4 ms·

Quantum mechanics flummoxes physicists again

16 points by jawngee 16y ago

gigafemtonano 16y ago
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 http://www.higgo.com/quantum/laymans.htm
StavrosK 16y ago
Or: Theory predicts experimental results perfectly.
- Groxx 16y ago
  And: Using quantum mechanics to flummox physicists who don't fully grasp quantum mechanics.
- DaniFong 16y ago
  Something few with love for physics left in their hearts could fail to marvel at, once more.
gojomo 16y ago
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?
- tbrownaw 16y ago
  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.
jacquesm 16y ago
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.
goodside 16y ago
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.
mikeknoop 16y ago
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.
deleted 16y ago
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Geee 16y ago
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.
- deleted 16y ago
  [deleted]

16 points by jawngee 16y ago

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 http://www.higgo.com/quantum/laymans.htm

StavrosK 16y ago

Or: Theory predicts experimental results perfectly.

Groxx 16y ago
And: Using quantum mechanics to flummox physicists who don't fully grasp quantum mechanics.
DaniFong 16y ago
Something few with love for physics left in their hearts could fail to marvel at, once more.

gojomo 16y ago

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?

tbrownaw 16y ago
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.

jacquesm 16y ago

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.

goodside 16y ago

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.

mikeknoop 16y ago

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.

deleted 16y ago

[deleted]

Geee 16y ago

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.

deleted 16y ago
[deleted]