We've gone to space, split the atom, and created devices small enough to travel through our blood. But it seems that in science, as in nature, there are some places we still can't reach.
Absolute zero is a physical limit that will almost certainly remain beyond our grasp, although lately, physicists have been getting within a hair's breadth of that goal. What they've found is that in the ultimate cold, matter becomes truly bizarre.
Absolute zero: zero degrees on the Kelvin scale, or -273.15 °C is as cold as it gets. Nothing in nature gets this cold; the coldest known region of space, the Boomerang nebula in the constellation Centaurus, is a balmy one degree Kelvin.
It's a physical limit, theoretically impossible to reach. Attaining absolute zero would break the law of thermodynamics, which says that getting there would require an infinite amount of work. At absolute zero, there is no heat. All atomic motion ceases — atoms no longer move or vibrate; they have no thermal energy whatsoever.
Even getting close to the limit is problematic. Objects cooled to absolute zero must be kept as still as possible. Anything touching an object being cooled to absolute zero would pass on its thermal energy, so instead, physicists use lasers to trap the atoms and damp their movement to slow them down to near as near motionless as possible.
The technique – known as laser cooling – has taken atoms to within a few billionths of a degree of 273.15°C.
Nobel science
At this extreme cold, the quantum world takes over and some very strange and useful behaviour is observed...
Absolute zero: zero degrees on the Kelvin scale, or -273.15 °C is as cold as it gets. Nothing in nature gets this cold; the coldest known region of space, the Boomerang nebula in the constellation Centaurus, is a balmy one degree Kelvin.
It's a physical limit, theoretically impossible to reach. Attaining absolute zero would break the law of thermodynamics, which says that getting there would require an infinite amount of work. At absolute zero, there is no heat. All atomic motion ceases — atoms no longer move or vibrate; they have no thermal energy whatsoever.
Even getting close to the limit is problematic. Objects cooled to absolute zero must be kept as still as possible. Anything touching an object being cooled to absolute zero would pass on its thermal energy, so instead, physicists use lasers to trap the atoms and damp their movement to slow them down to near as near motionless as possible.
The technique – known as laser cooling – has taken atoms to within a few billionths of a degree of 273.15°C.
Nobel science
At this extreme cold, the quantum world takes over and some very strange and useful behaviour is observed...
Read the rest on Cosmos Magazine
1 comments:
"...the law of thermodynamics..."
One little typo puts the reliability of the whole article at risk.
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