The International Space Station will soon be home to the coldest spot in the known universe. In their "Cold Atom Lab," NASA researchers plan to create an environment at one ten billionth of a degree above absolute zero. This is about 459 degrees below zero on the Fahrenheit scale.
"We're going to study matter at temperatures far colder than are found naturally," said Rob Thompson, the Project Scientist for NASA's Cold Atom Lab. "We aim to push effective temperatures down to 100 pico-Kelvin."
For perspective, the coldest temperature recorded on Earth was in Antarctica, at a relatively balmy minus 136 F. In the vast nothingness between stars in space, the temperature can reach minus 454 F, just 3 degrees Kelvin above absolute zero.
At absolute zero, all thermal activity theoretically stops, rendering the distinction between gases, liquids and solids meaningless. In this realm of quantum mechanics, atoms behave like both particles and waves, and matter can exist in two places at once.
"Mixtures of different types of atoms can float together almost completely free of perturbations," explained Thompson, "allowing us to make sensitive measurements of very weak interactions. This could lead to the discovery of interesting and novel quantum phenomena."
The 2016 launch of the Cold Atom Lab is planned for the International Space Station because these temperatures would be impossible to reach in a terrestrial environment.
"It's a basic principle of thermodynamics that when a gas expands, it cools. Most of us have hands-on experience with this. If you spray a can of aerosols, the can gets cold," Thompson said.
The Cold Atom Lab will expand tiny volumes of gas using what Thompson called "magnetic traps."
"On the ISS, these traps can be made very weak because they do not have to support the atoms against the pull of gravity. Weak traps allow gases to expand and cool to lower temperatures than are possible on the ground," he said.
No one can be sure what researchers will find as they enter the quantum world. Thompson listed quantum sensors, matter wave interferometers and atomic lasers as possible practical applications, but the effects of absolute zero have never before been observed.
"We're entering the unknown," he said. A detailed overview of the experiement can be seen on this poster from the Cold Atom Lab.