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July 26, 2021 Archives

Monday, July 26, 2021

CONTEXT: Sabine Hossenfelder: Has Physics Become Too Speculative?

Posted at 15:29 Permalink

CONTINUITY: Do-It-Yourself Cyanotype Photography

The cyanotype process was invented by astronomer John Herschel in 1842. The chemistry is sensitive only to ultraviolet light, so no darkroom is required. Exposure is usually by sunlight, which contains enough ultraviolet to (very slowly) form an image. This is the process used to make blueprints, and was used for that purpose well into the 20th century.

Posted at 14:47 Permalink

CONTEXT: The Galileo Project: Scientific Search for Extraterrestrial Artefacts

Here is the home page of The Galileo Project at Harvard University and a description of its three initial areas of research. According to project head, Prof. Avi Loeb of the Harvard astronomy department, more than US$ 1.7 million has been raised from private contributions to support the project.

Posted at 12:12 Permalink

THE HAPPENING WORLD: After Almost Twenty Years, Pirs Docking Module Departs International Space Station

The Pirs module was launched to the International Space Station (ISS) on 2001-09-14. It has supported numerous dockings of Soyuz and Progress craft, and as the airlock for many spacewalks from the Russian segment of the station. It is being towed away from the station by a departing Progress cargo ship, which will deorbit and burn up in the atmosphere later today. The operation frees up the docking port for the Nauka laboratory module, expected to arrive at the station in a few days.

There had been speculation that vacuum welding between the module and its ISS attach point might interfere with undocking, but this has been shown to be unfounded. The attach point will be inspected by cameras on the station's robotic arm to verify it is ready to receive the new module.


2021-07-26 19:13 UTC

Posted at 10:59 Permalink

TRACKING WITH CLOSEUPS: Explaining the Chain Fountain Phenomenon

Why, in particular, does metal ball chain rise over the lip of the container, while other kinds of chains don't?

Posted at 10:45 Permalink