Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: acsinuk on 21/10/2015 16:06:35

Title: Is intergalactic space magnetised?
Post by: acsinuk on 21/10/2015 16:06:35
If space is magnetised then the stars inside a galaxy will all rotate in a uniform pattern. Have just read an article by BryanG that demonstrates that even old galaxies are magnetise as is proven by the fact that light passing through them is polarized. 
If this is the case then stars will be forced to rotate magnetically and the need for dark matter will disappear.  See  http://dunlap.utoronto.ca/~bgaensler/papers/stories/301Gaensler-3.pdf
Title: Re: Is intergalactic space magnetised?
Post by: chris on 23/10/2015 07:46:36
For a magnetic field to exist there must be a source for that field: charged particles moving, for example. A field cannot come from nowhere, so what would be the origin of this field?
Title: Re: Is intergalactic space magnetised?
Post by: PmbPhy on 23/10/2015 09:54:10
If space is magnetised then the stars inside a galaxy will all rotate in a uniform pattern. Have just read an article by BryanG that demonstrates that even old galaxies are magnetise as is proven by the fact that light passing through them is polarized. 
If this is the case then stars will be forced to rotate magnetically and the need for dark matter will disappear.  See  http://dunlap.utoronto.ca/~bgaensler/papers/stories/301Gaensler-3.pdf
That idea is badly flawed. Even if space was magnetized, which it isn't, then it wouldn't cause a stars orbital speed to increase. It wouldn't even cause its rotational speed to increase.
Title: Re: Is intergalactic space magnetised?
Post by: acsinuk on 23/10/2015 11:48:50
Where is your proof that galaxies are not magnetised.  All the evidence surely is that they are?
Title: Re: Is intergalactic space magnetised?
Post by: Colin2B on 23/10/2015 12:57:49
If space is magnetised then the stars inside a galaxy will all rotate in a uniform pattern. Have just read an article by BryanG that demonstrates that even old galaxies are magnetise as is proven by the fact that light passing through them is polarized. 
If this is the case then stars will be forced to rotate magnetically and the need for dark matter will disappear.  See  http://dunlap.utoronto.ca/~bgaensler/papers/stories/301Gaensler-3.pdf
There is a big difference between polarising light and causing stars to rotate. All the data I've seen suggests the fields are not strong enough to do that.
Title: Re: Is intergalactic space magnetised?
Post by: PmbPhy on 23/10/2015 16:02:18
Where is your proof that galaxies are not magnetised.  All the evidence surely is that they are?
I don't like answering these kinds of questions anymore because almost always it is not that worthwhile to pursue ideas like these.

First of all it's not meaningful to speak of space as being magnetized in the sense that you used it here. See:
http://www.thefreedictionary.com/magnetized
Quote
Magnetized: to make magnetic.
You seem to be saying that the entire galaxy is a magnet which we know to be false.

In the second place, you're quite wrong in that (1) there is no evidence for the existence of such magnetization and (2) like Chris explained you can't have magnetization with nothing which is causing it to magnetize. Not to mention that it would also destroy the symmetry of space. I.e. if there is a magnetic field everywhere then in what direction is it pointing?

Think about it. If the galaxy was magnetized then everywhere you go, even in your bedroom, there would be a magnetic field other than that of the Earth's since the magnetic field around the Earth has been measured we know that the only field there is due to the Earth itself. Solar winds are streams of charged particles. If the universe was magnetized then no solar wind would ever reach the Earth. Those particles would go into orbit around the Sun, loose energy and then spiral back into the Sun. The existence of the Van Alan belt proves this not to be the case.

Regarding your request about proving that "galaxies are not magnetized" you should know that the science of physics is not about proving things. It's about running experiments and making observations to confirm things are as theorized. If not then the theory is wrong, etc.

See The science of physics is not about "proving" anything by Alan Guth at:
http://www.newenglandphysics.org/common_misconceptions/DSC_0002.MOV

And dark matter isn't just found in galaxies, its been hypothesized to be everywhere in the universe. See:
https://en.wikipedia.org/wiki/Dark_matter
Quote
Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but would account for most of the matter in the universe.
....
Structure formation (https://en.wikipedia.org/wiki/Dark_matter#Structure_formation)

Dark matter is crucial to the Big Bang model of cosmology as a component which corresponds directly to measurements of the parameters associated with Friedmann cosmology solutions to general relativity. In particular, measurements of the cosmic microwave background anisotropies correspond to a cosmology where much of the matter interacts with photons more weakly than the known forces that couple light interactions to baryonic matter. Likewise, a significant amount of non-baryonic, cold matter is necessary to explain the large-scale structure of the universe.
Title: Re: Is intergalactic space magnetised?
Post by: acsinuk on 24/10/2015 10:11:20
Thank you for your detailed reply.  However, you state "Solar winds are streams of charged particles. If the universe was magnetized then no solar wind would ever reach the Earth. "
But surely the only reason that charged particles will move is if there is an electro-magnetic or electro-static force pulling them forward.  If this was not so the H+ ions would just combine together as a gas molecule and drift. 
No; there is a huge voltage difference between the positive sun and our negative planet which is attracting the solar wind ions forward towards us.
Title: Re: Is intergalactic space magnetised?
Post by: jeffreyH on 24/10/2015 12:58:44
Words fail me. For once I feel nothing I say will have any impact.
Title: Re: Is intergalactic space magnetised?
Post by: PmbPhy on 28/10/2015 03:41:02
Quote from: acsinuk
But surely the only reason that charged particles will move is if there is an electro-magnetic or electro-static force pulling them forward.
I don't understand this comment. You're acting like there has to be a force on a particle in order to make it move. Surely you're aware of Newton's first law. See: https://en.wikipedia.org/wiki/Newton%27s_laws_of_motion#Newton.27s_first_law
Quote
The first law states that if the net force (the vector sum of all forces acting on an object) is zero, then the velocity of the object is constant.
That means that if a body is in motion then it will stay in motion unless acted upon by a force.

Regarding galactic magnetic fields: I was quite surprised to find this online. See: http://www.scholarpedia.org/article/Galactic_magnetic_fields
Quote
Magnetic fields are a major agent in the interstellar medium (ISM) of spiral, barred, irregular and dwarf galaxies. They contribute significantly to the total pressure which balances the ISM against gravity. They may affect the gas flows in spiral arms, around bars and in galaxy halos. Magnetic fields are essential for the onset of star formation as they enable the removal of angular momentum from the protostellar cloud during its collapse.
Thanks for asking this question. Otherwise I'd never have know about this! I love it when I'm properly proved wrong. [:)]
Title: Re: Is intergalactic space magnetised?
Post by: acsinuk on 31/10/2015 12:07:19
The confusion is Newtons energy is scalar but electro-magnetic energy is three dimensional in a set time. 
So  3D fundamental magneticflux energy, created by God, is formed by an electromagnetic force which is considered by an observer to be real scalar kinetic energy if it moves real matter forward or may increase the magnetic vibration of light-waves or the magnetic vibration of the inside of molecules resulting in an increase in temperature. However, negative energy can also be formed from anti-matter which will annihilate real energy and even more complex, it is possible to have virtual energy which is formed by magnetic energy which is at right-angles to the observer either in an up or down direction [Capacitive or Inductive VAR’s].