Temperature and Magnetism

1. Jun 7, 2004

Antonio Lao

It is an experimental fact that the strength of a magnetic field is inversely proportional to the temperature of the field generator.

Can we conclude from this that the hotter an object is, the weaker is its magnetic field. Conversely, the colder an object is, the stronger is its magnetic field.

This could mean that the magnetic field in the interior of planets and stars is very weak. Since the vacuum is very cold, its magnetic field must be very strong. This field is strong enough to drive the motion of cosmic radiation, to which its origin is still not clearly determined.

2. Jun 7, 2004

Icarus

If temperature were the only thing affecting magnetic field strength, then yes you could conclude that the hotter something is, the weaker its field. However, in truth, magnetic field strength in stars and planets is generally stronger than it is outside, because flux is constant, and inside, it is constrained into a smaller volume.

And vacuum is very cold, but it also does not have anything to drive a macroscopic magnetic field, so it's magnetic field strength is zero.

3. Jun 8, 2004

Antonio Lao

What is the cause of the high velocities of cosmic rays?