Absolute Zero

Absolute zero is theoretical because it can never be reached. Scientists, have, however, come very close to producing this temperature in laboratories. The temperature of absolute zero is -459.67 degrees Fahrenheit (-273.15 degrees C). On the Kelvin scale, its value is zero degrees. While this temperature has never quite been reached in a lab or observed in space, scientists have been able to observe the odd behavior and properties of matter that reaches temperatures approaching absolute zero.

One of the unexpected results of cooling matter very close to absolute zero was the discovery of a new state of matter. Solid, liquid, and gas are the common states of matter, but when matter, particularly a fluid such as liquid helium, reaches these incredibly low temperatures, it loses all its viscosity, and becomes a superfluid. These strange fluids exhibit the ability to flow against gravity, and to a degree, move from their containers into others.

Another phase of matter, called a Bose-Einstein condensate, can be produced at temperatures approaching absolute zero. Bose-Einstein condensates can only be seen when the temperature of a specimen is brought to within one billionth of one degree of absolute zero. Consequently, only the most specialized laboratories can attempt to study this fragile state of matter. Also, Bose-Einstein condensates have so far only been made from microscopically small amounts of matter, on the order of about 10,000 or fewer atoms. They are related to superfluids and behave in somewhat similar ways, but are usually produced from matter in a gaseous state.

The laws of physics which govern Bose-Einstein condensates are not fully understood, and seem to challenge the things we know about the nature of matter. The best way to understand these condensates without an in-depth knowledge of physics is to understand that when matter reaches this point, the atoms in it "collapse" into the lowest possible state of energy, and also begin to behave as if they were no longer discreet particles, but rather waves. Physicists have much more study and research ahead of them in order to fully understand this state of matter, which was only first observed in 1995.

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