why does earth produce a magnetic fiels?HOW?

Answer 1

http://video.google.com/videoplay?docid=3902466783636795302&q=Earth%27s+Invisible+Shield&total=7&start=0&num=10&so=0&type=search&plindex=0

hot metals (molten core) in earth's core system, move past the (solid core) causing, basically a static charge. (Electrons) is/are created, causing a magnetic field, which in turn forces more electrons into the metals, and in return creates a stronger magnetic field and on and on (the 2 forces power each other)

This is called electromagnetism.

Quantum electrodynamics seems to be the explaining theory behind this phenomenon
please read more
http://en.wikipedia.org/wiki/Quantum_electrodynamics


the polarity of the magnetic field basically "points" north.

over time, with liquid cores, the "polarity" of the field WILL switch.
it looks concerning during the switch, but once it finishes the switch we should be fine.
http://www.ifa.hawaii.edu/~barnes/ast110_06/tprai/comparison1_strip.gif

once it switches, north will be pointing DOWN/South

they claim in 1500 years our polarity will switch as it has done BEFORE in our history

Our magnetic field protects the earth and its atmosphere by deflecting charged particles from the sun (they are very damaging to life and even AIR)

if our core cools, we will loose the fluidness and movement of the metals. The electrons will be less produced and the mag field will start to drop, in return dropping the electrons even more, causing even more cooling until we have no more mag field

If we had no field, our atmosphere would be blown away into space like dust and Earth would become much like Mars.....

many claim Mars was "habitable" but for some reason its cores cooled and Mars now no longer has a strong magnetic field.

check the two pictures to see the difference between mars and earth and their magnetic fields
http://www.nasa.gov/images/content/135831main_earth_mars_mag.jpg
the purple lines represent the fields

Answer 2

At the center of the Earth is a large, moving, molten metal core. It produces electricity like a huge battery and produces a magnetic field around the planet that shields us from harmful solar radiation.

Answer 3

The rotating nickle-iron core creates the magnetic field.

Answer 4

because the earth's center the core is spin. and the motion that do the core make the earth have magnetic field

Answer 5

A solid nickel-iron core rotating against a molten outer core

Answer 6

We're not exactly sure how. It has something to do with rotation and moletent core and the atmosphere or fields that surround us.