The world's coldest freezer does not resemble an average person's mental image of a freezer at all. Instead, it's made up of magnets. Read On.
Scientists at Massachusetts Institute of Technology (MIT) are a step closer to absolute zero. At absolute zero, atoms will posses zero energy, meaning they come to a standstill, as the atom approaches absolute zero, it might exhibit previously unobserved properties which might improve our understanding of matter.
Sodium gas was cooled to just half-a-billionth of a degree above absolute zero, it is the first time that a gas was cooled below 1 nanokelvin. This record was achieved by cooling the atoms with a series of magnets.
At such low temperatures, the atoms cannot be confined within a physical container as they will stick to the walls. Hence, the MIT team has come up with a "Gravito-magnetic" trap. Atoms are confined within a magnetic field and "compressed" until the record breaking temperature was reached.
A view into the vacuum chamber where sodium atoms were cooled down to 500 picokelvin. The atoms where magnetically confined by the coil in the center which is 1 cm in diameter. The atoms were "levitated" 0.5 cm above the coil.
Images: COURTESY KETTERLE LAB