Several months ago, I walked out at the close of a banquet and found it to be raining briskly. It was plain there would be no taxis, so two other banqueteers and I made our way to the nearest subway entrance, got on a subway train, and trundled northward.
As it happened, my stop came first. I bade my friends farewell and got off the train. The next day I found out what had happened to them after I got off.
Three youngsters walked up to where my friends were sitting, and towered over them in what seemed to be a threatening manner. My friends were well aware of the violence that sometimes takes place in the subway and they were naturally apprehensive.
One of the youths said something in a low voice and one of my friends, plucking up courage, said, "I'm sorry, young man, I didn't hear you. Would you repeat it, please?"
Whereupon the young man, in a louder voice, said, "What I asked was: Was that Isaac Asimov that just got off the train?"
In a flash, the youngsters had changed from three threatening hoodlums into three concerned fans of culture with impeccable taste, andmy friends answered cheerily that indeed it was, and all was wine and roses thereafter.
I don't know if those intelligent young men on the subway ever read my science essays, but if they do, this one is dedicated to them.
Asimov then goes on to talk about the study of the galaxies with radio telescopes.