Magnetic levitation uses magnetic fields to levitate objects. Could you use electric fields to levitate objects?
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$\begingroup$ isn't this the Nobel prize winning [canceled] oil-drop experiment? $\endgroup$JEB– JEB2025-09-16 01:19:35 +00:00Commented Sep 16 at 1:19
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2 Answers
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Yeah, that's what happens when your hair rises because of static electricity... It's just really impractical because when you put a bunch of charge into something, it's really easy for it to flow into its environment and lose its charge at best, or zap people at worst.
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Yes, but it is less practical.
The force exerted by an electric field on an object scales as the electric charge of that object i.e. : $$\vec{F} = q \vec{E} $$ therefore one can only use this to levitate electrically charged objects. And making macroscopic objects with nonzero electric charge is quite hard since any built up charge will quickly leak into the environment.
A cave-at is that electric fields can attract electrically neutral objects. This happens due to electrostatic induction but it will be not be helpful to levitate objects.
On the other hand, it's very easy to make an electromagnet that repels another electromagnet.
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1$\begingroup$ You can attract uncharged objects in an electric field. The original electric effect noticed was uncharged chaff attracted to a charged piece of electrum (amber). $\endgroup$kangermu– kangermu2025-09-15 00:17:26 +00:00Commented Sep 15 at 0:17
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$\begingroup$ True, a strong electric field will polarise certain objects which will result in a net attractive force. This is however a subleading effect and as far as I understand will never help you to levitate stuff. $\endgroup$Gertian Roose– Gertian Roose2025-09-16 08:49:12 +00:00Commented Sep 16 at 8:49
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1$\begingroup$ It’s strange that this answer was accepted and has more upvotes than the one by @Andreas Christophilopoulos. This answer is factually incorrect. It says “electric field … can only … levitate electrically charged objects”. But anyone can rub a balloon on their hair and “levitate” uncharged bits of paper. And it says “making macroscopic objects with nonzero electric charges is quite hard”, when it happens all the time: rub ballon on hair, rub plastic tube with piece of fur, walk across a carpet, etc., etc. $\endgroup$kangermu– kangermu2025-09-16 11:55:16 +00:00Commented Sep 16 at 11:55
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$\begingroup$ @kangermu, I made a cave-at to adres your comments. You are definitely right, and thanks for pointing these things out, I should have picked my wording more carefully. What I meant is that it is hard to make macroscopic objects charged, and keep them charged for a long time... Off course we can rub a balloon through our hair, and it will be charged for a moment, but this won't last for long. $\endgroup$Gertian Roose– Gertian Roose2025-09-17 08:45:20 +00:00Commented Sep 17 at 8:45
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1$\begingroup$ @kangermu I think Gertian means caveat (in Latin: beware) i.e. be aware of the full picture. $\endgroup$The Worst Answerer– The Worst Answerer2025-09-17 16:42:50 +00:00Commented Sep 17 at 16:42