"Dark Matter" is a phrase we use to describe a hole in our understanding of the universe. To put it simply, when we look out into space, at very large scales li

"Dark Matter" is a phrase we use to describe a hole in our understanding of the universe. To put it simply, when we look out into space, at very large scales like galaxies, everything is just too heavy. It appears as if there is a LOT more matter out there than we can see. Things are orbiting faster than they should be, like galaxies are heavier than makes good sense.. Maybe there is some matter out there that is "dark", so we just can't see it. That would be a solution. Or maybe the laws of gravity we wrote down are bad at large scales. No one knows. Trust no one who tells you they know the answer: if they did they would have a Nobel Prize.