[untrained skeptic]

"One of the main theoretical arguments against anti-gravity is that it implies the availability of unlimited energy.

"If you design an anti-gravity machine, you've got a perpetual-motion machine," Robert Park of the American Physical Society told Nature. "

Only if it's a perpetual anti-gravity machine.

Something that counters the effects of gravity does not by definition require unlimited energy. That should be obvious.

[mhx]

That's right. For example, a magnet can be an anti-gravity machine, and it would be perfectly ok to build a machine with magnets in it and patent it. In fact gravity is a really weak force anyway.

It's a perpetual motion machine that's off limits.

[SunkenCiv]

Only if it's a perpetual anti-gravity machine. Something that counters the effects of gravity does not by definition require unlimited energy. That should be obvious.

:')

In any case, I'd waaaay prefer having one of those food replicators in my house.

[JoeSixPack1]

When they can 'ignore/neutralize/abandon or insulate from' gravitational energy determined by mass, without using a proportional force to negate that same gravitational pull, THEN they're on to something!

Casper the friendly ghost can do it! :-)