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Could I use electro magnets to repulse the earths magnetic field to levitate?

  1. May 19, 2012 #1
    I have this idea that I could use some electromagents that wen I run current through will repulse the earths magnetic field and that the higher voltage(or whatever electrical unti I decide to use) would send and object farther away from the ground and that the lower current would bring it closer to the ground.

    I really have no idea if it would work but it sems to me that it would.

    If it works, which hoefully it will it could be in theory used to make a suit that would let a person levitate.
     
  2. jcsd
  3. May 20, 2012 #2
    Earth's magnetic field is not perpendicular to the ground, so the person can't be lifted vertically upwards. You would move towards one of the poles, depending on where you are. Also, the earth's field is quite weak, and there is magnetic disturbance from various objects which sometimes exceed earth's intensity, meaning you would require a really really really strong magnet for any movement(and you might not like towards where the movement would be)
     
  4. May 20, 2012 #3
    So if I had a magnet powerful enough I would really be able to only go in one direction?
     
  5. May 20, 2012 #4

    Drakkith

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    The idea is simply not feasible due to the extremely weak magnetic field of the Earth. (compared to what conventional or superconducting electromagnets can do)
     
  6. May 20, 2012 #5
    http://upload.wikimedia.org/wikipedia/en/thumb/2/24/Schematic-of-combined-FACs-and-ionospheric-current-systems.png/587px-Schematic-of-combined-FACs-and-ionospheric-current-systems.png [Broken]
    http://en.wikipedia.org/wiki/File:Schematic-of-combined-FACs-and-ionospheric-current-systems.png

    "Could I use electro magnets to repulse the earths magnetic field to levitate?" It is safe to say that Pederson currents levitate, in a restricted sense.
     
    Last edited by a moderator: May 6, 2017
  7. May 20, 2012 #6
    I see. So if I was in the Pederson current area it might work with the right technoloy? But its a shame I dont live in Greenland. I'd have to use the Hall currents.
     
  8. May 20, 2012 #7

    K^2

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    There's a field gradient, so in principle, yes, you could levitate something in Earth's magnetic field. Trouble is, you need very strong electromagnets for that, and they'll end up being far heavier than what you could lift with them. The Earth's magnetic field is simply not strong enough for this to work in practice.
     
  9. May 21, 2012 #8
    The problem is that a magnetic dipole in a uniform field won't feel a net force at all, but only a torque that will align it with the field. The magnetic field of the earth is uniform to a very high accuracy on the scale of any magnet you would use.

    Pedersen currents are made up of charged particles, these will feel a net force in a uniform magnetic field.
     
  10. May 21, 2012 #9
    I see. What if I didnt use the Earths magnetic field, mabey the Sun's? it seems powerful enough to work.
     
  11. May 21, 2012 #10
    Remember that magnetic field varies with distance. THe sun is probably not the best idea for this reason.
     
  12. May 21, 2012 #11

    Drakkith

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    The average strength of the Sun's magnetic field at its surface is only 1 gauss, which is about twice what Earth's magnetic field is on it's surface. This falls off drastically by the time the magnetic field reaches us.
     
  13. May 23, 2012 #12

    mfb

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    In addition, the field gradient falls off even quicker than the field itself. While the magnetic field of the earth is strong enough to have some measurable influence, the variation in its strength is extremely low within interesting distances (~1m).

    If you have access to some stronger magnets on the ground (or some other devices), it is possible to levitate objects with a lot of different methods.
     
  14. Jun 1, 2012 #13
    So there is really no possible way this could work? Without the right technology that would be to heavy anyways?
     
  15. Jun 1, 2012 #14
    You could build a device that could create a *tremendous* current, which if flowing through a coil could produce a magnetic moment that if aligned in a certain way relative to the Earth's magnetic field (i.e., for that particular location) would produce a torque, which you could then via mechanical levering use to lift something up - but it would need some sort of an axle to rotate, so it could not simply levitate in the air.
     
  16. Jun 1, 2012 #15
    I'm entertaining the idea that it is possible to 'move away from the Earth'. If I understand this correctely? You would need to increase ones mass relative to Earth, your weight stays unchanged. Your levitating device/medium/platform would also need to be perpendicular to Earths guass field. To ballance your craft, alternate the.... I'll continue in the next post, pending results.
     
  17. Dec 24, 2013 #16
    You would have to build a spaceship close to the size of the earth or make the magnets inside of it strong enough for the flux to cover a very large portion of the earth. Now let’s say you could build a power source that could supply a massive amount of power to make this magnetic field (like the power source tony stark of iron man created) as soon as you applied the power the current would shoot up so high that the wires would vaporize instantly, but let’s say somehow we invented a wire and components that could handle this massive current, and could generate this magnetic field. The magnets would pull the ship to the nearest metal object(s) and would be impossible to pull off; it would also draw every metal object from miles away, It would soon be covered by miles of metal killing everyone and everything in the immediate location including the people inside the ship.

    I am not sure how you could avoid these problems unless you use it a safe distance away from anything metal including a metal spaceship, but I also believe that if the field is intense enough magnetism will have an influence on any object, as shown on TV where it was shows that you can levitate a frog in a super strong magnetic field (A magnetic field nowhere close to the strength this spaceship would need to generate.) so, at our current state of technology, I would have to say no. But, why does it have to be magnetism. Why not anti-gravity? I have no idea how that would work, so I could not think up ways to dispute it, like I can with magnetism.

    I saw a film where scientist levitated an object using high voltage. this is something has actually been done. It would be more practical to do it that way instead of using magnetism.
     
  18. Dec 24, 2013 #17
  19. Dec 24, 2013 #18
    The problem of using a super powerful magnet to generate a super powerful magnetic field is that it not only repel and attract other magnets or magnetic fields (such as the earth magnetic field) they also attract metal and if the field is strong enough it can attract non-metallic objects such as frog as you mentioned above (or anything else for that matter.) The ship would draw all matter affected by the field towards itself including itself. it would easily draw anything metal off the surface of the earth towards the ship you are in. The ship might even cave in on itself due to the strong magnetic field.
     
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