Mark Palenik
Jun7-04, 04:54 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>\nThe last time I tried to post this, I got this resopnse from the moderator:\n\n"If you are asking if it is possible to put an electron in a superposition\nof spin up and spin down then the answers is Yes, but this has nothing to do\nwith many worlds. . ."\n\nso, let me first of all say that I\'m not asking if an electron can be in a\nsuperposition of spin up and spin down, but trying to use the fact that idea\nof superposition to try to show that a local MWI should allow for some sort\nof "interaction" between worlds (although perhaps interaction is the wrong\nword for it).\n\nFirst of all, I want to know if the assumptions I\'m making are incorrect,\nbut if they are correct, I\'m not sure that it\'s necesarrily inconsistant\nwith experiment (or logic) in any way.\n\n>From what I gather from the MWI FAQ available on the internet, MWI is\nsupposed to be a local interpretation because splitting only occurrs\nlocally, rather than throughout the entire universe at once. So, for\nexample, an electron in a double slit experiment splits in two when it hits\nthe screen (as does the screen), you split when you observe the screen,\nsomeone else splits when he talks to you, etc. (of course, I\'m speaking of\nan idealized situation - I understand that in the real world a lot more\ninteractions would be taking place to cause more splitting and sooner).\n\nNow, if we do an experiment where there\'s a 50% chance that a radioactive\nparticle will decay after a certain amount of time, 50% of all worlds should\nhave see a decayed particle. For simplicity\'s sake, perhaps we can say\nthere are two worlds, one where the particle has decayed an one where it\nhasn\'t.\n\nIf a Geiger counter is set up to detect this decay, they geiger counter\nshould split into a "detected" and "undetected" world when the radiation\nfrom the decayed particle interacts/doesn\'t interact with it. At this point\nthere would be two distinct worlds, and the superposition of emitted/not\nemitted should cease to exist (by the standard definition of superposition,\ndespite the fact that MWI says the two states still exist).\n\nA device could be set so that at the half life of the particle, it would put\nan electron in a spin up state if radiation is detected, and a spin down\nstate if radiation is not detected.\n\nThe electron would not have yet split into two worlds when the Geiger\ncounter interacted with the radiation, since for a local interpretation of\nMWI, only local splitting between interacting particles occurs. So this\nelectron, unaffected by the previous splitting would be simultaneously set\ninto a spin up and spin down state when it finally does interact with\nsomething which has interacted with the geiger counter.\n\nHowever, and this is where my lack of knowledge becomes important, it seems\nreasonable to me to assume that rather than splitting into two worlds, one\nwith a spin up electron and one with a spin down electron, the electron\ncould simply be put into a superposition of spin up and spin down.\n\nIn this case, an observer would split into two separate worlds when\ninteracting with the electron, one in which decay has ocurred, and one in\nwhich it has not, but until another observer interacts with it, it would\nexist in a superposition that would in some way connect decayed/not decayed,\ndetected/not detected worlds.\n\nI don\'t know if this would have any real experimental implications, but as I\nsaid in my last post, it doesn\'t seem right - or at least, very odd.\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>The last time I tried to post this, I got this resopnse from the moderator:
"If you are asking if it is possible to put an electron in a superposition
of spin up and spin down then the answers is Yes, but this has nothing to do
with many worlds. . ."
so, let me first of all say that I'm not asking if an electron can be in a
superposition of spin up and spin down, but trying to use the fact that idea
of superposition to try to show that a local MWI should allow for some sort
of "interaction" between worlds (although perhaps interaction is the wrong
word for it).
First of all, I want to know if the assumptions I'm making are incorrect,
but if they are correct, I'm not sure that it's necesarrily inconsistant
with experiment (or logic) in any way.
>From what I gather from the MWI FAQ available on the internet, MWI is
supposed to be a local interpretation because splitting only occurrs
locally, rather than throughout the entire universe at once. So, for
example, an electron in a double slit experiment splits in two when it hits
the screen (as does the screen), you split when you observe the screen,
someone else splits when he talks to you, etc. (of course, I'm speaking of
an idealized situation - I understand that in the real world a lot more
interactions would be taking place to cause more splitting and sooner).
Now, if we do an experiment where there's a 50% chance that a radioactive
particle will decay after a certain amount of time, 50% of all worlds should
have see a decayed particle. For simplicity's sake, perhaps we can say
there are two worlds, one where the particle has decayed an one where it
hasn't.
If a Geiger counter is set up to detect this decay, they geiger counter
should split into a "detected" and "undetected" world when the radiation
from the decayed particle interacts/doesn't interact with it. At this point
there would be two distinct worlds, and the superposition of emitted/not
emitted should cease to exist (by the standard definition of superposition,
despite the fact that MWI says the two states still exist).
A device could be set so that at the half life of the particle, it would put
an electron in a spin up state if radiation is detected, and a spin down
state if radiation is not detected.
The electron would not have yet split into two worlds when the Geiger
counter interacted with the radiation, since for a local interpretation of
MWI, only local splitting between interacting particles occurs. So this
electron, unaffected by the previous splitting would be simultaneously set
into a spin up and spin down state when it finally does interact with
something which has interacted with the geiger counter.
However, and this is where my lack of knowledge becomes important, it seems
reasonable to me to assume that rather than splitting into two worlds, one
with a spin up electron and one with a spin down electron, the electron
could simply be put into a superposition of spin up and spin down.
In this case, an observer would split into two separate worlds when
interacting with the electron, one in which decay has ocurred, and one in
which it has not, but until another observer interacts with it, it would
exist in a superposition that would in some way connect decayed/not decayed,
detected/not detected worlds.
I don't know if this would have any real experimental implications, but as I
said in my last post, it doesn't seem right - or at least, very odd.
"If you are asking if it is possible to put an electron in a superposition
of spin up and spin down then the answers is Yes, but this has nothing to do
with many worlds. . ."
so, let me first of all say that I'm not asking if an electron can be in a
superposition of spin up and spin down, but trying to use the fact that idea
of superposition to try to show that a local MWI should allow for some sort
of "interaction" between worlds (although perhaps interaction is the wrong
word for it).
First of all, I want to know if the assumptions I'm making are incorrect,
but if they are correct, I'm not sure that it's necesarrily inconsistant
with experiment (or logic) in any way.
>From what I gather from the MWI FAQ available on the internet, MWI is
supposed to be a local interpretation because splitting only occurrs
locally, rather than throughout the entire universe at once. So, for
example, an electron in a double slit experiment splits in two when it hits
the screen (as does the screen), you split when you observe the screen,
someone else splits when he talks to you, etc. (of course, I'm speaking of
an idealized situation - I understand that in the real world a lot more
interactions would be taking place to cause more splitting and sooner).
Now, if we do an experiment where there's a 50% chance that a radioactive
particle will decay after a certain amount of time, 50% of all worlds should
have see a decayed particle. For simplicity's sake, perhaps we can say
there are two worlds, one where the particle has decayed an one where it
hasn't.
If a Geiger counter is set up to detect this decay, they geiger counter
should split into a "detected" and "undetected" world when the radiation
from the decayed particle interacts/doesn't interact with it. At this point
there would be two distinct worlds, and the superposition of emitted/not
emitted should cease to exist (by the standard definition of superposition,
despite the fact that MWI says the two states still exist).
A device could be set so that at the half life of the particle, it would put
an electron in a spin up state if radiation is detected, and a spin down
state if radiation is not detected.
The electron would not have yet split into two worlds when the Geiger
counter interacted with the radiation, since for a local interpretation of
MWI, only local splitting between interacting particles occurs. So this
electron, unaffected by the previous splitting would be simultaneously set
into a spin up and spin down state when it finally does interact with
something which has interacted with the geiger counter.
However, and this is where my lack of knowledge becomes important, it seems
reasonable to me to assume that rather than splitting into two worlds, one
with a spin up electron and one with a spin down electron, the electron
could simply be put into a superposition of spin up and spin down.
In this case, an observer would split into two separate worlds when
interacting with the electron, one in which decay has ocurred, and one in
which it has not, but until another observer interacts with it, it would
exist in a superposition that would in some way connect decayed/not decayed,
detected/not detected worlds.
I don't know if this would have any real experimental implications, but as I
said in my last post, it doesn't seem right - or at least, very odd.