# Crushing a magnetic field

What would happen if you crushed a magnetic field to an ever decreasing size?

Thanks.

EDIT:

How small could the field possibly go? Is there a limit on how small it could get?

Is there a maximum field density based on the size?

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It would get smaller. – Dale May 24 '12 at 17:46
and the field density would increase :-) – Rory Alsop May 24 '12 at 17:47
I would suggest to add a "mumbo-jumbo" tag. – yohBS May 24 '12 at 17:52
Fields can't move, so you can't crush them--- they are at fixed points. You should ask "what happens if I concentrate a given amount of field energy in a smaller and smaller region in a stronger and stronger magnetic field". This can't happen by crushing, and in fact, it is hard to see how to do it: you need a smaller and smaller solenoid. Without the precise setup, the question is not clear. Are you asking "what happens if you squeeze a static magnetic field into a region which is very small in all dimensions?" This is impossible by zero divergence. – Ron Maimon May 24 '12 at 18:20
@Ben yohBS is kind of making a valid point, though - it's not really clear what you mean by crushing a magnetic field, given that it's not a solid physical object and that it doesn't have a size (it fills all of space). Could you edit your question further to clarify what you mean? – David Z May 24 '12 at 19:39