Author Archives: gmcdavid

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About gmcdavid

Retired IT professional with a wide range of interests. Married. Three sons, two with autistic-spectrum disorders and the third being transgender with Ehlers-Danlos syndrome. From Chicago but now living in the Twin Cities metro, Minnesota. Episcopalian. Carleton College (BA 1972, physics) and Stanford University (MS 1974, Applied Physics; MS 1976 Statistics).

Maintaining Gaffneyis Gear

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We took four of colgaffneyis polearms (3 pikes and a partisan) to Fort William and back last weekend. You can see how they traveled here.These take a lot of abuse at our events. The heads are always getting rusty. The shafts have not received any maintenance in 5 years to my certain knowledge, and I suspect much longer. The problem was similar to that of rehabbing old tools, which I often done before (e.g. these posts). However, there was an issue of scale. The partisan is 6 feet long. Two of the pikes measure 10 feet, and the third 14. Continue reading →

The End of Time …

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… simulated in a Maryland lab

The Big Crunch: Physicists Make Time End

Physicists Recreate ‘End Of Time’ in Lab

(The technical details) Hyperbolic metamaterial interfaces: Hawking radiation from Rindler horizons and the “end of time”

It should be noted that this is a simulation of one possible way our universe might evolve, one that current observations suggest is incorrect. However, it is a solution of Einstein’s equations of General Relativity, and as such well worth studying.

When I was much younger something like this might have been called an “analog computer.” I have not seen that term much lately.

From Cocktail Party Physics

The Onion imitates Life

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From Best of the Web Today

“Shuttle’s Last Flight Leaves Russia With Space Monopoly”–headline, The Wall Street Journal, July 7

“USSR Wins Space Race as U.S. Shuts Down Shuttle Program”–headline, Onion, July 27

In the end, the U.S. is left to ponder an irony: It won the technological race to develop a space shuttle but lost the war. “You can argue that the Russians were on the right trajectory all along, by flying big, dumb boosters,” said Duke University space historian Alex Roland.