Posted on 11/10/2021 11:16:10 AM PST by Red Badger
The record for the coldest temperature ever achieved has been broken with the cooling of rubidium gas to 38 picokelvins (3.8 * 10-11 K). The work could lead to new insights into quantum mechanics.
Temperature is a measure of the energy in atoms' or molecules' vibrations. The lowest temperature theoretically possible is absolute zero – 0 K or −273.15 ºC (−459.67 ºF) – which would require a complete cessation of movement. That's probably impossible practically, but for decades physicists have shown we can get very, very close by using lasers to damp atomic motion.
In Physical Review Letters German scientists have reported going closer to zero than ever before.
Professor Ernst Rasel of Leibniz Universität Hannover and co-authors placed 100,000 rubidium atoms inside a magnetic trap at the top of the University of Bremen's 110 meter (360 feet) tall Bremen drop tower. The trap forms what is called a “matter-wave lens” that by focusing the atoms at infinity cools them to the point that they became a Bose-Einstein Condensate (BEC), a state of matter where collections of atoms can show quantum behavior as if they were a single subatomic particle/wave.
Turning off the trap allows the condensate to expand in all directions, cooling it further. The BEC was then allowed to free-fall down the length of the tower while detectors observed its behavior.
The whole process lasts just two seconds, although modeling suggests 17 seconds is possible, and the authors hope to exploit this longer timeline to explore BEC behavior with the distortions of vibrations removed.
In an accompanying viewpoint article the University of Portsmouth's Dr Vincenzo Tamma, who was not involved with the research, said the work could “test gravity at the quantum level.” Interference patterns in the BEC are determined in part by gravitational effects. With inconsistencies between our understanding of quantum physics and general relativity's description of gravity representing perhaps physics' greatest unsolved puzzle, the work provides an opportunity to explore physics at its most fundamental. Tamma also sees potential for the technique to search for certain forms of dark matter.
A hundred thousand atoms may sound like a lot, but it's actually about 50 million times less than make up the head of a pin, give or take a bit for variation in atomic, and pin-head, size. The coldest temperature achieved in something you could see was set when a 400 kilogram (882 pound) block of copper was cooled to 0.006 K. To get there, researchers required lead that had been mined thousands of years ago, giving time for radioactive isotopes formed through exposure to other radioactive elements in the ore to decay. This was provided through the fortuitous (for us) discovery of a Roman galley that sank of the coast of Sardinia bearing Spanish lead intended for use in the Roman civil wars.
Wow, Lasers! is there anything they cannot do ?
More seriously I wonder about E=Mc^2
if E=0 what happens to the M and C ?
I think I came pretty close to that on a visit to Minnesota a few year years ago.
Absolute zero:
Hell freezes over.
Lions win the Superbowl.
If you want to achieve absolute zero, just look inside the hearts of those who demand that five-year-olds be forced to be injected with an untested (on five-year-olds) serum that may very well damage their immune system for life. It doesn’t get any colder than that!
For E (Energy) to equal 0, either M or C or BOTH MUST be zero. It’s a Law.
If M (Mass) equal Zero, then the element falls apart into it’s various and numerous particles, which then will disappear as they would have no Strong or Weak Force to keep them together.
If C (Speed of Light) equal Zero, then the atom will freeze in space-time like a photograph of itself.
If BOTH go to Zero, then you can pick and place the parts, rearrange them and make whatever you want out of them, transmutation, essentially...........................
Joy Behar wins Miss Universe..................
I guess they haven’t been in the Adirondacks in Upstate NY in the winter.
Nope. The Buffalo Bills.
They ought to move their experiments to the South pole in winter, they wouldn’t have as much way to got to get to 0K..................
although her chances would improve if she transitioned to a male...then transitioned back to a female.
I knew this women that was so Frigid every time she spread her legs a little light came on
I knew this women that was so dumb that she took the light out of the Fridge to save money on electricity..............
But is it possible to have a WIND CHILL below absolute zero?
That’s why they did the experiment in a tower................
Once you get a Bose Einstein Condensate you’ve reached the coldest state of matter, Atoms are no longer individual particles but are all part of a wave. Light shined thru it slows down all the way to 38 miles per hour. It has to be measured with laser pulses lasting a billionth of a second. Anything longer would heat up the Condensate to normal matter again.
Cold cold heart
https://m.youtube.com/watch?v=Wn2e4Dhod7M
C is never zero; it's the speed of light in a vacuum. It's a constant, never changes.
If and only if.
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