“Billions and billions of stars.” Carl Sagan’s awestruck if indeterminate census of the universe became a comic catchphrase in the wake of his 1980s PBS series Cosmos. Johnny Carson would intone the line, exaggerating the astrophysicist’s sing-songish repetition of billions and we’d laugh. Not because Sagan’s estimate was so low (estimates currently put the figure at between 10 sextillion and 1 septillion), but in part because the mere idea of billions of suns and consequent solar systems like our own is a patently impossible notion to comprehend. Contemplating god (as a bearded chap on a throne or some vague organizing “force) is water off a duck compared to the mental rearrangements required by the proposition that everyone alive and who has ever lived amounts to nothing more than a mote of cosmic dust. Now that’s hilarious.