If probability wave is true wouldn't there be flickering?

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The discussion centers on the double slit experiment and the nature of photons, questioning whether a laser beam should exhibit flickering if photons are truly probabilistic. It is noted that at high intensities, fluctuations in photon arrival are not visible, but at lower intensities, individual photon impacts can create a flickering effect. The conversation also explores alternative theories about photon behavior, suggesting they might be particles influenced by an unseen wave, akin to "surfers" on a wave. Additionally, the mechanics of photon emission and directionality are clarified, emphasizing that photons are emitted from a known position but travel in unpredictable directions. The overall conclusion is that the observed patterns depend on the intensity of the light source and the nature of the detection method used.
  • #31
deansatch said:
but is it not about finding out what is going on in those unknown places?

That leads down a rabbit hole that no-one has ever escaped. Everyone that has tried has failed. Its a standing joke in physics a professor asked about so so who was an outstanding student with a lot of potential. The reply was he wanted to find out what QM really means. They all knew he was lost.

Sometimes you get these threads where people will quote Feynman or some other famous scientist that says no one understands QM. That's rubbish - plenty do. What's meant is no one understands it on the terms you wrote above. If you try you will get nowhere. Let go and slowly things will be clearer.

Watching Feynman's first lecture in the following may help:
http://www.vega.org.uk/video/subseries/8

Thanks
Bill
 
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  • #32
is that not like saying "just accept that things just are the way they are and don't question it"?
 
  • #33
deansatch said:
is that not like saying "just accept that things just are the way they are and don't question it"?

No - its a bit different.

What its saying is QM is a theory about observations. Attempts to extend it beyond that have succeed - but not in a unique way. Trouble is no-one has ever figured out how to experimentally prove any of them correct. And many many smart, and I mean smart, people have tried. Until someone does then its pretty meaningless to worry about it - so don't.

Another way of looking at it is this. Every theory, every single one, is based on primitives the theory accepts as fundamental. Future progress may explain those primitives in terms of other things - but you will have to accept them as well. Ultimate explanation is impossible. QM has observations as its primitive - if you don't like that and want other primitives exactly what have you gained? Its simply a reflection on how you want the world to behave - trouble is - nature doesn't particularly care about that.

Thanks
Bill
 
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  • #34
EDIT: That was in my head in a much more clear manner...reading it back sounds like gibberish
That will happen every time you to try to describe photons in natural language :smile:... Seriously, kidding aside, natural language describes things in classical terms, and photons aren't classical. You can try to think about the position of a photon if you want, and you can try to think about the position changing and call that the photon moving if you want... but neither concept is present in the math. The closest you can come is to say that there is a certain probability that a photon detector such as the screen will trigger if it is in a given place at a given time.

deansatch said:
so is it right to say that a photon doesn't actually exist and what we are measuring and calling a photon is merely the affect/result of an action. So a dot appearing and being recorded when 'firing a photon' is not where a photon has hit as it doesn't actually exist? The dot is just what happens to that particular material because of the reactions taking place at the source of the photon creation - everything in between is nothing?

I would much rather say that the dot appeared and was a recorded because a photon did exist at the exact place and time that the dot appeared - but just there. The dot appeared - that's real. The dot appeared because a small amount of energy was transferred from the electromagnetic radiation impinging on the screen to the photosensitive material on the screen - that's real. We call that quantized amount of energy a photon, so we're justified in saying that the photon really exists when it hits the screen.

Does it really exist before it hits the screen? Our experience with small classical objects like bullets, grains of sand, infinitesimal motes of dust, leads us to say "yes", or even "yes, of course". But that's an assumption not supported by any experimental evidence, and it's an assumption that is almost guaranteed to get us into trouble if applied to photons.
 
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  • #35
Nugatory said:
That will happen every time you to try to describe photons in natural language :smile:... Seriously, kidding aside, natural language describes things in classical terms, and photons aren't classical. You can try to think about the position of a photon if you want, and you can try to think about the position changing and call that the photon moving if you want... but neither concept is present in the math. The closest you can come is to say that there is a certain probability that a photon detector such as the screen will trigger if it is in a given place at a given time.

That's it. Let go of your classical intuition and your confusion will dissipate.

Thanks
Bill
 
  • #36
deansatch said:
is that not like saying "just accept that things just are the way they are and don't question it"?

bhobba said:
No - its a bit different...

I agree with Bhobba's response above. However, I also feel obligated to mention that David Mermin, one of the pioneers in the field, once summarized quantum mechanics by placing his tongue firmly in his cheek and saying "Shut up and calculate"... So deansatch, it's one thing to know how QM works, but another thing altogether to like it :smile:
 
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  • #37
Nugatory said:
However, I also feel obligated to mention that David Mermin, one of the pioneers in the field, once summarized quantum mechanics by placing his tongue firmly in his cheek and saying "Shut up and calculate"... So deansatch, it's one thing to know how QM works, but another thing altogether to like it :smile:

People say it was Feynman that said that - but really it was Mermin - although it's the type of thing Feynman would have said.

I don't think anyone likes the situation in QM, they just accept it. Even Einstein, whose real attitude to QM is often misrepresented, agreed it was correct - but incomplete. Its perfectly valid to hold Einstein's view and simply accept it until something better comes along. But until it does don't be consumed by the issue - you will get nowhere.

Thanks
Bill
 
  • #38
deansatch said:
I'm still trying to get my head round the movement (and existence) of photons. ie. Why do they move...if nothing propels them...why are they moving? Are they attracted towards something? I can't just accept that they move constantly for no reason.
You can try to ask this question in relativity subforum. It might be easier to take moving at the speed of light as basic idea and rather ask question why things are staying in place (moving inertially). Possible answer is that you can view massive particles as moving at the speed of light but not getting anywhere (not moving straight in the same direction).
deansatch said:
And how are they created? If a photon is created what is it created from?
Photon is viewed as excitation of electromagnetic field so in a sense you can say it's made from electromagnetic field.
 
  • #39
Maybe if you think of it as a symmetry? It's called lights duality, meaning that it has both wave and particle aspects. If you think of it as a field, then it should be about probabilities to my eyes. And those probabilities are actually probabilities, for me that is. The idea of a 'field' do not tell you that it has to be waves, neither does it tell you that it has to be particles. People likes waves, and it's a concept that seems to work, but I like probabilities myself, and a duality.
 
  • #40
Bill,

Even though I had trouble with QM in college, I enjoyed reading the paper you linked. . Your exposition helped me follow the application of the conceptual framework along with the notation.

Thank you!

Ralph Dratman
 

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