
Quantum mechanics flummoxes physicists again - jawngee
http://www.nature.com/news/2010/100722/full/news.2010.371.html
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goodside
Only trash like Nature are sensationalist enough to squeeze the word "flummox"
into the title of this article. The TLDR is that the experimenters tried and
failed to demonstrate a gaping flaw in quantum mechanics, which is widely
accepted by pretty much everyone. No flummoxing occurred, except in the minds
of Nature's editorial staff. These results were expected, agree nicely with
theory, and should be nothing but reassuring with regards to our understanding
of QM.

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StavrosK
Or: Theory predicts experimental results perfectly.

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DaniFong
Something few with love for physics left in their hearts could fail to marvel
at, once more.

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jacquesm
Einstein had a neat thought experiment where a person was enclosed in an
elevator. From inside the elevator it was impossible to tell acceleration from
gravity.

There might be something similar going on here, it could be that it is
impossible to deduce the true nature of the wave/particle duality from inside
the system, in other words we may find many explanations but we won't be able
to rule out the ones that aren't the true explanation from the ones that just
seem to explain the measurements.

Interesting stuff this, I wonder what the consequences will be (besides bigger
explosions) if we ever manage to completely master this and find a way to
unify gravity and the other fields.

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Geee
What I'd like to know about the two-slit experiment is how much apart those
slits are from each other, and where is the photon actually targeted at? Do
they aim at the middle or what?

Edit: After thinking a little bit, they just shoot them at random directions
so it's like sending photons in serial instead of parallel, but in serial mode
the photons shouldn't interfere.

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mikeknoop
The act of observing the electrons which causes them to revert back to
particles is the most intriguing thing to me. Remember though that "observe"
is tough at the electron level. You really can't observe without interfering.
I think for a greater understanding of whats in play, this "observational
interference" is what more research should be focussed on.

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gojomo
Am I reading this right -- adding a third slit eliminates the interference of
the two-slit case, making the distribution particle-like again?

I'd not heard that before. What happens with four slits?

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tbrownaw
I think it's saying that the 3-slit case acts like 3 2-slit cases clasically
superimposed on eachother. Each individual photon only goes through 2 of the
slits and generates that 2-slit interference pattern, rather than going
through all 3 slits and generating a very different interference pattern.

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gigafemtonano
While perhaps not 100% accurate, I found this resource invaluable in
understanding quantum mechanics and the two slit experiment:
<http://www.higgo.com/quantum/laymans.htm>

