Quantum bubbles levitate in orbit
The International Space Station operates the coldest refrigerator in the Universe. The exotic species of matter produced there will tell the fundamental laws of physics.
It’s about an experimental physics laboratory called Cold Atom Laboratory, or CAL, which has been in operation since 2018. It was built by specialists from the Jet Propulsion Laboratory (NASA) and the California Institute of Technology. They placed in it a vacuum chamber, lasers and an electromagnetic trap that keeps atomic gas away from its walls.
In this device the size of a small home refrigerator, rubidium and potassium atoms are cooled to a temperature of one millionth of a degree Kelvin (such cold spots do not exist in space; as a reminder, the temperature of absolute zero, or 0 K, is -273.15°C). This extremely low temperature of atoms is achieved by slowing their motion (momentum) with laser pulses (at CAL they move 200,000 times slower than at room temperature). The atoms are then imprisoned and shaped into bubbles of various shapes in a trap of magnetic fields.
When the atoms of a gas undergo such great cooling, they form what is known as a Bose-Einstein condensate. This is an exotic state of matter, also called the “fifth state of matter” (next to gases, liquids, solids and plasma), in which it reaches superfluidity, that is, viscosity disappears in it. In…
