REMEMBER those two friendly little guys from the movie ``Star Wars'' - R2-D2 and C-3PO? I used to think they were real robots (well, as real as anything is in Hollywood) until I read a story one day that said there were actors inside them, doing all the walking and talking. After that, I wasn't sure if there was such a thing as a real robot. But recently I found out that there are thousands of them in the United States and even more in Japan. Most are called ``industrial robots,'' which means they do jobs in industries and factories - jobs that are too hard, dirty, boring, or dangerous for people to do. They weld together big pieces of metal, lift heavy boxes, and assemble parts of machinery.
Industrial robots don't move around or talk, and most of them don't look like the Hollywood versions. Instead, they're usually a single mechanical ``arm'' or ``hand'' that is designed to do a certain job.
You can find pictures of many kinds of robots in books. And if you ever go to Boston, you can see some in person at that city's Computer Museum, which has the world's biggest collection of historic robots. There you can watch robots hop, walk, talk, and even turn the pages of a book. You'd probably enjoy meeting Shakey, the world's first mobile robot, and you can also see two pioneer explorers - the Mars Land Rover, a four-legged, four-foot-high robot that was designed to climb over rocks on the planet Mars, and Sea Rover, the world's smallest underwater robot.
It's difficult for scientists to agree on a definition of a true robot, but most would probably say that robots are machines that can be told to do different things by a computer. When people say that robots can ``see'' or ``hear,'' it means that they have built-in mechanical sensors that can detect light or respond to noises. In the same way, robots aren't really ``intelligent,'' because they can't think or reason without a computer to help them.
For all the hard work they do, robots can be a lot of fun, too. Some of them are even made out of funny materials - like coffee cans and coat hangers. One famous robot, Timel, was built from cardboard panels and fiberglass cloth, with a fishbowl for a head and potato-chip cans for wrists.
Today robots perform many useful services. In California, robot police units equipped with television cameras and guns can be sent into dangerous confrontations, and in New York City they're used to disarm bombs. A fast-food chain in Canada uses robot waiters to carry trays and clear tables, and in Japan robots direct traffic.
And what about tomorrow? It's fun to think ahead and try to imagine what robots will be doing for us in the future. Can you think of some jobs they'd be especially good at?