So I was wondering/daydreaming the other day if the Meissner Effect could be used somehow to lift a spacecraft on the planet earth. If you google magnetic levitation there is a wikipedia entry that has the formula for lift produced by a magnetic field.
Magnetic materials and systems are able to attract or press each other apart or together with a force dependent on the magnetic field and the area of the magnets. For example, the simplest example of lift would be a simple dipole magnet positioned in the magnetic fields of another dipole magnet, oriented with like poles facing each other, so that the force between magnets repels the two magnets.
Essentially all types of magnets have been used to generate lift for magnetic levitation; permanent magnets, electromagnets, ferromagnetism, diamagnetism, superconducting magnets and magnetism due to induced currents in conductors.
To calculate the amount of lift, a magnetic pressure can be defined.
For example, the magnetic pressure of a magnetic field on a superconductor can be calculated by:
So you take this formula and I used it on www.wolframalpha.com.
Pmag = B^2/(2*u0) , B = 0.000065, u0=4*pi*10^-7
Where Pmag is the force per unit in pascals.
B is the magnetic field just above the superconductor in teslas,
and u0 = 4pix10^-7 is the permeability of the vacuum (this should be air, which makes it even worse)
B = 0.00005 tesla (magnetic strength on the planets surface.)
Pmag = 0.000994718
If B = 0.000065 tesla (the magnetic strength at the north pole.)
Pmag = 0.00168107
Converting comparing to gravity you see that the magnetic strength
of the earth is nowhere near enough to lift anything.
You would probably need 9.8P or 9.8N to counteract gravity.
Please take these calculations with a grain of salt as I have 1 course in university physics which I nearly failed. It might be still possible with some weird configuration/apparatus.
I think I’ll ask the experts about my other ideas.