[Lee Stewart]

Silly Putty, the weird bouncy rubbery thing that became a bestselling toy in the second half of the 20th century, has some weird physical properties. It's a non-Newtonian fluid, which means it sometimes acts like a liquid and sometimes like a solid.

Some YouTube experimenters showed exactly what that means, dropping 50 pounds of Silly Putty from the top of a parking garage. Instead of bouncing back up, it shatters like glass and makes a crashing noise.