REACHING ABSOLUTE ZERO
In 2021, scientists at the University of Bremen in Germany came the closest anyone has ever gotten to achieving absolute zero using a cloud of 100,000 rubidium atoms that were suspended in a magnetic field and cooled to around two-billionths of a degree Celsius. The experiment created what’s known as a Boseeinstein condensate, a mysterious state of matter where atoms hardly move, clump together and behave like a single atom. This ultracool cloud was held in a vacuum chamber that was then tossed off a 37-metre-tall tower. On its descent, the magnetic field in the vacuum chamber was switched on and off to send the Bose-einstein condensate into a state of microgravity and reduce its temperature even further. For around two seconds, the scientists further cooled the condensate to about 38-billionths of a Kelvin.