# Magnetic force

Discussion in 'Physics & Math' started by Magical Realist, Jan 16, 2017.

1. ### Magical RealistValued Senior Member

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How does a massless magnetic field exert a force across space? Where is the force coming from? And what is being accelerated?

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Michael 345 likes this.

5. ### SeattleValued Senior Member

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Force = mass x acceleration and you are asking where does the force come from? It's fundamental which is another way of saying it just is. There are 4 fundamental forces and electromagnetism of one of those.

Charged particles (electrons) are the mass that is being accelerated.

7. ### Magical RealistValued Senior Member

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What force is causing the electrons to accelerate? Also how does the miniscule mass of the tiny electrons add up to such a powerful force?

Last edited: Jan 16, 2017
8. ### James RJust this guy, you know?Staff Member

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Magnetism is one aspect of the electromagnetic force, which is one of the four fundamental forces of nature. Very roughly speaking, magnetism is electricity viewed from a different perspective.

Both electric and magnetic forces act on electrically charged particles such as electrons and protons.

How does the action-at-a-distance nature of electric and magnetic forces work? The usual classical explanation of this is that charged particles create fields around themselves. Specifically, moving charged particles create magnetic fields around themselves. These fields extent throughout space. If another charged particle is nearby (since the field strength reduces with distance from the source charge), then that particle will feel a force.

The quantum field theory explanation of electromagnetic forces is a bit different. In that picture, the source particles disturb the electromagnetic field that exists everywhere. Forces are transmitted by "messenger" particles that propagate in the field. In the case of electromagnetism, those messenger particles are (virtual) photons.