Saturday, December 19, 2009

Dark Matter "discovered"?

Dark matter is an idea going back decades. Some astronomer noticed that galaxies rotated faster than expected. Each star in a galaxy orbits the central mass of the galaxy. Newton published the formula for the orbital speed of a satellite, the more massive the primary, the faster the satellite revolves.
When the faster galactic rotation was discovered, it was obvious that the galaxies were more massive than previously believed. It had been assumed that the mass of galaxies was made up of stars, bright objects that can be see in telescopes. Initially the nature of the extra dark matter was thought by some to be weakly interactive massive particles (WIMPS) and by others to be massive compact halo objects (MACHOS). Wimps were unknown sub atomic particles, MACHOs were chunks of rock floating in interstellar space where the sun doesn't shine. No sunlight, no see um.
When first announced, I always thought the MACHO idea was an fine explanation. Somehow over the years the WIMP concept has dominated, MACHO's are obsolete, and physicists are out looking for WIMPS.
According to the NY Times (reliable source that) the physicists are claiming to have detected a couple of WIMPS. The experiment has been running at the bottom of an old mine (to screen out cosmic rays) for years. Over all than time two, just two, events occured that signified the passage of WIMPS.
The experimenters did admit that the two events could have been caused by radioactivity in the rocks making up the mine, so they were only making a tentative claim of seeing WIMPS.
If I had been nursing an array of sensitive cyrogenic detectors in the bottom of a mine for years and years, I'd expect a few glitches from time to time. Hell, I get more glitches than that in my Compaq desktop.

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