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With a magnetic dipole, you need a gradient in magnetic field to exert force on the dipole. If the field is uniform, it will exhibit equal and opposite forces on each pole of the magnet and cancel out to zero net force. At human scale, the earth's magnetic field is basically uniform. This is why compasses don't get pulled along toward the north or south.
The parameter of a magnet you're looking for is the magnetic dipole moment, and the force on a dipole magnet in a magnetic field is F = m × (dB/dx). dB/dx is the gradient of the field, and is basically zero everywhere on earth for small x. So F=0 and this is impossible.
Google says the field is about 65 microtesla at the poles and 30 microtesla at the equator. So let's oversimplify and say the gradient is 65 - 30 => 35 microtesla/10,000 kilometers. Incidentally, this is a fun and rare occasion to thank the revolutionary french for their insane arbitrary definition of the kilometer, which we can just pull out and use exactly as they defined it. 35 microtesla/10,000 kilometers.
Say a guy is 180 lbs. (180 lbf)/(35 microtesla/10,000 kilometers) = 2.288×10^14 joules per tesla. A fridge magnet is about 0.1 J/T. So ludicrously, insanely strong magnets. 10^15 times stronger than a fridge magnet, and that span from the equator over the pole and back to the equator.
Apart from the strength of the magnet and gradient of the magnetic field, Earnshaw's Theorem makes this impossible, even if you had these insane magnets. A stable configuration of static point charges is impossible.
I read a fair amount of pulp sci-fi 50 years ago. A guy wrote a story ignoring the science where a Soviet inventor made a mag lift device for super cheap. The Soviets bragged about it and all the great things it would do. The people immediately used them to escape to Western Europe and the USA.
Well you could only in theory make this work at the magnetic poles because the direction of the field elsewhere is parallel to the surface rather than perpendicular to it
It doesn’t matter how strong the magnet is. The force holding you down is gravity not magnetism. You would need two magnets of the same polarity to push you up don’t know the math but in short one magnet pushes down against the earth to support you the other would push against the other to push you up.
Gravity and magnetism are two different forces. Something like a maglev train isn't repelling gravity, it is pushing against a magnetized rail on the track, with guides to keep it from sliding to the sides and propel it forwards.
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With a magnetic dipole, you need a gradient in magnetic field to exert force on the dipole. If the field is uniform, it will exhibit equal and opposite forces on each pole of the magnet and cancel out to zero net force. At human scale, the earth's magnetic field is basically uniform. This is why compasses don't get pulled along toward the north or south.
The parameter of a magnet you're looking for is the magnetic dipole moment, and the force on a dipole magnet in a magnetic field is F = m × (dB/dx). dB/dx is the gradient of the field, and is basically zero everywhere on earth for small x. So F=0 and this is impossible.
Google says the field is about 65 microtesla at the poles and 30 microtesla at the equator. So let's oversimplify and say the gradient is 65 - 30 => 35 microtesla/10,000 kilometers. Incidentally, this is a fun and rare occasion to thank the revolutionary french for their insane arbitrary definition of the kilometer, which we can just pull out and use exactly as they defined it. 35 microtesla/10,000 kilometers.
Say a guy is 180 lbs. (180 lbf)/(35 microtesla/10,000 kilometers) = 2.288×10^14 joules per tesla. A fridge magnet is about 0.1 J/T. So ludicrously, insanely strong magnets. 10^15 times stronger than a fridge magnet, and that span from the equator over the pole and back to the equator.
Apart from the strength of the magnet and gradient of the magnetic field, Earnshaw's Theorem makes this impossible, even if you had these insane magnets. A stable configuration of static point charges is impossible.
I read a fair amount of pulp sci-fi 50 years ago. A guy wrote a story ignoring the science where a Soviet inventor made a mag lift device for super cheap. The Soviets bragged about it and all the great things it would do. The people immediately used them to escape to Western Europe and the USA.
Well you could only in theory make this work at the magnetic poles because the direction of the field elsewhere is parallel to the surface rather than perpendicular to it
This is also true
Didn't know if it would post. Honestly it just makes sense for flying cars if it was even humanly possible
It doesn’t matter how strong the magnet is. The force holding you down is gravity not magnetism. You would need two magnets of the same polarity to push you up don’t know the math but in short one magnet pushes down against the earth to support you the other would push against the other to push you up.
Yes, OP knows this and is asking what if you use Earth's magnetic field as one of those two magnets.
Gravity and magnetism are two different forces. Something like a maglev train isn't repelling gravity, it is pushing against a magnetized rail on the track, with guides to keep it from sliding to the sides and propel it forwards.
What part of OP's question suggests they don't know gravity is different from magnetism?
They're asking about pushing against Earth's magnetic field.