Register | Sign In


Understanding through Discussion


EvC Forum active members: 65 (9162 total)
5 online now:
Newest Member: popoi
Post Volume: Total: 915,817 Year: 3,074/9,624 Month: 919/1,588 Week: 102/223 Day: 13/17 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   the underlying assumptions rig the debate
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 46 of 246 (322793)
06-18-2006 3:01 AM
Reply to: Message 45 by Iblis
06-18-2006 2:24 AM


Re: more on delayed-choice experiments
The "choice" referred to in the article is the mirror popping up.
No kidding Iblis. Gee....? Have I suggested anywhere at all here on this thread anything other than that?
The tricky part is that the order of events is such that the photon is generated BEFORE the mirror is in place.
Yea, and so the choice or observation is AFTER the effect and so affects the photon before measurement, right?
Btw, your descriptions of what scientists can and are doing with entangled photons is considerably different than what is reported.
To demonstrate open-destination teleportation, Pan and co-workers first teleported the unknown quantum state of a single photon onto a superposition of three photons. They were then able to read out this teleported state at any one of the three photons by performing a measurement on the other two photons.
Home – Physics World
By using a filter to reduce the intensity of the photons that are going to be teleported the researchers were able to significantly reduce the number of spurious detection events. The Vienna team could be 97% certain that the state had been teleported to photon 3 without actually having to detect it. Such a high accuracy means that the teleported photons could be used in “quantum repeaters” for long distance communication. The team now hopes to combine these results with a technique known as “entanglement purification” to further develop quantum communication over long distances.
Home – Physics World
Two macroscopic objects have been 'entangled' for the first time. Eugene Polzik and colleagues at the University of Aarhus in Denmark entangled two samples of caesium atoms, each containing about 1012 atoms, for half a millisecond - a long time by quantum standards. This demonstration could form the basis of new forms of 'quantum teleportation' and quantum computers (B Julsgaard et al 2001 Nature 413 400).
Home – Physics World
Edited by randman, : No reason given.
Edited by randman, : To correct mistating a setence.

This message is a reply to:
 Message 45 by Iblis, posted 06-18-2006 2:24 AM Iblis has not replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 47 of 246 (322800)
06-18-2006 3:51 AM
Reply to: Message 45 by Iblis
06-18-2006 2:24 AM


2nd response
Wheeler's delayed-choice experiment is a
variation on the classic (but not classical) two-slit experiment, which demonstrates the schizophrenic nature of quantum phenomena. When electrons are aimed at a barrier containing two slits, the electrons act like waves; they go through both slits at once and form what is called an interference pattern, created by the overlapping of the waves, when they strike a detector on the far side of the barrier. If the physicist closes off one slit at a time, however, the electrons pass through the open slit like simple particles and the interference pattern disappears. In the
delayed-choice experiment, the experimenter decides whether to leave both slits open or to close one off _after the electrons have already passed through the barrier_--with the same results. The electrons seem to know in advance how the physicist will choose to observe them.
http://suif.stanford.edu/~jeffop/WWW/wheeler.txt
What is the reason that "electrons seem to know in advance" what the choice will be? Isn't it that the delayed-choice demonstrably affects the path prior to the choice? Isn't that what is meant by "delayed"?
Clearly then, we see causality occuring from an event affecting the photon's path before the event. The article gets into some very interesting stuff about the observer, by the way, but what I am focussing on is the fact we see the delayed-choice affecting the photon before the choice takes place.
As a sidenote, I have always wondered considering relativity, why the idea is not advanced that photons travelling at the speed of light are not entangled with themselves at all points in time anyway and so, of course, we would see these results due to that, but that doesn't seem to popular idea (I am assuming for some obvious reason).
Edited by randman, : No reason given.

This message is a reply to:
 Message 45 by Iblis, posted 06-18-2006 2:24 AM Iblis has not replied

  
cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 48 of 246 (322802)
06-18-2006 4:07 AM
Reply to: Message 45 by Iblis
06-18-2006 2:24 AM


Re: more on delayed-choice experiments
(Oh, and a side note to cavediver: shoe's on the other foot now, huh)
Sorry, I'm not with you... can you elucidate?
But well done on talking through this stuff. At the end of day, as you have pointed out, Randman is using Wiki, New Scientist, popular science, dubious websites, etc, to develop his understanding of the most mis-represented area of physics, and is quite naturally hopelessly confused and misguided.

This message is a reply to:
 Message 45 by Iblis, posted 06-18-2006 2:24 AM Iblis has not replied

Replies to this message:
 Message 49 by randman, posted 06-18-2006 4:09 AM cavediver has replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 49 of 246 (322803)
06-18-2006 4:09 AM
Reply to: Message 48 by cavediver
06-18-2006 4:07 AM


Re: more on delayed-choice experiments
another post devoid of content

This message is a reply to:
 Message 48 by cavediver, posted 06-18-2006 4:07 AM cavediver has replied

Replies to this message:
 Message 51 by cavediver, posted 06-18-2006 4:14 AM randman has not replied

  
cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 50 of 246 (322804)
06-18-2006 4:11 AM
Reply to: Message 37 by randman
06-17-2006 10:50 PM


Re: Really?
Really, what is the mechanism for entanglement then?
What does it matter? It has nothing to do with what you are claiming so it is irrelevant.

This message is a reply to:
 Message 37 by randman, posted 06-17-2006 10:50 PM randman has replied

Replies to this message:
 Message 52 by randman, posted 06-18-2006 4:17 AM cavediver has not replied

  
cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 51 of 246 (322805)
06-18-2006 4:14 AM
Reply to: Message 49 by randman
06-18-2006 4:09 AM


Re: more on delayed-choice experiments
another post devoid of content
Just like yours but with surprisingly fewer words

This message is a reply to:
 Message 49 by randman, posted 06-18-2006 4:09 AM randman has not replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 52 of 246 (322806)
06-18-2006 4:17 AM
Reply to: Message 50 by cavediver
06-18-2006 4:11 AM


nothing, eh?
So you can't just admit you don't know?
And it does indeed have a lot to do with what we are talking about because entanglement plays a key role in the process.

This message is a reply to:
 Message 50 by cavediver, posted 06-18-2006 4:11 AM cavediver has not replied

  
cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 53 of 246 (322807)
06-18-2006 4:21 AM
Reply to: Message 36 by randman
06-17-2006 10:49 PM


Re: Yes it's possible
You being so knowledgeable of GR ought to appreciate that if entanglement can work over vast spans of space instantly, that working over segments of time is not at all surprising.
It is so easy for a layman to throw out some words like this and completely miss the fact that they have no clue about what they are talking. And as my science is QUANTUM gravity, it is not just about GR that I am so (I wish it were so) knowledgable.
Yes, similar ideas have been discussed, researched, and developed into whole bodies of work long ago, of which I played but a small part. None of it supports ANY of your fanciful claims.

This message is a reply to:
 Message 36 by randman, posted 06-17-2006 10:49 PM randman has replied

Replies to this message:
 Message 54 by randman, posted 06-18-2006 4:26 AM cavediver has replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 54 of 246 (322808)
06-18-2006 4:26 AM
Reply to: Message 53 by cavediver
06-18-2006 4:21 AM


Re: Yes it's possible
Yes, similar ideas have been discussed, researched, and developed into whole bodies of work long ago, of which I played but a small part. None of it supports ANY of your fanciful claims.
Uh huh. So we are getting around to the stage where you start admitting to details, but then assert somehow they don't support my claims, which in this case are merely the claims of science based on hard experiments.
How soon before you just clock off without ever offering one paper, or even a quote "from a dubious web-site" or some explanation in your own words?

This message is a reply to:
 Message 53 by cavediver, posted 06-18-2006 4:21 AM cavediver has replied

Replies to this message:
 Message 55 by cavediver, posted 06-18-2006 4:48 AM randman has replied

  
cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 55 of 246 (322810)
06-18-2006 4:48 AM
Reply to: Message 54 by randman
06-18-2006 4:26 AM


Re: Yes it's possible
How soon before you just clock off without ever offering one paper
A paper on what? "Why Randman's ideas of present affecting the past are wrong?" Papers are generally not written to debunk stupid ideas. Similarly, I do not waste my time going through the whole mathematics of entanglement just to prove to you that it contains no element of your claims. It's not my job. Readers of this site can either accept my credentials and believe me, or think I'm just making it all up for some bizarre reason. It's their perogative.
On the other hand, if someone starts a thread on, say - can someone explain the mathematics of entanglement? - well, I'll show up and start talking... I'm just a sucker for that.
my claims, which in this case are merely the claims of science based on hard experiments.
No, they are not. They are your misguided interpretations of some experiments, not helped by the sources you go to for your information.
or some explanation in your own words
Explanation of what? Of why science doesn't back your claims? It is your job to prove why science does back your claims, and my job to cry bullshit at appropriate moments.

This message is a reply to:
 Message 54 by randman, posted 06-18-2006 4:26 AM randman has replied

Replies to this message:
 Message 57 by randman, posted 06-18-2006 4:53 AM cavediver has replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 56 of 246 (322811)
06-18-2006 4:50 AM
Reply to: Message 45 by Iblis
06-18-2006 2:24 AM


Re: more on delayed-choice experiments
No, you still aren't getting it at all; and yes the reduction of the math to English is partly to blame.
The experiments are not conducted in math but with real apparatus.
The delayed-choice experiments and others involving variations of the 2-slit apparatus are not dependent on understanding math to understand the results of the experiments. The observed data is either an interference pattern or not, or something else observed that is a physical reality. So talking about what occurs in English as oppossed to math is perfectly reasonable and acceptable to discuss how the apparatus is set up and what results are yielded. To suggest otherwise, as you and cavediver have, is quite absurd, as is the idea that quoting a web-site to describe the experiments is somehow wrong.
It's not so complicated. The photons are somehow affected before the event that affects them occurs. Here is one person's description of this.
But then Chiao and his colleagues ran the same experiment with polarising filters in front of each of the two slits. Any photon going one way would become "labelled" with left-handed circular polarization, while any photon going through the other slit is labelled with right-handed circular polarization. In this version of the experiment, it is possible in principle to tell which slit any particular photon arriving at the second screen went through. Sure enough, the interference pattern vanishes -- even though nobody ever actually looks to see which photon went through which slit.
Now comes the new trick -- the eraser. A third polarising filter is placed between the two slits and the second screen, to scramble up (or erase) the information about which photon went through which hole. Now, once again, it is impossible to tell which path any particular photon arriving at the second screen took through the experiment. And, sure enough, the interference pattern reappears!
The strange thing is that interference depends on "single photons" going through both slits "at once", but undetected. So how does a single photon arriving at the first screen know how it ought to behave in order to match the presence or absence of the erasing filter on the other side of the slits?
Quantum mysteries
You are welcome to describe the process in English as well and show what you think is occurring.

This message is a reply to:
 Message 45 by Iblis, posted 06-18-2006 2:24 AM Iblis has not replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 57 of 246 (322812)
06-18-2006 4:53 AM
Reply to: Message 55 by cavediver
06-18-2006 4:48 AM


Re: Yes it's possible
Why don't you consider that bare assertions don't cut it, and that here you are suppossed to substantiate your claims, not present a resume as an argument, or is that too complicated a concept...?
You might start off describing what does occur, in English with these experiments, and how you think the descriptions of the vast majority of people I have read, including the experimenters themselves, are somehow totally wrong.
Edited by randman, : No reason given.

This message is a reply to:
 Message 55 by cavediver, posted 06-18-2006 4:48 AM cavediver has replied

Replies to this message:
 Message 58 by cavediver, posted 06-18-2006 5:16 AM randman has replied
 Message 59 by cavediver, posted 06-18-2006 5:22 AM randman has replied

  
cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 58 of 246 (322814)
06-18-2006 5:16 AM
Reply to: Message 57 by randman
06-18-2006 4:53 AM


Re: Yes it's possible
You might start off describing what does occur, in English with these experiments
The use of English in all of the descriptions is where it all goes wrong and is why you have these misguided ideas. English tends to force a classical interpretation on purely quantum phenomena. This is (fairly)advanced quantum mechanics. Basic quantum mechanics is a nightmare to describe in English without introducing incorrect concepts. This is the same, just much worse.
Let's just look at Gribben's quote above
quote:
The strange thing is that interference depends on "single photons" going through both slits "at once",
Notice the quotes? They are there because these quoted concepts are bogus and partly the source of the confusion.
There is a wave-function that evolves deterministically, based upon the constraints set up by the apparatus. Simple as that. There is no individual particle that can "know" something. There is an extended wavefunction... that is all. As soon as you try to interpret this classically, it all goes horribly wrong... as we see in this thread.

This message is a reply to:
 Message 57 by randman, posted 06-18-2006 4:53 AM randman has replied

Replies to this message:
 Message 60 by randman, posted 06-18-2006 5:25 AM cavediver has replied

  
cavediver
Member (Idle past 3643 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 59 of 246 (322815)
06-18-2006 5:22 AM
Reply to: Message 57 by randman
06-18-2006 4:53 AM


Re: Yes it's possible
Why don't you consider that bare assertions don't cut it, and that here you are suppossed to substantiate your claims, not present a resume as an argument, or is that too complicated a concept...?
BTW, if you hadn't noticed, this thread is all about YOUR assertions, which you are trying to back up with bogus and/or irrelevant references. I, and others, are just pointing out that your references do not support your claims.
Can you cite specifically those references that state emphatically that the present does affect the past. "seems to affect" does not cut it.

This message is a reply to:
 Message 57 by randman, posted 06-18-2006 4:53 AM randman has replied

Replies to this message:
 Message 62 by randman, posted 06-18-2006 5:38 AM cavediver has replied

  
randman 
Suspended Member (Idle past 4899 days)
Posts: 6367
Joined: 05-26-2005


Message 60 of 246 (322816)
06-18-2006 5:25 AM
Reply to: Message 58 by cavediver
06-18-2006 5:16 AM


Re: Yes it's possible
Actually, I think the problem is that, in fact, you guys are inserting the classical paradigm into a straightforward observation. There is a real process that goes on here, with real apparatus, and as such the process can be described in English. Imo, you are not engaging that in this thread.
There is a wave-function that evolves deterministically, based upon the constraints set up by the apparatus. Simple as that. There is no individual particle that can "know" something.
Agreed....to a certain extent. I and I believe most people recognize that the phrase the photon "knowing" is a mere description of a physical process, but what are they describing?
They are describing the fact the photon appears to react to an event that has not yet occurred, that the wave function "evolves" according to the apparatus in a manner that appears as if the wave function would "know" in advance what is going to happen.
Now, of course, the photon doesn't "know", but the most straightforward observation is that the wave function reacts holistically to an event such that it is affected, from our vantage point, prior to the event itsef.

This message is a reply to:
 Message 58 by cavediver, posted 06-18-2006 5:16 AM cavediver has replied

Replies to this message:
 Message 61 by cavediver, posted 06-18-2006 5:37 AM randman has replied
 Message 73 by RickJB, posted 06-18-2006 7:19 AM randman has not replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024