All around you, and on every surface of the earth, there is radiation pummeling the atoms that make up the matter that we can see and feel. Even as you read this sentence, you are being bombarded by radiation. Pew! Pew!
But fear not, it’s completely normal. This background radiation is safe. And though it cannot be seen directly, you can build a cloud chamber to help you indirectly observe radiation and begin to understand it.