View Full Version : Schrodinger's cat--what's the observer?
<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\'s something I\'ve never understood about the "Schrodinger\'s cat"\nthought experiement. Is the observer (who opens the box) implied to\nbe a metaphysical entity that is required to make the cat come out of\nits limbo state? Could the observer be a machine that opens the box,\nis impacted by the outcome, but doesn\'t observe as a human or animal\nwould metaphysically.\n\nIs it just a sort of pondering of the quantum theory of superposition\nand not ment to be factual for anything other than just being a\nparadox?\n\nI\'m confused.\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's something I've never understood about the "Schrodinger's cat"
thought experiement. Is the observer (who opens the box) implied to
be a metaphysical entity that is required to make the cat come out of
its limbo state? Could the observer be a machine that opens the box,
is impacted by the outcome, but doesn't observe as a human or animal
would metaphysically.
Is it just a sort of pondering of the quantum theory of superposition
and not ment to be factual for anything other than just being a
paradox?
I'm confused.
HallsofIvy
Jun23-04, 12:36 PM
The basic idea is to show that "quantum indeterminacy" which clearly holds for elementary particles and "micro" effects also can have "macro" consequences.
<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>\nEel wrote:\n> Here\'s something I\'ve never understood about the "Schrodinger\'s cat"\n> thought experiement. Is the observer (who opens the box) implied to\n> be a metaphysical entity that is required to make the cat come out of\n> its limbo state? Could the observer be a machine that opens the box,\n> is impacted by the outcome, but doesn\'t observe as a human or animal\n> would metaphysically.\n>\n> Is it just a sort of pondering of the quantum theory of superposition\n> and not ment to be factual for anything other than just being a\n> paradox?\n>\n> I\'m confused.\n>\n\nI believe it implied at some stage of the measuring process but not\nnecessarily in the "direct" observation of the state of the cat. For\nexample imagine you replace the human observer with a physical measuring\ndevice, |D> (by definition wouldn\'t a human observer also be a physical\nmeasuring device?). The state of the system becomes the tensor product\nstate of the state of Schrodinger\'s cat |0>|alive> + |1>|dead> with the\nmeasuring device becoming:\n\n|0>|alive>|D_alive> + |1>|dead>|D_dead>\n\n(don\'t worry about the notation too much if you haven\'t seen it before.\nThe first term just describes the state where the vial doesn\'t break,\nthe cat is alive and the measuring device detects the cat being alive.\nThe second term is when the vial breaks, the cat is killed and the\nmeasuring device detects the cat being dead. Each term contributes\nequally to the overall system state so there is a 50% chance of each\noutcome occuring).\n\nThe system is now in a superposition of the cat being alive and the\nmeasuring device detecting the cat as being alive and the cat being dead\nand the measuring device detecting that the cat is dead. What now? We\ncould add another measuring device to detect the state of the first\ndevice but what does this add? We will end up in a similar situation. At\nwhat stage does the system "collapse" into one of the possible outcomes?\n\nThis measurment chain can be extended infinitum (well there are limits\nbut let\'s ignore them for now) but we don\'t know what other measuring\ndevice "experience". All we know is that when we observe a system we\nnever seem this superposition. Does this mean the collapse of the system\noccurs at the stage when a human observes the system? Maybe. The only\nway we can know what state a system is in is by observation and this\nimplies interaction with a human. But if a human is just a physical\nmeasuring device wouldn\'t the state of the system be:\n\n|0>|alive>|D_alive>|Human detecting alive cat> +\n|1>|dead>|D_dead>|Human detecting dead cat>\n\nWhat\'s the deal? I don\'t know. Seems like a problem to me. Maybe the\nuniverse splits in two and in one universe "you" see a dead cat and in\nthe other universe "you" see the alive cat. But it\'s not as simple as\nthat otherwise this measurment problem would have been solved decades\nago. Have a look around the Internet for "Copenhagen interpretation of\nquantum mechanics" or "many worlds interpretation of quantum mechanics"\nor simply "the measurment problem in quantum mechanics".\n\nHope I haven\'t confused you anymore :)\n\n!Q\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>Eel wrote:
> Here's something I've never understood about the "Schrodinger's cat"
> thought experiement. Is the observer (who opens the box) implied to
> be a metaphysical entity that is required to make the cat come out of
> its limbo state? Could the observer be a machine that opens the box,
> is impacted by the outcome, but doesn't observe as a human or animal
> would metaphysically.
>
> Is it just a sort of pondering of the quantum theory of superposition
> and not ment to be factual for anything other than just being a
> paradox?
>
> I'm confused.
>
I believe it implied at some stage of the measuring process but not
necessarily in the "direct" observation of the state of the cat. For
example imagine you replace the human observer with a physical measuring
device, |D> (by definition wouldn't a human observer also be a physical
measuring device?). The state of the system becomes the tensor product
state of the state of Schrodinger's cat |0>|alive> + |1>|dead> with the
measuring device becoming:
|0>|alive>|D_{alive}> + |1>|dead>|D_{dead}>
(don't worry about the notation too much if you haven't seen it before.
The first term just describes the state where the vial doesn't break,
the cat is alive and the measuring device detects the cat being alive.
The second term is when the vial breaks, the cat is killed and the
measuring device detects the cat being dead. Each term contributes
equally to the overall system state so there is a 50% chance of each
outcome occuring).
The system is now in a superposition of the cat being alive and the
measuring device detecting the cat as being alive and the cat being dead
and the measuring device detecting that the cat is dead. What now? We
could add another measuring device to detect the state of the first
device but what does this add? We will end up in a similar situation. At
what stage does the system "collapse" into one of the possible outcomes?
This measurment chain can be extended infinitum (well there are limits
but let's ignore them for now) but we don't know what other measuring
device "experience". All we know is that when we observe a system we
never seem this superposition. Does this mean the collapse of the system
occurs at the stage when a human observes the system? Maybe. The only
way we can know what state a system is in is by observation and this
implies interaction with a human. But if a human is just a physical
measuring device wouldn't the state of the system be:
|0>|alive>|D_{alive}>|Human detecting alive cat> +
|1>|dead>|D_{dead}>|Human detecting dead cat>
What's the deal? I don't know. Seems like a problem to me. Maybe the
universe splits in two and in one universe "you" see a dead cat and in
the other universe "you" see the alive cat. But it's not as simple as
that otherwise this measurment problem would have been solved decades
ago. Have a look around the Internet for "Copenhagen interpretation of
quantum mechanics" or "many worlds interpretation of quantum mechanics"
or simply "the measurment problem in quantum mechanics".
Hope I haven't confused you anymore :)
!Q
John T Lowry
Jun27-04, 06:01 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>"!Q" <no_spam@null.org> wrote in message\nnews:cbbgan\\$bqt\\$1@lust.ihug.co.nz...\ n>\n> Eel wrote:\n> > Here\'s something I\'ve never understood about the "Schrodinger\'s cat"\n> > thought experiement. Is the observer (who opens the box) implied to\n> > be a metaphysical entity that is required to make the cat come out of\n> > its limbo state? Could the observer be a machine that opens the box,\n> > is impacted by the outcome, but doesn\'t observe as a human or animal\n> > would metaphysically.\n> >\n> > Is it just a sort of pondering of the quantum theory of superposition\n> > and not ment to be factual for anything other than just being a\n> > paradox?\n> >\n> > I\'m confused.\n> >\n>\n> I believe it implied at some stage of the measuring process but not\n> necessarily in the "direct" observation of the state of the cat. For\n> example imagine you replace the human observer with a physical measuring\n> device, |D> (by definition wouldn\'t a human observer also be a physical\n> measuring device?). The state of the system becomes the tensor product\n> state of the state of Schrodinger\'s cat |0>|alive> + |1>|dead> with the\n> measuring device becoming:\n>\n> |0>|alive>|D_alive> + |1>|dead>|D_dead>\n>\n> (don\'t worry about the notation too much if you haven\'t seen it before.\n> The first term just describes the state where the vial doesn\'t break,\n> the cat is alive and the measuring device detects the cat being alive.\n> The second term is when the vial breaks, the cat is killed and the\n> measuring device detects the cat being dead. Each term contributes\n> equally to the overall system state so there is a 50% chance of each\n> outcome occuring).\n>\n> The system is now in a superposition of the cat being alive and the\n> measuring device detecting the cat as being alive and the cat being dead\n> and the measuring device detecting that the cat is dead. What now? We\n> could add another measuring device to detect the state of the first\n> device but what does this add? We will end up in a similar situation. At\n> what stage does the system "collapse" into one of the possible outcomes?\n>\n> This measurment chain can be extended infinitum (well there are limits\n> but let\'s ignore them for now) but we don\'t know what other measuring\n> device "experience". All we know is that when we observe a system we\n> never seem this superposition. Does this mean the collapse of the system\n> occurs at the stage when a human observes the system? Maybe. The only\n> way we can know what state a system is in is by observation and this\n> implies interaction with a human. But if a human is just a physical\n> measuring device wouldn\'t the state of the system be:\n>\n> |0>|alive>|D_alive>|Human detecting alive cat> +\n> |1>|dead>|D_dead>|Human detecting dead cat>\n>\n> What\'s the deal? I don\'t know. Seems like a problem to me. Maybe the\n> universe splits in two and in one universe "you" see a dead cat and in\n> the other universe "you" see the alive cat. But it\'s not as simple as\n> that otherwise this measurment problem would have been solved decades\n> ago. Have a look around the Internet for "Copenhagen interpretation of\n> quantum mechanics" or "many worlds interpretation of quantum mechanics"\n> or simply "the measurment problem in quantum mechanics".\n>\n> Hope I haven\'t confused you anymore :)\n>\n> !Q\n\nI believe the wave function collapse took place (if it did at all) when\nthe noxious gas was released (or soon thereafter) and the cat succumbed.\nI don\'t believe the human (or machine) observer had anything to do with\nit.\n\nFor, what if the observer didn\'t open the box for say a couple of weeks.\nAnd say the cat was dead. Then he or she could make the additional\nobservation that (this observer is a forensic veterinarian) "This cat\nhas been dead for about ten days." So obviously nothing of any import\nhappened upon opening the box...\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>"!Q" <no_spam@null.org> wrote in message
news:cbbgan$bqt$1@lust.ihug.co.nz...
>
> Eel wrote:
> > Here's something I've never understood about the "Schrodinger's cat"
> > thought experiement. Is the observer (who opens the box) implied to
> > be a metaphysical entity that is required to make the cat come out of
> > its limbo state? Could the observer be a machine that opens the box,
> > is impacted by the outcome, but doesn't observe as a human or animal
> > would metaphysically.
> >
> > Is it just a sort of pondering of the quantum theory of superposition
> > and not ment to be factual for anything other than just being a
> > paradox?
> >
> > I'm confused.
> >
>
> I believe it implied at some stage of the measuring process but not
> necessarily in the "direct" observation of the state of the cat. For
> example imagine you replace the human observer with a physical measuring
> device, |D> (by definition wouldn't a human observer also be a physical
> measuring device?). The state of the system becomes the tensor product
> state of the state of Schrodinger's cat |0>|alive> + |1>|dead> with the
> measuring device becoming:
>
> |0>|alive>|D_{alive}> + |1>|dead>|D_{dead}>
>
> (don't worry about the notation too much if you haven't seen it before.
> The first term just describes the state where the vial doesn't break,
> the cat is alive and the measuring device detects the cat being alive.
> The second term is when the vial breaks, the cat is killed and the
> measuring device detects the cat being dead. Each term contributes
> equally to the overall system state so there is a 50% chance of each
> outcome occuring).
>
> The system is now in a superposition of the cat being alive and the
> measuring device detecting the cat as being alive and the cat being dead
> and the measuring device detecting that the cat is dead. What now? We
> could add another measuring device to detect the state of the first
> device but what does this add? We will end up in a similar situation. At
> what stage does the system "collapse" into one of the possible outcomes?
>
> This measurment chain can be extended infinitum (well there are limits
> but let's ignore them for now) but we don't know what other measuring
> device "experience". All we know is that when we observe a system we
> never seem this superposition. Does this mean the collapse of the system
> occurs at the stage when a human observes the system? Maybe. The only
> way we can know what state a system is in is by observation and this
> implies interaction with a human. But if a human is just a physical
> measuring device wouldn't the state of the system be:
>
> |0>|alive>|D_{alive}>|Human detecting alive cat> +
> |1>|dead>|D_{dead}>|Human detecting dead cat>
>
> What's the deal? I don't know. Seems like a problem to me. Maybe the
> universe splits in two and in one universe "you" see a dead cat and in
> the other universe "you" see the alive cat. But it's not as simple as
> that otherwise this measurment problem would have been solved decades
> ago. Have a look around the Internet for "Copenhagen interpretation of
> quantum mechanics" or "many worlds interpretation of quantum mechanics"
> or simply "the measurment problem in quantum mechanics".
>
> Hope I haven't confused you anymore :)
>
> !Q
I believe the wave function collapse took place (if it did at all) when
the noxious gas was released (or soon thereafter) and the cat succumbed.
I don't believe the human (or machine) observer had anything to do with
it.
For, what if the observer didn't open the box for say a couple of weeks.
And say the cat was dead. Then he or she could make the additional
observation that (this observer is a forensic veterinarian) "This cat
has been dead for about ten days." So obviously nothing of any import
happened upon opening the box...
George Buyanovsky
Jun27-04, 06:02 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>eel@javabox.com (Eel) wrote in message news:<a62a408.0406191958.2791f8d4@posting.google.c om>...\n> Here\'s something I\'ve never understood about the "Schrodinger\'s cat"\n> thought experiement. Is the observer (who opens the box) implied to\n> be a metaphysical entity that is required to make the cat come out of\n> its limbo state? Could the observer be a machine that opens the box,\n> is impacted by the outcome, but doesn\'t observe as a human or animal\n> would metaphysically.\n>\n> Is it just a sort of pondering of the quantum theory of superposition\n> and not ment to be factual for anything other than just being a\n> paradox?\n>\n> I\'m confused.\n\nThere is no paradox at all if to consider the observer<->event\ninteraction as wave-functions interference (non collapse) you may\nappreciate the beauty of QM MWI.\n\nBest,\nGeorge\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>eel@javabox.com (Eel) wrote in message news:<a62a408.0406191958.2791f8d4@posting.google.com>...
> Here's something I've never understood about the "Schrodinger's cat"
> thought experiement. Is the observer (who opens the box) implied to
> be a metaphysical entity that is required to make the cat come out of
> its limbo state? Could the observer be a machine that opens the box,
> is impacted by the outcome, but doesn't observe as a human or animal
> would metaphysically.
>
> Is it just a sort of pondering of the quantum theory of superposition
> and not ment to be factual for anything other than just being a
> paradox?
>
> I'm confused.
There is no paradox at all if to consider the observer<->event
interaction as wave-functions interference (non collapse) you may
appreciate the beauty of QM MWI.
Best,
George
Alex Green
Jun29-04, 04:23 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>"!Q" <no_spam@null.org> wrote in message news:<cbbgan\\$bqt\\$1@lust.ihug.co.nz>...\n> Eel wrote:\n> What\'s the deal? I don\'t know. Seems like a problem to me. Maybe the\n> universe splits in two and in one universe "you" see a dead cat and in\n> the other universe "you" see the alive cat. But it\'s not as simple as\n> that otherwise this measurment problem would have been solved decades\n> ago. Have a look around the Internet for "Copenhagen interpretation of\n> quantum mechanics" or "many worlds interpretation of quantum mechanics"\n> or simply "the measurment problem in quantum mechanics".\n>\n>\n\nThere seem to be three main approaches to the \'observer\'.\n\nIn the \'Consistent Histories\' approach of Hartle & Gell-Mann the\nobserver is considered to be an \'IGUS\'(Information gathering and\nutilising system (Hartle & Gell-Mann)). The universe is considered to\nbranch regularly (\'coarse grained histories\') and the IGU splits with\nit. Each IGUS has a continuous record of its \'life\' into the past as\nmemory.\n\nThe \'Operational Interpretation of Quantum Theory\' or \'Decoherence\nTheory\' has two strands.\n\nIn the first, due largely to Zurek et al the environment constitutes a\nsingle interacting system that provides a preferred configuration of\nthe universe. Any small particle in contact with this preferred basis\nwill experience \'superselection\' in which states that are compatible\nwith the state of the environment will be preferentially selected.\nAgain the observer is considered to be an IGUS and owes its state to\nthe environment.\nhttp://xxx.lanl.gov/PS_cache/gr-qc/pdf/9402/9402011.pdf\n\nIn the second, due largely to Zeh et al the size and location of the\nobserver is considered. This group or theorists also developed\ndecoherence theory. Zeh wonders whether the bulk of the brain might be\nexternal to the observer and hence speculates that the state of the\nbrain may depend on the state of the part of the brain that is the\nobserver as well as the environment.\n\nhttp://xxx.lanl.gov/PS_cache/quant-ph/pdf/9908/9908084.pdf\nIn fact Zeh goes futher and speculates that the observer might be a\nquantum state at a point.\n\nZeh is undoubtedly closer to the neuroscience of the observer than the\nothers. There is no doubt that the brain is largely non-conscious.\nIndeed, during general anaesthesia the cerebral cortex can be more\nactive than normal (White & Alkire (2003), Fiset et al (1999). The\nother problem with the IGUS is that it does not account for \'binding\'\nwhere all the modes of sensation seem to be accessible simultaneously\nand viewed as if from a point. (The \'cyclopean eye\' of cognitive\npsychology is due to brain activity - there is no \'point\' in the\noptical system from the retina to a data source).\n\nIn fact an information system cannot be responsible for conscious\nexperience. Information communicates a state from one place to\nanother. At the destination it just forms an array of bits that\nrequire observation.\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>"!Q" <no_spam@null.org> wrote in message news:<cbbgan$bqt$1@lust.ihug.co.nz>...
> Eel wrote:
> What's the deal? I don't know. Seems like a problem to me. Maybe the
> universe splits in two and in one universe "you" see a dead cat and in
> the other universe "you" see the alive cat. But it's not as simple as
> that otherwise this measurment problem would have been solved decades
> ago. Have a look around the Internet for "Copenhagen interpretation of
> quantum mechanics" or "many worlds interpretation of quantum mechanics"
> or simply "the measurment problem in quantum mechanics".
>
>
There seem to be three main approaches to the 'observer'.
In the 'Consistent Histories' approach of Hartle & Gell-Mann the
observer is considered to be an 'IGUS'(Information gathering and
utilising system (Hartle & Gell-Mann)). The universe is considered to
branch regularly ('coarse grained histories') and the IGU splits with
it. Each IGUS has a continuous record of its 'life' into the past as
memory.
The 'Operational Interpretation of Quantum Theory' or 'Decoherence
Theory' has two strands.
In the first, due largely to Zurek et al the environment constitutes a
single interacting system that provides a preferred configuration of
the universe. Any small particle in contact with this preferred basis
will experience 'superselection' in which states that are compatible
with the state of the environment will be preferentially selected.
Again the observer is considered to be an IGUS and owes its state to
the environment.
http://xxx.lanl.gov/PS_cache/gr-qc/pdf/9402/9402011.pdf
In the second, due largely to Zeh et al the size and location of the
observer is considered. This group or theorists also developed
decoherence theory. Zeh wonders whether the bulk of the brain might be
external to the observer and hence speculates that the state of the
brain may depend on the state of the part of the brain that is the
observer as well as the environment.
http://xxx.lanl.gov/PS_cache/quant-ph/pdf/9908/9908084.pdf
In fact Zeh goes futher and speculates that the observer might be a
quantum state at a point.
Zeh is undoubtedly closer to the neuroscience of the observer than the
others. There is no doubt that the brain is largely non-conscious.
Indeed, during general anaesthesia the cerebral cortex can be more
active than normal (White & Alkire (2003), Fiset et al (1999). The
other problem with the IGUS is that it does not account for 'binding'
where all the modes of sensation seem to be accessible simultaneously
and viewed as if from a point. (The 'cyclopean eye' of cognitive
psychology is due to brain activity - there is no 'point' in the
optical system from the retina to a data source).
In fact an information system cannot be responsible for conscious
experience. Information communicates a state from one place to
another. At the destination it just forms an array of bits that
require observation.
Alex Green
Jun29-04, 05:46 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>"John T Lowry" <jlowry100@earthlink.net> wrote in message news:<ApnCc.11610\n> ...\n> I believe the wave function collapse took place (if it did at all) when\n> the noxious gas was released (or soon thereafter) and the cat succumbed.\n> I don\'t believe the human (or machine) observer had anything to do with\n> it.\n>\n> For, what if the observer didn\'t open the box for say a couple of weeks.\n> And say the cat was dead. Then he or she could make the additional\n> observation that (this observer is a forensic veterinarian) "This cat\n> has been dead for about ten days." So obviously nothing of any import\n> happened upon opening the box...\n\nSurely science is about inferences. According to a strictly\nmetaphysical approach such as you are proposing you cannot even\nbelieve in electrons because all you can know is readings on meters\nand for all you know these are just part of some realistic dream. As\nDescartes showed in the seventeenth century, the world is not \'god\ngiven\', observers infer it\'s existence through science.\n\nMany physicists have a deeply held metaphysical belief called \'naive\nrealism\' in which they genuinely believe that they are directly\nperceiving nature (ie: that they are the natural objects in perception\n(!)). However, their experience is actually brain activity and how the\nbrain provides the experience we call \'observation\' on the basis of\nsense data must be one of the most exciting problems in modern\nscience. Naive Realists are depriving themselves of this entire new\nfrontier.\n\nThe problem of Schrodinger\'s cat is still valid (if perfect isolation\ncould occur) and certainly valid for small objects which can be\nisolated. The sequence of events is state vector of environment\nproduces change in state vector of cat and is changed itself then the\nobserver produces a change in the state vector of the environment and\nis changed itself. But what is the observer\'s state vector? How can\n\'we\', these things that dream be single, classical configurations with\nthe properties of an \'observer\'?\n\nBest Wishes\n\nAlex Green\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>"John T Lowry" <jlowry100@earthlink.net> wrote in message news:<ApnCc.11610
> ...
> I believe the wave function collapse took place (if it did at all) when
> the noxious gas was released (or soon thereafter) and the cat succumbed.
> I don't believe the human (or machine) observer had anything to do with
> it.
>
> For, what if the observer didn't open the box for say a couple of weeks.
> And say the cat was dead. Then he or she could make the additional
> observation that (this observer is a forensic veterinarian) "This cat
> has been dead for about ten days." So obviously nothing of any import
> happened upon opening the box...
Surely science is about inferences. According to a strictly
metaphysical approach such as you are proposing you cannot even
believe in electrons because all you can know is readings on meters
and for all you know these are just part of some realistic dream. As
Descartes showed in the seventeenth century, the world is not 'god
given', observers infer it's existence through science.
Many physicists have a deeply held metaphysical belief called 'naive
realism' in which they genuinely believe that they are directly
perceiving nature (ie: that they are the natural objects in perception
(!)). However, their experience is actually brain activity and how the
brain provides the experience we call 'observation' on the basis of
sense data must be one of the most exciting problems in modern
science. Naive Realists are depriving themselves of this entire new
frontier.
The problem of Schrodinger's cat is still valid (if perfect isolation
could occur) and certainly valid for small objects which can be
isolated. The sequence of events is state vector of environment
produces change in state vector of cat and is changed itself then the
observer produces a change in the state vector of the environment and
is changed itself. But what is the observer's state vector? How can
'we', these things that dream be single, classical configurations with
the properties of an 'observer'?
Best Wishes
Alex Green
Rahul Jain
Jun29-04, 05:53 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>"John T Lowry" <jlowry100@earthlink.net> writes:\n\n> For, what if the observer didn\'t open the box for say a couple of weeks.\n> And say the cat was dead. Then he or she could make the additional\n> observation that (this observer is a forensic veterinarian) "This cat\n> has been dead for about ten days." So obviously nothing of any import\n> happened upon opening the box...\n\nExcept that maybe the wavefunction at that time collapsed to where the\natom decayed at some specific moment and had been evolving unitarily\nbefore that.\n\n--\nRahul Jain\nrjain@nyct.net\nProfessional Software Developer, Amateur Quantum Mechanicist\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>"John T Lowry" <jlowry100@earthlink.net> writes:
> For, what if the observer didn't open the box for say a couple of weeks.
> And say the cat was dead. Then he or she could make the additional
> observation that (this observer is a forensic veterinarian) "This cat
> has been dead for about ten days." So obviously nothing of any import
> happened upon opening the box...
Except that maybe the wavefunction at that time collapsed to where the
atom decayed at some specific moment and had been evolving unitarily
before that.
--
Rahul Jain
rjain@nyct.net
Professional Software Developer, Amateur Quantum Mechanicist
Ron Hornbaker
Jun30-04, 05:35 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>"John T Lowry" <jlowry100@earthlink.net> wrote in message news:<ApnCc.11610\\$w07.9924@newsread2.news.pas.ea rthlink.net>...\n> "!Q" <no_spam@null.org> wrote in message\n> news:cbbgan\\$bqt\\$1@lust.ihug.co.nz...\n> >\n> > Eel wrote:\n> > > Here\'s something I\'ve never understood about the "Schrodinger\'s cat"\n> > > thought experiement. Is the observer (who opens the box) implied to\n> > > be a metaphysical entity that is required to make the cat come out of\n> > > its limbo state? Could the observer be a machine that opens the box,\n> > > is impacted by the outcome, but doesn\'t observe as a human or animal\n> > > would metaphysically.\n> > >\n> > > Is it just a sort of pondering of the quantum theory of superposition\n> > > and not ment to be factual for anything other than just being a\n> > > paradox?\n> > >\n> > > I\'m confused.\n> > >\n> >\n> > I believe it implied at some stage of the measuring process but not\n> > necessarily in the "direct" observation of the state of the cat. For\n> > example imagine you replace the human observer with a physical measuring\n> > device, |D> (by definition wouldn\'t a human observer also be a physical\n> > measuring device?). The state of the system becomes the tensor product\n> > state of the state of Schrodinger\'s cat |0>|alive> + |1>|dead> with the\n> > measuring device becoming:\n> >\n> > |0>|alive>|D_alive> + |1>|dead>|D_dead>\n> >\n> > (don\'t worry about the notation too much if you haven\'t seen it before.\n> > The first term just describes the state where the vial doesn\'t break,\n> > the cat is alive and the measuring device detects the cat being alive.\n> > The second term is when the vial breaks, the cat is killed and the\n> > measuring device detects the cat being dead. Each term contributes\n> > equally to the overall system state so there is a 50% chance of each\n> > outcome occuring).\n> >\n> > The system is now in a superposition of the cat being alive and the\n> > measuring device detecting the cat as being alive and the cat being dead\n> > and the measuring device detecting that the cat is dead. What now? We\n> > could add another measuring device to detect the state of the first\n> > device but what does this add? We will end up in a similar situation. At\n> > what stage does the system "collapse" into one of the possible outcomes?\n> >\n> > This measurment chain can be extended infinitum (well there are limits\n> > but let\'s ignore them for now) but we don\'t know what other measuring\n> > device "experience". All we know is that when we observe a system we\n> > never seem this superposition. Does this mean the collapse of the system\n> > occurs at the stage when a human observes the system? Maybe. The only\n> > way we can know what state a system is in is by observation and this\n> > implies interaction with a human. But if a human is just a physical\n> > measuring device wouldn\'t the state of the system be:\n> >\n> > |0>|alive>|D_alive>|Human detecting alive cat> +\n> > |1>|dead>|D_dead>|Human detecting dead cat>\n> >\n> > What\'s the deal? I don\'t know. Seems like a problem to me. Maybe the\n> > universe splits in two and in one universe "you" see a dead cat and in\n> > the other universe "you" see the alive cat. But it\'s not as simple as\n> > that otherwise this measurment problem would have been solved decades\n> > ago. Have a look around the Internet for "Copenhagen interpretation of\n> > quantum mechanics" or "many worlds interpretation of quantum mechanics"\n> > or simply "the measurment problem in quantum mechanics".\n> >\n> > Hope I haven\'t confused you anymore :)\n> >\n> > !Q\n>\n> I believe the wave function collapse took place (if it did at all) when\n> the noxious gas was released (or soon thereafter) and the cat succumbed.\n> I don\'t believe the human (or machine) observer had anything to do with\n> it.\n>\n> For, what if the observer didn\'t open the box for say a couple of weeks.\n> And say the cat was dead. Then he or she could make the additional\n> observation that (this observer is a forensic veterinarian) "This cat\n> has been dead for about ten days." So obviously nothing of any import\n> happened upon opening the box...\n\nRon Hornbaker\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>"John T Lowry" <jlowry100@earthlink.net> wrote in message news:<ApnCc.11610$w07.9924@newsread2.news.pas.earthlink. net>...
> "!Q" <no_spam@null.org> wrote in message
> news:cbbgan$bqt$1@lust.ihug.co.nz...
> >
> > Eel wrote:
> > > Here's something I've never understood about the "Schrodinger's cat"
> > > thought experiement. Is the observer (who opens the box) implied to
> > > be a metaphysical entity that is required to make the cat come out of
> > > its limbo state? Could the observer be a machine that opens the box,
> > > is impacted by the outcome, but doesn't observe as a human or animal
> > > would metaphysically.
> > >
> > > Is it just a sort of pondering of the quantum theory of superposition
> > > and not ment to be factual for anything other than just being a
> > > paradox?
> > >
> > > I'm confused.
> > >
> >
> > I believe it implied at some stage of the measuring process but not
> > necessarily in the "direct" observation of the state of the cat. For
> > example imagine you replace the human observer with a physical measuring
> > device, |D> (by definition wouldn't a human observer also be a physical
> > measuring device?). The state of the system becomes the tensor product
> > state of the state of Schrodinger's cat |0>|alive> + |1>|dead> with the
> > measuring device becoming:
> >
> > |0>|alive>|D_{alive}> + |1>|dead>|D_{dead}>
> >
> > (don't worry about the notation too much if you haven't seen it before.
> > The first term just describes the state where the vial doesn't break,
> > the cat is alive and the measuring device detects the cat being alive.
> > The second term is when the vial breaks, the cat is killed and the
> > measuring device detects the cat being dead. Each term contributes
> > equally to the overall system state so there is a 50% chance of each
> > outcome occuring).
> >
> > The system is now in a superposition of the cat being alive and the
> > measuring device detecting the cat as being alive and the cat being dead
> > and the measuring device detecting that the cat is dead. What now? We
> > could add another measuring device to detect the state of the first
> > device but what does this add? We will end up in a similar situation. At
> > what stage does the system "collapse" into one of the possible outcomes?
> >
> > This measurment chain can be extended infinitum (well there are limits
> > but let's ignore them for now) but we don't know what other measuring
> > device "experience". All we know is that when we observe a system we
> > never seem this superposition. Does this mean the collapse of the system
> > occurs at the stage when a human observes the system? Maybe. The only
> > way we can know what state a system is in is by observation and this
> > implies interaction with a human. But if a human is just a physical
> > measuring device wouldn't the state of the system be:
> >
> > |0>|alive>|D_{alive}>|Human detecting alive cat> +
> > |1>|dead>|D_{dead}>|Human detecting dead cat>
> >
> > What's the deal? I don't know. Seems like a problem to me. Maybe the
> > universe splits in two and in one universe "you" see a dead cat and in
> > the other universe "you" see the alive cat. But it's not as simple as
> > that otherwise this measurment problem would have been solved decades
> > ago. Have a look around the Internet for "Copenhagen interpretation of
> > quantum mechanics" or "many worlds interpretation of quantum mechanics"
> > or simply "the measurment problem in quantum mechanics".
> >
> > Hope I haven't confused you anymore :)
> >
> > !Q
>
> I believe the wave function collapse took place (if it did at all) when
> the noxious gas was released (or soon thereafter) and the cat succumbed.
> I don't believe the human (or machine) observer had anything to do with
> it.
>
> For, what if the observer didn't open the box for say a couple of weeks.
> And say the cat was dead. Then he or she could make the additional
> observation that (this observer is a forensic veterinarian) "This cat
> has been dead for about ten days." So obviously nothing of any import
> happened upon opening the box...
Ron Hornbaker
John T Lowry
Jun30-04, 05:39 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>I\'ve been reading Zurek\'s articles on decoherence and it looks to me\nthat that notion is much more likely than the MWI (though I enjoyed\nthinking about that when Everett\'s first articles on the subject came\nout).\n\n\n"George Buyanovsky" <buyanovsky@attbi.com> wrote in message\nnews:d7221cc2.0406221727.43757611@posting .google.com...\n> eel@javabox.com (Eel) wrote in message\nnews:<a62a408.0406191958.2791f8d4@posting .google.com>...\n> > Here\'s something I\'ve never understood about the "Schrodinger\'s cat"\n> > thought experiement. Is the observer (who opens the box) implied to\n> > be a metaphysical entity that is required to make the cat come out\nof\n> > its limbo state? Could the observer be a machine that opens the\nbox,\n> > is impacted by the outcome, but doesn\'t observe as a human or animal\n> > would metaphysically.\n> >\n> > Is it just a sort of pondering of the quantum theory of\nsuperposition\n> > and not ment to be factual for anything other than just being a\n> > paradox?\n> >\n> > I\'m confused.\n>\n> There is no paradox at all if to consider the observer<->event\n> interaction as wave-functions interference (non collapse) you may\n> appreciate the beauty of QM MWI.\n>\n> Best,\n> George\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>I've been reading Zurek's articles on decoherence and it looks to me
that that notion is much more likely than the MWI (though I enjoyed
thinking about that when Everett's first articles on the subject came
out).
"George Buyanovsky" <buyanovsky@attbi.com> wrote in message
news:d7221cc2.0406221727.43757611@posting.google.c om...
> eel@javabox.com (Eel) wrote in message
news:<a62a408.0406191958.2791f8d4@posting.google.com>...
> > Here's something I've never understood about the "Schrodinger's cat"
> > thought experiement. Is the observer (who opens the box) implied to
> > be a metaphysical entity that is required to make the cat come out
of
> > its limbo state? Could the observer be a machine that opens the
box,
> > is impacted by the outcome, but doesn't observe as a human or animal
> > would metaphysically.
> >
> > Is it just a sort of pondering of the quantum theory of
superposition
> > and not ment to be factual for anything other than just being a
> > paradox?
> >
> > I'm confused.
>
> There is no paradox at all if to consider the observer<->event
> interaction as wave-functions interference (non collapse) you may
> appreciate the beauty of QM MWI.
>
> Best,
> George
>
George Buyanovsky
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"John T Lowry" <jlowry100@earthlink.net> wrote in message news:<SciEc.5179\\$lh4.1721@newsread1.news.pas.ear thlink.net>...\n> I\'ve been reading Zurek\'s articles on decoherence and it looks to me\n> that that notion is much more likely than the MWI (though I enjoyed\n> thinking about that when Everett\'s first articles on the subject came\n> out).\n\nZurek\'s decoherence may be interpreted as a non-explicit version of\nMWI. Interpretations are basically one of ways to help people to\ncomprehend formalism.\n\nBest,\nGeorge\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>"John T Lowry" <jlowry100@earthlink.net> wrote in message news:<SciEc.5179$lh4.1721@newsread1.news.pas.earthlink.n et>...
> I've been reading Zurek's articles on decoherence and it looks to me
> that that notion is much more likely than the MWI (though I enjoyed
> thinking about that when Everett's first articles on the subject came
> out).
Zurek's decoherence may be interpreted as a non-explicit version of
MWI. Interpretations are basically one of ways to help people to
comprehend formalism.
Best,
George
<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\nRahul Jain <rjain@nyct.net> writes\n>"John T Lowry" <jlowry100@earthlink.net> writes:\n>\n>> For, what if the observer didn\'t open the box for say a couple of weeks.\n>> And say the cat was dead. Then he or she could make the additional\n>> observation that (this observer is a forensic veterinarian) "This cat\n>> has been dead for about ten days." So obviously nothing of any import\n>> happened upon opening the box...\n>\n>Except that maybe the wavefunction at that time collapsed to where the\n>atom decayed at some specific moment and had been evolving unitarily\n>before that.\n\nThis discussion has happened before. For what its worth (probably not\nmuch) listening to my betters, I came to the conclusion that to all\nintents and purposes, the cat was (definitively) either alive or dead\nvery soon after the event occurred. Mind you, I have been known to be\nterribly wrong.\n\nConsider a cat. It comprises a rather large number of quantum mechanical\nstates, all of which are nominally entangled and so are really just one\nstate, or better a superposition of a large number of possible\nalternative entangled states.\n\nI hope I have the tech nomenclature right.\n\nAnyway, proceeding ....\n\nNow (after a period of time) these states will fall into two groups,\nroughly describable as \'cat alive\' (CA) and \'cat dead\' (CD). There is\nlikely to be a rather large number of possible states comprising CA & CD\nbut I would suggest very very few that allow for \'cat both dead and\nalive\'. That would indeed be a very tight balancing act to maintain for\nall these states for any period of time without time evolving into\neither CA or CD. An entanglement of CA & CD would be a very delicate\nthing to achieve indeed.\n\nSo one might conclude that the cat is either alive or dead, but not\nboth.\n\nPerform 10,000 experiments and you will find that half the time the cat\nis alive and half the time the cat is dead (please note that no cats\nwere harmed in this thought experiment). That is true. That is, this\nhighly macroscopic experiment gives you a probability of the outcome.\n\nIn effect the cat is a valid observer.\n\nNote that I am NOT saying that this is also so for microscopic events. I\nam happy to accept that its possible to have a superposition where the\nparticle IS in both states at once. With exquisite experimental setups\nwhere the probability of either state can be maintained at 50% for\n\'extended periods\'. Here, its hard for the particle to time evolve (by\ninteraction with \'the outside\') away from the 50% mix.\n\n--\nOz\nThis post is worth absolutely nothing and is probably fallacious.\n\nBTOPENWORLD address about to cease. DEMON address no longer in use.\n>>Use oz@farmeroz.port995.com (whitelist check on first posting)<<\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Rahul Jain <rjain@nyct.net> writes
>"John T Lowry" <jlowry100@earthlink.net> writes:
>
>> For, what if the observer didn't open the box for say a couple of weeks.
>> And say the cat was dead. Then he or she could make the additional
>> observation that (this observer is a forensic veterinarian) "This cat
>> has been dead for about ten days." So obviously nothing of any import
>> happened upon opening the box...
>
>Except that maybe the wavefunction at that time collapsed to where the
>atom decayed at some specific moment and had been evolving unitarily
>before that.
This discussion has happened before. For what its worth (probably not
much) listening to my betters, I came to the conclusion that to all
intents and purposes, the cat was (definitively) either alive or dead
very soon after the event occurred. Mind you, I have been known to be
terribly wrong.
Consider a cat. It comprises a rather large number of quantum mechanical
states, all of which are nominally entangled and so are really just one
state, or better a superposition of a large number of possible
alternative entangled states.
I hope I have the tech nomenclature right.
Anyway, proceeding ....
Now (after a period of time) these states will fall into two groups,
roughly describable as 'cat alive' (CA) and 'cat dead' (CD). There is
likely to be a rather large number of possible states comprising CA & CD
but I would suggest very very few that allow for 'cat both dead and
alive'. That would indeed be a very tight balancing act to maintain for
all these states for any period of time without time evolving into
either CA or CD. An entanglement of CA & CD would be a very delicate
thing to achieve indeed.
So one might conclude that the cat is either alive or dead, but not
both.
Perform 10,000 experiments and you will find that half the time the cat
is alive and half the time the cat is dead (please note that no cats
were harmed in this thought experiment). That is true. That is, this
highly macroscopic experiment gives you a probability of the outcome.
In effect the cat is a valid observer.
Note that I am NOT saying that this is also so for microscopic events. I
am happy to accept that its possible to have a superposition where the
particle IS in both states at once. With exquisite experimental setups
where the probability of either state can be maintained at 50% for
'extended periods'. Here, its hard for the particle to time evolve (by
interaction with 'the outside') away from the 50% mix.
--
Oz
This post is worth absolutely nothing and is probably fallacious.
BTOPENWORLD address about to cease. DEMON address no longer in use.
>>Use oz@farmeroz.port995.com (whitelist check on first posting)<<
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n"Oz"\n\n> So one might conclude that the cat is either alive or dead,\n> but not both. [..... ]\n> Note that I am NOT saying that this is also so for microscopic\n> events.\n\nImagine we have an ensemble of dead cats. And imagine\nwe measure on each one the projection operator on the\nstate defined as\npsi = 1/sqrt2 [|cat alive> + exp (i theta) |cat dead>]\n\nIn a certain % of cases the state of the specific cat\nwill become "psi". Now we can measure whether the resulting\ncat is |dead> or |alive>. In 50% of cases we find the cat\nto be alive. Thus we have resuscitated a dead cat.\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"
> So one might conclude that the cat is either alive or dead,
> but not both. [..... ]
> Note that I am NOT saying that this is also so for microscopic
> events.
Imagine we have an ensemble of dead cats. And imagine
we measure on each one the projection operator on the
state defined as
\psi = 1/sqrt2 [|cat alive> + \exp (i \theta) |cat dead>]
In a certain % of cases the state of the specific cat
will become "\psi". Now we can measure whether the resulting
cat is |dead> or |alive>. In 50% of cases we find the cat
to be alive. Thus we have resuscitated a dead cat.
The cat can also be an observer so this solves the paradox.
p.kinsler@imperial.ac.uk
Jul12-04, 01:00 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>scerir <scerir@libero.it> wrote:\n\n> "Oz"\n\n> > So one might conclude that the cat is either alive or dead,\n> > but not both. [..... ]\n> > Note that I am NOT saying that this is also so for microscopic\n> > events.\n\n> Imagine we have an ensemble of dead cats. And imagine\n> we measure on each one the projection operator on the\n> state defined as\n> psi = 1/sqrt2 [|cat alive> + exp (i theta) |cat dead>]\n\n> In a certain % of cases the state of the specific cat\n> will become "psi". Now we can measure whether the resulting\n> cat is |dead> or |alive>. In 50% of cases we find the cat\n> to be alive. Thus we have resuscitated a dead cat.\n\nAnd if you can construct a machine that can apply such a handy\nprojection operator, you could indeed use it to resuscitate dead\ncats. Was I supposed to get stuck thinking about the difficulty\nof cat resuscitation, and not notice that making your projection\noperator was equivalent?\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</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 <scerir@libero.it> wrote:
> "Oz"
> > So one might conclude that the cat is either alive or dead,
> > but not both. [..... ]
> > Note that I am NOT saying that this is also so for microscopic
> > events.
> Imagine we have an ensemble of dead cats. And imagine
> we measure on each one the projection operator on the
> state defined as
> \psi = 1/sqrt2 [|cat alive> + \exp (i \theta) |cat dead>]
> In a certain % of cases the state of the specific cat
> will become "\psi". Now we can measure whether the resulting
> cat is |dead> or |alive>. In 50% of cases we find the cat
> to be alive. Thus we have resuscitated a dead cat.
And if you can construct a machine that can apply such a handy
projection operator, you could indeed use it to resuscitate dead
cats. Was I supposed to get stuck thinking about the difficulty
of cat resuscitation, and not notice that making your projection
operator was equivalent?
--
---------------------------------+---------------------------------
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/
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