Monthly Archives: September 2010

Selling books again

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I am once again selling books from my library. I shipped one today, getting $78 for it. Today I listed another 10 math, physics, and statistics books at Amazon.com. My pricing strategy is simple: For any given book my price is clearly the lowest. In a couple cases that still let me set a price in 3 digits. There is also a history book I want to sell, but I am giving colgaffneyis members a chance at it before going to Amazon.

Again there was a quantum mechanics text that, after some thought, decided I could not bear parting with. I wonder if it was the same book as back in 2005.

A quick look at the end of Gaelic Ireland

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Liam Swords, in The Flight of the Earls, includes a brief account of the Nine Years’ War, the last and greatest of Irish rebellions against Queen Elizabeth I of England, but is more concerned with the aftermath. On September 14, 1607, Hugh O’Neill, Earl of Tyrone and leader of the rebellion, Rory O’Donnell, Earl of Tyrconnell, and nearly 100 of their family and followers fled from Ireland on a ship. Continue reading →

A Laser Strike at the Galactic Center

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Great picture at APOD

Why are these people shooting a powerful laser into the center of our Galaxy?

Phil Plait explains:

The laser shoots up into the sky and excites atoms in the upper atmosphere, causing them to glow. That makes an artificial and very bright star in the sky! The telescope can then use that star to track the distortions in the atmosphere and compensate for them, allowing the images it makes to be incredibly clear and sharp.

With the laser, modern computers, and adaptive optics astronomers have solved a problem with Earth-based optical telescopes that goes back to Galileo.

Note that this is a technique for visible light observations. Space-based observatories are needed for the parts of the electromagnetic spectrum that are blocked by the Earth’s atmosphere.

Joss Whedon teaches Physics

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mia_mcdavid has been introducing our foster daughter, carpe_noctum_93, to the wonders of Joss Whedon’s creation, going through our complete DVD collections of both Buffy and Angel. Back in July I heard Jennifer Ouellette speak at Convergence, and decided it was time to read her book, The Physics of the Buffyverse.

Behind the fantastic properties of the vampires, demons, etc., there is actually a lot of good physics in the series. From electricity and the mechanics of martial arts to the Many World Interpretation of quantum mechanics, the writers of the series drew upon wide variety of concepts in physics. Ouellette neatly disentangles the real science from the fantastic elements, maintaining a witty style quite appropriate for the subject matter. It is absolutely non-technical—no math needed (Though that reminds me that I want to read her latest book).