ROBERT SIEGEL, host:
From the high-tech machines of the present and the future, we're going to turn now to news about an amazingly complex machine from the past. It's from about 2,000 years ago, from Greece and it has an intricate system of bronze gears that look a bit like the workings of a fancy timepiece.
As NPR's David Kestenbaum reports, scientists have used some very new technology to study this contraption, and they're finding that it is surprisingly sophisticated.
DAVID KESTENBAUM: It seems miraculous that this device survived at all. It spent nearly 2,000 years on the ocean floor.
Professor MIKE EDMUNDS (Cardiff University): It was discovered when some sponge divers were blown off-course in a storm in 1900.
KESTENBAUM: Mike Edmunds is a professor of physics and astronomy at Cardiff University in Wales. The divers took shelter near the tiny island of Antikythera, which is now part of Greece.
Professor EDMUNDS: When the storm subsided, they thought oh, we'll go and see if there are any sponges around. And they dived down, and they were surprised to find a shipwreck.
KESTENBAUM: The shipwreck has been dated to 65 B.C. Divers retrieved the fragments of a mysterious machine now known as the Antikythera Mechanism. It was broken into 80 pieces, some parts fused into a kind of brick from their time under the ocean, other parts missing. Researchers worked out that the original device had some 30 gears and was about the size of a shoebox. Inscriptions indicated it was used at least to predict the location of the moon and sun. Some thought it might have been capable of more.
In this latest effort, Edmunds and a team of researchers took a fresh look at the inscriptions with a new optical device, and they took a three-dimensional X-ray of the pieces - a sort of body scan. He says they found the device could do what amounted to some pretty complicated math.
Professor EDMUNDS: It was capable of predicting when you might expect eclipses, lunar and solar eclipses, based on a cycle known to the Babylonians called the Saros Cycle, but it had a dial that indicated in which months you were going to maybe get eclipses.
KESTENBAUM: The machine could also reproduce the subtle variations in the moon's orbit. It was kind of a mechanical calculator: Turn a knob, and a dial magically tells you the answer, all by a very clever arrangement of gears.
Professor EDMUNDS: This is more complicated than any device known for 1,000 years afterwards, and the thing that we've been able to show, I think, is that it is just beautifully designed. It shows real technological intelligence, and that of course is interesting because it makes you think well, if they could do that, what the hell else could they do?
KESTENBAUM: What do you think this thing was used for?
Professor EDMUNDS: That's a very good question. We're not sure about that. Now we know what it does, but we're not sure exactly why you would want to do those things.
KESTENBAUM: Some researchers think the device also had pointers for the positions of planets. One theory has been is that it could have been used for horoscopes: an elaborate, mechanical fortune-teller. Francois Charette(ph) doesn't think that's very likely. He's a researcher at Ludwig Maximilians University in Munich.
Dr. FRANCOIS CHARETTE: It cannot have been astrological because it's too early.
KESTENBAUM: The new research examined the style of the Greek letters on the object.
Dr. CHARETTE: The date is between 150 and 100 B.C., and so that was just the infancy of astrology in Greek or Roman culture.
KESTENBAUM: David Wright is one of the world's authorities on the Antikythera Mechanism. He's actually built a working model of it based on his studies, and he said it might have been a rich man's showpiece. Writers at the time mention such things.
Mr. DAVID WRIGHT: We have an anecdote in Cicero, who was, after all, alive at the time this thing was lost at sea in which an instrument of this type is used in exactly that way. It's got out to entertain the guests after dinner with a learned discussion of how eclipses happen.
KESTENBAUM: The expertise for building machines like this apparently disappeared. Francois Charette says there is evidence for a mechanical calendar emerging 1,000 years later in another place once known for technological innovation - Baghdad. The research is being reported in the journal Nature and at a conference in Greece.
David Kestenbaum, NPR News.