Perhaps you’ve heard of the “computer.” A sort of magical electro-abacus, the computer is capable of performing dozens of calculations per second and may one day fit inside a modestly-sized living room. Indeed, computers are used for everything from statistical calculations and word processing to playing text-based games or sending electronic mail to colleagues. But what about supercomputers?

So-called supercomputers are, at heart, simply very, very, exceedingly, mind-meltingly, brain-bendingly, noggin-tobogganingly fast computers. We’re talking quadrillions of arithmetic operations each second, here — more than enough power to get a decent Diablo III frame rate. But what are supercomputers used for? Well, back in the ’90s, IBM’s Deep Blue supercomputer was built with the noble goal of putting humans in their place by beating the world chess champion, Garry Kasparov, in a six-game match. Deep Blue lost, so IBM’s team worked on it some more, and the next year Kasparov was finally defeated (though he claimed IBM secretly had humans help the machine). Playing chess may sound unimportant, but IBM’s website assures the public, “Behind the contest, however, was important computer science,” going on to list a handful of noble applications like financial modeling and medical drug development that Deep Blue probably should have been doing instead of trouncing Kasparov. (After the chess matches, Deep Blue was dismantled, lest it be put to any legitimately beneficial use.)

Fortunately, other supercomputers have worked for humans instead of against them. Supercomputers crack cryptographic codes, model complex molecular and nuclear physics, detect overlooked oil and natural gas deposits in old sonar readings and analyze stock markets. A supercomputer was used for much of the special effects in the “Lord of the Rings” movies, and (in case you thought they were always good) a supercomputer is responsible for the weather forecasts you see on the news. Proctor & Gamble even used a supercomputer’s airflow simulation to make their Pringles potato chips more aerodynamic so they’d stop blowing off the assembly line.

But although supercomputers are much cheaper and more widespread than they used to be, not everyone can afford one. Some groups have instead turned to a different solution: instead of having one enormous computer do all the work, why not split the task up into little jobs that many computers can do? This is the theory behind distributed computing projects; interested citizens can download programs that contribute to these projects when their computers aren’t in use.

One example is SETI@home, a SETI (Search for Extraterrestrial Intelligence) project where average home computers are used to search radio telescope data for narrow-bandwidth signals from space, which would be evidence of technologically advanced alien life. The Folding@home project models protein folding for disease research when you’re not using your computer. DistrRTgen does the same for studying password security, eOn models theoretical chemistry on long time scales, the Quake-Catcher Network detects earthquakes and Electric Sheep mathematically evolves trippy animations that double as screensavers.

Afraid you’re being made obsolete? Fear not! Some similar projects actually require human interaction! NASA’s Clickworkers project, for example, relies on humans to identify specific geological features in photos of Mars. When data from many “clickworkers” are combined, NASA gets an accurate mapping of the locations and sizes of craters. Similarly, Duolingo combines many novice human language translations of text to produce high-quality translations for articles and websites.

It’s always nice to see how humans are still relevant in our age of machines. There are some things humans will always be better at, like playing soccer and learning languages, right? (This list used to include driving cars and playing chess, too. And remember John Henry?) So go out and take part in one of these awesome projects that put you or your computer to use for the public good. Just don’t be surprised when you’re no longer needed. This is probably around when your vacuum cleaner will finally beat you at chess.