Gravity is the reason things with mass or energy are attracted to each other. It is why apples fall toward the ground and planets orbit stars. Magnets attract some types of metals, but they can also ...

In orbit, astronauts float weightless because they’re in continuous free-fall around Earth. To recreate gravity, engineers ...

Physicists have spent a century trying to reconcile the smooth fabric of spacetime in general relativity with the jittery ...

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights. Gravity is the reason things with mass or energy are ...