Science Forums 2

[CraigD]

Originally Posted by gregdevid

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.