Can any one tell me about low temperatures?

Question

producation and measurement of low temperatures

Answer 1

The lowest temperature is absolute zero (0 Kelvin or -273 C).  The closest temperature in the universe (assuming aliens haven't gotten colder) is achieved in atomic physics labs, and is known as a Bose-Einstein Condensate (1*10^-6 K or so).  To get this, a cloud of atoms is cooled using laser cooling, down to fractions of a degree K.  Then, the cloud is trapped using a magneto-optical trap.  This is kind of like a magnetic bowl that confines the very cold cloud.  Then depth of the trap (similar to the height of the bowl) is slowly lowered.  The hottest atoms are the ones moving the fastest, so they will travel the farthest from the center of the trap.  As you lower the bowl, the hottest atoms will have enough energy to escape from the trap and the average temperature of the remaining atoms will decrease every time a hot one escapes.  If the trap depth is lowered slow enough, this process can continue until the average temperature is extremely low.  This is known as evaporative cooling, which is also responsible for you coffee cooling.  At some point, the atoms get so cold a new type of matter forms, which is the BEC.

Answer 2

Low temperatures can either be comparative or relative.

Answer 3

the lowest temperature is 0K and is called absolute zero.equivalent to -273 celcius degrees