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Astrolabes at the Museum for the History of Science at Oxford.

If you ever want to embarrass me, try to get me to enthuse about a display of astrolabes. They’re the kind of thing I should love. They’re devices for showing what is visible in the sky at any given time. They’re very similar to the planispheres that people use today. The mathematics behind them is elegant. The best also tend to have extraordinarily ornate metalwork to complement the sophistication of the devices. Yet, when they’re hanging up like this, they leave me cold.

I think the reason is that an astrolabe on display is a dead astrolabe. There are better ways to show a static night sky. What you need is an astrolabe in motion to appreciate them. That’s what makes this talk by Tom Wujec so good. He demonstrates how you could use an astrolabe to tell the time. In his hands, an astrolabe becomes a lot more interesting.

Tom Wujec demos the 13th-century astrolabe video from TED.

It’s easy to underestimate how much you can do if you’re willing to observe intently. What I also like about this talk is that Tom Wujec emphasises the importance of connecting with the night sky. You could claim accurate clocks have broken this connection, but I’m not sure that’s the case. Where I live light pollution is often so bad that I could not use an astrolabe. He’s right to point out that you can lose things with progress. Ironically Global Astronomy Month with try to show how immense the universe is, while artefacts like this show that on a day-to-day basis for urban dwellers the visible world is much smaller than the cosmos of the past.

You can see many astrolabes like the one below at the Museum of the History of Science, Oxford.

A Persian Astrolabe at the Museum for the History of Science at Oxford.

A Persian Astrolabe at the Museum for the History of Science at Oxford.