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Bose–Einstein Condensate

en.wikipedia.org

11–20 of 22 posts

Re: Bose–Einstein Condensate

#12

BECs are interesting. Currently working on getting a project funded, lots of interesting answers may come from it. Anyone working with BECs?

Can you provide some details? I'm in Boulder Colorado where Cornell Wieman created the first condensate and won a nifty prize for it.

Greetings from the Denver tech center! Condensed matter is awesome. I wish I was more than a fan/self study neophyte. Good luck to you!

Re: Bose–Einstein Condensate

#13

BECs are interesting. Currently working on getting a project funded, lots of interesting answers may come from it. Anyone working with BECs?

My PhD work was in experiential BEC studies. What are you interested in?

gravitational wave detection

Re: Bose–Einstein Condensate

#14
post #3

At the beginning of the article, it mentions the phrase "the 5th state of matter", which I've heard before; personally, I find it quite misleading. Even if you exclude all of the intermediary states and all of the non-classical states (things like glasses and liquid crystals), there are a lot of exotic states of matter. The Wikipedia page for "States of matter" includes a lot of them[0]. Though perhaps the idea is th…

>On an unrelated note, its interesting to see the Riemann zeta function turn up here. Does anyone know why it cropped up here, in the critical temperature equation? The page on Bose-Einstein statistics[1] doesn't seem to include it at all. A complete derivation is beyond me at the moment but if you look at the equation in the section on the non-interacting Bose Einstein's gas [2] you'll note that they provide an equa…

Qua? I believe the zeta function goes back to 1859, and arose in number theory... https://en.m.wikipedia.org/wiki/On_the_Number_of_Primes_Less...

Re: Bose–Einstein Condensate

#15
post #3

At the beginning of the article, it mentions the phrase "the 5th state of matter", which I've heard before; personally, I find it quite misleading. Even if you exclude all of the intermediary states and all of the non-classical states (things like glasses and liquid crystals), there are a lot of exotic states of matter. The Wikipedia page for "States of matter" includes a lot of them[0]. Though perhaps the idea is th…

> interesting to see the Riemann zeta function turn up here. Does anyone know why it cropped up here, in the critical temperature equation?

I don’t know if this is satisfactory, but here’s a technical answer: A lot of field theory calculations (when including 1-loop quantum effects) involve summing over all the modes/states in the field. In thermal equilibrium we can think of the time axis as a circle, and the wave frequencies get quantized into integers (upto a multiple of the temperature) aka Matsubara frequencies. So now, the calculation involves summing over all natural numbers (raised to some power), which is basically the zeta function. A more careful explanation can even justify the 3/2 (from the fact that we have 3 spatial dimensions, and a boson has action scaling as momentum squared) but it’s been a while since I’ve thought about this.

Re: Bose–Einstein Condensate

#16
What I really look forward with BECs (although simple atomic interferometers based on ultracold atoms would do, too) is super-sensitive magnetic field detection.

One can detect magnetic fields from a shielded laptop, even many meters away, and figure out what's happening inside (e.g. leaking secrets etc).

I think, not a terribly difficult experiment, but nobody has performed it: need ultracool physicists and hackers in one lab room

Re: Bose–Einstein Condensate

#17
Roger Penrose, in Shadows of the Mind, reckoned Bose-Einstein condensates in the microtubules of neurons might be the engine of consciousness.

Apart from the weird quantum stuff, another interesting part of that perspective is that neurons are made up of countless microtubules and it might be the microtubules that are the basic computation unit of the brain. So then you can think of each neuron as a processor in its own right, and the computational complexity of the brain might be an order of magnitude higher than commonly supposed.

Re: Bose–Einstein Condensate

#20

Earlier quoted context omitted.

>On an unrelated note, its interesting to see the Riemann zeta function turn up here. Does anyone know why it cropped up here, in the critical temperature equation? The page on Bose-Einstein statistics[1] doesn't seem to include it at all. A complete derivation is beyond me at the moment but if you look at the equation in the section on the non-interacting Bose Einstein's gas [2] you'll note that they provide an equa…

Qua? I believe the zeta function goes back to 1859, and arose in number theory... https://en.m.wikipedia.org/wiki/On_the_Number_of_Primes_Less...

I meant that it's the reason the Zeta function appears in the formula, not that it is the original reason for the Zeta function to exist.
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