Has anybody ever achieved absolute zero?

Answer 1

No, its not possible to reach absolute zero> To do so would violate the Second Law of Thermodynamics....

Heat energy always flows from warmer to colder regions. Say you wish to cool a single hydrogen ato to absolute zero (0 K). As you approach 0 K then what ever instrument you are using to extract heat energy from the hydrogen will always be warmer than the hydrogen... hence heat will flow to the atom and hence heat it up. For a hotter object to extract heat from a cooler object would violate the Second Law of Thermodynamics.

Also, Planck's form of the third law of thermodynamics states that the entropy of a perfect crystal vanishes at absolute zero. However, if the lowest energy state is degenerate (more than one microstate), this cannot be true.

However, temperatures very close to 0 K have been obtained. In 2003, MIT announced a record cold temperature of 450 pK, or 4.5 × 10^-10 K in a Bose-Einstein condensate of sodium atoms (http://en.wikipedia.org/wiki/Absolute_zero).

Answer 2

Absolute Zero

In theory, the lowest possible temperature, and therefore the lowest possible total energy of a system. Although it might be expected that all particle motion would stop at absolute zero, this is not in fact the case. The Heisenberg uncertainty principle asserts that even at the minimum conceivable temperature, subatomic particles would still possess a residual kinetic energy known as zero point energy. A strange outcome of this fact is that the closely packed electrons in a metal at absolute zero would have the same energy as an ordinary gas at 50,000°C.

Temperatures within a few billionths of a degree of absolute zero have been achieved in the laboratory. At such low temperatures, substances have been seen to enter a peculiar state, known as the Bose-Einstein condensate, in which their quantum wavefunctions merge and particles lose their individual identities.

Denoted by zero degrees on the Kelvin scale (0 K = -273.16°C), absolute zero is physically unattainable according to the third law of thermodynamics. At first sight, this might seem unreasonable. There is no upper temperature limit so why should there be a lower one? In trying to understand this, it is helpful to think in terms of temperature ratios rather than temperature differences – the ratio from 10,000 K to 1,000 K, say, being the same as that from 0.001 K to 0.0001 K. Just as by supplying more and more energy to a system we can add as many zeros before the decimal point of the Kelvin reading as we choose, so by continuing to take energy out of a system we can add an arbitrary number of zeros after the decimal point. Yet just as we can never reach an infinitely high temperature, so we can never attain an infinitely low one – absolute zero itself.

Answer 3

Not that I have heard or read, absolute zero is -273.15 degrees celcius or zero Kelvin (0K) named after Lord Kelvin this is the standard scale used in science. This is the closest I know of:

NIST scientists chilled a cloud of cesium atoms very close to absolute zero using lasers to catch the atoms in an optical lattice. The atoms reached 700 nanokelvins, or 700 billionths of a degree above absolute zero. Zero kelvin (minus 273 degrees Celsius), or absolute zero, is the temperature at which atomic thermal motion would cease.

There are a number of ways of supercooling things down, such as lasers and also cryogenically where you use liquid nitrogen and some magnets as well.

Answer 4

the situation is *attaining* absolute 0. Even interior the non-public reaches of area, the cosmic heritage radiation keep the universe approximately 4 tiers *above* absolute 0. So, say you carried out absolute 0 in a laboratory (there are some right here in the international that have come *close* to absolute 0, yet have not carried out it...) - the situation is *protecting warmth OUT of the area that's carried out absolute 0.* So, in case you may gain it, it won't 'unfold'.... think of of it this way - this is *accessible* for all the warmth power interior the room you're in precise now to flow, say, a espresso mug, lowering something of the room to absolute 0. yet, because of the fact warmth has a tendency to radiate, it is going to for sure flow from a hotter merchandise into areas the place this is cooler - equalizing the temperature.

Answer 5

No.

It is physically impossible to reach absolute zero because of the way it is defined. Sort of like the inverse of infinity. Can't reach infinity, can't reach the inverse either. But you are allowed to approach absolute zero as close as your budget and cleverness allows. Can't have a negative absolute temperature of any value either, again by definition of what absolute temperature means.

Answer 6

Isn't liquid hydrogens temp ablosute zero?

Answer 7

Yes, it was achieved before any matter was formed....the universe had to be zero!

Answer 8

No..due to the fact that, at absolute zero, all molecular motion will cease and therefore the substance will have no energy ..no energy... no substance.

Answer 9

Not on Earth, It's happened in other places within the Universe though.

Answer 10

They've been within a few decimal places.