Hazards of Earth'sMagnetic Field?
959019
The earths magnetic field is static, but an Alternating Current source will fluctuate, reversing its  North-south polarity 60 times a second.\n\nThe affects of fluctuating magnetic fields are very different from the effects of a fixed field.\n\n"A strong changing magnetic field can induce electrical currents in conductive tissue, such as the brain. Since the magnetic field will penetrate tissue, it can be generated outside of the head to induce currents within, hence Transcranial magnetic stimulation. These currents will depolarize neurons in a selected part of the brain, leading to changes in the patterns of neural activation."\n\nSee the link below for more details:
1128220
Earth's magnetic field is fading. Today it is about 10 percent weaker than it was when German mathematician Carl Friedrich Gauss started keeping tabs on it in 1845, scientists say. \n\nIf the trend continues, the field may collapse altogether and then reverse. Compasses would point south instead of north.
1048978
Doubtul.  The earth's magnetic field simply isn't that strong.  If it were, it would overwhelm any electronic devices on earth due to induced current.  While overall it's strong enough to protect us from harm from the solar wind and other nasty charged particles in space, it's not strong enough to harness locally for any useful work.
827354
The magnetic field of Earth is caused by molten iron rotating around in the core.  The lines of magnetic flux follow the right-hand rule (RHR).  Curve the fingers of your right hand into a loose fist and extend your thumb upward.\n\nAs the molten iron swirls around in the direction of your curled fingers, the flux is emitted in the direction of your extended thumb.  The flux is created because the swirling molten iron creates an electrical current that follows the swirl.  That current, like a current going through a coil, creates the magnetic flux.\n\nA flux is simply a line of force and that force, like all forces, has direction.  In this case, the force points outward in the direction of your thumb.  That's called the magnetic north pole, by convention.  \n\nHowever, because the magnetic flux exits the Earth at this pole it really is the south pole.  This can be verified because the north pole of a compass needle will point north and, as you well know, north is attracted to south.  Thus, the magnetic north pole is really the south pole...argh...physics is so complicated.\n\nAs to why like poles repel and dissimilar poles attract, blame in on the direction of the forces...the flux of that magnetic current.  (Magnetism does not really flow, but the forces act as though it does.)  Two similar poles either push each other away (e.g., two south poles) or pull away from each other (e.g., two north poles) because the forces are toward or away from the two magnets respectively.  Two dissimilar poles attract each other because the alligned forces pull one toward the other when they are all in the same direction.  [See source.]
1164491
Very much. Magnet has nothing to do with earth's magnetic north and south. It has it's own north and south and will very much attract like it does on earth. I think you are confused with compass which will not work in space with no north and south.
16892
yes, magnetic fields have nothing to do with air density or gravity or any conditions that differ between space and earth, so there is absolutely no reason at all they wouldnt work in space.
698914
For a world to have a (global) magnetic field, it must have a liquid metallic core and it must rotate fast enough.  The Moon is solid throughout (we believe) and it doesn't rotate nearly fast enough even if it did have a molten interior.
364801
Well, technically, it is the Earth's Core.  But if you're referring to MAN-MADE magnets, you are typically looking at superconducting magnets.\n\nRight now, it seems like the two contenders are superconductors at MIT and in Japan.\n\n\nThis may be the next contender:\n\nhttp://www.research.fsu.edu/researchr/springsummer99/departments/abstracts/BiggestMagnet.html
315912
Other than direct discharges from lightning, fluctuations in the magnetic field can generate currents in the electrical grid.  This happens as a result of solar activity such as solar wind and flares bombarding the Earth's magnetic field causing it to flex.\n\nLong distance transmission lines are especially vulnerable to this as their length is enough to act as a generator from the magnetic changes.  Grids can shut down and transformers have been melted  due to power surges generated by strong solar storms.
36195
Actually our geographic north is south pole of our big earths magnet and similarly with south....\n\nActualy it is just a convention we can consider anything as north or south,..... similar to positive and negative chages.\n\nRecently scientists have found that the earth's polarity is changing, while this process is going on there will be a break down in our earth's protective magnetic field.\n\nSo cosmic radiations can through earth's atmos.....\n\nFor this stage to sttain there is around a 1000 years to go.
1150478
It's widely believed in the scientific community that the earth has a liquid mantle (that's where magma/lava comes from) and a solid super-hot iron core.  Good luck digging through that.
688899
The human body is not capable of being made magnetic.  It shows virtually no response to magnetic fields as high as 3 Tesla and more--and as a reference, the magnetic field of the earth is 0.0005 Tesla...\n\nA sufficiently intense magnetic field COULD levitate the human body, though--it's been done with bugs and frogs, without any perceptable injury or even awareness of the field.
606554
Not that big!\n\nMagnetism is stronger than gravity by order of thousands.\nThe earths magnetic field is bigger and stronger than the earths gravitational field.\nMagnetism is stronger than gravity otherwise you would not be able to pick things up with a magnet
108424
Earth's magnetic field (and the surface magnetic field) is approximately a magnetic dipole, with one pole near the geographic 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\n\nThe locations of the magnetic poles are not static but wander as much as 15km every year (Dr. David P. Stern, emeritus Goddard Space Flight Center, NASA). The two poles wander independently of each other and are not at directly opposite positions on the globe. Currently the south magnetic pole is farther from the geographic south pole than the north magnetic pole is from the north geographic pole.\n\nThe field is similar to that of a bar magnet, but this similarity is superficial. The magnetic field of a bar magnet, or any other type of permanent magnet, is created by the coordinated motions of electrons (negatively charged particles) within iron atoms. The Earth's core, however, is hotter than 1043 K, the Curie point temperature at which the orientations of electron orbits within iron become randomized. Such randomization tends to cause the substance to lose its magnetic field. Therefore the Earth's magnetic field is caused not by magnetised iron deposits, but mostly by electric currents in the liquid outer core.\n\nAnother feature that distinguishes the Earth magnetically from a bar magnet is its magnetosphere. At large distances from the planet, this dominates the surface magnetic field.\n\nElectric currents induced in the ionosphere also generate magnetic fields. Such a field is always generated near where the atmosphere is closest to the Sun, causing daily alterations which can deflect surface magnetic fields by as much as one degree.\n\nMagnetic field variations\n \nGeomagnetic variations since last reversal.The strength of the field at the Earth's surface ranges from less than 30 microteslas (0.3 gauss) in an area including most of South America and South Africa to over 60 microteslas (0.6 gauss) around the magnetic poles in northern Canada and south of Australia, and in part of Siberia.\n\nMagnetometers detect minute deviations in the Earth's magnetic field caused by iron artefacts, kilns, some types of stone structures, and even ditches and middens in geophysical survey. Using the magnetic instruments adapted from airborne devices developed during World War II to detect submarines, the magnetic variations across the ocean floor have been mapped. The basalt -- the iron-rich, volcanic rock making up the ocean floor -- contains a strongly magnetic mineral (magnetite) and can locally distort compass readings. The distortion was recognized by Icelandic mariners as early as the late 18th century. More important, because the presence of magnetite gives the basalt measurable magnetic properties, these magnetic variations have provided another means to study the deep ocean floor. When newly formed rock cools, such magnetic materials record the Earth's magnetic field.\n\nIn October 2003, the Earth's magnetosphere was hit by a solar flare causing a brief but intense geomagnetic storm, provoking unusual displays of aurorae.\n\nMagnetic field reversals\n\n\n\nMain article: geomagnetic reversal \nBased upon the study of lava formations in Hawaii, it has been deduced that the Earth's magnetic field reverses at intervals, ranging from tens of thousands to many millions of years, with an average interval of approximately 250,000 years. The last such event, called the Brunhes-Matuyama reversal, occurred some 780,000 years ago.\n\nThe mechanism responsible for geomagnetic reversals is not well understood. Some scientists have produced models for the core of the Earth wherein the magnetic field is only quasi-stable and the poles can spontan
728471
Geomagnetic field reversals and changes in intensity are understandable from an energy standpoint as natural consequences of intermittent and/or variable nuclear fission chain reactions deep within the Earth. Moreover, deep-Earth production of helium, having 3He/4He ratios within the range observed from deep-mantle sources, is demonstrated to be a consequence of nuclear fission.
270208
Intensity of current and magnetic permeability of the core.
4253
yes - assuming there are no nearby magnetic fields that are stronger than the earth's, or no strongly magnetic materials (such as metal) very close to the compass