Scientists Create Gas Colder Than Absolute Zero

Until recently, the coldest temperature a gas could get to was "absolute zero" on the Kelvin scale -- a beyond-freezing minus 273 degrees Celsius (-460 degrees Farenheit). Physicists at Ludwig-Maximilians University Munich and the Max Planck Institute of Quantum Optics in Garching have achieved a temperature colder than absolute zero. Such a discovery could help scientists understand concepts such as dark energy. In the mid-19th century, mathematical physicist and engineer Lord Kelvin created th...