You've probably heard the phrase "we are made of stardust." It turns out that's not poetry — it's chemistry. Almost every atom in your body was forged inside a star. There's exactly one major exception. Which element in you did NOT come from a star?

Bananas are mildly radioactive. This is true, it's harmless, and it's used so often as a teaching tool that scientists made up a half-joking unit of measurement around it. What is the radioactive ingredient in a banana?

Out in the vacuum of space, two clean pieces of the same bare metal pressed together can permanently fuse into one solid piece — no heat, no torch, no welder required. Engineers call this "cold welding," and it has actually caused spacecraft hardware to jam. Why does it happen in space but basically never on Earth?

Your stomach runs on hydrochloric acid, the same family of acid used in industrial cleaning. It's so strong that doctors have documented it corroding a swallowed metal razor blade in under a day. So here's the real question: why doesn't your stomach digest itself?

Look at very old cathedral windows and you'll notice the glass is often thicker at the bottom than the top. For generations, people explained this with a confident, satisfying, and completely wrong story. What's the busted myth?

Stumper. There's a microscopic animal called the tardigrade, or "water bear," that is arguably the toughest creature on Earth. In a real experiment, scientists strapped living tardigrades to the outside of a spacecraft and exposed them directly to the open vacuum of space for ten days. What happened when they brought them back and added water?