Absolute zero is the lower limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reaches its minimum value, taken as 0. The theoretical temperature is determined by extrapolating the ideal gas law; by international agreement, absolute zero is taken as −273.15° on the Celsius scale (International System of Units), which equates to −459.67° on the Fahrenheit scale (United States customary units or Imperial units). The corresponding Kelvin and Rankine temperature scales set their zero points at absolute zero by definition.

It is commonly thought of as the lowest temperature possible, but it is not the lowest enthalpy state possible, because all real substances begin to depart from the ideal gas when cooled as they approach the change of state to liquid, and then to solid; and the sum of the enthalpy of vaporization (gas to liquid) and enthalpy of fusion (liquid to solid) exceeds the ideal gas's change in enthalpy to absolute zero. In the quantum-mechanical description, matter (solid) at absolute zero is in its ground state, the point of lowest internal energy.

Absolute zero is the temperature at which entropy reaches its minimum value.

Absolute Zero may also refer to:

See also

Absolute Zero is a 2006 disaster film, directed by Robert Lee, and written by Sarah Watson. It stars Jeff Fahey and Erika Eleniak. The film is about polar shift, which brings a new ice age in Florida, and everywhere within 30 degrees north and south of the equator.

Plot

David Koch (Jeff Fahey), a climatologist employed by Inter Sci, proposes a theory that the last ice age was triggered by Earth's polar shift in a single day. When unusually cold weather strikes Miami and the birds start to return from the south a few months earlier, he is sent to Antarctica to find out what is happening.

Once there, he discovers a frozen body of a human that is at least 10,000 years old. What is interesting is his appearance—he looks as if he was instantly frozen in place. He also discovers cave paintings that show the sun falling down. A sudden blizzard then destroys a base camp and kills some members of his team.

Back in Miami, he presents his findings to his co-workers and his boss. He claims that another polar shift is only a couple of hours away and the new ice age is inevitable. However, nobody believes him. According to the current theories, the shifting of the poles should last at least 200 years so the climate changes, if any, wouldn't appear overnight. David's one-time love Bryn (Erika Eleniak) supports his theory with numerous stories about the falling sun followed by a darkness and terrible cold.