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I saw a video by Michio Kaku, showcasing levitation of a small object with a superconductor cooled by liquid nitrogen. It's the same technology used by some trains.

Hypothetically, how possible is it to achieve free human flight by some way of:

  1. Putting a thin, light (say 5kg) bed, under a human in a fly suit. The bed is coated with the magnetic material of one polarity.
  2. This bed has some sort of continuous thrust mechanism, with the required thrust to keep only it afloat & to fly it around. (It's very light due to carbon nano tubes, high technlology etc.)
  3. On top of this bed is a freely floating human in a suit made of the opposing superconductor (or however this works)

So essentially the bed is what's really flying around and has tiny thrust requirements because of it's weight and the human is levitated at essentially minimal cost (due to the superconductor)

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Do you have a link to this? –  user29350 Sep 13 '13 at 22:10
    
Added link in body. –  Baconbeastnz Sep 13 '13 at 23:41

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up vote 3 down vote accepted

There's a lovely children's novel in which much the same idea is employed for building a "perpetumobile", something that cannot be possible for all we know about physics.

The easiest law stating that it can't work is Newtons third law: for every force (like the one that levitates the human) there must be an equal and opposite counter force, in this case upon the bed, pressing it downwards – because what human's suit interacts with, magnetically, is the bed. In effect, this amounts to exactly the same as if it were an ordinary lightweight bed without any superconductors at all: the bed plus human weights as much as a bed and a human together, inevitably. Making the bed extremely light always still leaves the human's weight to be stemmed by the thrust mechanism.

Note that the superconductor-floating is in principle not even so different from simply lying on the bed via old-fashioned "contact repulsion": on a subatomic scale, there is no such thing as contact: atoms aren't solid balls with a hard edge, but combinations of multiple particles swirling around in various quantum states. Rather, there is repulsion between the particles; most importantly Pauli repulsion (that can only be observed on quantum scales), but also electrodynamic interactions, which is basically the same as with superconductors and magnets.

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