Scientists create coldest temperature ever in a lab to help understand quantum mechanics

Coldest temperature ever recorded in a lab Scientists in Germany have broken the record for the coldest temperature ever recorded in a lab. CTV Science and Technology Specialist Dan Riskin explains how.

TORONTO — Scientists have broken the record for the coldest temperature ever recorded in a lab, achieving a temperature just trillionths of a degree away from absolute zero by dropping freezing, magnetized gas down a tower 120 metres tall.

The exact temperature scientists measured was 38 trillionths of a degree above -273 degrees Celsius — the closest that has ever been measured to absolute zero in a lab.

Absolute zero in Kelvin, a temperature thought to be impossible for anything in the universe to reach, is -273.15 degrees Celsius.

The feat was achieved while German researchers were aiming to study the wave properties of atoms to gain a better understanding of quantum mechanics, a discipline of science that examines how the world functions at the subatomic level, where particles can exist in two places simultaneously.

Researchers at the lab at the Centre for Applied Space Technology and Microgravity at the University of Bremen created one of “the coldest places in the universe” for just a few seconds, according to a German press release on the research.

Although no thermometers can actually measure a temperature that low, scientists were able to calculate the number by looking at the movement of the atoms in the newly-cold gas. Temperature is actually a measurement of the kinetic energy of particles that make up an object or space, which allowed researchers to calculate how cold the gas was.

Extremely low temperatures have the unique property of making atoms and other particles act in extremely strange ways. In fact, extremely low temperatures can create what some call a fifth state of matter: a Bose-Einstein condensate (BEC), which is when a gas made up of bosons, a fundamental particle, is cooled to close to absolute zero.

At this temperature, these separate particles start to act as one quantum entity, with the same wave function, something that was predicted by Albert Einstein almost a century ago based on the quantum formulations of the physicist Satyendra Nath Bose.

Studying the BEC allow scientists to gain a better picture of how subatomic particles behave.

Researchers utilized the drop tower at the University of Bremen — a microgravity lab where scientists use free fall to study objects at near weightlessness — in order to extend the duration of the BEC longer than would normally be possible.

They flipped a magnetic field off and on as the BEC fell to slow down the atoms, allowing researchers to create the slowest spreading BEC, and also the coldest yet.

According to the release, the slowed expansion of the BEC allowed researchers to observe it for up to two seconds.

The research is described in a paper published in the journal Physical Review Letters at the end of August.