I only discovered this now, fully a year after everyone else blogged about it, but it’s so awesome I have to write about it: A mechanical, binary adding machine that uses marbles to flip the bits. There are several gorgeous close-up pictures of the device on the web site of the designer, Matthias Wandal, but the best way to understand it is to watch that video of it in action!

I’m a huge, huge fan of projects that make digital logic visualizable — like the German geeks who created a mechanical Pong game driven by magnetic relays, or the MIT folks who built logic gates using water. Today’s computer users have no idea how computer logic works, which you could argue is a problem of cultural literay: If you don’t understand how chips “think” then you can’t understand what they’re good at and what they’re horrible at. We live in a world increasingly governed by computer logic; we owe it to kids to explain the thinking processes that run their personal Matrices, because they’ll spend their lives bumping up against the mechanosocial rulesets of Facebook or Mindbook or whatever they hell they’re wetwired into 25 years from now.

That’s why we need awesome rigs like this woodpunk engine of marbleocity. What I particularly like is that fact that it’s powered by gravity and governed by the laws of Newtonian physics, which required the Wandel to tinker quite a bit, because bouncy marbles are not the most precise bits, as it were. From Wandel’s writeup:

Also tricky was getting the rockers to consistently work. I spent a lot of time figuring out what dimensions to make them so that they would correctly work, even if two marbles arrive onto the rocker right on top of each other. I knew it was physically possible to build such a rocker, because the lego rockers I built into the original Lego marble machine had this property by a fluke. The trick turned out to be to make peak of the rocker, which divides the marbles, short enough, and the rocker shallow enough. That way, if a marble arrives before the rocker has had a chance to flip, the previous marble, which is still on the rocker, will deflect the next marble onto the other side, even if the rocker has not yet flipped.

These things cost $250, and I’m currently trying to figure out how to convince my wife that we should buy one. Since she reads this blog, I’m assuming this posting constitutes my first rhetorical salvo. And hey, it’s educational! For the kids!

I’m not joking, though; I really do believe that the “aha” factor of seeing how computer logic works is transformative. To quote my own blog post from four years ago:

Back in grade seven in 1980, I found a book in my library showing how to build logic gates out of magnetic relays. I went to Radio Shack, bought about 20 relays, and spent the next few months building increasingly complex logical operations, including little adders that could calculate the sums of binary numbers. My parents thought I’d gone insane.

My favorite moment was when I built a flip-flop gate — the basis of computer RAM. It’s just a simple feedback operation: You click a switch that activates a set of relays that begin feeding electricity back to themselves, so they remain eternally on. (They’ll only turn off if you run out of electricity or if you purposely “erase” the memory by actively breaking the circuit.) I built a flip-flop circuit, flipped the switch, watched the relay click on and remain on. It was a trippy, Frankensteinan moment. I’d created a piece of memory — a device that seemed to display some tiny piece of self-consciousness. Very heady stuff when you’re 10 years old!

At any rate, when I started using computers a few years later, I had a reverse-Matrix experience with them: When I ran a program I could imagine it as this enormous football field of electromagnetic relays clacking on and off, the logic muttering to itself like a chorus of crickets at night.

It is, of course, inherently asinine to quote oneself, but I’m taking on mulligan on this one because I wanted to repeat the same story/point here and didn’t think I could rephrase it more succintly.

(Thanks to Ned Gulley for this one!)