What is the lowest possible temperature?

Scientists believe that the lowest possible temperature
that can be achieved is -273.15 degrees centigrade. This temperature, which is also
called absolute zero, has been established on the basis of observation of relationship
between temperature and pressure of a gas. When a given mass of gas contained in a fixed
volume, its pressure decreases in direct proportion to its temperature. This phenomenon
means that at the absolute zero temperature of all gases mus fall down to
zero.

In the kelvin unit of measuring temperature, the
absolute zero is taken is zero temperature. It is impossible to reach 0 degrees kelvin
temperature. The lowest temperature so far reached in laboratories is of the order of
0.00001 degree kelvin.