Researchers Chill Mirror to Near Absolute Zero

An anonymous reader writes "Physicists have managed to cool a dime-sized mirror to within one degree of absolute zero. This is the lowest laser-induced freeze yet achieved with a visible object. Laser cooling involves firing pulses of light at a specific frequency that exactly matches an atom's motions."

Other uses...

[Anonymous Coward]

Could they make a cheaper version of this system to build more efficient air-conditioners?

Mirror

[biocute]

What's the significance of chilling a dime-sized mirror, vs chilling a dime?

Conservation of Energy...

[btgreat]

A couple of people made posts that got my brain ticking.. Someone mentioned that this confirms quantum theory in that adding light energy reduces the temperature, thereby reducing the energy of the system. In response, someone mentioned it was like noise cancellation. The problem I see with this analogy, and the idea of the experiment in general is that while I can see similarities, when we talk about noise cancellation, no energy is lost. It is still there, even though destructive interference cancels the noise where the waves overlap. The sound waves will continue to travel, and if they leave the area where they are destructively influenced, the noise will start back up. With the photons reducing temperature situation, where is the energy going? We start with high speed atoms and light, and end with low speed atoms and no light; isn't the energy being destroyed? I am not very up on my quantum mechanics, but can see two possibilities: either energy isn't really conserved under quantum mechanics, or the atom is rereleasing a photon after the initial photon hits it and slows it down. Perhaps neither is right, but could someone please explain the apparent lack of conservation of energy here?

Re:This is cool stuff and all...

[YGingras]

It has many applications in astronomy. During the winter, the only expedition to climb to the top of the Mauna Kea are to fill the liquid nitrogen and liquid helium tanks of those huge telescopes. We don't realize it but getting pretty picture in IR requires that you more of less shut down the black body radiation of your optics. With liquid helium they cool the CCDs to 4.5 Kelvin. They use so much of the stuff that they need to fill the tanks every other week. I admit that I have no idea how big is the said tank but laser cooling would open the way to mostly unattended (think orbital) telescopes for a much broader part of the spectrum. At the moment we send IR orbital scopes with big tanks of liquid helium which is dead lift weight that could be used for larger optics and we drop the scopes in the ocean when they run out of the stuff. Spitzer, unlike Hubble, will be useless soon and will not be able to perform observations even if all the mechanical and electronics are still in top condition. If you ever visit the Mauna Kea, notice the frost patches inside the observatory. It's kind of cold up there but the best experience is inside the observatory: it's freezing, everyone is dizzy after climbing the stair (the air is really thin) and you see all those big pipes with cryo-steam. It feels like the visit to the cryo chamber in Akira.

Blessed are the Buckyballs

[Anonymous Coward]

The problem here is that an incoherent mass has been
convinced that it is not only coherent energy, but 180deg out of phase
with a coherent light source (almost). Seems to me that QM
might even have a problem or two with this.

Re:Conservation of Energy...

[smaddox]

We start with high speed atoms and light, and end with low speed atoms and no light; isn't the energy being destroyed?

You actually DO end up with light. More energetic light, to be more specific.

It can almost be simplified to classical collision physics. The photon hits the atom and bounces off, slowing down the atom and in turn, the photon "speeds up" (gets red shifted).

cooling 1g under 1K trivial. TFA has typos/errors?

[viking80]

There must be some error in TFA. Looks like it was written by someone with little understanding. To cool a 1g item under 1K is trivial. You can buy coolers that can keep large volumes way down in the mK range. Commercial literature give numbers like 1mW cooling at 35mK.

TFA says that the purpose of cooling was to "...cancel the natural forces entirely, so quantum forces apply exclusively."

That is of course incorrect. Quantum mechanics *are* the natural forces(,excluding gravity?), and cooling is often used to bring matter to the ground state or similar, so quantum effects take on macroscopic and often more observable (and intriguing) properties.

If there is a real breakthrough here, does anyone have the original scientific reference?

Re:Conservation of Energy...

[Anonymous Coward]

How does getting redshifted speed it up? Isn't the red end of the spectrum the lower energy, lower frequency, longer wavelength one?

If ...

[can56]

Scientists can use lasers to cool atoms/crystals/mirrors to near absolute zero, does that mean: a) really god-damn-cold-fusion is possible, or b) by increasing the power of the lasers, hot-fusion may occur?. Sorry, but I'm waiting for someone (less drunk and more eloquent than I) to comment on the definition of temperature, the scales (K/F/C), and what this experiment could lead to.

Re:Conservation of Energy...

[Engine]

You are correct. The scattered light is blue shifted due to the energy it takes away.

Re:Confirms quantum theory

[Fission86]

Actually no, what they do is, and I had Nobel Laureate Eric Cornell explain this to me himself, use a very specific laser tuned to one of the main absorbsion energies of that atom. The atom absorbs the light, and then emits more energy than it takes in, as it is absorbing photons and then emitting them, during the emittion process the atom gives off the original momentum of the photon plus a recoil momentum equal to the original absorbed photon. This effect, being done by several beams around your object, reduces temperature.

as a side note: If I remember correctly this process only cools to about 4.5K, so Eric Cornell used a process called magnetic evaporation to reduce the temperature further, I remember not understanding it on a quantum level but he made an analogy to a hot cup of coffee, you lose 1/4 of your sample but 1/2 of your total temperature)

Re:A Question for the Scientists Out There

[ioshhdflwuegfh]

From what I understand about absolute zero, there is no energy in the system, including the energy required to keep electrons in orbit around the nucleus of an atom.

Absolute Zero means that the temperature of the system is exactly 0 Kelvin. What is temperature, on the other hand, is not so easy to define. For example, it has nothing to do with the Heisenberg uncertainty principle, which relates energy and time, or position and momentum. Energy is an all together different physical quantity than temperature.

Therefore, the atoms would collapse in on themselves, creating an extremely dense substance. Am I right in thinking this would happen?

Not quite: the laws of quantum mechanics would prevent such collapse: standard quantum-mechanical description of atom already presupposes that the atom is at 0 Kelvin. What happens however is that matter at low temperature can undergo phase transitions, like when water freezes and becomes in many regards quite different a substance, ice.

Similarly, when many ordinary metals are cooled down they become superconducting (conduct electricity without any resistance), or liquid Helium becomes superfluid (can flow outside the open container in which it was stored at higher temperatures). The latter two phenomena are essentially quantum-mechanical, and they tell us to expect new phenomena/states of matter sitting at low temperatures. That's one of the reasons why low temperatures are interesting.

If so, would this doom the earth to become a black hole, or do something similar?

Many think the main problem with Earth is about its warming up, not cooling down...