Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: DoctorBeaver on 09/08/2009 15:45:32

Title: What happens to the magnetism if all the molecules in a magnet get ripped apart?
Post by: DoctorBeaver on 09/08/2009 15:45:32
I was replying to Sheepie's thread about singularities when I had another of my silly thoughts that I have neither the knowledge nor the intellect to fathom out.

Imagine you chuck billions of magnets into a black hole. As they get closer, tidal forces will push them together. The law of averages says that some will be orientated in the same direction and will thus repel each other. I assume that at some point the external forces will overcome the magnetic repulsion & they will be pushed together.

But, when they get close enough to the centre of the black hole, they will be ripped to pieces. I think I'm right in saying that single molecules or single atoms cannot be dipoles (can they?). Certainly single particles can't, which is how the magnets will end up.

So where does the magnetism go? Does it get booted out in the form of EM radiation? If so, would a magnet being ripped apart emit more EM than a similar mass of a non-magnetic substance?
Title: What happens to the magnetism if all the molecules in a magnet get ripped apart?
Post by: lyner on 09/08/2009 16:03:44
Would you have the same problem envisaging  a charged capacitor ending up in a black hole? I think we are in the same ballpark there. As electrons get re arranged with increasingly savage conditions some em energy would be transferred. I don't think it's harder than that.
(V. glib but you know what I mean).
Title: What happens to the magnetism if all the molecules in a magnet get ripped apart?
Post by: DoctorBeaver on 09/08/2009 16:13:59
Transferred to where? Other electrons?
Title: What happens to the magnetism if all the molecules in a magnet get ripped apart?
Post by: lyner on 09/08/2009 21:42:50
To internal energy - i.e. increase in temperature.
Title: What happens to the magnetism if all the molecules in a magnet get ripped apart?
Post by: DoctorBeaver on 09/08/2009 23:17:37
So the magnetism gets converted to heat. OK, that makes sense. Do you happen to know what effect, if any, intense gravity has on the temperature of a particle?
Title: What happens to the magnetism if all the molecules in a magnet get ripped apart?
Post by: lyner on 10/08/2009 10:23:46
Yes. The "magnetism" involved putting energy into the system to arrange the charges a certain way. That can turn up as kinetic energy when the  'magnet' is torn apart. It's a bit like the "what happens to the energy in a coiled spring in acid' question that we had recently.

Btw: One particle doesn't 'have temperature'. Temperature is the average Kinetic Energy of a large number of particles (a statistical thing). As the particle falls deeper and deeper towards the BH, its Gravitational Potential Energy becomes more and more Negative (an attractive field) so its KE will increase so that the total energy is conserved. Once it is actually a part of the central mass, it will lose its identity as a particle and be in a different state so I couldn't really say what happens to 'it'.
Title: What happens to the magnetism if all the molecules in a magnet get ripped apart?
Post by: DoctorBeaver on 10/08/2009 11:13:22
Point taken about temperature. I got carried away with myself there.

So, the overall energy of the system is maintained and there wouldn't be increased EM radiation due to the initial magnetism. You would, though, get increased kinetic energy. Does that mean that if it collided with something it would do more damage than if there were no initial magnetism?
Title: What happens to the magnetism if all the molecules in a magnet get ripped apart?
Post by: peppercorn on 10/08/2009 12:14:21
I'm not totally up on this subject, but I was given to understand this would be linked to the concept of entropy.

The loss of any macro-scale magnetism occurring beyond the event horizon would seem consistent with an increase in the systems entropy (i.e. inside the black hole).

Matter within a black hole is predicted to represent the highest state of entropy possible (apart from Hawkin's recent predictions).
Title: What happens to the magnetism if all the molecules in a magnet get ripped apart?
Post by: Soul Surfer on 10/08/2009 23:03:41
Beaver that is where you are totally wrong!  Individual atoms and sub atomic particles ARE mostly magnetic the reason your material is a magnet in the first place is the fact that these have been aligned in some way to ensure that these individual magnetic particles combine coherently.