Why speed bumps made from Silly Putty are a good idea

Silly Putty has an interesting property. It's soft when you squeeze it slowly, but rock hard if you hit it with a hammer. Someone came up with the good idea of making speed bumps (or "sleeping policemen," as they cleverly call them in the UK) out of a Silly Putty like substance. That way, slow drivers get a smooth ride, but the faster you go, the more the bump punishes you. It would be fun to design the speed bump in such a way that it rips the undercarriage out of any car going twice the speed limit.

[via Clive Thompson]