Far out cosmology: magnetic fields origin (Introduction)

by David Turell @, Thursday, July 27, 2023, 18:11 (483 days ago) @ David Turell

New possibility:

https://www.newscientist.com/article/2384429-we-may-have-finally-figured-out-how-galaxy...

"We may finally know how the magnetic fields that now permeate the universe first arose. Much of the universe was once a churning unmagnetised plasma, and a new set of simulations shows how that plasma may have developed powerful magnetic fields.

"Lorenzo Sironi at Columbia University in New York and his colleagues simulated turbulence in plasma to study a phenomenon called the Weibel instability. When a fluid is turbulent, asymmetries can develop when more particles happen to be moving in one direction than the others. These asymmetries in charged particles cause tiny magnetic fields to spontaneously arise.

"The researchers found that the Weibel instability creates a small “seed” magnetic field, which forces charged particles to bunch together. That clumping, along with the swirling plasma, drives an increase in magnetism. “The turbulence takes these magnetic field lines and twists them, stretches them, folds them and that effectively makes them stronger,” says Sironi. This could grow a tiny magnetic field to the galactic and even intergalactic scales we see now, they found.

"This is important because the beginnings of large-scale magnetic fields has been an open question among astronomers for a long time. Individual objects such as stars and planets can generate their own magnetic fields easily through internal processes, but galaxies and clusters, and even the spaces between galaxies, are also often full of magnetic fields, and the origins of those have been tougher to tease out.

“'This could possibly provide a mechanism as to the reason some of the most pristine regions in the universe have a nonzero magnetic field,” says Sironi. “This is a mechanism for magnetising the universe.” It isn’t the only possible mechanism, he says, but it is a promising one. Understanding these magnetic fields could also help astronomers figure out the properties of turbulent plasmas across the universe, which are extremely difficult to measure directly."

Comment: a very possible answer. But doesn't help dhw who want to know why God's universe is so big. God wanted it that way.


Complete thread:

 RSS Feed of thread

powered by my little forum