Video Throughput: Astronomy in Tolkien’s Universe
In this video, I use a scene from the Hobbit as a jumping off point to talk about astronomical calendars, eclipse and how old civilizations knew way more about the universe than we give them credit for.
As always, love these. Not a lot to add other than my understanding has been that people who have bothered to think about it have always believed the Earth is roughly a globe, in part for reasons discussed here. As triumphant and elegant as his experiment was, Eratosthenes did not come up with the idea of using long-distance trigonometry to test the size and curvature of the Earth on his own. The notion of the Earth as a very large globe would have been a well-known theory to him, which he surely regarded as almost certainly correct even beforehand (by looking at ships sailing over the horizon and disappearing hull-first).Report
My people — the applied mathematicians — have been around for a very long time :^)Report
Since 1972, there have been 27 leap seconds used to synchronize precise time keeping with the variation in the Earth’s rate of rotation. Since they occur on an “as needed” basis, unlike leap days or daylight saving time changes, software has not always dealt gracefully with them. Eg, processes that depend on precise timing don’t like it when a second is inserted or dropped in the system clock. The International Bureau of Weights and Measures has decreed there will be no more leap seconds from 2035 to 2135. That resolution goes to the ITU for a final vote.Report
Perhaps a topic for a future Thursday Throughput. This afternoon SpaceX conducted what appeared to be a highly successful wet dress rehearsal for a Super Heavy/Starship launch. Something over seven million pounds of liquid methane and liquid oxygen loaded into a rocket designed to put 150 tons in low-earth orbit, that is a critical part of NASA’s return to the moon, and may be cheap enough to operate to put everyone who is not a government space agency out of the launch business. Also today, Pakistan, a country of 220M people, sits in darkness because their electric grid collapsed — again.Report