- 3182 - ATOMS - at absolute zero temperature? The highest-resolution image of atoms so far has been captured, breaking a record set in 2018 at Cornell University. They captured this image using a praseodymium orthoscandate crystal.
- ----------------------- 3182 - ATOMS - at absolute zero temperature?
- The Cornell scientists used a technique called “ptychography“, in which an electron microscope is used to analyze the crystal by calculating the angles of scattered electrons to work out the shape of the atoms that scattered them.
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- This 2021 image is double the resolution of a zoomed-in image of atoms made in 2018
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- In 2018 the scientists used a 2D material to limit the amount of electron scattering that happens in a thicker material and makes it difficult to tell where the electrons had scattered from.
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- In 2021 these scientists reported that molecules in an ultra-cold gas can chemically react at distances up to 100 times greater than they can at room temperature.
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- The chemical reactions tend to slow down as the temperature decreases. They found that molecules at frigid temperatures just a few hundred billionths of a degree above absolute zero (−273.15°C or 0 kelvin) can still exchange atoms, forging new chemical bonds in the process, due to weird quantum effects that extend their reach at low temperatures.
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- Why is absolute zero (0 kelvin or −273.15°C) an impossible goal? Because the work needed to remove heat from a gas increases the colder you get, and an infinite amount of work would be needed to cool something to absolute zero.
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- In quantum terms, the “Heisenberg’s uncertainty principle“, says the more precisely we know a particle’s speed, the less we know about its position, and vice versa. If you know your atoms are inside your experiment, there must be some uncertainty in their momentum keeping them above absolute zero.
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- The lowest temperature ever measured in the solar system was on the Moon. Last year, 2020, NASA’s Lunar Reconnaissance Orbiter, measured temperatures as low as −240°C in permanently shadowed craters near the lunar south pole, 10 degrees colder than temperatures measured on Pluto.
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- The coldest temperature known place in the universe is the Boomerang Nebula, 5,000 light years away from us in the constellation Centaurus. Scientists reported in 1997 that gases blowing out from a central dying star have expanded and rapidly cooled to 1 kelvin, one degree warmer than absolute zero.
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- Usually, gas clouds in space have been warmed to at least 2.7 kelvin by the cosmic microwave background, the relic radiation left over from the big bang. But the Boomerang Nebula’s expansion creates a kind of cosmic refrigerator, allowing the gases to maintain their unusual cool.
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- If you count artificial satellites, things get colder still. Some instruments on the European Space Agency’s “Planck space observatory“, launched in May 2009, are frozen down to 0.1 kelvin, to suppress microwave noise that would otherwise fog the satellite’s vision.
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- The space environment, combined with mechanical and cryogenic refrigeration systems using hydrogen and helium, chill the coldest instruments to 0.1 kelvin in four sequential steps.
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- The lowest temperature ever recorded back here on Earth in a laboratory, September 2003, scientists at the Massachusetts Institute of Technology announced that they’d chilled a cloud of sodium atoms to a record-breaking 0.45 nanokelvin, 0.000045 Kelvin
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- Earlier, scientists at the Helsinki University of Technology in Finland achieved a temperature of 0.1 nanokelvin in a piece of rhodium metal in 1999. However, this was the temperature for just one particular type of motion, a quantum property called nuclear spin, not the overall temperature for all possible motions.
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- In everyday solids, liquids and gases, heat or thermal energy arises from the motion of atoms and molecules as they zing around and bounce off each other. But at very low temperatures, the odd rules of quantum mechanics reign.
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- Molecules don’t collide in the conventional sense; instead, their quantum mechanical waves stretch and overlap. When they overlap they can form a “Bose-Einstein condensate“ , in which all the atoms act identically like a single “super-atom”.
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- The first pure Bose-Einstein condensate was created in Colorado in 1995 using a cloud of rubidium atoms cooled to less than 170 nanokelvin, 0.000170 Kelvin
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- June 5, 2021 ATOMS - at absolute zero temperature? 3182
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