Why does a tiny rock sink to the bottom of a lake, while a giant boat can stay afloat? When any object hits water, it displaces some amount of water. To float, the object needs to be lighter than the ...

Throwing a paper aeroplane on Earth is simple: fold, flick, and watch it glide. But what if you tried that same move in outer space? No gravity pulling it down, no air to help it fly, and no wind to ...