

Photons cooled down to room temperature, made into a blob of matter - juiceandjuice
http://www.msnbc.msn.com/id/40358307/ns/technology_and_science-science/

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1053r
A slightly more informative article, which references the paper published in
nature (unfortunately, I couldn't find a copy of that that wasn't behind a
paywall).

[http://www.nature.com/news/2010/101124/full/news.2010.630.ht...](http://www.nature.com/news/2010/101124/full/news.2010.630.html)

Note that the photons weren't made into matter. They were made into a Bose-
Einstein Condensate, which is where all of the component particles share
quantum properties and interact with the rest of the universe in "lockstep".

[http://en.wikipedia.org/wiki/Bose%E2%80%93Einstein_condensat...](http://en.wikipedia.org/wiki/Bose%E2%80%93Einstein_condensate)

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juiceandjuice
To be a little more clear though (from the Nature article): "Bose-Einstein
condensates (BECs) are a bizarre quantum phase of matter. "

I can email people the copy if they want, I won't post it though.

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Shamiq
Is it readable by those of us who fall under the "layman" category?

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iwr
What does "temperature" mean with regard to photons? A photon has an energy
level given by its wavelength or frequency. But temperature is a macroscopic
phenomenon (equivalent to the kinetic energy of a group of particles).

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iwr
So reading more about this: <http://en.wikipedia.org/wiki/Photon_gas> , it
looks like a scenario where a blackbody container was created, with a
Boltzmann "temperature" peak equal to the energy level of the incident
photons. Thus, all absorbed photons would be re-emitted at with the same
distribution as the blackbody walls. And apparently, this phenomenon was
tested in an ultra-low temperature scenario.

Still, I wonder. Given the low temperatures, the Boltzmann distribution
suggests photons in the microwave or lower frequencies.

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Qz
Actually the article says the photons were in a room-temperature scenario.

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powrtoch
"The physics behind the Bose-Einstein condensation is the transition from a
particle-like behavior at high temperatures to a wave-like behavior at cold
temperatures"

I'm no physicist, but isn't this backwards?

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aerique
I'm probably a very shallow individual for asking but are there pictures of
this?

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danparsonson
Noobie question: how do they know that this actually happened? I would have
thought that having some sort of detector inside the tiny mirror box would
disturb the experiment? How do you measure something like this?

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danparsonson
Should've read the other article linked on here
([http://www.nature.com/news/2010/101124/full/news.2010.630.ht...](http://www.nature.com/news/2010/101124/full/news.2010.630.html)):

 _The team could tell when the transition had occurred because the small
number of photons in the BEC formed an intense beam of yellow light — like a
laser — in the centre of the cavity, surrounded by the 'gas' of remaining
normal photons. To double-check that they were seeing a BEC of light, the
researchers repeated the experiment with different numbers of photons. In each
case, once the transition had taken place, they measured the spectrum of light
leaking from the cavity and found that it matched theoretical predictions for
the corresponding BEC._

(BEC == Bose-Einstein Condensate)

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djcapelis
Should it be called matter if it's mass-less? Or is the article wrong and did
this have a mass?

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gowiththeflow
Not a physics major, but my guess is E=mc^2 still applies.

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jules
A physics major, this is correct, in the sense that if the photons in the
"matter of photons" have total energy E, then it acts like an object of mass m
(under the condition that the total momentum is zero, which I presume is
approximately true because the photons are moving in random directions?).
However, photons do not have rest mass. The formula for photons is E = pc,
where p is the momentum of the photon. The full form is E^2 = (mc^2)^2 +
(pc)^2, where m is the rest mass and p is the momentum. Taking p = 0 for an
object at rest gives E = mc^2, taking m = 0 for a photon gives E = pc.

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epynonymous
tele-transportation is just years away!

