(I'm sorry for my poor English.) I draw a sketch showing the intensity of the magnetic field at two points p1 and p2, where the distance from the source (a wire carrying a current, for example) to p2 is greater than it's for p1. Is the shape of the curve correct? Is it correct that t2-t1/c is the distance traveled by the wave? Also, why is the final magnitude of B less in p2 than it's in p1 (what occurs in each point right after the wave pass)?