NASA is trying to build the coldest spot in the universe on board the International Space Station. It’s just as well: in space, no one can hear the astronauts’ teeth chattering.
The Cold Atom Laboratory, to give the deep-freeze chamber its official title, will be designed to make things even colder than the freezing void of space, which drives the mercury way, way down to 3 degrees Kelvin, or -454 degrees Fahrenheit. NASA scientists are shooting for as close to absolute zero as you can get; they think they might be able to reach 100 pico-Kelvins, or just one ten-billionth of a degree above absolute zero.
Sorry, Boomerang Nebula (previous universal cold spot record-holder at -457 degrees F); you've got some serious competition. The Cold Atom Laboratory is coming for the title in 2016, when it's scheduled to launch for the ISS.
As one gets closer and closer to 0 degrees Kelvin, molecular motion slows and comes close to stopping completely. The strange rules of the cold universe will allow scientists to get a better look at the weird world of quantum physics, starting with a construction called Bose-Einstein Condensates. A BEC occurs when a bunch of particles called bosons are cooled to near absolute zero, at which point they condense into a wave of matter.
You can mix BECs together and they won’t behave like a regular gas, but will interfere with each other the way that waves of energy will interact with each other.
“The Cold Atom Lab will allow us to study these objects at perhaps the lowest temperatures ever,” project scientist Rob Thompson said in a statement.
So how does it work? To get near absolute zero, the first step the Cold Atom Lab employs is a special three-step process. The material that will be supercooled is hit with a certain frequency laser, then a radio frequency field that removes atoms excited to a certain energy state, leaving behind just the unexcited, cold atoms. The third stage is a process called “adiabatic expansion.” The radio field is turned off and the cloud expands. And, thanks to the trusty laws of thermodynamics, we know that when a gas expands, it cools. This final expansion is enough to kick the atoms down near absolute zero.
So, then, why does the Cold Atom Lab have to be sent into orbit? The low-gravity conditions are actually just the right environment for the device, Thompson said.
“On the ISS, these traps can be made very weak because they do not have to support the atoms against the pull of gravity,” Thompson said. “Weak traps allow gases to expand and cool to lower temperatures than are possible on the ground.”
Where might NASA’s deep quantum freeze lead? Even the scientists aren’t quite sure what practical applications might turn up down the road: quantum sensors? Near-unbreakable cryptography? It might even be possible to bring the quantum world into the visible realm.
If the team manages to get the temperature down low enough, they might be able “to assemble atomic wave packets as wide as a human hair--that is, big enough for the human eye to see,” Thompson said. “We’re entering the unknown.”