How does Earth’s magnetic field protect us?

Newsgroups	sci.physics
From	Sam Wormley <swormley1@gmail.com>
Subject	How does Earth’s magnetic field protect us?
Date	2015-09-14 20:18 -0500
Message-ID	<APCdnZTLMKpx7GrInZ2dnUU7-dEAAAAA@giganews.com> (permalink)

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How does Earth’s magnetic field protect us?
> http://www.askamathematician.com/2014/07/q-how-does-earths-magnetic-field-protect-us/

> Physicist: High energy charged particles rain in on the Earth from
> all directions, most of them produced by the Sun.  If it weren’t for
> the Earth’s magnetic field we would be subject to bursts of radiation
> on the ground that would be, at the very least, unhealthy.  The more
> serious, long term impact would be the erosion of the atmosphere.
> Charged particles carry far more kinetic energy than massless
> particles (light), so when they strike air molecules they can kick
> them hard enough to eject them into space.  This may have already
> happened on Mars, which shows evidence of having once had a magnetic
> field and a complex atmosphere, and now has neither (Mars’ atmosphere
> is ~%1 as dense as ours).
>
> Rule #1 for magnetic fields is the “right hand rule”: point your
> fingers in the direction a charged particle is moving, curl your
> fingers in the direction of the magnetic field, and your thumb will
> point in the direction the particle will turn.  The component of the
> velocity that points along the field is ignored (you don’t have to
> curl your fingers in the direction they’re already pointing), and the
> force is proportional to the speed of the particle and the strength
> of the magnetic field.

> As it happens, the Earth has a magnetic field and the Sun fires
> charged particles at us (as well as every other direction) in the
> form of “solar wind”, so the right hand rule can explain most of what
> we see.  The Earth’s magnetic field points from south to north
> through the Earth’s core, then curves around and points from north to
> south on Earth’s surface and out into space.  So the positive
> particles flying at us from the Sun are pushed west and the negative
> particles are pushed east (right hand rule).


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How does Earth’s magnetic field protect us? Sam Wormley <swormley1@gmail.com> - 2015-09-14 20:18 -0500
  Re: How does Earth’s magnetic field protect us? gilber34 <invalid@invalid.com> - 2015-09-14 20:36 -0500
    Re: How does Earth’s magnetic field protect us? Fabian Russell <root@localhost.localdomain> - 2015-09-15 04:09 +0000
      Re: How does Earth's magnetic field protect us? john <johnsefton288@gmail.com> - 2015-09-15 03:05 -0700
  Re: How does Earth’s magnetic field protect us? jimp@specsol.spam.sux.com - 2015-09-15 01:33 +0000

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