You would think, considering my background, that had I ever so slight a chance to drag fantasy into any serious discussion of science, I would at once do so with neon lights and fireworks blasting.
And yet, in [the previous essay] on entropy, I completely ignored the most famous single bit of fantasy in the history of science. Yet that was only that I might devote another entire essay to it.
Okay, that's not a personal anecdote, just Asimov referring to himself and his reputation. So it's more of a personal "reference" than an "anecdote," but in the Encyclopedia Asimova we include everything.
The "most famous single bit of fantasy in the history of science" to which he refers is "Maxwell's Demon." Mathematician James Clerk Maxwell, in an effort to explain to the layperson how entropy works.