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Q & A: Earth's gravity and magnetism

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Most recent answer: 09/19/2017
Q:
Hi there,Hope you are doing fine.I'm really confused about Earths Magnetic field. as I know Gravity and Magnetism are different forces but we always hear about Earth Magnetic Field and its effect of compass.my question is, does Earth has two separated field of forces, which are gravitational and magnetic forces? or it is only gravitational force and we call it magnetic field as a figure of speech?and if Earth has them both, where the magnetic force comes from? i mean is Earth charged electrically?thanks in advance.
- Hussain (age 28)
Baghdad, Iraq
A:

Yes, there are two distinct fields. The gravity arises because all masses cause gravity. The magnetism comes from some complicated current patterns circulating deep within the Earth. Although the graviity is nearly constant over time, those complicated current patterns can change rather dramatically, like patterns of water boiling in a pot. Sometimes the Earth's magnetic field even switches direction.

Here's a discussion of the complicated physics leading to the magnetic field:
https://en.wikipedia.org/wiki/Dynamo_theory
https://en.wikipedia.org/wiki/Dynamo_theory.

Mike W.


(published on 09/19/2017)

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