Magnetic Field Changes: Instant or Gradual?

[limitkiller]

Does a change in a magnet cause a change in the magnetic field everywhere instantly?or does the change appear in the nearer points first?

 

[Doug Huffman]

There is no instantaneity. Photons mediate the EMF.

 

[limitkiller]

thank you

 

[limitkiller]

what about gravity?does moving a mass towards the other effect it instantly?

 

[Doug Huffman]

A graviton has not yet been captured, but as a mediating boson (no mass no charge spin 2) it will be limited to lightspeed just like the photon.

 

[limitkiller]

could you elaborate please?I mean how do these bosons know how far is the other mass?or is it regulated by the number of bosons which reach the mass?(doesn that mean putting a third mass in between would absorb some of the bosons and affect the gravity).

 

[Drakkith]

A change in either the gravitational or electromagnetic fields propagates along at c (light speed). As for bosons mediating the forces, I highly recommend not getting into the concept of bosons and virtual particles at this point. Classical physics works just fine.

 

[tech99]

Does a change in a magnet cause a change in the magnetic field everywhere instantly?or does the change appear in the nearer points first?

I think the change in magnetic field would be accompanied by an electric field, so an EM wave is created. A magnetic field is carried along by an EM wave at velocity c..