The ISS's New Device Will Make Atoms Colder Than the Vacuum of Space

Later this year, the International Space Station will receive a new piece of scientific equipment known as the Cold Atom Lab (CAL). It's essentially a high-tech refrigerator that can cool matter to one billionth of a degree above absolute zero—the physically impossible-to-reach temperature at which atoms theoretically stop moving (minus 459.67 degrees Fahrenheit).

Because it will be able to cool matter to such extremes in the unique zero-gravity environment of space, CAL will provide researchers with fascinating new insights into the properties of matter.

"At room temperature, atoms bounce off each other in all directions at a few hundred meters per second," Rob Thompson, CAL Project Scientist at NASA's Jet Propulsion Laboratory (JPL), said in a statement. "But in CAL they'll slow down a million-fold and condense into unique states of quantum matter."

One of the first experiments aboard CAL will investigate particle behavior and interactions by experimenting with ultra-cold, low-density gases.

"The way atoms behave in this state gets very complex, surprising and counterintuitive, and that's why we're doing this," said Eric Cornell from the University of Colorado and the National Institute of Standards and Technology, who will lead these first experiments.

In 2001, Cornell shared the Nobel Prize in physics for creating Bose-Einstein condensates—a state of matter in which groups of atoms are cooled to just above absolute zero, at which point they begin to act like one single atom and display wave-like properties.

In space, the properties of these Bose-Einstein condensates become even stranger—they hold their wavelike form much longer than on Earth, something scientists aboard the ISS will be able to investigate further.

CAL may even be able to help scientists address one of the biggest questions in physics today: how to reconcile quantum mechanics and general relativity, the two main theories describing how the universe works at different scales.

General relativity, developed by Albert Einstein, governs the behavior of gravity and large objects—such as the planets, stars and galaxies—whereas quantum mechanics deals with the strange physics of the very small—atoms and subatomic particles.

A view of Earth from the ISS taken on April 27. The SpaceX Dragon Resupply Ship is visible at the top of the shot. NASA

Researchers from the University of Rochester and the University of Berkeley plan to use CAL to test a cornerstone of Einstein's theory known as the equivalence principle, in an experiment inspired by Galileo.

Instead of dropping cannonballs off the Leaning Tower of Pisa like the great Italian scientist, the researchers will drop atoms inside CAL, allowing them to fall for several seconds. This will enable them to work out the differences in how the atoms accelerate, which could reveal links between gravity and the quantum world.

"Many more experiments are planned for this 'cool' new laboratory—and no one knows where they will lead," Thompson said. "With CAL, we're entering the unknown."

The ISS's New Device Will Make Atoms Colder Than the Vacuum of Space | Tech & Science