What is called absolute zero?

The temperature of a body, is the measure of the energy the body has stored, like this when a body has stored a certain amount of energy, has a certain temperature when power is supplied to the body, the temperature rises, when energy is withdrawn, the temperature drops.

At different levels of temperature (ie energy), molecules of the body are moving at speeds proportional to the level of energy, so that, for example, when the water heats, its molecules moving increasingly fast, at some point (boiling point), the molecules tend to separate because its moving is fast, and therefore the water changes phase and is turn into vapor.

Instead, when you go removing energy (cools) of the body the molecules are moving ever more slowly, in the example of water, when we cooled, the molecules begin to lose energy (kinetic energy, ) and when you reach a certain point, the water begins to solidify, this because the molecules have so few kinetic energy, that can not overcome the intermolecular attractive forces, and begin to form crystal lattices, so ice crystals form . But even in that state, water molecules keeps some movement, and of course even vibrate, this because they are not withdrawn all the energy they possess.



Now, while it remove more energy to a body, its temperature falls more and more and their molecules are becoming increasingly motionless, but there is a theoretical limit (because experimentally nobody reached to this point) in that have removed all the energy, and the molecules would stop completely, and therefore would be the lowest temperature which theoretically could be reached.

By extrapolation, it has determined that this temperature would be
-459.67ºF or -273.15ºC

This temperature is theoretical because so far not been able to reach this low level of energy (zero energy), experimentally, was reached to bring the temperature to -460 ° F by magnetic cooling.

The "absolute" temperature scales, are named for this temperature, because in the absolute scales the lowest temperature is absolute zero, so also in these scales there are no negative temperature values. The absolute scales are:

Escala Rankine 0R = -459,67 º F
Escala Kelvin 0K = -273,15 º C

The conversion formulas between temperatures are:

K = ºC + 273,15
R = ºF + 459,67