And to be specific, vaccums work by creating a low pressure locality inside of a gas. Same principle behind a backwards fan. Push the gas one way, you create a

And to be specific, vaccums work by creating a low pressure locality inside of a gas. Same principle behind a backwards fan. Push the gas one way, you create a small low pressure point that other gas then fills. In a vaccume-cleaner the region of gas that can rush in to fill the low pressure point is at the end of a nozzle. Really, you're not vacuuming up objects, they're just along for the ride in their immediate atmosphere. (...And in space, you have no atmosphere to manipulate.)