Confusion Abounds In Discussing QM

[bhobba]

Hi All

Have a look at the following discussion about QM:


Its long so I do not expect too many people to watch it in its entirety. But it does show confusion about QM even amongst educated people, and the physicist involved IMHO seemed a bit 'confused' himself. You can easily see how the general educated public can form some 'strange' ideas when they try to integrate it into their world view. I gave a long reply with my views, but there is only so much I can get across.

It makes me think that before anyone discusses QM they should at least read Susskind's excellent book, otherwise debating it, even with a physicist present, can quickly become not that enlightening, and even leading to rather 'silly' conclusions.

Thanks
Bill

 

[MichPod]

It makes me think that before anyone discusses QM they should at least read Susskind's excellent book,

Hi bhobba,

You mean vol.2 of his "Theoretical Minimum" amateur series, or anything else?

BTW, I cannot see any long reply (of yours) under that video.

 

[bhobba]

Yes - vol 2 - of course he did videoes as well. It's just an example how even obviously intelligent people can get confused without at least a smattering of the technical detail.

When I click on it it says you have to go to youtube. Click on the message, go to youtube, and my thoughts is the first comment.

Thanks
Bill

 

[MichPod]

It's just an example how even obviously intelligent people can get confused without at least a smattering of the technical detail.

I did not watch the video yet, but speaking generally I really don't know what can be done about it. QM is not simple, and for my humble opinion and experience even physicists teaching QM can easily have and spread misconceptions about it. I really do not understand how one can safely chat about QM without working hard and investing at least 10 hours (better 50-100) before that into its studying, but obviously people are interested in such topics whatever their preparation level may be.

When I click on it it says you have to go to youtube. Click on the message, go to youtube, and my thoughts is the first comment.

Looks bad for me. Please share your comments here (better do it ASAP). Your comment are not visible there for me. Youtube is notorious for hiding comments from whoever its AI considers as spammers in the way that people still see the comments they posted but nobody else can see them. I am afraid that may be the case, so nobody except for you can see your comment.

 

[bhobba]

I wrote:

My background is I am trained as a mathematician and have read many books on QM, my favorite being Ballentine - QM - A Modern Development. An issue is beginner discussions often talk about the so called wave-particle duality, but that is an old idea done away with by Dirac with his Transformation Theory in December 1926, but published in early 1927. For the history see:
https://arxiv.org/pdf/1006.4610.pdf.
For a much better explanation of the double slit that avoids the wave-particle thing see:
https://arxiv.org/ftp/quant-ph/papers/0703/0703126.pdf.

Then what is the actual basis of QM? See:
https://www.scottaaronson.com/democritus/lec9.html.
What is an observation? These days it's simply considered an interaction between what is being measured, and what is doing a measurement. This creates something called a mixed state where outcomes like a definite position, or whatever, happens with a certain probability by a process called decoherence. It's also the answer to Scrodingers cat. The cat and the atomic nucleus are entangled so are one system. When you chug through the math it turns out the cat is a mixed state - it's alive or dead - not in some kind of superposition. No consciousness required - that's an old idea very much out of fashion with a history I will not go into. That is also the answer to the delayed choice experiment. Most of the time decoherence cannot be undone. But in simple cases it can - so all that's going on is after the observation we undo it. The only 'weird' thing is why can we only predict probabilities? Who knows - maybe nature is just like that. After all every theory has assumptions, and as the paper on what QM actually is says, QM is simply an extension of probability theory. Also regarding Bell please remember once two particles are entangled you have one single system - not two separate particles. The entanglement is only broken if you have some apparatus that just observes one particle and then, and only then, can you say there are two particles. To see a modern interpretation have a look at Consistent Histories:
http://quantum.phys.cmu.edu/CHS/histories.html.

To see a comparison of various interpretations with our modern understanding of decoherence at a bit more philosophical level see:
http://philsci-archive.pitt.edu/5439/1/Decoherence_Essay_arXiv_version.pdf.
What does it mean? What does any description of the world out there mean? Is that a question that can even be reasonably asked? Nature is as nature is. But what I will say is observer as used in QM simply means measurement in a general sense - nothing to do with conscious observers. Any interaction can be a measurement. For example photons from the Cosmic Microwave Background is enough to give a definite position to a dust particle by decoherence. So basically the common-sense world out there exists because it is constantly being observed by other parts of that world.
Also you might find the following interesting::
https://arxiv.org/abs/quant-ph/0609163

Thanks
Bill

 

[bhobba]

If that fails I totally wasted my time. Yes I agree with your comments - you need some technical knowledge of the subject to have a constructive discussion. If my reply is not visible to others try:
https://www.youtube.com/results?search_query=the+muliversity+project

The video is Quantum Physics and its Spooky Interpretations: Consciousness, Many Worlds and More. It works fine for me, but If that fails for you I totally wasted my time. Thanks
Bill

 

[MichPod]

If that fails I totally wasted my time. Yes I agree with your comments - you need some technical knowledge of the subject to have a constructive discussion. If my reply is not visible to others try:
https://www.youtube.com/results?search_query=the+muliversity+project

The video is Quantum Physics and its Spooky Interpretations: Consciousness, Many Worlds and More. It works fine for me, but If that fails for you I totally wasted my time.Thanks
Bill

To see what happens there, log off from Youtube site, then try to check if you still can see your comment.
And if not, somebody might want to post your comment there still, so your work is not lost.

 

[bhobba]

To see what happens there, log off from Youtube site, then try to check if you still can see your comment.
And if not, somebody might want to post your comment there still, so your work is not lost.

You hit it - it's not there if I log out. As far as I am concerned that multiverse mob are not worth my time. It's a pity - all I was trying to do is correct misconceptions, but it seems someone actually, for some reason, does not like that. Sad really.

Thanks
Bill

 

[MichPod]

Well, at least it may be helpful here. I, BTW, am not hurry to accept your explanations (of course, not that I share the idea of conscious observer to any extent), but I am much less qualified than you to have a discussion about these subtle topics (unfortunately, also no much time to develop my qualification furhter). Anyway, thanks for the links, looks interesting and I will look through them.

 

[MichPod]

It's a pity - all I was trying to do is correct misconceptions, but it seems someone actually, for some reason, does not like that. Sad really.

Nope. It's just bad algorithms of Youtube AI. It's 99% that you were not banned by the host.

 

[EPR]

Well, i'd say it's either this(no reality except that which is observed), or the MWI.

Quantum fields can become classical reality in both ways(as you say via decoherence and world splitting). Or so they say. I am still struggling with this viewpoint.

 

[bhobba]

Well, at least it may be helpful here. I, BTW, am not hurry to accept your explanations

That doesn't matter really - the point is to start to break down the more obvious misconceptions. Professional physicists don't agree on many issues.

Thanks
Bill

 

[bhobba]

Quantum fields can become classical reality.

In some ways looking on QM as a limiting case of QFT is a better way.

Thanks
Bill

 

[bhobba]

Nope. It's just bad algorithms of Youtube AI. It's 99% that you were not banned by the host.

Well they gave a email so I sent them a note. We will see.

Thanks
Bill