I had a McDonald’s toy that was a self balancing Superman on a point. Obviously this cube is something else in that it can move around but I wonder if it’s even possible to build a non mechanical cube that could balance on its point
Anything that balances is mechanical, you will always end up moving something to compensate for being off center. For instance, you could have two fans spinning to pump air from one side of the device to the other but that would still be mechanical. You could do the same with fluid and so on. But all of it would eventually require a mechanical component to output the reaction force.
Ion drives or selectively colored surfaces don't have enough impulse to do the job, those are the only non-mechanical reaction devices that I know of, but maybe there are others that could work?
Not necessarily. It can also be done with buoyancy. A hot air balloon just before it takes off is effectively "balanced" on its basket and does so because the bit at the top is positively buoyant. You can also get toys that stand up on the bottom of a swimming pool using the same principle.
You could certainly build an ultralight cube with a very small weight in one corner and a helium balloon in the opposite corner, and get it to stand up on its point, at least until the helium leaks out.
There are plenty of things that self center despite not having active mechanics in the sense we are talking about. Bobbleheads, an egg that you shake to have the yolk hold it in place, a lot of springy stuff in general.
Obviously there’s a mechanical force at play, but there’s a huge difference between “some springs make this work” and “these motors make it work”
