I know some people who would spin themselves in tight, angry circles at the idea that anything I've written would be considered hard science fiction.
@leroc Again, I suspect you've not been looking very hard.
Also, with no disrespect to me or the short story in question, being #1 on most Amazon "bestseller" lists is not an especially huge achievement. The company has literally thousands of micro-categories it slices its wares into (the story is also #1 in "45-Minute Literature & Fiction Short Reads," a rarified category indeed). This was more an observation about "hard SF" than "#1."