Breakthroughs, discoveries, and DIY tips sent six days a week. Terms of Service and Privacy Policy. Outer space is a vast nothingness. It’s not a perfect vacuum ...

There’s no such thing as a complete vacuum. Even in the cosmic void between galaxies, there’s an estimated density of about one hydrogen or helium atom per cubic meter. But these estimates are largely ...

Physicists want to create vacuums in space, but to do that they need to figure out how to measure the presence of tiny amounts of matter. Dina Genkina, our computing and hardware editor, explains how ...