Question: The Earth's magnetic field and space flight (potentially science fiction)?

( Back )

Answer #1:

the ship would be pushed. Not earth. Even though i doubt this is even possible, but im not a geologist.

Answer #2:

The magnitude of the magnet magnetic power would need to increase at the craft rises...or else it'd shoot up at an extreme amount of unstable velocity. You could still have the craft have engines that activate once a certain elevation is reached that the magnet force would be useless, presumably the momentum would be of great assistance. Also, earths magnetic poles are "moving" and they are not fully understood just yet, so it's a difficult call to make if it would have any adverse effects on electronics or the magnet.

Answer #3:

I'm just going to hit on field strengths. The average rare-earth magnet has a magnetic field about 34000 times the strength of the earth's magnetic field at the poles. Think about a neodymium or whatever rare-earth magnet with another one, and some stabilizing mechanism ("levitated"). Think about how far that one will "levitate" (magnetic force equal to gravity).

A typical neodymium magnet might have a density around 7.5 g/cm^3=7500 kg/m^3. Let's say, arbitrarily, that your platform is about 100m x 100m x 10m=10^5 m^3. That's a mass of around 7.5*10^10^8 kg. That means, at say a distance of 100km from the surface of the planet, gravitational force would be around 7*10^9 N, so you need a magnetic force that is equal to that. If your platform is, say, 100 time that size in each dimension, then your mass is 10^6 times the one here, so your gravitational force is around 7*10^15 N. That's the gravitational force for a 10km x 10km x 1km platform of a very strong permanent magnet. Even if you assume it's 1000km from the surface of the planet, the force is then 7*10^13 N. I don't know offhand the strength of force between two Nd magnets, but keep in mind that the Earth is about 1/34000 that strength.

Also consider that ferromagnetic materials are very vulnerable to shocks or high temperatures, which demagnetize them. This would make it a bit difficult to get it into orbit.

Then consider how directionally dependent the static magnetic force is. You need the platform to be precisely aligned and need it to always be directly above the geomagnetic pole, as the earth rotates and revolves. If it's not, and it tips a little bit in any direction, then it would eventually change position enough that the force is attractive. Then you'd have 1.4*10^16 N of force attracting the platform to the earth.

Then consider that that is the gravitational force for a 10km x 10km platform, not a larger one, and it is made entirely of a very strong permanent magnet.

In other words, the earth's magnetic field is extremely weak, while gravity is extremely strong. Draw your own conclusions about plausibility.

Answer #4:

Dude, I was think about this sort of thing myself. Only, I thought it would be great to design a "car" that could make use of the earth's magnetic forcefield and in this way we could reduce or even eliminate our need for fossil fuels to "get around town." If a flying machine could be invented using magnetism, why couldn't a car? My only problem is that I do not know enough about science/physics to give you a practical solution.





** Powered by Yahoo Answers