If it walks like a duck, eats like a duck, and shits like a duck...

 ...it might only be a mechanical "digesting" duck.

Such was one of the iconic inventions of the dawn of the mechanical age, "The Duck." The steampunk creature of clockwork limbs could not only move, but simulate eating food and - sparing no effort in attention to detail - pass droppings as well, although the actual product was pre-stored and didn't involve actual biological digestion.

Such was the invention of Jacques de Vaucanson, widely considered to be one of the fathers of robotics or at least automata. He created this duck in 1738, for demos to the elite, using it to finance further creations.

Before you scoff too loudly at such frivolity, keep in mind that Vaucanson's major accomplishments included automated, programmable looms, which could be programmed with punch cards - in 1745. Later this same media storage format would be used to input data into the world's first computers.

You can still generate a punched-card design at emulators like this. I would recommend the 'bcd' command from the bsdgames package on Unix systems, but that's such lost technology that it's barely worth mentioning.

World-record house of cards builder

Well, the holidays always seem to bring out the odd hobbies in people, right? You may find yourself in an idle hour or two over winter break with a deck of cards in your hand. If so, and you undertake to build a structure of some sort, realize that you have already been beaten forever by this man.

The Two-Deck Turnover Trick - Try It!

Take two decks of ordinary playing cards. Keep the packs separate. Shuffle each of them. Now place both decks face down side-by-side and begin simultaneously drawing one card off each deck and revealing them.

Odds are better than 50/50 that at some point before you reach the bottom of the decks, you will eventually draw the exact same card of suit and rank from either deck at the same time.

I originally saw this in a recreational math book years ago, but I'll give the credit to this fascinating poker odds wizard, since seeing the trick on that page reminded me of it.