This footage may be 8 years old, but it doesn’t make it any less impressive. Watch as then high school student Anna Gu demonstrates a bridge she made from layered and glued sheets of paper that was so strong that the hook that held the weights failed before it did. Design here.
While that title might sound like hyperbole, it is the truth. If concrete truly did dry out, it could be reconstituted with water like dry pasta, and couldn’t be used to build things. MinutePhysics explains the not so subtle differences between something being “dry” and “set.”
If you’ve ever been clocked on the head by a golf ball, you’d be certain they’re hard as a rock. But they’re actually quite pliable. Here’s slow-mo footage of a golf ball as it hits a steel wall at 150mph. While it’s likely it was a practice ball, a regular ball still flexes quite a bit.