Is it true that the Earth's magnetosphere is expanding?
486058
No.The magnetosphere is the result of Earth`s magnetic field. It depends directly on the magnetic field. But is not expanding or getting smaller, at least not at a large scale. There are variations, but little ones. The magnetic field is created by Earth`s spinning melted iron core. If the angular speed of the core decreases or increases, then the magnetic field and the magnetosphere will do the same thing. For now, thank`s God, is constant.
555359
No, because all of the materials used to make people are constantly being recycled.\n\nThe mass of the earth is increasing, however, because of the constant bombardment of the planet with cosmic dust and stuff.
212109
Apparently there is believed to be none now, but there may have been in the past.  Here is a quote from the link below:\n\nObservations of the magnetic fields on Mars by the Mars Global Surveyor spacecraft have revealed that parts of the planet's crust has been magnetized. This magnetization has been compared to alternating bands found on the ocean floors of Earth. One interesting theory, published in 1999 and reexamined in October 2005 in a publication by the same group, is that these bands could be evidence of the past operation of plate tectonics on Mars. However, this has yet to be proven or widely accepted and remains an area of active research.
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.
300354
There was a report on Discovery that Earth maginetic field is shifting.this shift of poles will take thousand of years so there is no sudden change.During this change magnetic field will completely stop and there will be no defense againest solar radiation.This will cause cancer to human biengs.\nthere is a movie,"The Core" in which they shown the after effects of eliminated magnet field.
934445
A molten core of super heated metal (believed to be Iron and Nickel) is spinning at the center of the earth faster than the exterior of the earth is rotating.\n\nCharged Particles create a magnetic field when they move.
219376
The earth has two magnetic poles, a north pole and a south pole.\n\nThe effect of both poles can be detected by a good compass from anywhere on earth.
692139
Assuming that humans don't destroy the world...which is a pretty BIG assumption, I think maybe in a few thousand years the Earth's magnetic field may weaken to the point where it no longer deflects the harmful radiation from the sun and all life as we know it on this planet will cease to exist, and Earth will become very Mars-like...a very thin atmosphere and no surface water. But hey, that's just me.
798707
Interesting question samsam.\n\nMost people's immediate reaction would be to say that "of course it isn't".\n\nBut I can tell you that the earth increases in mass by 2 tons every single day !\n\nIt is estimated that around 20 tons of space debris in the form of dust, micro-meteorites, ice, and sometimes larger particles, hits the earth's atmosphere very day. Most of this burns up, but an estimated 2 tons of it will find its way to the ground.\n\nI will leave the physicists and mathematicians amongst you to calculate if the resultant changes in gravity will alter our orbit enough to destroy the Earth before the Sun explodes into a red giant !
452277
Earth's magnetic field constantly fluctuates to some degree (it's weakened by about 10% since the 19th Century), but the majority of geophysicists see no hard evidence that the field is about to reverse like it's done in the past.\n\nEven should it reverse, the whole cycle takes thousands of years, and still would have little effect on our electrical power systems. Nor would planes fall from the sky, although reliance on magnetic compasses would have to be adjusted.\n\nGod should be spelled B-I-G B-A-N-G\nPBrax@netscape.com
699383
First of we have to understand magnetism. All magnetic objects produce invisible lines of force that extend between the poles of the object. An easy way to visualize this is to spread iron filings on a sheet of paper and place a bar magnet under the paper. The iron filings will arrange themselves around the magnet and along the magnetic field lines.\n\nIn the simplest terms, Earth can be thought of as a dipole (2-pole) magnet. Magnetic field lines radiate between Earth's north and south magnetic poles just as they do between the poles of a bar magnet. Charged particles become trapped on these field lines (just as the iron filings are trapped), forming the magnetosphere.\n\nThe origin of the Earth's magnetic field is not completely understood, but it is generally believed to be associated with electrical currents produced by convective effects and rotation in the spinning liquid metallic outer core of iron and nickel. This mechanism is generally known as the dynamo effect. \n\nBecause of the rotating outer core, this then produces an electric current, which in turn, produces a magnetic field that is also known to interact with the fluid motion to create a secondary magnetic field. Together, the two fields are stronger than the original and lie essentially along the axis of the Earth's rotation.\n\nHope this helps you out a little :)
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.
129623
The dynamo theory (that the earth is maganetic) is actually due to the fact that the outer crust is molten iron.  This iron is moving around inside the earth at very high temperatures.  Physics tells us that moving metals will create  a magnetic field.  This is why we have the magnetic field around the earth.
289063
Solar Storms\n\nBy Sten Odenwald\nSpecial to The Washington Post\nWednesday, March 10, 1999; Page H01\n\nFor thousands of years, the aurora borealis or "northern lights" have lit the skies and human imagination with ghostly incandescence. Most often seen in Arctic regions but occasionally visible as far south as the Mediterranean, they have inspired awe, fright and a fair measure of misunderstanding.\n\nTiberius Caesar mistook their red glows for a fire in progress and dispatched an army to Ostia in 34 A.D. to inspect damage. But until the 19th century, no one seriously thought that they could hurt anybody -- unless, as an Old Norse legend warned, you happened to whistle at one!\n\nNow we know better. Technological advances have made it possible for auroras and other "storms" in space to make themselves felt in the form of power blackouts, satellite failures and even pipeline explosions.\n\nSpace weather generally varies with the 11-year sunspot cycle: the more sunspots, the more storms and the more voluminous the "solar wind," as scientists call the stream of charged particles that incessantly blows off the face of the sun. Already, we are well on the way to the next solar maximum, expected to peak next year.\n\nThe maximum usually coincides with an increase in two other kinds of extremely bad "space weather." In one, powerful solar flares hurl protons and electrons almost to the speed of light. That acceleration produces blasts of X-rays that radiate into space. Both the particles and radiation can disrupt short-wave communication on Earth.\n\nWere that not enough, the sun also can spawn billion-ton clouds of plasma and their associated magnetic fields. Traveling at more than 1 million mph, some of these "coronal mass ejections" (CMEs) may arrive at the Earth in only a few days.\n\nIn many ways, they actually are more noxious than the more familiar solar flares. CMEs pummel Earth's magnetic field like a sledgehammer 1 million miles wide and upset the delicate balances of trapped particles in the Van Allen radiation belts and elsewhere within the boundaries of Earth's magnetic field. [See illustration below].\n\nThe first indication that space weather has worsened usually is a spectacular auroral display in Arctic regions. When the solar wind hits the Earth's magnetic field, electrons and protons inside the field are accelerated into currents that flow along the gossamer-thin magnetic field lines and converge on the polar regions.\n\nAs they enter the thickening atmosphere about 500 miles above our heads, the particles collide with atoms and molecules of oxygen and nitrogen, which shed their added energy as light, producing ethereal shapes and colors.\n\nBut that's not all. The motion of other populations of charged particles within Earth's magnetic field causes great currents of charged particles to circulate in space like a 10,000-mile-wide river. These invisible stratospheric rivers can alter the geomagnetic field temporarily and produce "magnetic storms."\n\nHumanity began feeling the effects of the solar maximum as soon as technology became sophisticated enough to respond. During the late 1800s, vast networks of wires were strung to carry telegraph and telephone traffic, setting the stage for a giant-scale reenactment of one of history's most famous physics experiments.\n\nEnglish physicist Michael Faraday discovered in his lab that, if you take a magnet and move it near a loop of wire, electrical current flows in the wire. The moving field induced a corresponding motion of charge in the wire. Faraday's "magnetic induction" soon was put to use in the first electric generator.\n\nExactly the same thing happened when solar storms triggered changes in Earth's magnetism, affecting thousands of miles of telegraph wires. Electrical currents induced by the changing fields often were so powerful that telegraphers didn't need
1173935
Magnetic field has to do with the polarize charge of material, such as Iron.  \n\nIt is believed there is significant Iron near the center of the earth and yes rotation will cause the charges to align and thus create a magnetic field.  This is called the "Dynamo Theory".\n\nJUST BEING IRON DOES NOT MAKE THINGS MAGNETIC.\n\n"Previous theorists have assumed that the entire Core (or the Inner and/or Outer Core) rotates as a single flowing object within the Earth. If that were the case, then all of the charged (ionized) Iron material  would follow a relatively circular path around a single axis that we could call the Magnetic Axis. Basic Physics tells us that when electrical charges follow a closed (relatively) circular path (which is effectively a current), a magnetic field is always created as a result. The measurable evidence of this scenario would be a simple "dipole" magnetic field, with a single North Pole and a single South Pole, geographically exactly opposite each other on the surface of the Earth."\n\nSo if this theory where correct the Earth stopping it's rotation would in allow the magnetic field to fad.  But there are major problems with the theory.  For example it is known that the magnetic poles have flipped (Switched places) several time in Earths past.  Will if we have magnetic poles because of the earth's rotation to switch poles we'd need to reverse the cores rotation.  This would be an ungodly amount of energy.  There is nothing known that would do this once let alone a number of times.  And even if something could do it, we should have seen signs of the massive damage that would have resulted with these forces in play, like the Earth falling apart.   But in fact the poles shifting seems to be a pretty peaceful process on a planetary scale. \n\nAnd that is only one problem with the theory.  This is actually a very, very complex subject and there really is no way to know what effect the Earth stopping would have on the magnetic fields.  But I have attached a link to a very good article on the subject and it's pretty easy reading (Keeps the scientific jargon down and uses layman terms.)\n\nOthers are correct tough in what holds us to the Earth is gravity, not magnetics.  So it's the Mass (How big and dense it is) that keeps us here.  And rotation actually wants to make thing's fly away from it.  So we stay because the Earths gravity overcomes the acceleration.  So the acceleration of 1000mph is actually always enacting upon us, making us want to fly off the planet.  So stopping the Earth will not make us fly off as others have posted.\n\nThink of the spinning rids at the fairs and theme parks.  When you spin you are thrown away from the axis, the best example is the cylinder you go in and stand up against the wall.  When it spins your back is pushed against the wall, even as it turns so you are now spinning vertically like a tired, instead of horizontal like a top.  But when they stop the ride you don't go flying out.  That's because the wall holds you in and your move with the ride.  Well gravity acts like the wall and you move with the earth.\n\nYou would go flying of the earth if it continued to rotate and the gravity field somehow disappeared.
716050
I just saw a NOVA on this. One thing that was mentioned is that during the reversal, it's possible that for a period there would be 4 poles. There is evidence from rocks and computer models to support his. During this time, radiation would funnel into the lower latitudes where we, as a world, are heavily populated instead of the currently unpopulated poles. There would be an increase in cancer rates but not enough to be considered a "radiation epidemic". People in the lower latitudes would see the aurora borealis as well during this time as well - quite a bonus.\n\nCheck out http://www.pbs.org/wgbh/nova/magnetic/ for more information.
83937
Yes the universe is expanding, thanks to dark energy and perhaps the shape of space itself.\n\nThe space, as far as I know, existed already. From what I understand, our universe exists within a 5th dimension. The "big bang" was really the collision of two membranes that caused a big release of energy along the contact surface and the formation of all matter (initially in the form of a quark-gluon plasma). This matter has kept expanding since and can probably expand indefinately along the 5th dimensional membrane, but there's really no way to know. Some speculate that the reason the expansion of the universe is accelerating right now is that we are in for another collision at any moment, which will destroy all matter as we know it. Sleep tight.