Re: [Phys-l] EM, is it energy

[Jack Uretsky <jlu@hep.anl.gov>]

It is easy to get lost in meaningless jumbles of wards, like, "if a wave 
is flowing in empty space."  Think of an experiment - even an idealized 
one.  For example, consider an an isolated antenna, and an e-m wave 
incident on the antenna.  Now ask about the forces on the antenna.  Ask 
about the energy imparted to the antenna, and how you would measure that 
energy.
				Regards,
					Jack


On Fri, 30 Nov 2007, carmelo@pacific.net.sg wrote:

> Quoting "LaMontagne, Bob" <RLAMONT@providence.edu>:
> > ?? If the wave is traveling through empty space, what are these "forces"
> > acting upon? Do you mean fields?
> >
> > Wave is energy? Guess it depends on what the definition of "is" is! Oops
> > - I guess this is more appropriate for the PHYSOC list
> >
> > Bob at PC
>
> This was quoted from BBC News: (Not my idea!)
> http://news.bbc.co.uk/1/hi/sci/tech/1702259.stm
>
> Ironically, many physicists prefer to consider energy as an "abstract
> concept", yet explain the flow of energy through Poynting vector as if
> it is a material being. Poynting Vector gives the direction of flow of
> "abstract concept"?
>
>
> Alphonsus
>
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