Generating Electromagnetic Waves

Caio Ferrari

Every book I ever read describes a electromagnetic wave as a phenomena generated by charged particles accelerating. This will produce a change in electric field that induces a magnetic field.
But, due to Maxwell equations a change in magnetic field will also produce an electric field. So, if a hold a permanent magnet bar into an spring mass system, does it will produce an electromagnetic wave???

mfb

How does the permanent magnet generate its magnetic field? With charged electrons and their spin.
How do you change the magnetic field? By accelerating the object with its charges ;).

Moving a permanent magnet up and down should produce electromagnetic waves, probably with a terrible efficiency.

Caio Ferrari

So, even a magnetic field is generated by a charged particles accelerated. That's ok.
It means that the only source of electromagnetic waves is a electric charge.

But I've never seen a book or even a example in which a wave is produced by a permanent magnet. Even a pulsar produces its waves because the electrons are being accelerated by a very strong magnetic field.

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mfb Mentor	How does the permanent magnet generate its magnetic field? With charged electrons and their spin. How do you change the magnetic field? By accelerating the object with its charges ;). Moving a permanent magnet up and down should produce electromagnetic waves, probably with a terrible efficiency.

Caio Ferrari	So, even a magnetic field is generated by a charged particles accelerated. That's ok. It means that the only source of electromagnetic waves is a electric charge. But I've never seen a book or even a example in which a wave is produced by a permanent magnet. Even a pulsar produces its waves because the electrons are being accelerated by a very strong magnetic field.