*sigh* I said my good-byes too soon, it seems...the course actually has 200 more pages of physics torture before we reach the chemistry part of the course. Unpleasant news, yes, but I know I can take it...can this forum? BTW, I got 100% on my test today, thanks to the help I received on these boards! But no rest for the wicked! Press on, press on! We are studying fluid dynamics now. Q. If you release a Ping-Pong ball beneath the surface of water, it will rise to the surface. Would it do the same if it were submerged in a big blob of water floating weightless in an orbiting spacecraft? A. I think it would possibly do so, since the water will still be pressing on it from all angles, no? and thus pushing it to the edge of the blob? Q. What physics principle underlies this observation: The windows of older passenger trains sometimes break when a high-speed train passes by on the next track. Thanking you in advance. A. Is this like a tornado, POPPING the window out because it sucks the air out?