Absolute Zero is supposed to be the absolute coldest temperature there is. You just can't go any lower than that. Pretty simple, right?
Well, apparently no one defined "absolute" to a group of German scientists, who took on the age-old question of "How cool is cool?" for themselves.
Nature
Huh. Looks like Lord Kelvin's getting the cold(er) shoulder.
Sure, it's only a few billionths we're talking about here, but as far as "temperature limbo" goes, that's still an amazing breakthrough. They shimmied below a threshold that was supposed to be absolute, after all.
This isn't some useless endeavor, either. The techniques and results could be turned towards creating new types of matter in the laboratory, and could theoretically play a role in the development of quantum devices. Plus, since the behavior of sub-absolute zero gas seems to mimic that of so-called "dark energy", it could help us better understand this mysterious force.
Needless to say, these guys shouldn't have their assets frozen anytime soon.
So the next time you're caught out in the cold, freezing and miserable, just remember that it could always be colder; science is making sure of that.
Well, apparently no one defined "absolute" to a group of German scientists, who took on the age-old question of "How cool is cool?" for themselves.
Schneider and his colleagues reached such sub-absolute-zero temperatures with an ultracold quantum gas made up of potassium atoms. Using lasers and magnetic fields, they kept the individual atoms in a lattice arrangement. At positive temperatures, the atoms repel, making the configuration stable. The team then quickly adjusted the magnetic fields, causing the atoms to attract rather than repel each other. “This suddenly shifts the atoms from their most stable, lowest-energy state to the highest possible energy state, before they can react,” says Schneider. “It’s like walking through a valley, then instantly finding yourself on the mountain peak.”
At positive temperatures, such a reversal would be unstable and the atoms would collapse inwards. But the team also adjusted the trapping laser field to make it more energetically favourable for the atoms to stick in their positions. This result, described today in Science1, marks the gas’s transition from just above absolute zero to a few billionths of a Kelvin below absolute zero.
Huh. Looks like Lord Kelvin's getting the cold(er) shoulder.
Sure, it's only a few billionths we're talking about here, but as far as "temperature limbo" goes, that's still an amazing breakthrough. They shimmied below a threshold that was supposed to be absolute, after all.
This isn't some useless endeavor, either. The techniques and results could be turned towards creating new types of matter in the laboratory, and could theoretically play a role in the development of quantum devices. Plus, since the behavior of sub-absolute zero gas seems to mimic that of so-called "dark energy", it could help us better understand this mysterious force.
Needless to say, these guys shouldn't have their assets frozen anytime soon.
So the next time you're caught out in the cold, freezing and miserable, just remember that it could always be colder; science is making sure of that.