The Scientific Pioneer Returns by Nelson S. Bond

I looked at Bert Donovan and he looked at me. Judging by the faces of our two screwball intellectuals, there was something smelly on the _Saturn_. But it was all a deep and dark mystery to me.

I said, "Hank, for old times' sake, would you brush that off again lightly for me? In words of one syllable, what has the little letter _i_ got to do with space flight, gray skies and time-travel?"