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2020 December 02

It’s now been one year since I set up this blog, and I still haven’t gotten around to writing what I thought was going to be my first post!

Music

Ricky Montgomery - This December

Mother Mother - Ghosting

Bach - Passacaglia and Fugue in C Minor BWV 582 It took me some searching to find a performance that I liked that also had a “score”. There was quite a bit of variation depending on the organ and the performer. I was surprised to find that I liked the visualization here quite a bit more than a traditional score, especially the inclusion of the theme (as grey bars) during the passacaglia which helps provide context for the variations.

Perturbator - Birth of the New Model

Previously I mentioned Skolem’s paradox as a bizarre quirk of mathematical logic, but since reading Scott Aaronson’s excellent post on the continuum hypothesis I have learned that the Löwenheim-Skolem construction plays a key role in proving that the continuum hypothesis is independent of ZFC!

Observing Ramadan requires fasting from sunrise to sunset. The Burj Khalifa, the tallest building in the world, experiences significantly longer daylight at the top, so observers living above the 80th floor must break fast two minutes later, and observers living above the 150th floor must break fast three minutes later; it is unclear if fast also begins earlier. Observers living in permanent day or night either follow the times of the nearest city with daily cycles or of Mecca; those in orbit follow the times of where they launched from.

Recent work has resulted in the discovery of a “carbonaceous sulfur hydride” system that is capable of superconductivity at 15 C at the soul-crushing pressure of 267 gigapascals. If this pressure is too impractical to apply, let us refer to the announcement earlier this year of “room temperature” superconductivity through the innovative technique of lowering the temperature of the room.

Marcus Garvey supposedly died of a stroke after reading his own unflattering obituary that was erroneously published – possibly the only case of an obituary causing the subject’s death.

Optimizing compilers for C use all kinds of smart tricks to speed up the code they produce – sometimes too “smart”. A clever C program was used to trick such compilers into claiming that they could find a counterexample to Fermat’s Last Theorem. The author writes:

Faced with this incredible mathematical discovery, I held my breath and added a line of code at the end of the function to print the counterexample: the values of a, b, and c. Unfortunately, with their bluffs called in this fashion, all of the compilers emitted code that actually performed the requested computation, which of course does not terminate. I got the feeling that these tools – like Fermat himself – had not enough room in the margin to explain their reasoning.

Videos

Why organs sound scary, as well as an overview of the history of organs, how they operate, and the cultural context of organ in earlier movies.

Line rider animation of Beethoven’s 5th symphony; animation by DoodleChaos.

A problem arises during a piano performance and is handled.

Antiques Roadshow: Chekhov’s Gun

Images

Crystalline bismuth. The appearance is in part due to surface oxidation.

The Rosette Nebula, image found here

One minute after Deep Impact struck comet Tempel 1.

Sand dunes in Rub’ al Khali, the erg covering the lower third of the Arabian peninsula. Random fact: “erg” is sometimes pluralized as “areg”, although “ergs” is much more common.

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