Pinball and Astrophysics: I Get It

I admire really smart people who can explain complicated stuff in terms that I can understand. (Which includes, of course, everyone who writes articles for Dr. Dobb's Journal.)

Take Glenn Allen, for instance. Glenn is a research scientist at the MIT Kavli Institute for Astrophysics and Space -- and if that doesn't qualify you as being a smart guy, I don't know what does. Glenn is also a team member of NASA's Chandra X-ray Observatory, which was launched by the Space Shuttle Columbia in 1999, and which is the most sophisticated X-ray observatory built to date. Chandra is designed to observe X-rays from high-energy regions of the universe, such as the remnants of exploded stars.

One of the recent accomplishments of astronomers, thanks to Chandra, was to map the rate of acceleration of cosmic ray electrons in a supernova remnant. The new map shows that the electrons are being accelerated at close to the theoretically maximum rate. This discovery provides evidence that supernova remnants are key sites for energizing charged particles. The map was created from an image of Cassiopeia A, a 325-year-old remnant produced by the explosive death of a massive star. The blue, wispy arcs in the image trace the expanding outer shock wave where the acceleration takes place. The other colors in the image show debris from the explosion that has been heated to millions of degrees.

Okay, I admit that I didn't understand that at all -- at least until Glenn explained it. "The electrons pick up speed each time they bounce across the shock front, like they're in a relativistic pinball machine," Glenn explained. "The magnetic fields are like the bumpers, and the shock is like a flipper."

Ah, pinball I can understand. Thanks Glenn. Bumpers, flippers, and loud bada-bings are what I grew up with. And I'd be somewhere down the line, Glenn tilted a machine a time or two as well.

Here's a bit of trivia about Chandra: It's operating system is written in C++, and its architecture was built around C++ There are numerous papers that discuss software elements in Chandra, such as those at the Chandra X-Ray Center. The paper Elements of The Chandra Data Analysis System, by M. S. Noble of the Harvard-Smithsonian Center For Astrophysics, provides some details on Chandra innards, and the C++ parts make more sense to me than the astrophysics stuff.

Posted by Jon Erickson at 12:16 PM  Permalink