Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Alan McDougall on 31/05/2016 05:42:45

Title: Can Schrodinger cat also exist in two places(boxes) at the same time?
Post by: Alan McDougall on 31/05/2016 05:42:45

Can Schrodinger's cat also exist in two places(boxes) at the same time?

Scientists have come to the conclusion that not only can Schrodinger cat be both died or alive in the box, but can exist in more that one box in an another box due to quantum uncertainty?

http://www.livescience.com/54890-schrodinger-cat-can-be-in-two-places.html?cmpid=NL_LS_weekly_2016-5-30


Alan
Title: Re: Can Schrodinger cat also exist in two places(boxes) at the same time?
Post by: hamdani yusuf on 31/05/2016 14:28:44
why do you put the limit at only two?
Title: Re: Can Schrodinger cat also exist in two places(boxes) at the same time?
Post by: Alan McDougall on 31/05/2016 15:06:55
why do you put the limit at only two?

You are correct, but the article only mentioned two places!
Title: Re: Can Schrodinger cat also exist in two places(boxes) at the same time?
Post by: hamdani yusuf on 31/05/2016 17:15:56
When a scientific study is presented to the laymen, some aspects need to be simplified to make them understandable. But this rises the risk of them to be misleading, as shown in this video.

Title: Re: Can Schrodinger cat also exist in two places(boxes) at the same time?
Post by: PmbPhy on 31/05/2016 23:06:17
Quote from: Alan McDougall
Can Schrodinger's cat also exist in two places(boxes) at the same time?
No. Absolutely not.

Quote from: Alan McDougall
Scientists have come to the conclusion that not only can Schrodinger cat be both died or alive in the box, but can exist in more that one box in an another box due to quantum uncertainty?
I know that's what some physicists believe but they're dead wrong. In fact quantum mechanics (QM) cannot be used to make such a prediction, i.e. QM does not say any such thing. It's a serious misconception. Not only have I come to this conclusion (which is an easy conclusion to come to) but I conferred with several of my colleagues about this (all of whose names you'd know if I listed them out) who also conclude the same thing.

The misconception is based on a misinterpretation of the meaning of the probability density. (more after I do my laundry)wave

http://www.livescience.com/54890-schrodinger-cat-can-be-in-two-places.html?cmpid=NL_LS_weekly_2016-5-30


Alan
[/quote]
Title: Re: Can Schrodinger cat also exist in two places(boxes) at the same time?
Post by: agyejy on 01/06/2016 00:32:09
No. Absolutely not.

You really should be careful about making absolute statements like that when talking about science. At best scientific theories provide us with models of reality but how exactly those models correspond to reality is largely unprovable. That is the entire reason Occam's Razor exists. Given multiple models or reality that all give identical predictions there is really no way to objectively prove which one is correct. Thus science has chosen to default to whatever model makes the smallest number of/least objectionable assumptions because generally that model has the highest chance of being correct.

In this particular case we have several models (also known as interpretations) of Quantum Mechanics that so far all make the same predictions. There are ongoing efforts to design experiments for which the different models give different predictions for the outcome. The various tests of the Bell inequalities is the first example of this and are used to rule out the local hidden variable interpretations of Quantum Mechanics. There are still far too many other interpretations to call the matter settled and the Occam's Razor choice is generally thought to be the Copenhagen interpretation which again wins mainly on the basis of fewer/less objectionable assumptions. However, recent experiments have demonstrated that the wavefunction isn't completely epistemic (i.e. a purely mathematical construct) and instead has at least some ontic properties (i.e. what we might call a physical existence). So it is clear going forward that the Copenhagen interpretation must be modified if not outright replaced as it is a pure epistemic theory (i.e. it says the wavefunction is just math).

Quote
I know that's what some physicists believe but they're dead wrong. In fact quantum mechanics (QM) cannot be used to make such a prediction, i.e. QM does not say any such thing. It's a serious misconception. Not only have I come to this conclusion (which is an easy conclusion to come to) but I conferred with several of my colleagues about this (all of whose names you'd know if I listed them out) who also conclude the same thing.

The misconception is based on a misinterpretation of the meaning of the probability density. (more after I do my laundry)wave

You have no actual proof of any the assertions made here. Even if we accept you at your word that your colleagues are famous scientists and that they agree with your conclusion that is at best an improper appeal to authority. You have given no indication of their fields of expertise (if they aren't working at the cutting edge of Quantum Mechanics they cannot be considered experts in Quantum Mechanics) nor do we have any idea of how well the views of you and your colleagues represent the views of the majority of experts in Quantum Mechanics. Furthermore, as I demonstrated above the particular question you are answering doesn't actually have an absolute answer as the experts in Quantum Mechanics have yet to experimentally settle the question of the best possible model for Quantum Mechanics. However, experiments have narrowed down the possibilities by proving that Quantum Mechanics is inherently nonlocal and/or inherently unreal and that the wavefunction is at least in some sense physically real.

From a purely Copenhagen viewpoint the answer to "Can a particle physically be in two places at once?" is "No" simply because the wavefunction is thought to be entirely non-physical. Unfortunately as I've said previously experiments have proven that in some sense there is something physical about the wavefunction so the naive Copenhagen answer can't be true. In the end given the currently limited experimental evidence we have that can be used to differentiate between the various interpretations of Quantum Mechanics the best answer we can give is that there is a pretty good chance that a particle can be physically in more than one place at the same time.
Title: Re: Can Schrodinger cat also exist in two places(boxes) at the same time?
Post by: Alan McDougall on 01/06/2016 01:57:48
Quote from: Alan McDougall
Can Schrodinger's cat also exist in two places(boxes) at the same time?
No. Absolutely not.

Quote from: Alan McDougall
Scientists have come to the conclusion that not only can Schrodinger cat be both died or alive in the box, but can exist in more that one box in an another box due to quantum uncertainty?
I know that's what some physicists believe but they're dead wrong. In fact quantum mechanics (QM) cannot be used to make such a prediction, i.e. QM does not say any such thing. It's a serious misconception. Not only have I come to this conclusion (which is an easy conclusion to come to) but I conferred with several of my colleagues about this (all of whose names you'd know if I listed them out) who also conclude the same thing.

The misconception is based on a misinterpretation of the meaning of the probability density. (more after I do my laundry)wave

http://www.livescience.com/54890-schrodinger-cat-can-be-in-two-places.html?cmpid=NL_LS_weekly_2016-5-30


Alan
[/quote]

Could there be confusion between quantum non-locality and this new thought experiment where the idea of multiple cats existing in a unknown state of either dead or alive in two boxes?