Thread: 2 Questions

Firstly, I know that earth has a magnetic field and I seem to remember reading somewhere that the sun has multiple magnetic fields.

Extending this a bit further, does the galaxy have a larger magnetic field and if it did would there be any way to look at it, from earth?

This made me wonder about whether a black hole could have a magnetic field, despite the strong gravity? and what would that look like?

My other question involves "free-roaming" planets, my view is 2-fold, firstly if planets are as common as it appears from recent observations? what happens when stars explode in supernova's, I had the view that the planets close to the star when that happens will very likely get swallowed by the exploding star, but if the planets in the outer orbits survive the explosion they would just drift off into space

My other thought was could systems develop without the star at the core, hence sort of dark systems just drifting through space, which led me to wonder about how common this sort of thing would be, and perhaps when we see planets in odd orbits etc are planets that were caught by the stars gravity as it traveled past.

So my questions are is there any info on this sort of thing or is there any evidence at the moment regarding this stuff

Also could I get some thoughts from the forum regarding these questions, just trying to get some discussion going around both of these issues.

Originally Posted by Always.Asking

Firstly, I know that earth has a magnetic field and I seem to remember reading somewhere that the sun has multiple magnetic fields.

Extending this a bit further, does the galaxy have a larger magnetic field and if it did would there be any way to look at it, from earth?

This made me wonder about whether a black hole could have a magnetic field, despite the strong gravity? and what would that look like?

My other question involves "free-roaming" planets, my view is 2-fold, firstly if planets are as common as it appears from recent observations? what happens when stars explode in supernova's, I had the view that the planets close to the star when that happens will very likely get swallowed by the exploding star, but if the planets in the outer orbits survive the explosion they would just drift off into space

My other thought was could systems develop without the star at the core, hence sort of dark systems just drifting through space, which led me to wonder about how common this sort of thing would be, and perhaps when we see planets in odd orbits etc are planets that were caught by the stars gravity as it traveled past.

So my questions are is there any info on this sort of thing or is there any evidence at the moment regarding this stuff

Also could I get some thoughts from the forum regarding these questions, just trying to get some discussion going around both of these issues.

If a galaxy has a magnetic field? if it moves perpendicular to its extent it would have a resultant magnetic field. It could be strong, after all, it only decrease proportional with radius. Probably it evens up around the sun, through magneticly charged electron emission. So if you wanna check the galaxies magnetic field you have to be outside the solar system. Or further out then earth in any case.

So I ask you back, do the galaxy have a magnetic field?

Originally Posted by LeavingQuietly

If a galaxy has a magnetic field? if it moves perpendicular to its extent it would have a resultant magnetic field. It could be strong, after all, it only decrease proportional with radius. Probably it evens up around the sun, through magneticly charged electron emission. So if you wanna check the galaxies magnetic field you have to be outside the solar system. Or further out then earth in any case.

So I ask you back, do the galaxy have a magnetic field?

Im not sure if it does?

I assume if what u say is correct with regards to being out of the solar system in order to detect it we actually dont know?

Does gravity effect magnetic fields? Can a magnetic field escape a black hole?

This may answer some of your questions.
http://www.astro.ku.dk/RelViz/ostman/bhe.html

Black hole electrodynamics is the theory of electrodynamics outside a black hole. This is evident since we cannot gain information about anything inside the event horizon

A rotating charged black hole creates a magnetic field around the hole because the inertial frame is dragged around the hole. Far from the black hole at infinity the black hole electric field is that of a point charge, and the magnetic field is a dipole

Originally Posted by Always.Asking

Originally Posted by LeavingQuietly

If a galaxy has a magnetic field? if it moves perpendicular to its extent it would have a resultant magnetic field. It could be strong, after all, it only decrease proportional with radius. Probably it evens up around the sun, through magneticly charged electron emission. So if you wanna check the galaxies magnetic field you have to be outside the solar system. Or further out then earth in any case.

So I ask you back, do the galaxy have a magnetic field?

Im not sure if it does?

I assume if what u say is correct with regards to being out of the solar system in order to detect it we actually dont know?

Does gravity effect magnetic fields? Can a magnetic field escape a black hole?

Well, no since magnetic fields have mass and lightspeed (so a magnetic field cannot escape a black hole). Gravitons have lightspeed. But in the case of mass, the gravitational object sends out gravitons that decrease the mass of the subject because the speed gets closer to rest speed.
the graviton thereby has negative mass. That's why it doesn't release energy when it attracts.

Originally Posted by LeavingQuietly

Well, no since magnetic fields have mass and lightspeed (so a magnetic field cannot escape a black hole). Gravitons have lightspeed. But in the case of mass, the gravitational object sends out gravitons that decrease the mass of the subject because the speed gets closer to rest speed.
the graviton thereby has negative mass. That's why it doesn't release energy when it attracts.

magnetic fields have mass, thats certainly news to me, but I am hardly an expert on this stuff

My view was if a magnetic field can exist in space (i.e. perfect vacuum) then it has no mass

And gravitons with negative mass? are u sure about these statements, can u provide a few references.

Nothing as far as Im aware has negative mass, because then u start going up against general relativity. I.e. neg mass = faster than light speed in velocity

Thanks for the link Harold, that answers my question regarding the black holes and their magnetic fields, back to the rogue planets questions I guess.

Originally Posted by Always.Asking

Originally Posted by LeavingQuietly

Well, no since magnetic fields have mass and lightspeed (so a magnetic field cannot escape a black hole). Gravitons have lightspeed. But in the case of mass, the gravitational object sends out gravitons that decrease the mass of the subject because the speed gets closer to rest speed.
the graviton thereby has negative mass. That's why it doesn't release energy when it attracts.

magnetic fields have mass, thats certainly news to me, but I am hardly an expert on this stuff

My view was if a magnetic field can exist in space (i.e. perfect vacuum) then it has no mass

And gravitons with negative mass? are u sure about these statements, can u provide a few references.

Nothing as far as Im aware has negative mass, because then u start going up against general relativity. I.e. neg mass = faster than light speed in velocity

Thanks for the link Harold, that answers my question regarding the black holes and their magnetic fields, back to the rogue planets questions I guess.

well, magnetic fields have energy, but gravity fields don't; example:

a big steady object is composed by materials fallen to it from all directions and are thereby more still. Thus matter is less on earth then floating around in space, I refer to relative mass in special relativity.

So either the gravitons have no mass or negative mass, either way you put it it can escape itself...

Yes... lonely planets floating around in space 1. is heavily conducting & cold 2. spins like most things. they have a little magnetic field, I don't know about molten core though. It's an interesting question though. Nasa has some kinda cool telescope, you can ask them.