How are electromagnetism and space-time related, and can electromagnetic fields exert a force on space-time?

Physicists think there is a deep connection between gravity and the other fundamental fields in nature that make up the Standard Model of physics. The search for this deep connection is the search for what Einstein called a Unified Field Theory. Today we call it Quantum Gravity Theory.

A popular science fiction technology is to use electromagnetic fields to manipulate the local geometry of space-time. All that general relativity says is that any form of energy can cause space-time to become curved. Too much curvature and you may end up with black holes or worm holes. The form of the energy can be anything; raw mass, the energy latent in electromagnetic fields, neutrinos etc. So, electromagnetic fields are not intimately related to space-time any more than mass is; its just another form of energy that can serve to generate curvature via its own gravitational field.

The problem is that, because gravity is so weak, you have to concentrate a LOT of energy in one place in order to make any significant change in the local gravity. An entire planet like earth has barely enough gravity to win a tug-of-war with a toy magnet over a paper clip!

Return to Dr. Odenwald's Gravity page at the Astronomy Cafe Blog.