Students are usually told in science class that absolute zero -- zero kelvin, or about -460 degrees Fahrenheit -- is the lowest temperature threshold.
But scientists have created a temperature beyond absolute zero, reported LiveScience.
The implications of the new research suggest that engines could theoretically be more than 100 percent efficient. It also offers potential explanations for "dark energy," the matter that may cause the universe to expand.
The researchers manipulated a gas in order to force most of the gas particles into high energy states, giving it the negative reading (objects at positive temperatures contain particles with mostly low energy states).
But the resulting gas was not colder than absolute zero -- if you can wrap your mind around it. "Yet the gas is not colder than zero kelvin, but hotter. It is even hotter than at any positive temperature — the temperature scale simply does not end at infinity, but jumps to negative values instead," researcher Ulrich Schneider, who is a University of Munich in Germany physicist, told LiveScience.
In fact, objects with negative temperatures -- below zero kelvin -- are always hotter than objects with positive temperatures. In addition, when an object at a negative temperature releases energy, "they can actually absorb entropy," a measure of chaos or disorder, unlike objects at positive temperatures which increase entropy.
[Image: Thermometer Showing Winter Cold on Shutterstock]