how powerful can a magnet be?

Question

Can a very small magnet be very powerful? I know everyone's heard of the toys called "Magnetix", which has supposedly caused the death of a child. They are so powerful, that they actually caused his intestines to close, forcing bacteria into his blood stream.

There was the James Bond movie, "Live and Let Die", where he had a watch with a super-high powered magnet, which you could use to grab a piece of metal from 10 feet away. I don't know if they are THAT powerful, but think of the possibilities. A super powerful magnet is in the ceiling of a convienence store. Someone goes in and brandishes a gun. The magnet causes the gun to go flying out of the robbers hand, and the robbery is botched.

Anyone think that would work? Could magnets be THAT powerful, or THAT beneficial to humanity?

Answer 1

There is a theoretical limit to the strength of a magnet. Magnetic field is measured on Gauss. The practical limit to a useful magnetic field is on the order of 40,000 Gauss (compared to Earth's magnetic field of 1 Gauss). Typical iron saturates at about this level meaning that even a stronger magnet will not produce a greater force on a piece of iron.

To figure the maximum strength of a magnet. you can figure the change in the magnetic field energy as a piece of iron (or another magnet) approaches the magnet. When the objects are just ready to come in contact, the maximum force is around 100 psi. Meaning that a 1 square inch magnet can produce a force of 100 lbs. Keep in mind that the force drops off quickly as the pieces separate. There are ways to adjust the geometry to make the force drop off more slowly but the limit of about 100 pounds per square inch still holds.

The James Bond or "disarming convenience store" magnet is fiction and will remain so. This is because the field strength drops off so quickly. To do these kinds of actions requires a magnet that is at least as big in diameter as the distance that you expect it to act at. So to grab a piece of metal 10 feet away, you would need a 10 foot (and probably bigger) diameter magnet.

Answer 2

About James bond I think that is a bit hard because even if you can make such a magnetic field that is less expensive than what the thief takes, you still have the problem to redirect the field towards him and don't affect other things.

Also the dead of the kid I don't think it can be caused by a magnetic field of such a small magnet, maybe other characteristics of the toy but not the magnetic field. There are some experiments with very strong magnetic fields where frogs are placed and "fly" on the field and the frog is harmless.

Also magnets are already being used all the time, even electricity is created by magnets, the electric generators and electric motor must have magnets.

You know MAG-LEV, the train that is being built or is finished in Germany?, it's also other application, it awesome.

Other thing if you can redirect magnetic fields in that way, I was thinking that Buildings would never be the same, no columns to sustain the floors but repelling magnets.

Also the stronger a permanent magnet is, the more powerful electric cars would be with less electricity spent, no more oil would be needed.

However there is always the economic problem

Answer 3

Well, I'm not an expert; I;ve just got a pass degree in physics. My humble opinion is that permanent magnets are close to the theoretical maximum. But the most powerful magnets we can make are superconducting magnets with a field of a few teslas. These require cryogenic cooling and superconducting coils with electricity flowing through them. You can't make permanent magnets as strong. The strongest magnetic fields yet discovered in nature are near the magnetic poles of neutron stars. They go up to 10^9 tesla. In theory, if you could generate a magnetic field of 10^18 tesla, you could hold a wormhole open, so, if you could build a wormhole in the first place, you would have a cheap way to travel a long way. The Earth's magnetic field is less than 1/10000 tesla. If you ever visit NZ or any other country with an aluminium smelter, get the guide to show you the crowbar trick. Aluminium smelters use a lot of current. The guide holds a crowbar and the strong magnetic field around the buzzbars, which carry a few 100000 amps, rips it across the room.

Answer 4

In physics, magnetism is one of the phenomena by which materials exert an attractive or repulsive force on other materials. Some well known materials that exhibit easily detectable magnetic properties are iron, some steels, and the mineral lodestone; however, all materials are influenced to greater or lesser degree by the presence of a magnetic field.

I realy dont know how. But I am sure that is possible.

The magnetic field of sun is holding the earth and other plants to rovolve arount it, same is the case of moon with earth.

Answer 5

when i read about the magnetix i just got scared well, i dont know how powerful can it be but a small is not so powreful try this:
just take two magnets and put one magnet on top of ur hand and other below ur hand just below the other magnet in the fingers it attracts other but in the middle portion it does not hope it helps
and they r beneficial also but to some extent

Answer 6

Electromagnets can be made to be extremely powerful - such as the ones that lift cars. They can also be made very mild and used as sensors, such as on traffic light signals. Also, neodymium compound magnets can be made quite potent. Nothing really compares to the TV magnets, though.

As for helping humanity, once we discovered the rules of magnetism and learned to control the coercive property we started using them for all sorts of things we are dependent on - such as computers. If you remove the magnets from your computer, it won't work. Of course there's also the most famous of all magnets, and its contributions to mankind: the compass.

I hope this helps a tad.

Answer 7

A magnet would NOT cause his intestines to close, unless he was made out of metal. What probably happened was that he swallowed two or more magnets, and they clung together, holding his intestines shut.