Science IS cool: NASA to create the universe's coldest environment

NASA is planning to create the coldest spot in the entire universe on board the International Space Station. A laboratory capsule will be cooled to a temperature of 100 pico-Kelvin to conduct new research into the quantum properties of atoms.

The temperature will be one ten-billionth of a degree warmer than absolute zero - the point at which all atoms stop moving completely. Absolute zero is known as 0 degrees Kelvin - the equivalent of -273.15 degrees Celsius. See below for more temperature comparisons.

NASA's plan involves using lasers to cool materials known as Bose-Einstein Condensates in order to study their behaviour at super-low temperatures. When matter is so cold, the disinction between solids, liquids and gases no longer applies, and all matter takes on new forms that display strange quantum properties.

Rob Thompson, from NASA's Jet Propulsion Lab, is the head of the Cold Atom Lab (CAL), which is running the experiement. "We're going to study matter at temperatures far colder than are found naturally", he said in a statement.

Outer space is, of course, incredibly cold. Temperatures in the deepest recesses of the universe, light years from any star, can reach lows of 3 degrees Kelvin, or -270 Celsius. But nothing naturally approaches the temperatures that will be generated in the CAL.

The experiment is scheduled to take place in 2016. It is being conducted in space because gases cool more efficiently under low gravity.

"It's a basic principle of thermodynamics that when a gas explodes, it cools", Thompson explained. " Most of us have hands-on experience with this. If you spray a can of aerosols, the can gets cold.”

"Quantum gases are cooled in much the same way.  In place of an aerosol can, however, we have a ‘magnetic trap.’

“On the ISS, these traps can be made very weak because they do not have to support the atoms against the pull of gravity.  Weak traps allow gases to expand and cool to lower temperatures than are possible on the ground.”

The practical applications of the research are yet to be determined - as Thompson puts it, "We're entering the unknown". Speculation suggests that it could provide the key to improved lasers and quantum sensors.

How cold is cold? Low temperatures compared, in Kelvin and Celsius:

Lowest temperature ever recorded in Britain: 246K (-27 C) *

Coldest commercial freezer: 239K (-34 C)

Freezing point of mercury: 234K (-39 C)

Lowest temperature ever recorded on Earth: 184K (-89 C)

Freezing point of pure ethanol: 159K (-114 C)

Freezing point of butane: 139K (-134 C)

Night-time on Mercury: 94K (-179 C)

Freezing point of nitrogen: 63K (-210 C)

Lowest temperature in the Solar System: 34K (-239 C) **

Lowest temperature in deep space: 3K (-270 C)

Temperature that will be reached by the Cold Atom Lab: 0.0000000001K (-273.1499999999 C)

* Most recently recorded at Altnaharra in Scotland, on 30 December 1995.

**In a crater on the dark side of the Moon, if you were wondering.

What are Bose-Einstein Condensates?

In 1995, researchers discovered that if you took a few million rubidium atoms and cooled them near absolute zero, they would merge into a single wave of matter.  The trick worked with sodium, too.  In 2001, Eric Cornell of the National Institute of Standards & Technology and Carl Wieman of University of Colorado shared the Nobel Prize with Wolfgang Ketterle of MIT for their independent discovery of these condensates, which Albert Einstein and Satyendra Bose had predicted in the early 20th century.

If you create two BECs and put them together, they don't mix like an ordinary gas. Instead, they can "interfere" like waves: thin, parallel layers of matter are separated by thin layers of empty space. An atom in one BEC can add itself to an atom in another BEC and produce – no atom at all.