Absolute Zero
There is no known absolute upper limit for temperature. In other words, if we keep putting energy into a substance, the particles in the substance will keep gaining translational kinetic energy, and the temperature of the substance can increase forever, or at least as long as we keep putting energy into the substance. However, there is a lower limit for temperature. The particles in a given substance only have a certain amount of translational kinetic energy which is available to be lost. When all available translational kinetic energy has been removed from the particles in a substance, we say the substance has reached absolute zero. Note: Some of the translational kinetic energy in a substance is not available to be removed, and so even the particles in a substance at absolute zero would have some translational kinetic energy.
In addition, absolute zero is only a limit and is an unattainable limit at that. No substance can ever quite reach absolute zero; substances can only get close to absolute zero. Click HERE to learn about a group of scientists at MIT who have been able to cool a substance to within a billionth of a Kelvin above absolute zero. Click HERE to access lots of absolute zero resources from NOVA.
In addition, absolute zero is only a limit and is an unattainable limit at that. No substance can ever quite reach absolute zero; substances can only get close to absolute zero. Click HERE to learn about a group of scientists at MIT who have been able to cool a substance to within a billionth of a Kelvin above absolute zero. Click HERE to access lots of absolute zero resources from NOVA.