Where would the energy go when cancelling waves in vacuum?

Question

If two EM waves 180 deg. out-of-phase meet in a vacuum they would cancel out.
1. Where would the energy go?
2. How would you explain the result using photons?

Take a look here before answer:
http://www.advancedphysics.org/forum/showthread.php?t=2459

Answer 1

You've asked a GREAT question!

This very question lead Nobel Prize winning Physicist, Richard Feynman, to state, "...the electric and magnetic fields are only mathematical book keeping, and weren't 'real' in an observable sense..." Turns out, he retracted this statement and said it was wrong when "Vacuum Polarization" experiments provided direct evidence of the Electromagnetic field...

Anyway, the short answer, when the EM waves are canceling-out at some observation point, no power/energy flows from the source.

This simple, insightful observation, leads into Feynman's fascinating idea that the emission of EM-radiation is dependent on the 'observer' of the radiation...

To add a little more, while Feyman was a Graduate student at Princeton he worked out a solution to Maxwell's Equations involving "direct-action" as he called it. That is, it was a solution that didn't involve any fields at all, just the emitter and absorber of the radiation acting directly on each other.

Answer 2

O.K. I had a look at your link. It's the usual thing, a lot of guys sitting around waving their hands about and talking claptrap.

Have you ever tried to generate an EM plane wave ? They do not exist. They are just a theoretical abstraction which is useful when dealing with huge numbers of photons apparently originating in a distant source. People talking about EM plane waves are basically saying, "This is just an approximation but It's accurate enough for me!" which is fine but they then forget that it's just a simplification and start to treat it as though it's physically possible.

So , your first premise ' If two EM waves 180 deg. out-of-phase meet in a vacuum they would cancel out.' is not falsifiable.

Best of Luck - Mike

Answer 3

EM waves, being waves, are no longer localized. they have the two region and direction. For waves to cancel thoroughly over a huge quantity, they might could desire to could desire to have an identical region and direction---they could be interior an identical state, and any accounting for the ability might could desire to contain the source of the wave, i.e. the boundary situations of the state. If the two waves have opposite area and comparable amplitude at one factor in area, then they cancel at that one factor. The power is going into the wave at different places, the place the waves combine constructively. Photons are debris whose dynamics are desperate by skill of the photon wave function. The photon wave function behaves like classical EM waves, as a fashion to make the pronounced density of photons equivalent to the classical power density.

Answer 4

i am not so much of a brilliant person and definitely not in advanced physics! but i am really interested in physics and the realities they open to me.

I think in my own humble opinion from my generalization of my readings in every possible things i can read, energy has always been here and will be for the rest, they just transform. and matter is also another transformation of energy in E=mc^2.

There are many kinds of energies.

when the energy of the waves met they cancelled out, but the energy, where does it go? I think the energy is still there having been tranformed to potential energy, but what object is holding the potential energy maybe the one i cannot answer, maybe, the waves is holding the potential energy until a system near it will absorb the potential energy when the conditions are right for it to occur.

If the system can be separated forever from outside influences, the potential energy will be there for infinity logically. the net transfer and absorption of energies will be zero.

Answer 5

I don't know and nobody could give me a good aswer for that every time I asked it.

Answer 6

1. no idea
2. ask your teacher

Answer 7

It would be radiated into space.