| Now we've got a few minutes before we leave for today. So I'll touch on an interesting subject. |
| More than a hundred years ago |
| an extraordinary mechanism was found by sponge divers at the bottom of the sea near the island of Antikythera. |
| It astonished the whole international community of experts on the ancient world. |
| Was it an astrolabe? Or Was it an an astronomical clock? |
| For decades, scientific investigation failed to yield much light and relied more on imagination than the facts. |
| However research over the last half century has begun to reveal its secrets. |
| The machine dates from around the end of the 2nd century B.C. |
| and is the most sophisticated mechanism known from the ancient world. |
| It is now known as the Antikythera mechanism. |
| Now, when the Antikythera Mechanism was found, it was submerged in a shipwreck. |
| Of course, it was in terrible condition, some parts entirely corroded away. |
| It was a fairly small device, about the size of a shoebox, |
| a meticulous mesh of gears within a wooden shell. |
| There were rotating dials and other markings on the top, |
| with words and icons showing the Sun and moon, |
| and different points of reference in the stars. |
| In other words, this was a device that could track the phases of the moon. |
| This kind of thing would be invaluable during a ship's journey at sea. |
| Since then, scientists have been carefully looking at the device for clues on where and when it was made, |
| and they concluded that it dated back to somewhere between 150 and 100 BCE. |
| In other words, it was about a 50 year time span it could have been invented and used within. |
| So! this was an important breakthrough in the field of archaeology... |
| because before we found the Antikythera Mechanism, |
| the only evidence we could find of a similar star-tracking devices was a thousand years earlier. |
| Now, as I just said earlier, |
| when the Antikythera Mechanism was found, it was entirely corroded away. |
| This is because the Antikythera Mechanism is made entirely of bronze. |
| Well... this would make sense as bronze was widely used in Greece back then. |
| In fact, because bronze was malleable, |
| it was easy to melt the the metal down into bronze coins, |
| which was used as money in Greece. |
| Okay! Back to where I said about the Antikythera Mechanism being made of bronze. |
| You see.. Bronze easily corrodes underwater, |
| so after spending nearly 2,000 years at the bottom of the sea, |
| symbols, of course, were rubbed down to almost nothing by water and silt, |
| and the gears, as you can imagine... |
| had been crusted together into one mass with rust and other deposits. |
| So, cleaning it was an uphill battle, and never completely successful. |
| We could really only get a solid idea of how many gears were laid out |
| after using gamma-rays to see inside, |
| kind of similar to the way X-rays are used to see your bones. |
| So! After scanning the insides, |
| we found an incredibly complex creation. |
| The plethora of gears didn't only track the phases of the moon, |
| The Antikythera Mechanism also kept track of the lunar year and the solar year. |
| In addition, they ticked to align with the earth's own rotation, |
| and could accurately predict when an eclipse would happen. |
| This is all amazing, |
| but the one particularly mind-blowing trait of this device was that it was so incredibly precise |
| that it actually accounted for an irregularity in our moon's orbit |
| that would require some extremely complex math to replicate in a mechanical device. |
| I suppose I could say the Antikythera Mechanism is an amazing piece of engineering |
| that revolutionized the archaeological community. |