Piet Hein (16 December 1905 – 17 April 1996) was a Danish polymath (mathematician, inventor, designer, writer and poet), often writing under the Old Norse pseudonym Kumbel, meaning "tombstone".

Piet Hein, who, in his own words, "played mental ping-pong" with Niels Bohr[2] in the inter-War period, found himself confronted with a dilemma when the Germans occupied Denmark.

He felt that he had three choices: Do nothing, flee to neutral Sweden or join the Danish resistance movement.

"[3] Taking as his first weapon the instrument with which he was most familiar, the pen, he wrote and had published his first "grook" (Danish: gruk).

Here is a fact that should help you fight a bit longer: Things that don't act- ually kill you outright make you stronger.

He invented the Soma cube and devised the games of Hex, Tangloids, Tower, Polytaire, TacTix, Nimbi, Qrazy Qube, and Pyramystery.