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Bose-Einstein
condensate manipulated by magnets. (H. Fu et al., Phys. Rev. Lett. 2018) |
Scientists just set a new record for the coldest temperature ever measured in a lab, dumping magnetised gas 393 feet (120 metres) down a tower to produce the bone-chilling temperature of 38 trillionths of a degree above -273.15 Celsius.
The German
researchers were looking into the quantum features of a so-called fifth state
of matter: Bose-Einstein condensate (BEC), a gas derivative that only exists at
extremely low temperatures.
Matter
begins to act like one giant atom during the BEC phase, making it an extremely
interesting subject for quantum physicists interested in the mechanics of
subatomic particles.
Temperature
is a measure of molecular vibration; the higher the collective temperature of a
group of molecules, the more they move.
Absolute
zero, or minus 459.67 degrees Fahrenheit, or minus 273.15 degrees Celsius, is
the temperature at which all molecular motion ceases. Scientists have even
devised a separate scale for extremely cold temperatures, known as the Kelvin
scale, in which 0 Kelvin equals absolute zero.
Strange
things start to happen around absolute zero. According to research published in
the journal Nature Physics in 2017,
light transforms into a liquid that can be poured into a container. According
to a study published in the journal Nature Communications in 2017, supercooled
helium no longer experiences friction at very low temperatures. Researchers at
NASA's Cold Atom Lab have even seen atoms exist in two places at the same time.
Scientists
trapped a cloud of 100,000 gaseous rubidium atoms in a magnetic field within a
vacuum chamber in this world-record-breaking experiment. According to NewAtlas,
they then chilled the chamber to roughly 2 billionths of a degree Celsius above
absolute zero, which would have achieved a world record in and of itself.
But for
the researchers who wanted to push the boundaries of physics, this wasn't cold
enough; they needed to simulate deep-space conditions to get much colder. As a
result, the team brought its setup to the Bremen drop tower, a microgravity
research centre at the University of Bremen in Germany, run by the European
Space Agency.
They
slowed the rubidium atoms' molecular speed to nearly nothing by putting the
vacuum chamber into free fall while rapidly switching the magnetic field on and
off, allowing the BEC to float unrestrained by gravity.
The
resulting BEC remained at 38 picokelvins (38 trillionths of a Kelvin) for
nearly 2 seconds, setting a "absolute negative record," according to
the team, who published their findings in the journal Physical Review Letters.
Scientists
from the National Institute of Standards and Technology (NIST) in Boulder,
Colorado used specialised lasers to set the previous record of 36 millionths of
a Kelvin.
The
Boomerang Nebula, located in the Centaurus constellation around 5,000 light
years from Earth, is the coldest known natural point in the universe. According
to the European Space Agency, its average temperature is -272 C (approximately
1 Kelvin).
According
to the current study's authors, they could theoretically maintain this
temperature for up to 17 seconds under completely weightless conditions, such
as in space. According to MIT experts, very freezing temperatures may one day
aid scientists in the development of stronger quantum computers.
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