Silly putty LOL.
But if the earth has layers like a candy bar, it explains all of the nuts on the outside.
Lol!
I remeber reading a book by John Brunner, in which the police had something called “Caratands.” They were soft until you hit someone, and they turned rock hard. Silly putty in special gloves could do this! Normal hand movements , no problem. But smack someone and it’s like hitting them with a brick! Maybe I need to make a pair for my next trip to Cleveland?
Karatand;
“
...a Karatand... It was in effect a palmless glove made of impact-sensitive plastic about a quarter-inch thick. Pressed, pinched, drawn on or off the hand, it remained flexible and nearly as soft as good leather. Struck against a resistant surface, its behavior changed magically, and while the interior stayed soft to act as a cushion against bruising, its outer layers became as rigid as metal.
He thrust his fingers into it and spun around, slamming his fist at the wall. There was a solid thud, and the muscles of his upper arm and shoulder complained, but the Karatand reacted as designed. It was several seconds before he could straighten his fingers against the resistance of the relaxing plastic.”