Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

electrons on earth moving with us, due to rotation of earth, revolution of earth, sun and our galaxy right?
Then, why is there no magnetic field around a piece of copper wire?

share|cite|improve this question

Because along with electrons there are also protons who also move with the copper wire. They have opposite charge, so create magnetic field of the opposite direction. The electrons' and protons' magnetic fields cancel each other.

share|cite|improve this answer

To good approximation Earth is an Inertial System. Charges at rest with us in this inertial system do not produce a magnetic field, as Maxwell's equations hold in any Inertial system. Viewed from another Inertial system magnetic fields of electrons and protons cancel, as explained in answer (1). Viewed in the Earth's Intertial system protons are needed to compensate the Coulomb field produced the electrons at rest with respect to us. You see here that what is a magnetic field to the one inertial system is a Coulomb field as viewed from the other system.

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.