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September 19, 2021 Archives

Sunday, September 19, 2021

TRACKING WITH CLOSEUPS: Making Water Drops Spin with Hydrophobic Material

Posted at 13:01 Permalink

THE HAPPENING WORLD: Has the XENON1T Experiment Detected Dark Energy?

A SCANALYZER post on 2021-09-10 discussed the XENON1T experiment and its detection of the decay of Xenon-124 with a half life of 1.8×1022 years, the rarest physical phenomenon ever directly observed. Now, a paper in Physical Review D (full text [PDF]) examines whether the excess electron recoils observed by XENON1T could be due to “chameleon-screened dark energy” quanta produced in the Sun.

Wouldn't it be ironic if a massive detector built to observe dark matter particles ended up detecting dark energy?

Posted at 12:26 Permalink

CONTEXT: Cellular Automata Laboratory, the Music Video

Just like Peter Schickele's P. D. Q. Bach concerts, I couldn't resist slipping a little something of my own in. Cellular Automata Laboratory is a little-known and, in my opinion, underappreciated cornerstone of Fourmilab. In 1988 and 1989 Rudy Rucker and I developed the original Cellular Automata Laboratory for MS-DOS, using every dirty trick in the armamentarium of the whacked-out 80x86 assembly language programmer to wring acceptable performance out of the machines available to us and our audience, which amounted to IBM PC/AT and clones running an 80286 processor at 6 MHz. At one point, I hooked an oscilloscope up to an extension card to verify the inner loop of my evaluator and screen update code was driving the memory as hard as it could be driven, without waiting for the processor.

In 2017, impressed with the spectacular progress in browser-based applications implemented in JavaScript and the power of the canvas graphics facility, I decided to explore whether Cellular Automata Laboratory might be resurrected as a Web application. Well, it worked, and in June 2017 it went live—try it for yourself! (Here is a more detailed history of Cellular Automata Laboratory and the complete development log of the Web edition.)

One of the innovations in the Web version was “shows”—the ability to script self-running demonstrations, and this was used to create a series of YouTube videos illustrating various cellular automata rules implemented in it. These were, however, all silent movies. Now, Jason Higley has set the Cellular Automata Laboratory demonstrations to freely redistributable music, which dramatically improves the flow and watchability of the video. Enjoy!

Posted at 11:29 Permalink

CONTINUITY: Weekly Space Report: Starship and Starbase Developments, Inspiration4, Starlink Laser Satellite Links

Separately, Elon Musk appears to have confirmed that Starlink will be used to provide global coverage for satellites in Earth orbit using Ka band microwave or laser links to Starlink satellites. This could be a game changer for those operating low Earth orbit constellations, who now must rely on occasional passes over ground stations or costly geosynchronous relays.

Posted at 10:46 Permalink