On Wed, May 25, 2011 at 4:50 PM, <mix...@bigpond.com> wrote: > In reply to Joshua Cude's message of Wed, 25 May 2011 16:08:10 -0500: > Hi, > [snip] > >What do mean by "we"? It's not from observing e-m waves that we know the > >fields are perpendicular. It follows from Maxwell's equations, which > predict > >the waves. So, certainly some people can explain in arbitrary detail why > >they are perpendicular, given what we know about the properties of the > >fields as described by Maxwell's equations. > > I think you have this backwards. The mathematical models were developed to > describe the facts on the ground, not the other way around. >
Maxwell's equations were developed to describe laboratory electricity and magnetism experiments. The resulting equations then predicted the existence of electromagnetic waves with the correct speed. As Maxwell put it: "The conclusion was inescapable: light is “an electromagnetic disturbance in the form of waves” propogated in the ether." The equations also require that the field are perpendicular. > Regards, > > Robin van Spaandonk > > http://rvanspaa.freehostia.com/project.html > >
