MIT Physicists Use Fundamental Atomic Property To Turn Matter Invisible:
A new study confirms that as atoms are chilled and squeezed to extremes, their ability to scatter light is suppressed.
An atom's electrons are arranged in energy shells. Like concertgoers in an arena, each electron occupies a single chair and cannot drop to a lower tier if all its chairs are occupied. This fundamental property of atomic physics is known as the Pauli exclusion principle, and it explains the shell structure of atoms, the diversity of the periodic table of elements, and the stability of the material universe.
Now, MIT physicists have observed the Pauli exclusion principle, or Pauli blocking, in a completely new way: They've found that the effect can suppress how a cloud of atoms scatters light.
Normally, when photons of light penetrate a cloud of atoms, the photons and atoms can ping off each other like billiard balls, scattering light in every direction to radiate light, and thus make the cloud visible. However, the MIT team observed that when atoms are supercooled and ultrasqueezed, the Pauli effect kicks in and the particles effectively have less room to scatter light. The photons instead stream through, without being scattered.
In their experiments, the physicists observed this effect in a cloud of lithium atoms. As they were made colder and more dense, the atoms scattered less light and became progressively dimmer. The researchers suspect that if they could push the conditions further, to temperatures of absolute zero, the cloud would become entirely invisible.
The team's results, reported today in Science, represent the first observation of Pauli blocking's effect on light-scattering by atoms. This effect was predicted 30 years ago but not observed until now.
Journal Reference:
Yair Margalit, Yu-Kun, Furkan Çağrı Top, and Wolfgang Ketterle. Pauli blocking of light scattering in degenerate fermions, Science (DOI: 10.1126/science.abi6153)
(Score: 2, Touché) by Anonymous Coward on Sunday November 21 2021, @03:11AM (1 child)
All that energy expended for super-freezing, super-pressing, and god knows what other foolishness, when you could simply deploy an SEP field.
Eggheads are overeducated morons.
(Score: 5, Funny) by Runaway1956 on Sunday November 21 2021, @03:51AM
Oh, come on now. Did you see the department tag?
I often heard that "It's cold enough to freeze the balls off a brass monkey." No one has ever defined the exact temperature at which that happens. We didn't keep brass monkeys aboard ship for research purposes. Nor do brass monkeys run wild in any of the states or provinces that I have frequented. It would be great to find out just when their balls fall off, then I can be more sure of whether I want to be outdoors when it happens. Of course, if the monkeys turn invisible before their balls fall off, that would make this line of research more difficult.
(Score: 1) by fustakrakich on Sunday November 21 2021, @04:11AM
Oh the irony!
Get too close to the stage, and you'll disappear into the event horizon
La politica e i criminali sono la stessa cosa..
(Score: 3, Informative) by Mojibake Tengu on Sunday November 21 2021, @01:18PM
https://arxiv.org/abs/2103.06921 [arxiv.org]
Respect Authorities. Know your social status. Woke responsibly.
(Score: 0) by Anonymous Coward on Sunday November 21 2021, @07:06PM (2 children)
...are photons mass-carrying now? Without (rest) mass I think they don't have inertia, which means interacting with atoms won't redirect the atoms?
Am I way behind stuck in 1970s science education, have things changed so much? Or is this really such a wrong phrase?
(Score: 2) by ChrisMaple on Monday November 22 2021, @05:31AM
Nichols Radiometer (1901).
(Score: 0) by Anonymous Coward on Monday November 22 2021, @09:51PM
Yeah, I am pretty sure you only need relativistic mass to impart momentum.
The lack of rest mass for a photon is pretty meaningless as it is very hard to keep a photon from moving.
(Score: 0) by Anonymous Coward on Monday November 22 2021, @11:54PM
So... does this make extremely cold dense objects made from ordinary matter candidates for dark matter? Or is this effect already well known in those studies?