If light has no charge and mass, how can it have an electric field?

[jlyu002@ucr.e]

Since it does have an electric field, if we were to put a positive test charge near it, would it exhibit an inward field or an outward field?

 

[Matterwave]

A photon doesn't produce an electric field, it is a neutral particle as you stated in the title. Photons are the excitations of the electric field.

 

[Vanadium 50]

A test charge would move first in one direction, then the other.

 

[sophiecentaur]

A test charge would move first in one direction, then the other.

And it does this, frequently, up in the ionosphere - or you wouldn't hear HF transmissions from all over the World.

 

[jaydnul]

A test charge would move first in one direction, then the other.

Do you know of any video or specific experiments that show this behavior? I'm really interested.

 

[Cthugha]

Do you know of any video or specific experiments that show this behavior? I'm really interested.

"Direct measurement of light waves", E. Goulielmakis et al., Science 305, 1267 (2004). http://www.attoworld.de/Documents/papers/Science/Science305p1267_2004.pdf.

These are not charges at rest moving back and forth, but you see a modulation in the kinetic energy/momentum of moving electrons, which is close enough, I guess.

 

[Drakkith]

Do you know of any video or specific experiments that show this behavior? I'm really interested.

Turn on a radio. It uses this exact behavior.

 

[Vanadium 50]

Do you know of any video or specific experiments that show this behavior? I'm really interested.

Yes. It's called a "radio antenna".

 

[WhatIsGravity]

Funny, now I'm curious too... can there exist a photon without some sort of external/residual/whatever of a field? I know the e and m fields balance/cancel when traveling at c... really? And apologies, holiday weekdnd, kinda been drinking.

 

[Drakkith]

Funny, now I'm curious too... can there exist a photon without some sort of external/residual/whatever of a field? I know the e and m fields balance/cancel when traveling at c... really? And apologies, holiday weekdnd, kinda been drinking.

A photon is the quanta of interaction of the EM field, so no, it cannot exist without the EM field.

 

[WhatIsGravity]

A photon is the quanta of interaction of the EM field, so no, it cannot exist without the EM field.

Does a photon create it's own EM field, as it goes, or is that field just there?

 

[Drakkith]

Does a photon create it's own EM field, as it goes, or is that field just there?

To my knowledge, the field always exists.