Why is light not affected by magnetic fields?

[Jonthegreat]

That's about as satisfying as NOT dying while driving today.

 

I enjoy playing with ideas that people simply accept because there have not been found any reasons why it IS NOT true. Gravity is a big one. The concept of the "speed of light" is another one.

 

Perhaps a drawing is in order for my question. I see proper answers but none are as satisfying as what I am looking for.

 

I appreciate the responses!!! If I HAPPEN to come across anything landmark in my design, I'll be referencing this site as a haven for people who have questions!!

[gregdevid]

Moderation note: the first 5 post of this thread were moved from 17768, because they are more of an in-depth discussion of physics than a simple question & answer

 

in my humble oppinion:

 

light is not affected by magneting or static electrical fields because it has no mass and it's speed is constant !

magnets and static electricity creat a force field which can accelerate objects that have mass and gain gain or loose kinetic energy and momentum, like say other magnets or an electrically chared charged piece of metal, but light itself travels at the speed of light, had no "rest mass" which means no mass for the purpose of this discussion and therefore will travel in a streight line unless one of the following happens.

1.it hits a reflecting or refracting surface

2. it enters a gravitational field, in which case, the curve in space itself will make it "curve".

 

simply put, since light had no mass and cannot be accelerated (as acceleration shanges speed), it will not react to a force.

hi,

 

EM fields bend the path of moving particles such as in the Solar Wind, or simply in a TV tube which uses EM fields to deflect (bend) electron paths.

Since light is both a wave and a particle at the same time, you might think that this would cause light to be bent if only you had a strong enough field.

[CraigD]

EM fields bend the path of moving particles such as in the Solar Wind, or simply in a TV tube which uses EM fields to deflect (bend) electron paths.

Since light is both a wave and a particle at the same time, you might think that this would cause light to be bent if only you had a strong enough field.

Solar wind particles (mostly protons and electrons) and electrons are charged particles. Photons, however, have zero charge. Thus electrodynamics, either the Classical electromagnetism developed in the 19th century or the Quantum electrodynamics (QED) developed in the 20th, predicts that regardless of its strength, light won’t be bent by a magnetic field.

 

QED gives us another way of looking at it. Magnetic force, the interaction that defines magnetic fields, is composed of photons. Because they follow Bose-Einstein statistics, photons don’t interact in a momentum-effecting way. So photons can’t be affected by magnetic fields.