I know you said you want to say sayonara to talking about astrophysics with me, because you're worried about using up too much oxygen on topics about which people don't really care.

But maybe you don't mind discussing with me a poltiical topic.

You mention September 11 2001.

I had a friend - the late Harry Lindenhofen of Ocean Pines, and may God rest his soul, who used to carpool with me to lectures in Delaware.

Harry said that what happened on Sept 11 2001 would have been completely impossible back in the early 1960's and earlier, because in that era all cities were protected by a sensitive alert system and that there would be military response for any airplanes departing from scheduled routes and heading towards metropolitan regions.

Lindenhofen had a background in the military. He was quite a character and I miss him, although sometimes he would call me at 3 AM and ask me questions about quantum physics.... ( not really, but it seemed that way... )

Doug