What is the role of earth's magnet?

Question

The earth behaves like a magnet and the shape of the earth's magnetic field resembles that of a Bar magnet of length 1/5th of the earth's diameter,buried at its centre.
What is the role of this Magnet?has it got something to do with gravity?

Answer 1

Earth's magnetic field (and the surface magnetic field) is approximately a magnetic dipole, with one pole near the north pole and the other near the geographic south pole. An imaginary line joining the magnetic poles would be inclined by approximately 11.3° from the planet's axis of rotation. The cause of the field is probably explained by dynamo theory. The magnetic field extends several tens of thousands of kilometres into space as the magnetosphere.

Dynamo theory describes the process through which motion of a conductive body in the presence of a magnetic field acts to regenerate that magnetic field. This theory is used to explain the presence of anomalously long-lived magnetic fields in astrophysical bodies. In such bodies, dynamo action depends on the presence of highly conducting fluids such as the Earth's liquid iron, outer core or the ionized gas of the sun. Dynamo theory of astrophysical bodies uses magnetohydrodynamic equations to investigate how the flow of the conducting materials in the interior of an object can continuously regenerate the magnetic fields of planetary and stellar bodies. It was actually once believed that the dipole, which comprises the Earth's magnetic field and is misaligned along the rotation axis by approximately 11 degrees, was caused by permanent magnetization of the materials in the earth. This means that dynamo theory was originally used to explain the sun's magnetic field in its relationship with that of the Earth. However, this theory, which was initially proposed by Joseph Larmor in 1919, has been modified due to extensive studies of magnetic secular variation, paleomagnetism (including polarity reversals), seismology, and the solar system's abundance of elements.

In the case of the Earth, the magnetic field is believed to be caused by the convection of molten iron and nickel, within the outer planetary core, along with Coriolis effect caused by the overall planetary rotation. When conducting fluid flows across an existing magnetic field, electric currents are induced, creating another magnetic field. When this magnetic field reinforces the original magnetic field, a dynamo is created which sustains itself. Similar magnetic fields are present in many celestial bodies including most stars such as the Sun (which contains conducting plasma) and active galactic nuclei.

The magnetosphere of Earth is a region in space whose shape is primarily determined by the distortion of Earth's internal magnetic field and by solar wind plasma and the interplanetary magnetic field (IMF). In the magnetosphere, a mix of free ions and electrons is held mainly by magnetic and electric forces that are much stronger than gravity and collisions are rare. In spite of its name, the magnetosphere is quite non-spherical. On the side facing the Sun, the distance to its boundary (which can vary) is about 70,000 km (10-12 Earth radii or RE, where 1 RE=6371 km; unless otherwise noted, all distances here are from the Earth's center). The boundary of the magnetosphere ("magnetopause") is roughly bullet shaped, about 15 RE abreast of Earth and on the night side (in the "magnetotail" or "geotail") approaching a cylinder with a radius 20-25 RE. The tail region stretches well past 200 RE, and the way it ends is not known. The neutral gas envelope of Earth ("geocorona") continues to about 4-5 RE, with diminishing density and minimal interaction with the plasmas of the magnetosphere. So does the upwards extension of the ionosphere, known as the plasmasphere.

What follows is a condensed overview of the Earth's magnetosphere only. To avoid an overlong presentation, this section gives a general introduction. The

motion of particles trapped in the magnetosphere (MOT),
physics of magnetic storms and plasma flows (MSPF), and
the history of magnetospheric research (HIST)
will be covered separately. This is a nontechnical overview and more technical discussions are cited at the end.

Answer 2

Some scientists suspect that the magnetic Field may be caused by uranium deposits within the earths core. that would explain why the magnetic Field grows and wanes. It would also explain why the poles switch. Imagine a glob of uranium inside the earth. as the uranium reacts and gives off heat and ma genetic energy, it becomes less dense as the uranium degrades into other particles. (the earths magnetic Field weakens) then, the dense uranium left over migrates back together in the center and the cycle starts anew. It is important to not, that we would not be nuked if the magnetic Field suddenly went away. (this has happened many times when the poles have switched) What would happen is that the aura borialis would become much stronger, and a little atmosphere would be stripped away by the solar winds.

Answer 3

Relatively close to Earth (out to about 8 Earth Radii or 50,000 km at the Equator), Earth's magnetic field looks approximately like that of a bar magnet, as shown in the figure. There are some strange places on Earth that make the dipole different that in the picture. And if we go further out into space, Earth's magnetic field gets weaker and is affected by charged particles in space. We will talk more about this in the Sun-Earth Connection page. We call Earth's magnetic field and the particles and space within this field, Earth's "magnetosphere."

Answer 4

The magnetic field of the earth protects us to a point from harmful solar radiation. When the sun blasts a bunch of high-energy particles toward us, that magnetic field shields us from ~98-99% of those things.

If it wasn't for that magnetic field, suposedly caused by the molten core at the center of the Earth, we would be roasted. But of course there are a lot more factors than that.

Answer 5

Accoding to the Newton's law all the thing in this universal have it own forces between objects and this forces is call gravitational force. For exp. we are an object which at earth, we(people) and earth have it own mass so they will attract together with certain of forces and this force is call granvitational force. This gravitational force is prevent the objects to throw out from earth when earth is spinning. the gravitational force is produce by the earth and our body.

Answer 6

Magnets, always with the magnets.

Answer 7

its like soul in the body reamove it every thing will stop like dead

Answer 8

something strange...