## Friday, November 17, 2006

### Relativistic pinball machine

The folks from NASA's Chandra X-ray observatory claim, using their new images, that high-energy cosmic rays are generated by shockwaves in supernova remnants.

The picture above is a 325-year old remnant of Cassiopeia A. The particles are supposed accelerate back and forth across the shock wave much like balls in a pinball machine except that the speed is nearly the speed of light in the supernova case.