Almost all galaxies are frisbee-shaped. How did so many end up like flattened discs in the first place? Well, it all comes down to gravity… mostly. And that's because these galaxies are filled with tons of gas and they're in constant rotation around an axis, just like a fidget spinner. But at the same time, gravity is doing its work of collapsing everything down towards the center. But things collapse differently on this plane, which is rotating in a circle around that axis in the middle. Because swirling around sort of halts that collapse due to centripetal force, which keeps everything pushed to the center when it moves in a circle. And that's how the disc is born. But newer simulations suggest that discs can form another way, it's possible that galaxies merge or that filaments of gas add to galaxies and grow them out into disk shapes. So, in the end, is our galaxy just a giant fidget spinner? [sigh] Who am I to say?