Physical meaning of parts of electromagnetic wave

littlepapa87

in

E = E_0exp i(k dot r - wt) or E = cos(k dot r - wt)

what does k dot r physically represent? Can r be any position in space or must it lie on the wave?

(I physically understand what a dot product is)

Dr Lots-o'watts

That's a plane wave, it occupies all of space.

If you want a beam that is localized along a line, E_0 has to be a function of distance from the line.

jtbell

Yes.

A 3-dimensional plane wave fills space. It doesn't lie "along" a line or other single path. See the diagram and associated instructions in the following post for a more realistic picture of a plane electromagnetic wave than you see in many textbooks.

http://www.physicsforums.com/showpos...90&postcount=6