Julian Cope presents Head Heritage

UPDATE: alun who is a specialist in this very subject of archeoastronomy makes some very interesting points about the problems with Hansen's theory.

The latest astronomer to work on the disc is Ralph Hansen from Hamburg who said: “I wanted to explain the thickness of the crescent on the sky disc of Nebra because it is not a new moon phase.” ... [but] If Hansen is right, the disc is irrelevant to his theory. Hansen started by looking for a specific moon phase. There's two assumptions in this. One is that the phase is accurately depicted on the disc. The other is that the phase can also be accurately identified when observing the moon. It's not the phase that I'd look for. Over the course of two years the Moon would pass by the Pleiades (in various phases) twenty-five times. The easiest phase to observe would be first sighting of the New Moon passing by the Pleiades, and here's my first problem: this method would work just as well. It would be out of step with Hansen's method, but no more inaccurate. It's a bit like the difference between an hourly bus service which leaves once an hour on the hour and one that leaves once an hour at five minutes past the hour.

Another issue is that the Moon doesn't just pass the Pleiades. It travels through the whole zodiac over twenty-nine days. What happens if, like me, you don't think the seven rivet cluster is the Pleiades? Let's say it's Praesepe in Cancer. Once again because we're talking about fixed cycles it makes no difference to the accuracy. The intercalary months would fall in different years, so this system would be out of step with Hansen's model, but no less accurate.

What you have then is a use for the disc which works just as well if the Moon phase is wrong and whatever the cluster is. Hansen's method doesn't tell us much about the disc, but says a lot about how intelligent modern astronomers are. Is knowing when to insert an extra month really an astronomical problem? I don't think so. It's a social problem, and that means that astronomi