Bibliolater 📚 📜 🖋 @bibliolater@qoto.org

Drought In Europe Mid-June

Source: European Drought Observatory (EDO), for the period of June 11-20, most recent data available

#News #EuropeanNews #Europe #ClimateChange #Drought #Droughts

Amazing thunderstorm photos captured at 37,000 feet by airline pilot Santiago Borja.

Web: https://www.santiagoborja.com/
Instagram: https://www.instagram.com/santiagoborja/

Besides doing a bunch of useless research on the motion of planets, Kepler did some practical work on the volume of wine barrels. The story is interesting! Roberto Cardil writes:

"Kepler had several children before his first wife died. In 1613, he married for the second time in a celebration in Linz, Austria. Kepler bought a barrel of wine for the wedding but questioned the method the wine merchant used to measure the volume of the barrel and thus determine the price. In consequence, afterwards Kepler set out both to determine the correct volume of a wine barrel or cask, and to find the proportions that optimize the volume of such a barrel."

To determine the volume of a wine barrel, Kepler thought of any solid body as made up of thin layers, took the sum of the volumes of these layers, and then took a kind of limit where the thickness of these layers became infinitesimal.

Otto Toeplitz wrote:

"Working out finer approximations of various barrel shapes, Kepler consulted Archimedes and discovered that his own method of indivisibles had enabled him to obtain results in a far simpler and more general way than Archimedes, who had been struggling with cumbersome and difficult proofs. What he did not suspect was that Archimedes, too, had found his results by the same method of indivisibles (for his book The Method was lost until 1906!)."

I guess these "indivisibles" are like "infinitesimals".

For more, read this:

Roberto Cardil, Kepler: The Volume of a Wine Barrel, https://www.maa.org/press/periodicals/convergence/kepler-the-volume-of-a-wine-barrel

The "optimization" problem is not quite clearly explained here, but it seems to be maximizing the volume of a barrel while keeping its volume as measured by the wine merchant constant! 😈

Tonight's #YouTube watch:

best physics equation | virial theorem | gravothermal catastrophe
https://www.youtube.com/watch?v=9CdE5a3xyxE

This person has an amazing sense of comic timing, and a perfect deadpan delivery ("It's fine"), and manages to make physics that I juuuuust barely understand (some of, sometimes) extremely fun.

Unexpectedly delightful.

#map Map showing the different geographical poles of inaccessibility on the globe. A pole of inaccessibility is a location that is the furthest away from a set of geographical features, often the coastline. Red dots represent terrestrial poles of inaccessibility (such as the Eurasian pole of inaccessibility), while blue dots represent oceanic poles of inaccessibility (including Point Nemo).

Produced by Gaianauta in 2008 https://www.wikiwand.com/en/File:Distancia_a_la_costa.png

#geography #cartography

Electrified Lightning in the cloud of a Volcanic eruption

c18.masto.host remains open to new members with an interest in the #18thcentury!

I started this instance on 1 Nov. 2022 in order to establish a home for colleagues in interdisciplinary global #18c studies (with many neighbors joining from #17c and #19c). We had a big push of new members in November and December, along with a donation drive to cover server costs. Early this year, many created placeholder accounts but were not yet ready to dive in. As the community grows, I hope they return!

This is kind of cool: the Cistercian numerals are a forgotten number system developed by the Cistercian monastic order in the early thirteenth century [1,2].

Interestingly, Cistercian numerals are much more compact than Arabic or Roman numerals; with a single character you could write any integer from 1 to 9999.

#math

References
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[1] "Cistercian numerals", https://en.wikipedia.org/wiki/Cistercian_numerals

[2] "The Forgotten Number System", https://www.youtube.com/watch?v=9p55Qgt7Ciw