Anti Gravity Balls
This little scientific puzzle comes from Japan. Inside the clear tube is a clear liquid. Floating in the liquid are 4 clear spheres, but they all float at different heights in the tube. It could seem that maybe they are all of different densities?
But when you turn the tube upside down, they do not change position. Now the sphere that was floating at the top seems to be quite happy to be at the bottom of the tube. And vice versa. So the heaviest sphere now seems to be the lightest.
Obviously, since the spheres are nearly as wide as the tube, they cannot actually change position with each other. But it is strange that their relative buoyancy seems to be reversed when you turn the tube upside down. Perhaps there really is is an anti-gravity effect going on here?