Coldest Place in the Universe

Chris Gondek writes "The Sydney Morning Herald has an article on how NASA has released a high-quality image of the coldest place found in the universe. Five thousand light years from Earth in the constellation of Centaurus, the nebula, a gas cloud formed from a dying star, has a temperature of minus 272 degrees. It is only one degree warmer than absolute zero, the coldest possible temperature, when atoms cease to vibrate and radiate no heat whatsoever. This radiation is the remnant of the Big Bang, the explosion which forged the universe in trillion-degree temperatures. More than 11 billion years later, this heat has cooled to minus 270 degrees, but is still detectable."

Comments

Damn That's Cold....

[Anonymous Coward]

Almost as cold as Hillary Rosen's heart 8^)

I thought I found that last month...

[Anonymous Coward]

You mean it's *not* my ex-girlfriend's soul?

Coldest place in the Universe?

[FungiSpunk]

My bosses office at pay review time...

Grumble, grumble - absolute zero

[altairmaine]

As it turns out, absolute zero is not the "coldest possible temperature". It is impossible to attain absolute zero, as a little basic quantum mechanics tells us. Particles will ALWAYS retain some amount of energy, the "Zero Point Energy", which cannot be removed. More accurately, we can say that absolute zero is the lower bound on the range of possible temperatures - but is not included.

Re:Grumble, grumble - absolute zero

[JohnFluxx]

I just thought... one way to perhaps show that you can't reach zero is that to cool something you either need:

*) Something colder, to cool it - but you can't get colder than 0.

*) A bigger space to put the nonzero heat it - but trivally if you expand something with non-zero temperature into an finite space, then the result is still going to be above zero.

*) If it radiates/conducts/etc heat away, then it must be into an area that has a non-zero heat, so that will (instinctively) also radiate an equal or greater amount of heat back again. Hmm, thinking about it this means you can't have a one-way heat shield, or something that absorbes without emitting. (Unless a material stops radiating/conducting below a certain temperature.)

There's probably some other cases I missed - I don't know anything about this field. :) Is there any other way to cool something other than these cases?

Re:Grumble, grumble - absolute zero

[Tim C]

Energy is not quantised. The energy states of a bound particle, eg an electron orbiting a nucleus, are quantised.

The energy of a free particle is not, and can take on pretty-much any value.

Re:Grumble, grumble - absolute zero

[Anonymous Coward]

yes. the zero point energy is correct... but not to be a pest, atoms cannot vibrate as is suggested in the original post. only molecules may vibrate. the zero point energy comes into play for molecules because the energy, E, of a simple harmonic oscillator (simplest approximation) will be:

E = nu ( v + 1/2)

where v is the vibrational quantum number and nu is related to the force contant. nu is positive, and v is always a non-negative integer, so even when v is zero the energy is nu/2. freshman chemistry students are told that this is to accomodate the heisenberg uncertainty principle in that a particle that is not vibrating would have a definite position and momentum.

another poster hinted on what has been stated eloquenty for hundreds of years and restated by homer: in this house, we obey the laws of thermodynamics! the third law states:

"if the entropy of every element in its most stable state at T=0 is taken as zero, then every substance has a positive entropy which at T=0 may become zero, and which does become zero for all perfect crystalline substances, including compounts"

WTF? an alternate statement has more meaning in our context:

"it is impossible to reach T=0 in a finite number of steps".

thus, as altairmaine suggests, it is impossible to reach absolute zero. other posters suggested that it is only possible to cool things by contact with a colder substance. for those people i would suggest doing a google search on the term "adiabatic demagnetization". research into bose-einstein condensates work with clusters of atoms at fractions of a kelvin, and it is not because they have a super-secret stash of a zero-kelvin heat sink. :)

reference: "Physical Chemistry" by Peter Atkins. 5th ed.

Re:Grumble, grumble - absolute zero

[jovlinger]

ah. You have taken the "hell is endothermic" physics test (google that for a laugh: any test whose answers include "take into account the fact that I still have not succeeded in having sexual relations with her" has got to be good).

On a more serious note, look into laser evaporation. It turns out that if you have a laser and an atom, you can tune laser so that only in the presence (sp?) of positive dopler shift (ie, atom moving towards the laser source) will the atom be able to absorb a photon. If you gradually tune the laser to a smaller and smaller band, and you have such a laser pointing from every which way, you have effectively used a laser to cool the atom.

Think of it as shooting ball bearings to stop a bowling ball.

Re:Grumble, grumble - absolute zero

[Tempest]

Actually, there is another method of cooling an object, you physically slow it's atomic vibration. It's been demonstrated down to at least 0.0000001 C above absolute zero (see NASA's site) using lasers and magnetic traps. Research utilizing the technique include Bose-Einstein Condensates and Superfluids.

~~~~~Chris Giorgi~~~~~

I Apologize in Advance

[dupper]

from the star-trek-episode-ideas dept.

Most frigid place in the universe? They've already shown Janeway's quarters.

Ba-dum-ch-OW! That hurt!

Re:yahoo for the big bang _THEORY_

[SomeGuyFromCA]

> Entropy and evolution can never co-exist.

Sure they can. Entropy only applies in a closed system. The earth is continually receiving energy from the sun, hence the earth is not a closed system.

Besides, who's to say God and evolution cannot coexist? What if that's the method He used?

Re:Hrm

[meringuoid]

"This radiation is the remnant of the Big Bang, the explosion which forged the universe in trillion-degree temperatures. More than 11 billion years later, this heat has cooled to minus 270 degrees, but is still detectable."

When was the Big Bang theory proven and the guesstimation of 11 billion years determined to be fact?

When Penzias and Wilson detected the microwave background radiation. Despite Fred Hoyle's best efforts, steady state theory could never convincingly explain the properties of the microwave background, which were precisely as Big Bang theory predicted. As for the 11 billion years, notice that the article actually says 'more than 11 billion years' - 11 billion is the lower end of the scale for age estimates.

New Project

[WoTG]

... and all of a sudden, 1000 Overclockers wonder, "How do I get my Athlon to Centaurus?"

Vibration

[4lex]

The lowest level of energy ("fundamental" energy level of a quantum system), which we can equate to absolute zero, because there is no allowed state with less energy *does* have energy, including vibrational energy. Atoms *cannot* "cease" to vibrate, because by doing so they would violate Heisenberg's indetermination principle (they would have an exactly determinate position _and_ moment).

I hope someone corrects me if I am wrong :)

Re:If only...

[mauthbaux]

I can just imagine all of the overclocking freaks trying to figure out a way to use the nebula to keep their processors at a reasonable temperature.... Imagine computing life without heat-sinks or fans!
of course, all those flaming processors would end up creating enough heat to send the whole nebula boiling away, and we'd be back searching for the ultimate cooling solution once again....

Houston we have a problem here

[cvmvision]

Did I miss something in my science class?

The temperature of the microwave background radiation is 3K. This means that unless something is shielding an object (or large gas mass) it will be irradiated (heated) to this temperature. And because of the nature of blackbody radiation - the thing doing the shielding would need to be colder than 3K - else it would be a source of 'hot' radiation itself.

And then how do you take a picture of something that is only 1K? This object would emit less radiation than the 3K background - thus it would be a dark spot. It could reflect light - but not all the light is reflected (or is it due to some cool QM effect that I don't know about)? Anyway the absorbed light from other stars would most likely over years - heat the gas mass to a temperature between the 3K background and temperature of the star surface (5000K). Probably something in the neighborhood of 4K.

Conclusion - unless there is some sort of active cooling, nothing can cool down to less than temperature of the background radiation (3K). Is this an early April fools joke - or state schools worthless?

Re:Houston we have a problem here

[Xilman]

Conclusion - unless there is some sort of active cooling, nothing can cool down to less than temperature of the background radiation (3K).

Correct.

There is active cooling in this case, and it works the same as a domestic refrigorator. Both systems cool down because gases are expanded, thereby doing work. That energy has to come from somewhere and it comes from the heat content of the gas: it cools in other words.

At the center of nebulae like these is a star which is driving off the remnants of what was previously its outer layers. That is, its atmosphere is expanding. If the heat loss through expansion is greater than the heat input from the rest of the universe, the gas will cool.

Paul

She's as cold as ice....

[caluml]

In 1995, American researchers cooled rubidium atoms to less than 170 billionths of a degree above absolute zero.

I know a girl like that....

Re:Is everything going to cool down eventually?

[meringuoid]

Does this show that every body in this universe is untimately going to cool down and reach this near-absolute-zero temperature? Is this possible for our solar system? Where does all the enery go in such case?

This nebula is weird because it's _colder_ than the ambient background temperature of the universe; some process must be going on to cool it, apparently the rapid expansion of the gas.

Ultimately, yes, the Universe seems doomed to cool down indefinitely. The Universe is expanding, and it seems that it isn't going to stop; the galaxies end up spread out much further, the background radiation redshifts further and further down into radio noise, the stars start dying off... The future is a cold, cold place. No energy is destroyed, it's just spread out thinner and thinner over time.

Note from mom

[andy@petdance.com]

Be sure to wear a sweater.

Love,
Mom