Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. Join them; it only takes a minute:

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

I am in no way a physicist but I do have a fascination with physics. My question is if magnets are being explored / studied as a potential source to achieve the speed of light and if that is even physically possible?

share|cite|improve this question
Hi Kyle. Welcome to Physics.SE. Can you provide some reference for your study? – Waffle's Crazy Peanut Apr 27 '13 at 1:56
In fact electromagnetism is what inspired Einstein to formulate special relativity, the theory which implies the speed of light limit. – Michael Brown Apr 27 '13 at 2:21
Kyle, you should clarify what you mean by "achieve the speed of light". Do you mean some form of magnetic propulsion similar in spirit to Maglev trains? – Brandon Enright Apr 27 '13 at 2:58

It is not physically possible to accelerate any object with mass to the speed of light using magnets. There are a few reasons for this.

First, it is a widely held belief that it is impossible for anything with mass to achieve light speed period; that it would take an infinite amount of energy to accomplish this and there is slightly less energy than that in all of existence.

Second, since magnets operate on the principles of the electromagnetic force, and since a photon (i.e. light) is an embodiment of the electromagnetic force in the form of fluctuating electric and magnetic fields, then using a magnet to accelerate something means that on a very basic level, you are using massless photons to impart momentum on the object. Furthermore, since light is limited to light speed and since they have no mass, they can never impart enough momentum on something with mass to achieve the same speed as them. That means that one cannot achieve light speed using any means that, at its most basic level, utilizes the electromagnetic force (rockets, solar sails, a good hard push, and magnets are all included).

Having said all of this, you may be interested to know that we currently do use magnets to accelerate things to very nearly the speed of light. In particle accelerators, an advanced array of magnets are aligned and used such that they can accelerate a proton (or other particle) to extremely close to the speed of light.

share|cite|improve this answer
Thanks for the response. I'm circling back to this question. I thought that light was an energy and that energy needed mass of something E=mc^2. Let me please reiterate that I am not a physicist. I was more or less taking a science fiction perspective towards this. I see magnetic force as being similar to gravity. If there was a way to use magnets to make something seem weightless that would allow the object to be moved at great speeds. Of course I've done zero studies about this and am just throwing ideas out there. – Kyle Nov 9 '13 at 4:11

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.