Richard Feynman and quantum mechanics ..

The non amateur stuff. Hawking, black holes, that sort of thing

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brian livesey
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Richard Feynman and quantum mechanics ..

Post by brian livesey »

Some years ago, I recall Feynman in a TV interview saying that it's a puzzle that we can see anything with our eyes other than a sort of "white out".
Feynman said that, according to quantum theory, the light our eyes receive comes in from all directions and should, therefore, interfere with itself, so that we don't see any coherent images at all. This is obviously not the case and Feynman was puzzled to know why we are able to see discreet images in the chaos of light rays.
Does anyone have any thoughts on this? It might be that since the Feynman interview, a solution has been offered.
Last edited by brian livesey on Thu Oct 04, 2012 2:59 pm, edited 5 times in total.
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David Frydman
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Re: Richard Fyndman and quantum mechanics ..

Post by David Frydman »

Is it because our eyes are lenses that make sense of the light rays and we have an iris to control it also?

I obviously don't know as I have little knowlege of quantam theory.

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stella
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Re: Richard Fyndman and quantum mechanics ..

Post by stella »

It's 'Richard Phillips Feynman.'
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Re: Richard Fyndman and quantum mechanics ..

Post by joe »

Feynman.

I'm guessing that he was discussing this in the interview because he was the person who found an answer to his own puzzle. His book, "QED - The Strange Theory of Light and Matter", goes some way to explain what happens. As it concerns quantum mechanics, you won't be surprised that probability plays a large part.
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brian livesey
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Re: Richard Feynman and quantum mechanics ..

Post by brian livesey »

Thanks for the spelling correction Stella. Can you elaborate a little, Joe, on Feynman's explanation for the phenomenon?
I'm not sure if the TV interview was before or after the publication of his book.
Last edited by brian livesey on Thu Oct 04, 2012 9:21 am, edited 1 time in total.
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Re: Richard Fynman and quantum mechanics ..

Post by joe »

I don't think I can, Brian. It's quite a complicated subject as I'm sure you are aware and although Feynman explains it very clearly, he does so starting from basics and building on them - it would be difficult to put it into a few sentences.

He points out that it's commonly accepted that when light is reflected from a mirror, the angle of incidence is always the same as the angle of reflection. This is not true however. When photons strike a mirror they reflect at every angle possible. He then goes on to explain about the probability of the eye receiving light from the shortest path(s) which are, coincidentally, those where the angles of incidence and reflection are similar.

Anyway, it may not be a direct explanation of the phenomenon you are talking about but it goes a long way to explain how light behaves. I recommend the book.
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brian livesey
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Re: Richard Fynman and quantum mechanics ..

Post by brian livesey »

Thanks for that.
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Re: Richard Fynman and quantum mechanics ..

Post by Mogget »

We must also not forget that the images that we see are a result of "post processing" in the brain.
brian livesey
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Re: Richard Feynman and quantum mechanics ..

Post by brian livesey »

Feynman was referring to a phenomenon that's independent of eye/brain processes. This implies that there's nothing the brain can do to alter the situation and, yet, we see coherent images.
You might be thinking that what the brain does to sort out the chaos of multi-directional light rays that confront the visual system is analogous to adaptive optics; Feynman didn't indicate that he had this in mind. To him the puzzle was external.
At last Stella, after numerous editings, I got the spelling right! I'm convinced that this increasing lack of concentration is due to creeping dementia.
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