# Is there a way to know how the magnetic field was at the very beginning of our universe?

I recently read that

Gamma-ray bursts are catastrophic events, related to the explosion of massive stars 50 times the size of our sun. If you ranked all the explosions in the universe based on their power, gamma-ray bursts would be right behind the Big Bang,

I'm asking this question in the tentative to compare the Big Bang to a gamma-ray burst. I keep in mind that a key difference between both is that Big Bang was Not an explosion, but want to know similarities to point out.

Near the formation of a black-hole they tell in this same article that matter and magnetic field play a key role the gamma-ray bursts.

I know magnetic fields are induced by charge displacement. Is it possible there was a kind magnetic field before protons and electrons formed, or during the first expansion phase?

Here are pictures I modified from Wikipedia's chronology of the universe to illustrate:

• Do we have a way to know how magnetic fields were at that time?

Close-up (image borrowed from donsnotes ):

• Any way we could have information on magnetism at this point of universe creation?
• In the Electroweak Era?
• During the Great Unification Theory (GUT) Era?
• And then in the Plank Era?
• Not my field, but since quarks have charge, they also induce magnetism. So from they were formed $10^{-12}$s after BB, and until they became confined in hadrons (including protons and neutrons) $10^{-6}$s after BB, there should be a microsecond of magnetic fields without protons and neutrons. Whether you call this "the first expansion phase" is up to you, I guess, but note that it is much later (well, a picosecond) than inflation which ended around $10^{-32}$s after BB. – pela Aug 2 '17 at 22:04
• It should be noted that the Big Bang was not an explosion. – Phiteros Aug 2 '17 at 22:59
• Not my field either, but I would think, strong magnetic fields require objects of some size and mass bound together and rotating. A soup of free charged particles (I think) wouldn't create significant magnetic fields. Also see here en.wikipedia.org/wiki/… – userLTK Aug 4 '17 at 15:40

## 2 Answers

Is there a way to know how the magnetic field was at the very beginning of our universe?

I don't know of one. But then again I think there was no magnetic field at all at the very beginning of the universe. I can't point to any material that proves this beyond a doubt. But I can say that a quiescent black hole "has no hair", so it has no magnetic field, and the evolution of the universe is said to be something like pulling away from a black hole. See Hawking saying the universe is like a time reversed black hole here.

I recently read that "Gamma-ray bursts are catastrophic events, related to the explosion of massive stars 50 times the size of our sun. If you ranked all the explosions in the universe based on their power, gamma-ray bursts would be right behind the Big Bang". I'm asking this question in the tentative to compare the Big Bang to a gamma-ray burst. I keep in mind that a key difference between both is that Big Bang was Not an explosion, but want to know similarities to point out.

There aren't many similarities. A gamma-ray burst is where some of the infalling matter is directed by magnetic fields generated by infalling matter and converted into gamma rays. The Big Bang is when the space of the universe started expanding.

Near the formation of a black-hole they tell in this same article that matter and magnetic field play a key role the gamma-ray bursts.

True enough. But as far as I know matter and magnetic fields played no role in the Big Bang.

I know magnetic fields are induced by charge displacement. Is it possible there was a kind magnetic field before protons and electrons formed, or during the first expansion phase?

It's possible I suppose. A magnetic field is associated with curl aka "rot" which is short for rotor. The early universe could have had an overall magnetic field, or gravitomagnetic field, if it was somehow rotating. See Mark Hadley's Galaxy sized twist in time pulls violating particles back into line. Also see the universe may have been born spinning. But I think it's rather speculative stuff myself.

Do we have a way to know how magnetic fields were at that time?

I don't think so. The early universe was said to be maelstrom. Hence I think information about the initial state got scrambled.

Magnetic fields play a role in gamma-ray bursts (GRB) because you have a star that is collapsing into a black hole the magnetic fields serve to funnel a small portion of material into two jets coming out of the poles. If the jet happens to be pointing in the direction of the Earth, we see a very bright light source and that's what we call a GRB.

Clearly none of this has any analog in the Big Bang.