Researchers Chill Mirror to Near Absolute Zero 202
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."
Re:This is cool stuff and all... (Score:4, Informative)
I imagine that (Score:5, Informative)
Confirms quantum theory (Score:5, Informative)
It confirms our understanding of light and matter and how they interact. You would think that shining light (energy) on something would warm it up. If it cools it down, something strange is going on.
In a broader sense, it means that we can manipulate matter and energy in ways nobody imagined 100 years ago (well, except for Einstein).
I thought this was a breakthrough (Score:5, Informative)
1. Others have gotten much, much closer to 0 K using atoms and laser cooling.
2. Others have gotten much, much closer to 0 K using solid objects and different cooling methods.
3. Their method has the potential of getting closer to 0 K.
So, even if it is not a breakthrough it is still impressive.
Re:This is cool stuff and all... (Score:2, Informative)
Re:So.... (Score:2, Informative)
Re:Confirms quantum theory (Score:5, Informative)
And about the mirror versus using an actual dime or something else--a perfectly smooth, very thin object probably makes atomic-level laser targeting much easier than a relatively rough object such as a coin.
Website on laser cooling and trapping (Score:3, Informative)
http://www.colorado.edu/physics/2000/bec/lascool1
Re:I thought this was a breakthrough (Score:4, Informative)
Re:Confirms quantum theory (Score:4, Informative)
Re:I thought this was a breakthrough (Score:3, Informative)
Laser Cooling (Score:3, Informative)
I may be wrong on this, as I'm just an undergrad physics major, but in my experience laser cooling involves detuning a laser slightly below some atomic transition frequency, and counterpropagating the same beam back. What happens is as a laser moves quickly in the direction of the beam, it observes the laser's frequency to be higher due to the Doppler shift, and suddenly this laser that was not resonating with the atoms comes into resonance, and the atom starts absorbing photons, which have momentum. This knocks the atom back such that it can't move quickly in the direction of the laser. Often this is done with six beams along three orthogonal axes so that you cool the atoms in all directions.
Re:Confirms quantum theory (Score:4, Informative)
Re:Confirms quantum theory (Score:3, Informative)
Re:Confirms quantum theory (Score:2, Informative)
As you say, though, whichever analogy you use, it's not possible to remove all the energy in the system due to Heisenbergs Uncertainty principle and the effect of zero-point energy: absolute zero is a theoretical minimum temperature, not one that can be practically achieved for any length of time or for any object with mass.
Re:Obligatory Star Trek Refference (Score:3, Informative)
Plus many books have used the same reference too.... but now I'm rambling.