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Meta
Category Archives: astronomy
witness on Whidbey
I watched Behind the Curve (2018), a documentary about the Flat Earth movement. In the beginning, Mark Sargent says (I paraphrase), “I know the Earth is not round because I can see Seattle from here [Whidbey Island].” If I knew … Continue reading
Posted in astronomy, mathematics
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do you speak my calendar?
In MacBSD, the command cal 9 1752 shows the shortening of that month in the British Empire. If I reinstall MacOS and choose Italian as its default language, will the shift show up instead in October 1582?
Posted in calendars, history, neep-neep
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calendar reform
Each month shall have 30 days, except within a lune spanning 157°15′57″ (5.242199 × 30°) of longitude, wherein the month shall be extended by one day which shall not affect the cycle of the week. The lune so affected shall … Continue reading
Posted in calendars
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Friday thirteen come on Friday this month
Somewhere or other I recently mentioned having heard that, because the Gregorian calendar cycle of 400 years is a multiple of 7 days, the 13th of the month is not evenly distributed and falls more often on Friday than on … Continue reading
Posted in calendars
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links from spaaace
Average illumination near the Moon’s south pole, showing which crater floors never (or almost never) see sunlight. Unfortunately the text doesn’t quantify what the whitest pixel means, i.e., how much time the most-illuminated point spends in shadow. Wobbling time exposure … Continue reading
Posted in astronomy
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another thought that I’m never likely to have occasion to apply
If one has the luxury of designing a calendar from scratch, it might be good to put leap day at aphelion, where its angular value is least.
in memory
Dan Alderson once made a map of nearby stars by mounting little colored spheres on threads strung between holes in two sheets of heavy clear plastic. It occurs to me that, taking the stars in pairs, he could use half … Continue reading
Posted in astronomy, fandom, mathematics
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