Why Are Galaxies Flat Instead of Round?

Every galaxy should be a sphere — gravity pulls in equally from every direction. So why does almost every big galaxy in the universe, including our own Milky Way, look like a flat disc instead of a ball? The answer starts with a spinning cloud of gas, a trick borrowed from ice skaters, and a collision effect that erases every direction of motion except one. And there's a twist: not every galaxy is flat at all. If "why" questions like this live in your head, subscribe — this channel is built on exactly this kind of question. #galaxy #space #astronomy #universe #sciencefacts