To boil it way down: The root claim is that there is a way to craft a special closed box that when you apply electricity to it, the box starts moving (linearly) without either pushing off of anything or throwing anything out. If that were true, it'd mean an awful lot for space travel; changing direction in space requires a ship to either crash into something or throw bits of itself away until it runs out of bits. If this thing works the way it is claimed to, a spaceship using it could control its motion forever, powered by merely the light of the nearest star.
(... it probably doesn't work the way it's claimed to, because if it does, there's a lot of interesting things we should already have seen by now in the "closed boxes moving around as if by magic" category; the universe is a big, big place of big, big possibilities. But lack of observation doesn't make it impossible, just unlikely).
> we should already have seen by now in the "closed boxes moving around as if by magic" category
I agree if it's true such phenomena must be quite likely. But maybe not in the amperage range that we witness here on earth. There are places in the universe that see amperages 10 billion times higher than what we see here. Perhaps you might see some box-ish things moving out there as if by magic.
Makes me wonder if it could somehow convert the energy to mass and throw that off, as it were. Though it's probably something more exotic, assuming it's not an error of some type.
(... it probably doesn't work the way it's claimed to, because if it does, there's a lot of interesting things we should already have seen by now in the "closed boxes moving around as if by magic" category; the universe is a big, big place of big, big possibilities. But lack of observation doesn't make it impossible, just unlikely).