf
Applications:
"4/3 Problem Resolution"
http://www.softcom.net/users/der555/elecmass.pdf
"Action-reaction Paradox Resolution"
http://www.softcom.net/users/der555/actreact.pdf
"Energy Density Correction"
http://www.softcom.net/users/der555/enerdens.pdf
"Proposed Quantum Mechanical Connection"
http://www.softcom.net/users/der555/quantum.pdf
David Rutherford
May6-04, 07:52 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\nchronon wrote:\n> David Rutherford <drutherford@softcom.net> wrote in message news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...\n>\n>>Has there ever been a double slit experiment done in time rather than\n>>space? In other words, take the usual double slit setup where the slits\n>>are separated in space, and rotate the whole thing so that the slits are\n>>separated in time, rather than space. This would amount to having only\n>>one slit opening and closing successively.\n>>\n>>Maybe it would be a little clearer if I draw a picture. A\n>>two-dimensional slice of the usual double slit setup would look like this,\n>>\n>>_________________________ detection screen\n>> A\n>>\n>>\n>>_______ ________ ________ x\n>> |\n>> |\n>> [] source |_______y\n>>\n>\n>\n> The double slit experiment relies on diffraction in space. In this\n> setup you would need diffraction in time,\n\nRight.\n\n> and its difficult to see how\n> that would come about\n\nI\'m starting to get the impression that this experiment hasn\'t been\ndone. If someone does it (I don\'t have the means to do it) and the\nresults are what I\'ve described, _then_ we can try to explain "how that\nwould come about". Sometimes we let what we _think_ couldn\'t happen,\nstand in the way of discovering what can.\n\n> - it would require that a slit opened for a\n> short time affected the speed of what was going through it so the\n> faster stuff from the first opening caught up with the slower stuff\n> from the second.\n\nWhat\'s this "stuff" you are referring to?\n\n--\nDave Rutherford\n"New Transformation Equations and the Electric Field Four-vector"\nhttp://www.softcom.net/users/der555/newtransform.pdf\n\nApplications:\n"4/3 Problem Resolution"\nhttp://www.softcom.net/users/der555/elecmass.pdf\n"Action-reaction Paradox Resolution"\nhttp://www.softcom.net/users/der555/actreact.pdf\n"Energy Density Correction"\nhttp://www.softcom.net/users/der555/enerdens.pdf\n"Proposed Quantum Mechanical Connection"\nhttp://www.softcom.net/users/der555/quantum.pdf\n\n\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>chronon wrote:
> David Rutherford <drutherford@softcom.net> wrote in message news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...
>
>>Has there ever been a double slit experiment done in time rather than
>>space? In other words, take the usual double slit setup where the slits
>>are separated in space, and rotate the whole thing so that the slits are
>>separated in time, rather than space. This would amount to having only
>>one slit opening and closing successively.
>>
>>Maybe it would be a little clearer if I draw a picture. A
>>two-dimensional slice of the usual double slit setup would look like this,
>>
>>__{_______________________} detection screen
>> A
>>
>>
>>__{_____} __{______} __{______} x
>> |
>> |
>> [] source |__{_____y}
>>
>
>
> The double slit experiment relies on diffraction in space. In this
> setup you would need diffraction in time,
Right.
> and its difficult to see how
> that would come about
I'm starting to get the impression that this experiment hasn't been
done. If someone does it (I don't have the means to do it) and the
results are what I've described, _then_ we can try to explain "how that
would come about". Sometimes we let what we _think_ couldn't happen,
stand in the way of discovering what can.
> - it would require that a slit opened for a
> short time affected the speed of what was going through it so the
> faster stuff from the first opening caught up with the slower stuff
> from the second.
What's this "stuff" you are referring to?
--
Dave Rutherford
"New Transformation Equations and the Electric Field Four-vector"
http://www.softcom.net/users/der555/newtransform.pdf
Applications:
"4/3 Problem Resolution"
http://www.softcom.net/users/der555/elecmass.pdf
"Action-reaction Paradox Resolution"
http://www.softcom.net/users/der555/actreact.pdf
"Energy Density Correction"
http://www.softcom.net/users/der555/enerdens.pdf
"Proposed Quantum Mechanical Connection"
http://www.softcom.net/users/der555/quantum.pdf
Matt Leifer
May6-04, 12:15 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>Here is a link to a Bruckner + Zeilinger paper, which seems to answer\nthe double slit in time question you posed.\n\nPhys. Rev. A 56, 3804–3824 (1997)\n\nIt seems that you can have diffraction effects in time that are\nanalogous to the more usual effects in space. Furthermore, such\neffects require quantum mechanics, since they are present in solutions\nto the Schroedinger equation, but not the classical wave equation.\n\nThis is really interesting, as it seems to be a symmetry that is\nunique to quantum mechanics, but has not received much attention.\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>Here is a link to a Bruckner + Zeilinger paper, which seems to answer
the double slit in time question you posed.
Phys. Rev. A 56, 3804–3824 (1997)
It seems that you can have diffraction effects in time that are
analogous to the more usual effects in space. Furthermore, such
effects require quantum mechanics, since they are present in solutions
to the Schroedinger equation, but not the classical wave equation.
This is really interesting, as it seems to be a symmetry that is
unique to quantum mechanics, but has not received much attention.
<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>David Rutherford <drutherford@softcom.net> wrote in message news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...\n> Has there ever been a double slit experiment done in time rather than\n> space? In other words, take the usual double slit setup where the slits\n> are separated in space, and rotate the whole thing so that the slits are\n> separated in time, rather than space. This would amount to having only\n> one slit opening and closing successively.\n>\n\nI think the light passing through the slit the second time can never\n"catch up" with the light passing through the first time, so no\ninterference can occur. My guess is, it would just result in the same\npattern you would get if the slit was continuously open (highest\nintensity at point A, less and less further away from it that is).\nApart from diffraction patterns that is of course, like Fresnel rings.\n\nWhat is "interference in time" anyway, i find it hard to picture\nsomething with it. Isn\'t the necessary condition for interference\nexactly that 2 waves are meeting at the same time? I could be wrong\nhere, don\'t know.\n\nGreetz,\n\nWouter\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>David Rutherford <drutherford@softcom.net> wrote in message news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...
> Has there ever been a double slit experiment done in time rather than
> space? In other words, take the usual double slit setup where the slits
> are separated in space, and rotate the whole thing so that the slits are
> separated in time, rather than space. This would amount to having only
> one slit opening and closing successively.
>
I think the light passing through the slit the second time can never
"catch up" with the light passing through the first time, so no
interference can occur. My guess is, it would just result in the same
pattern you would get if the slit was continuously open (highest
intensity at point A, less and less further away from it that is).
Apart from diffraction patterns that is of course, like Fresnel rings.
What is "interference in time" anyway, i find it hard to picture
something with it. Isn't the necessary condition for interference
exactly that 2 waves are meeting at the same time? I could be wrong
here, don't know.
Greetz,
Wouter
<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>David Rutherford <drutherford@softcom.net> wrote in message news:<MdydnRwPVf_-Swvd4p2dnA@softcom.net>...\n\n> What\'s this "stuff" you are referring to?\n\nI suppose I should have said \'waves\'. The double slit experiment can\napply to electromagnetic waves or to the quantum wavefunction.\n\nmleifer@perimeterinstitute.ca (Matt Leifer) wrote in message news:<3e5b4164.0405041153.b7efa68@posting.google.c om>...\n> Here is a link to a Bruckner + Zeilinger paper, which seems to answer\n> the double slit in time question you posed.\n>\n> Phys. Rev. A 56, 3804?3824 (1997)\n>\n> It seems that you can have diffraction effects in time that are\n> analogous to the more usual effects in space. Furthermore, such\n> effects require quantum mechanics,\n\nI haven\'t looked at this yet, but I did remember that quantum\nwavepackets do spread out, so that you could have part of the second\nwavepacket catching up with part of the first. However, I think the\nbest way to look for interference effects over time would be to use\nsome sort of time delay apparatus.\n\nLooking at the two possibilities:\n\nElectromagnetic waves: A google search for \'coherence time\' brings up\nsome interesting results.\n\nQuantum wavefunction of particles: It is possible to create coherent\nbeams of particles, but my guess would be that they behave like\nelectomagnetic waves, and don\'t tell us much about specifically\nquantum effects.\n\nThe really interesting question to me would be whether a radioactive\ndecay wavefunction has a significant coherence time. This is required\nfor the Schrodinger\'s cat thought experiment, and hence for a lot of\nthe philosophical ideas of quantum mechanics, but I don\'t know how\nmuch work has been done on the question.\n\nStephen Lee\nwww.chronon.org\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>David Rutherford <drutherford@softcom.net> wrote in message news:<MdydnRwPVf_-Swvd4p2dnA@softcom.net>...
> What's this "stuff" you are referring to?
I suppose I should have said 'waves'. The double slit experiment can
apply to electromagnetic waves or to the quantum wavefunction.
mleifer@perimeterinstitute.ca (Matt Leifer) wrote in message news:<3e5b4164.0405041153.b7efa68@posting.google.com>...
> Here is a link to a Bruckner + Zeilinger paper, which seems to answer
> the double slit in time question you posed.
>
> Phys. Rev. A 56, 3804?3824 (1997)
>
> It seems that you can have diffraction effects in time that are
> analogous to the more usual effects in space. Furthermore, such
> effects require quantum mechanics,
I haven't looked at this yet, but I did remember that quantum
wavepackets do spread out, so that you could have part of the second
wavepacket catching up with part of the first. However, I think the
best way to look for interference effects over time would be to use
some sort of time delay apparatus.
Looking at the two possibilities:
Electromagnetic waves: A google search for 'coherence time' brings up
some interesting results.
Quantum wavefunction of particles: It is possible to create coherent
beams of particles, but my guess would be that they behave like
electomagnetic waves, and don't tell us much about specifically
quantum effects.
The really interesting question to me would be whether a radioactive
decay wavefunction has a significant coherence time. This is required
for the Schrodinger's cat thought experiment, and hence for a lot of
the philosophical ideas of quantum mechanics, but I don't know how
much work has been done on the question.
Stephen Lee
www.chronon.org
alistair
May10-04, 05:02 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\nIt seems that you can have diffraction effects in time that are\nanalogous to the more usual effects in space\n\n\nIs this related to the interchangeability of space and time axes in relativity?\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>It seems that you can have diffraction effects in time that are
analogous to the more usual effects in space
Is this related to the interchangeability of space and time axes in relativity?
David Rutherford
May10-04, 05:02 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>\np.kinsler@imperial.ac.uk wrote:\n> David Rutherford <drutherford@softcom.net> wrote:\n>\n>>[...]\n>>________________________ detection screen\n>> A\n>\n>\n>>_______ _______ ________ x\n>> |\n>> |\n>> [] source |______ t\n>\n>\n>>Notice that the source is firing midway in time between the openings of\n>>the slit. In principle, if the results of this experiment are analogous\n>>to the usual _double_ slit experiment, then there should be a maximum\n>>intensity detected in the region of A on the detection screen.\n>\n>\n> The only way I can see you getting interference out of this is\n> if the your detection screen (actually at a single point)\n> retained its coherence between pulses; so what you have is like\n> two pulses of light arriving at an atom at different times.\n\nIf I\'m interpreting the diagram correctly, there would be more than two\npulses. Please refers to Feynman\'s "Lectures on Physics", vol. 3, pg.\nIII-1-4, fig. 1-3. If you replace the x, in the interference pattern on\nthe far right, with t, and interpret the peaks of the waves as pulses\nseparated in time, then I see more than two pulses (there are five in\nthe diagram).\n\n> Depending on the time interval between pulses, and the\n> evolution of the detector atom in the meantime, the final\n> state of the atom would differ. After both pulses, you could\n> then read-out the state of the atom.\n>\n> You _could_ see some kind of interference-like effect if you\n> repeated the experiment with many different time intervals,\n> plotting (say) the atomic inversion as a function of time\n> interval.\n\nThe appearance of pulses occurring over time would indicate, in my\nopinion, that interference is occurring in time. Is this kind of\ninterference allowed in the standard model? Do advanced and retarded\nwaves exist, and can they interfer with each other, in the standard model?\n\n--\nDave Rutherford\n"New Transformation Equations and the Electric Field Four-vector"\nhttp://www.softcom.net/users/der555/newtransform.pdf\n\nApplications:\n"4/3 Problem Resolution"\nhttp://www.softcom.net/users/der555/elecmass.pdf\n"Action-reaction Paradox Resolution"\nhttp://www.softcom.net/users/der555/actreact.pdf\n"Energy Density Correction"\nhttp://www.softcom.net/users/der555/enerdens.pdf\n"Proposed Quantum Mechanical Connection"\nhttp://www.softcom.net/users/der555/quantum.pdf\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 wrote:
> David Rutherford <drutherford@softcom.net> wrote:
>
>>[...]
>>__{______________________} detection screen
>> A
>
>
>>__{_____} __{_____} __{______} x
>> |
>> |
>> [] source |__{____} t
>
>
>>Notice that the source is firing midway in time between the openings of
>>the slit. In principle, if the results of this experiment are analogous
>>to the usual _double_ slit experiment, then there should be a maximum
>>intensity detected in the region of A on the detection screen.
>
>
> The only way I can see you getting interference out of this is
> if the your detection screen (actually at a single point)
> retained its coherence between pulses; so what you have is like
> two pulses of light arriving at an atom at different times.
If I'm interpreting the diagram correctly, there would be more than two
pulses. Please refers to Feynman's "Lectures on Physics", vol. 3, pg.
III-1-4, fig. 1-3. If you replace the x, in the interference pattern on
the far right, with t, and interpret the peaks of the waves as pulses
separated in time, then I see more than two pulses (there are five in
the diagram).
> Depending on the time interval between pulses, and the
> evolution of the detector atom in the meantime, the final
> state of the atom would differ. After both pulses, you could
> then read-out the state of the atom.
>
> You _could_ see some kind of interference-like effect if you
> repeated the experiment with many different time intervals,
> plotting (say) the atomic inversion as a function of time
> interval.
The appearance of pulses occurring over time would indicate, in my
opinion, that interference is occurring in time. Is this kind of
interference allowed in the standard model? Do advanced and retarded
waves exist, and can they interfer with each other, in the standard model?
--
Dave Rutherford
"New Transformation Equations and the Electric Field Four-vector"
http://www.softcom.net/users/der555/newtransform.pdf
Applications:
"4/3 Problem Resolution"
http://www.softcom.net/users/der555/elecmass.pdf
"Action-reaction Paradox Resolution"
http://www.softcom.net/users/der555/actreact.pdf
"Energy Density Correction"
http://www.softcom.net/users/der555/enerdens.pdf
"Proposed Quantum Mechanical Connection"
http://www.softcom.net/users/der555/quantum.pdf
David Rutherford
May11-04, 05:10 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>Please replace my words "diffraction pattern", below, with "interference\npattern". I was thinking the latter, but writing the former.\n\nDavid Rutherford wrote:\n> Oz wrote:\n>\n>>David Rutherford <drutherford@softcom.net> writes\n>>\n>>\n>>>I think you are misunderstanding me. The screen in the second experiment I\n>>>described in my OP (which is the one I\'m asking about), has only _one_ slit,\n>>>_not_ two. The opening of the slit twice in succession is what causes it to be a\n>>>two slit experiment in time, rather than space.\n>>\n>>\n>>OK.\n>>\n>>How are you to get a diffraction pattern with one slit?\n>>\n>>You won\'t.\n>\n>\n> All I\'m doing is rotating the diagram of the usual double slit\n> experiment (along with the diffraction pattern) in spacetime and\n> analyzing what that would mean (if a correspondence can be made between\n> the two) by looking at the resulting rotated diagram. There would\n> actually be no diffraction pattern on the detection screen at the end of\n> the test. There would only be a round spot (for a round slit), if I\'m\n> analyzing it correctly. But that spot would have been pulsing over the\n> course of the detection.\n>\n> The pulsing would start out faint, then increase in intensity until the\n> region A (in time), then it would fade out again. You can see this if\n> you follow the diffraction pattern (check out the Feynman reference I\n> gave in an earlier post) from one end of the pattern to the other.\n> Imagine each peak in the pattern\'s intensity is a pulse. Each pulse\n> occurs on the detection screen at a point directly opposite the slit, so\n> all the pulses occur at the same place, but at different times.\n> Remember, the slit exists all along the line with the gaps in it, but is\n> open only at gaps "1" and "2". The maximum intensity pulse occurs midway\n> in time between the two openings of the slit, and _simultaneously_ with\n> the emission of the particle. Remember, the source "[]" only \'exists\' at\n> time "A" in the rotated diagram. In other words, that\'s when the\n> particle(s) is emitted.\n>\n> The diffraction pattern is only apparent if you look at the pattern of\n> the pulses along the t-axis. The pulses all occur at the same place\n> (same x-coordinate), but at different times.\n>\n> The best way for you to get an idea for what\'s happening is to draw the\n> usual double slit diagram on a piece of paper with the usual\n> interference pattern and imagine the screens (slit and detection) are\n> along the t-axis. Take a pen or a piece of clear acetate with a straight\n> line on it to act as a line of constant t. Now run the line\n> perpendicular to the screens from one end of the screens to the other\n> and analyze what happens when, and what the implications are.\n>\n>\n>>You *would* get a *time-varying* diffraction pattern if the two sources\n>>were of different frequencies.\n>\n>\n> There\'s only one source and there would be a time-varying spot directly\n> across from the slit, if I\'m analyzing the rotated diagram correctly.\n>\n\n--\nDave Rutherford\n"New Transformation Equations and the Electric Field Four-vector"\nhttp://www.softcom.net/users/der555/newtransform.pdf\n\nApplications:\n"4/3 Problem Resolution"\nhttp://www.softcom.net/users/der555/elecmass.pdf\n"Action-reaction Paradox Resolution"\nhttp://www.softcom.net/users/der555/actreact.pdf\n"Energy Density Correction"\nhttp://www.softcom.net/users/der555/enerdens.pdf\n"Proposed Quantum Mechanical Connection"\nhttp://www.softcom.net/users/der555/quantum.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>Please replace my words "diffraction pattern", below, with "interference
pattern". I was thinking the latter, but writing the former.
David Rutherford wrote:
> Oz wrote:
>
>>David Rutherford <drutherford@softcom.net> writes
>>
>>
>>>I think you are misunderstanding me. The screen in the second experiment I
>>>described in my OP (which is the one I'm asking about), has only _one_ slit,
>>>_not_ two. The opening of the slit twice in succession is what causes it to be a
>>>two slit experiment in time, rather than space.
>>
>>
>>OK.
>>
>>How are you to get a diffraction pattern with one slit?
>>
>>You won't.
>
>
> All I'm doing is rotating the diagram of the usual double slit
> experiment (along with the diffraction pattern) in spacetime and
> analyzing what that would mean (if a correspondence can be made between
> the two) by looking at the resulting rotated diagram. There would
> actually be no diffraction pattern on the detection screen at the end of
> the test. There would only be a round spot (for a round slit), if I'm
> analyzing it correctly. But that spot would have been pulsing over the
> course of the detection.
>
> The pulsing would start out faint, then increase in intensity until the
> region A (in time), then it would fade out again. You can see this if
> you follow the diffraction pattern (check out the Feynman reference I
> gave in an earlier post) from one end of the pattern to the other.
> Imagine each peak in the pattern's intensity is a pulse. Each pulse
> occurs on the detection screen at a point directly opposite the slit, so
> all the pulses occur at the same place, but at different times.
> Remember, the slit exists all along the line with the gaps in it, but is
> open only at gaps "1" and "2". The maximum intensity pulse occurs midway
> in time between the two openings of the slit, and _simultaneously_ with
> the emission of the particle. Remember, the source "[]" only 'exists' at
> time "A" in the rotated diagram. In other words, that's when the
> particle(s) is emitted.
>
> The diffraction pattern is only apparent if you look at the pattern of
> the pulses along the t-axis. The pulses all occur at the same place
> (same x-coordinate), but at different times.
>
> The best way for you to get an idea for what's happening is to draw the
> usual double slit diagram on a piece of paper with the usual
> interference pattern and imagine the screens (slit and detection) are
> along the t-axis. Take a pen or a piece of clear acetate with a straight
> line on it to act as a line of constant t. Now run the line
> perpendicular to the screens from one end of the screens to the other
> and analyze what happens when, and what the implications are.
>
>
>>You *would* get a *time-varying* diffraction pattern if the two sources
>>were of different frequencies.
>
>
> There's only one source and there would be a time-varying spot directly
> across from the slit, if I'm analyzing the rotated diagram correctly.
>
--
Dave Rutherford
"New Transformation Equations and the Electric Field Four-vector"
http://www.softcom.net/users/der555/newtransform.pdf
Applications:
"4/3 Problem Resolution"
http://www.softcom.net/users/der555/elecmass.pdf
"Action-reaction Paradox Resolution"
http://www.softcom.net/users/der555/actreact.pdf
"Energy Density Correction"
http://www.softcom.net/users/der555/enerdens.pdf
"Proposed Quantum Mechanical Connection"
http://www.softcom.net/users/der555/quantum.pdf
Just found an earlier Bruckner + Zeilinger paper, which seems to answer the double slit in time question you posed.
Phys. Rev. A 56, 3804–3824 (1997)
David Rutherford
May12-04, 01:42 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\nMatt Leifer wrote:\n\n> Here is a link to a Bruckner + Zeilinger paper, which seems to answer\n> the double slit in time question you posed.\n>\n> Phys. Rev. A 56, 3804–3824 (1997)\n>\n> It seems that you can have diffraction effects in time that are\n> analogous to the more usual effects in space. Furthermore, such\n> effects require quantum mechanics, since they are present in solutions\n> to the Schroedinger equation, but not the classical wave equation.\n>\n> This is really interesting, as it seems to be a symmetry that is\n> unique to quantum mechanics, but has not received much attention.\n\nThanks, Matt. I looked at the abstract, but I don\'t have a subscription\nto the journal, so I couldn\'t access the paper. I\'ll have to visit a\ncollege library to read the paper. It doesn\'t seem, though, that this is\nan attempt to explain, theoretically, the results of any experiment(s)\nthat was actually done.\n\n--\nDave Rutherford\n"New Transformation Equations and the Electric Field Four-vector"\nhttp://www.softcom.net/users/der555/newtransform.pdf\n\nApplications:\n"4/3 Problem Resolution"\nhttp://www.softcom.net/users/der555/elecmass.pdf\n"Action-reaction Paradox Resolution"\nhttp://www.softcom.net/users/der555/actreact.pdf\n"Energy Density Correction"\nhttp://www.softcom.net/users/der555/enerdens.pdf\n"Proposed Quantum Mechanical Connection"\nhttp://www.softcom.net/users/der555/quantum.pdf\n\n\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>Matt Leifer wrote:
> Here is a link to a Bruckner + Zeilinger paper, which seems to answer
> the double slit in time question you posed.
>
> Phys. Rev. A 56, 3804–3824 (1997)
>
> It seems that you can have diffraction effects in time that are
> analogous to the more usual effects in space. Furthermore, such
> effects require quantum mechanics, since they are present in solutions
> to the Schroedinger equation, but not the classical wave equation.
>
> This is really interesting, as it seems to be a symmetry that is
> unique to quantum mechanics, but has not received much attention.
Thanks, Matt. I looked at the abstract, but I don't have a subscription
to the journal, so I couldn't access the paper. I'll have to visit a
college library to read the paper. It doesn't seem, though, that this is
an attempt to explain, theoretically, the results of any experiment(s)
that was actually done.
--
Dave Rutherford
"New Transformation Equations and the Electric Field Four-vector"
http://www.softcom.net/users/der555/newtransform.pdf
Applications:
"4/3 Problem Resolution"
http://www.softcom.net/users/der555/elecmass.pdf
"Action-reaction Paradox Resolution"
http://www.softcom.net/users/der555/actreact.pdf
"Energy Density Correction"
http://www.softcom.net/users/der555/enerdens.pdf
"Proposed Quantum Mechanical Connection"
http://www.softcom.net/users/der555/quantum.pdf
David Rutherford
May12-04, 01:45 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>[Moderator\'s note: We\'re very close to running afould of both the\n"overly repetitive" and "overly speculative" clauses in the s.p.r\ncharter. It\'s probably time to let this discussion wind down.\n\nNote that even in relativistic physics, time is different from\nspace. -TB]\n\nWouter wrote:\n> David Rutherford <drutherford@softcom.net> wrote in message news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...\n>\n>>Has there ever been a double slit experiment done in time rather than\n>>space? In other words, take the usual double slit setup where the slits\n>>are separated in space, and rotate the whole thing so that the slits are\n>>separated in time, rather than space. This would amount to having only\n>>one slit opening and closing successively.\n>>\n>\n>\n> I think the light passing through the slit the second time can never\n> "catch up" with the light passing through the first time, so no\n> interference can occur.\n\nIf the light passing through the slit is diffracted in time, then the\nwave spreads out in time. Part of it goes backward in time and part goes\nforward in time. This would happen at both openings of the slit, so you\nwould get interference in time from the time-diffracted parts of the\nwaves from the two openings of the slit. I\'m not saying this is what\nwould happen in reality - it\'s just what the double slit experiment\nseems to imply when it\'s rotated in spacetime, as I described.\n\n--\nDave Rutherford\n"New Transformation Equations and the Electric Field Four-vector"\nhttp://www.softcom.net/users/der555/newtransform.pdf\n\nApplications:\n"4/3 Problem Resolution"\nhttp://www.softcom.net/users/der555/elecmass.pdf\n"Action-reaction Paradox Resolution"\nhttp://www.softcom.net/users/der555/actreact.pdf\n"Energy Density Correction"\nhttp://www.softcom.net/users/der555/enerdens.pdf\n"Proposed Quantum Mechanical Connection"\nhttp://www.softcom.net/users/der555/quantum.pdf\n\n\n\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>[Moderator's note: We're very close to running afould of both the
"overly repetitive" and "overly speculative" clauses in the s.p.r
charter. It's probably time to let this discussion wind down.
Note that even in relativistic physics, time is different from
space. -TB]
Wouter wrote:
> David Rutherford <drutherford@softcom.net> wrote in message news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...
>
>>Has there ever been a double slit experiment done in time rather than
>>space? In other words, take the usual double slit setup where the slits
>>are separated in space, and rotate the whole thing so that the slits are
>>separated in time, rather than space. This would amount to having only
>>one slit opening and closing successively.
>>
>
>
> I think the light passing through the slit the second time can never
> "catch up" with the light passing through the first time, so no
> interference can occur.
If the light passing through the slit is diffracted in time, then the
wave spreads out in time. Part of it goes backward in time and part goes
forward in time. This would happen at both openings of the slit, so you
would get interference in time from the time-diffracted parts of the
waves from the two openings of the slit. I'm not saying this is what
would happen in reality - it's just what the double slit experiment
seems to imply when it's rotated in spacetime, as I described.
--
Dave Rutherford
"New Transformation Equations and the Electric Field Four-vector"
http://www.softcom.net/users/der555/newtransform.pdf
Applications:
"4/3 Problem Resolution"
http://www.softcom.net/users/der555/elecmass.pdf
"Action-reaction Paradox Resolution"
http://www.softcom.net/users/der555/actreact.pdf
"Energy Density Correction"
http://www.softcom.net/users/der555/enerdens.pdf
"Proposed Quantum Mechanical Connection"
http://www.softcom.net/users/der555/quantum.pdf
<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>wsmet@lycos.nl (Wouter) wrote in message news:<6d477e12.0405061120.358b3cd9@posting.google. com>...\n> David Rutherford <drutherford@softcom.net> wrote in message news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...\nSnip\n> What is "interference in time" anyway, i find it hard to picture\n> something with it. Isn\'t the necessary condition for interference\n> exactly that 2 waves are meeting at the same time? I could be wrong\n> here, don\'t know.\n\nThe unspoken assumption in the original question: In a normal\nexperiment, I measure "intensity", which is the time-average of the\nsquare of the electric field, which is what instruments measure.\nIf you rotate the diagram in space-time, you need an instrument to\nmeasure the square of the electric field averaged in position, but\nmeasured instant-by-instant at a sampling rate much faster than the\nradiation frequency.\n\nAssuming we did this experiment at RF, you need apertures that open\nand shut fast compared to RF, N antennas sampling the radiation at\nclose-spacing,are only weakly coupled to the radiation (otherwise they\nabsorb it significantly), and a post-processing stage where you sum up\nthe input from your N antennas, which could be done analogue, and a\nfast A/D converter.\n\nBut in principle it works, trivially - there isn\'t actually any\nPhysics here, just Fourier transform maths. See any standard\nphased-array antenna for pulsed/ chirped radar.\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>wsmet@lycos.nl (Wouter) wrote in message news:<6d477e12.0405061120.358b3cd9@posting.google.com>...
> David Rutherford <drutherford@softcom.net> wrote in message news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...
Snip
> What is "interference in time" anyway, i find it hard to picture
> something with it. Isn't the necessary condition for interference
> exactly that 2 waves are meeting at the same time? I could be wrong
> here, don't know.
The unspoken assumption in the original question: In a normal
experiment, I measure "intensity", which is the time-average of the
square of the electric field, which is what instruments measure.
If you rotate the diagram in space-time, you need an instrument to
measure the square of the electric field averaged in position, but
measured instant-by-instant at a sampling rate much faster than the
radiation frequency.
Assuming we did this experiment at RF, you need apertures that open
and shut fast compared to RF, N antennas sampling the radiation at
close-spacing,are only weakly coupled to the radiation (otherwise they
absorb it significantly), and a post-processing stage where you sum up
the input from your N antennas, which could be done analogue, and a
fast A/D converter.
But in principle it works, trivially - there isn't actually any
Physics here, just Fourier transform maths. See any standard
phased-array antenna for pulsed/ chirped radar.
David Rutherford
May14-04, 04:08 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>David Rutherford wrote:\n\n> [Moderator\'s note: We\'re very close to running afould of both the\n> "overly repetitive" and "overly speculative" clauses in the s.p.r\n> charter. It\'s probably time to let this discussion wind down.\n>\n> Note that even in relativistic physics, time is different from\n> space. -TB]\n\nI\'m not interested in what theoretical physics has to say about what\n_can_ or _can\'t_ happen. I\'m interested in what actually _does_ or\n_doesn\'t_ happen.\n\nI\'m trying to determine whether or not the experiment I described has\nbeen done and, if so, were the results the same as those implied by the\nrotated double slit experiment, as I described. No one has answered that\nquestion yet. All I\'ve seen, so far, are references to theoretical\npapers, not experimental papers.\n\n> Wouter wrote:\n>\n>> David Rutherford <drutherford@softcom.net> wrote in message\n>> news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...\n>>\n>>> Has there ever been a double slit experiment done in time rather than\n>>> space? In other words, take the usual double slit setup where the slits\n>>> are separated in space, and rotate the whole thing so that the slits are\n>>> separated in time, rather than space. This would amount to having only\n>>> one slit opening and closing successively.\n>>>\n>>\n>>\n>> I think the light passing through the slit the second time can never\n>> "catch up" with the light passing through the first time, so no\n>> interference can occur.\n>\n>\n> If the light passing through the slit is diffracted in time, then the\n> wave spreads out in time. Part of it goes backward in time and part goes\n> forward in time. This would happen at both openings of the slit, so you\n> would get interference in time from the time-diffracted parts of the\n> waves from the two openings of the slit. I\'m not saying this is what\n> would happen in reality - it\'s just what the double slit experiment\n> seems to imply when it\'s rotated in spacetime, as I described.\n>\n\n--\nDave Rutherford\n"New Transformation Equations and the Electric Field Four-vector"\nhttp://www.softcom.net/users/der555/newtransform.pdf\n\nApplications:\n"4/3 Problem Resolution"\nhttp://www.softcom.net/users/der555/elecmass.pdf\n"Action-reaction Paradox Resolution"\nhttp://www.softcom.net/users/der555/actreact.pdf\n"Energy Density Correction"\nhttp://www.softcom.net/users/der555/enerdens.pdf\n"Proposed Quantum Mechanical Connection"\nhttp://www.softcom.net/users/der555/quantum.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>David Rutherford wrote:
> [Moderator's note: We're very close to running afould of both the
> "overly repetitive" and "overly speculative" clauses in the s.p.r
> charter. It's probably time to let this discussion wind down.
>
> Note that even in relativistic physics, time is different from
> space. -TB]
I'm not interested in what theoretical physics has to say about what
_can_ or _can't_ happen. I'm interested in what actually _does_ or
_doesn't_ happen.
I'm trying to determine whether or not the experiment I described has
been done and, if so, were the results the same as those implied by the
rotated double slit experiment, as I described. No one has answered that
question yet. All I've seen, so far, are references to theoretical
papers, not experimental papers.
> Wouter wrote:
>
>> David Rutherford <drutherford@softcom.net> wrote in message
>> news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...
>>
>>> Has there ever been a double slit experiment done in time rather than
>>> space? In other words, take the usual double slit setup where the slits
>>> are separated in space, and rotate the whole thing so that the slits are
>>> separated in time, rather than space. This would amount to having only
>>> one slit opening and closing successively.
>>>
>>
>>
>> I think the light passing through the slit the second time can never
>> "catch up" with the light passing through the first time, so no
>> interference can occur.
>
>
> If the light passing through the slit is diffracted in time, then the
> wave spreads out in time. Part of it goes backward in time and part goes
> forward in time. This would happen at both openings of the slit, so you
> would get interference in time from the time-diffracted parts of the
> waves from the two openings of the slit. I'm not saying this is what
> would happen in reality - it's just what the double slit experiment
> seems to imply when it's rotated in spacetime, as I described.
>
--
Dave Rutherford
"New Transformation Equations and the Electric Field Four-vector"
http://www.softcom.net/users/der555/newtransform.pdf
Applications:
"4/3 Problem Resolution"
http://www.softcom.net/users/der555/elecmass.pdf
"Action-reaction Paradox Resolution"
http://www.softcom.net/users/der555/actreact.pdf
"Energy Density Correction"
http://www.softcom.net/users/der555/enerdens.pdf
"Proposed Quantum Mechanical Connection"
http://www.softcom.net/users/der555/quantum.pdf
AceOfAllTrades
May21-04, 02:46 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>Greetings,\n\n> Note that even in relativistic physics, time is different from\n> space. -TB\n\nAccording to Stephen Hawking\'s NBP what appears to us as\ntime could really be just be imaginary time. In Hawking\'s\nNBP time is treated like a spatial coordinate. According to\nHawking\'s NBP, the universe is a 4-sphere, with time being\none of the four coordinates.\n\n> Note that even in relativistic physics, time is different from\n> space. -TB\n\nI am not certain this statement is 100% accurate. According\nto relativistic physics, I am not sure you can ever really look\nat time and space as two completely separate entities. I think\nthere is only space-time. Sometimes the space component\nwill dominate, sometimes the time component will dominate.\nI don\'t think you can every really completely divorce the two\naccording to relativity.\n\nI am just a lay person, but this is what I have heard.\n\n> I think the light passing through the slit the second time can\n> never "catch up" with the light passing through the first time,\n> so no interference can occur.\n\nAs I understand it, according to QM light cannot travel at\nexactly c. Some photons travel a little faster, some travel\na little slower. So, theoretically speaking some photons\n*can* overtake other photons, or so I would suppose.\n\nBest regards,\nmichael\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>Greetings,
> Note that even in relativistic physics, time is different from
> space. -TB
According to Stephen Hawking's NBP what appears to us as
time could really be just be imaginary time. In Hawking's
NBP time is treated like a spatial coordinate. According to
Hawking's NBP, the universe is a 4-sphere, with time being
one of the four coordinates.
> Note that even in relativistic physics, time is different from
> space. -TB
I am not certain this statement is 100% accurate. According
to relativistic physics, I am not sure you can ever really look
at time and space as two completely separate entities. I think
there is only space-time. Sometimes the space component
will dominate, sometimes the time component will dominate.
I don't think you can every really completely divorce the two
according to relativity.
I am just a lay person, but this is what I have heard.
> I think the light passing through the slit the second time can
> never "catch up" with the light passing through the first time,
> so no interference can occur.
As I understand it, according to QM light cannot travel at
exactly c. Some photons travel a little faster, some travel
a little slower. So, theoretically speaking some photons
*can* overtake other photons, or so I would suppose.
Best regards,
michael
backdoorstudent
Jun22-04, 02:32 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>Check this out:\nhttp://arxiv.org/abs/quant-ph/0306007\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>Check this out:
http://arxiv.org/abs/http://www.arxiv.org/abs/quant-ph/0306007
alistair
Jul2-04, 04:31 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\nWouter wrote:\n> David Rutherford <drutherford@softcom.net> wrote in message news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...\n>\n>>Has there ever been a double slit experiment done in time rather\nthan\n>>space? In other words, take the usual double slit setup where the\nslits\n>>are separated in space, and rotate the whole thing so that the slits\nare\n>>separated in time, rather than space. This would amount to having\nonly\n>>one slit opening and closing successively.\n>>\n>\n>\n> I think the light passing through the slit the second time can never\n> "catch up" with the light passing through the first time, so no\n> interference can occur.\n\n>If the light passing through the slit is diffracted in time, then the\n>wave spreads out in time. Part of it goes backward in time and part\ngoes\n>forward in time.\n\nALISTAIR writes:\n\nIsn\'t it the case that only virtual photons can go backwards in time?\nA photon emitted from a light source would be breaking the second law\nof thermodynamics if it went backwards in time.\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>Wouter wrote:
> David Rutherford <drutherford@softcom.net> wrote in message news:<F5ydnTa8q5SRshDdRVn-hQ@softcom.net>...
>
>>Has there ever been a double slit experiment done in time rather
than
>>space? In other words, take the usual double slit setup where the
slits
>>are separated in space, and rotate the whole thing so that the slits
are
>>separated in time, rather than space. This would amount to having
only
>>one slit opening and closing successively.
>>
>
>
> I think the light passing through the slit the second time can never
> "catch up" with the light passing through the first time, so no
> interference can occur.
>If the light passing through the slit is diffracted in time, then the
>wave spreads out in time. Part of it goes backward in time and part
goes
>forward in time.
ALISTAIR writes:
Isn't it the case that only virtual photons can go backwards in time?
A photon emitted from a light source would be breaking the second law
of thermodynamics if it went backwards in time.
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