...neutrino,

The Sudbury Neutrino Observatory (SNO), now under construction in a Canadian mine shaft, will revolutionize this technology; nevertheless, the best one can hope for is some rough estimate of the direction of the source of individual neutrinos. The pesky critters just don't interact much! (Which is why they get here at all!)

...frame!

Once again Physics comes around to the same conclusion that has been reached by Psychology.

...Principle.

You could open the door and look out, of course, but that would be cheating; besides, how do you know the view is not just an excellent illusion?

...generated)

If it weren't for supernovae, there wouldn't be any heavy elements floating around the Galaxy to make planets out of and none of us would be here! Think of yourself as a sort of ``supernova fossil.''