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Re: Lenz's Law


Peter Craft asked about analogies between Lenz's Law and Newton's Third

As with Hugh Haskell, I do not see any analogy here. But I do see an
analogy with Newton's Second Law in that they are both inertia type
principles. Just as a system made of matter resists a change in its state of
motion, a system of E and B fields resists a change in the values of those

High also wondered about the assymetry of the +/- signs between Lenz's
Law and Maxwell-Ampere's Law. If this assymetry did not exist, the "inertia"
of changing E and B fields would not exist. A change in either field would
create a run away cascading process that would drive both field strengths to

I have wondered, as I suppose all of us have, why the universe should
obey any physical laws at all. Going way out on a philosophical limb, my own
personal solution is precisely the existence of these generalized
inertia-like laws. Imagine a number of universes at some time being created.
Those univereses that did not obey some sort of underlying law would be
inherently unstable and quickly self-destruct.

Ed Schweber
Physics Teacher
Solomon Schechter Day School
West Orange, NJ