An idea that came to me in my sleep.. making things hover

Zac Naloen · Post by **Zac Naloen** » 2006-02-11 07:24am

Is there any particular reason why you couldn't get an array of electromagnets aligned on the bottom of an object at say a 45 degree angle with the poles pointed down, causing them to repel against each other and cause of an inanimate object to therefore hover on the spot.

I understand thers power limitations but is this even possibly?

AMX · Post by **AMX** » 2006-02-11 08:29am

Doesn't work.
With all the magnets mounted to the object, all repulsive forces will act inside the object, trying to rip it apart; but none will act between the object and the ground.

Post by **Surlethe** » 2006-02-11 09:41am

Thinking about it, for the same reason, why can't you lift yourself with your own bootlaces?

Molyneux · Post by **Molyneux** » 2006-02-11 10:36am

Surlethe wrote:Thinking about it, for the same reason, why can't you lift yourself with your own bootlaces?

Well, technically, I think you *could* lift yourself off the ground by yanking on the bootlaces if you were strong enough; however, you couldn't support yourself in midair, so you'd land on your ass.

Post by **Surlethe** » 2006-02-11 12:17pm

Molyneux wrote:
Surlethe wrote:Thinking about it, for the same reason, why can't you lift yourself with your own bootlaces?
Well, technically, I think you *could* lift yourself off the ground by yanking on the bootlaces if you were strong enough; however, you couldn't support yourself in midair, so you'd land on your ass.

No, you couldn't. Newton's third law guarantees this: if you're lifting something, there has to be an equal and opposite force; for example, when you're jumping, you exert a force on the earth, and it exerts one back on you. If you try to lift yourself by your bootstraps, however, you exert a force on your foot, and it exerts one back on you; since they're both part of your body, the net force on you is zero, and you don't go anywhere.

Flakin · Post by **Flakin** » 2006-02-11 12:23pm

At school once our physics teacher put a £50 note on the floor and told anyone who could jump across it while holding onto the front of their feet that it was theirs.

Of course noone could do it. Although, I did do a pretty good job of falling over it.

Post by **K. A. Pital** » 2006-02-11 12:30pm

Magnets have to be ground-mounted to make objects hover, as it was said above. Actually, that's how magnetic hovertrains work. It's a good trick for something that has a fixed road - possibly if humans find a way to generate shitloads of energy, car roads can also be turned to huge magnets for hovering cars. Correct me if I'm wrong.

GrandMasterTerwynn · Post by **GrandMasterTerwynn** » 2006-02-11 12:54pm

Molyneux wrote:
Surlethe wrote:Thinking about it, for the same reason, why can't you lift yourself with your own bootlaces?
Well, technically, I think you *could* lift yourself off the ground by yanking on the bootlaces if you were strong enough; however, you couldn't support yourself in midair, so you'd land on your ass.

In that scenario, the only reason you'd leave the ground at all is because you abruptly change your center of gravity, lose your balance, and fall on your ass.

Dooey Jo · Post by **Dooey Jo** » 2006-02-11 12:59pm

That won't work. It'd be like trying to lift yourself by your hair...

However, if your magnets are really strong, they might be able to push against the magnetic field of the Earth and hover that way. They'd have to be properly aligned to the field though, so you'd need some form of stabilisers once in the air...

The Silence and I · Post by **The Silence and I** » 2006-02-11 03:21pm

And good luck getting THAT to work anywhere but near the poles.