Cosmologic philosophy: a new unproven theory, fractons (Introduction)

by David Turell , Monday, July 26, 2021, 20:49 (1216 days ago) @ David Turell

No proof, but if you can imagine it and create it on a big computer, it must exist:

https://www.quantamagazine.org/fractons-the-weirdest-matter-could-yield-quantum-clues-2...

"The theoretical possibility of fractons surprised physicists in 2011. Recently, these strange states of matter have been leading physicists toward new theoretical frameworks that could help them tackle some of the grittiest problems in fundamental physics.

"Fractons are quasiparticles — particle-like entities that emerge out of complicated interactions between many elementary particles inside a material. But fractons are bizarre even compared to other exotic quasiparticles, because they are totally immobile or able to move only in a limited way. There’s nothing in their environment that stops fractons from moving; rather it’s an inherent property of theirs. It means fractons’ microscopic structure influences their behavior over long distances.

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"To see what’s so exceptional about fracton phases, consider a more typical particle, such as an electron, moving freely through a material. The odd but customary way certain physicists understand this movement is that the electron moves because space is filled with electron-positron pairs momentarily popping into and out of existence. One such pair appears so that the positron (the electron’s oppositely charged antiparticle) is on top of the original electron, and they annihilate. This leaves behind the electron from the pair, displaced from the original electron. As there’s no way of distinguishing between the two electrons, all we perceive is a single electron moving.

"Now instead imagine that pairs of particles and antiparticles can’t arise out of the vacuum but only squares of them. In this case, a square might arise so that one antiparticle lies on top of the original particle, annihilating that corner. A second square then pops out of the vacuum so that one of its sides annihilates with a side from the first square. This leaves behind the second square’s opposite side, also consisting of a particle and an antiparticle. The resultant movement is that of a particle-antiparticle pair moving sideways in a straight line. In this world — an example of a fracton phase — a single particle’s movement is restricted, but a pair can move easily.

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"The immovability of fractons makes it very challenging to describe them as a smooth continuum from far away. Because particles can usually move freely, if you wait long enough they’ll jostle into a state of equilibrium, defined by bulk properties such as temperature or pressure. Particles’ initial locations cease to matter. But fractons are stuck at specific points or can only move in combination along certain lines or planes. Describing this motion requires keeping track of fractons’ distinct locations, and so the phases cannot shake off their microscopic character or submit to the usual continuum description.

"Their resolute microscopic behavior makes it “a challenge to imagine examples of fractons and to think deeply about what is possible,” said Vijay, a theorist at the University of California, Santa Barbara. “Without a continuous description, how do we define these states of matter?'”

Comment: unproven, created by giant computer simulations. Lots of new excitement. Please remember theoretical physicists live on grant money. They must invent new ideas to get those grants. Lets not stop them, but lets wait and see what, if anything, develops for real.