Watch 'xkcd' explain space travel using the simplest words possible

Would love to know where he gets his list; can’t find a source for it at xkcd.com. At first I suspected GitHub, but apparently no. Wiktionary? Nope. The Reading Teacher’s Book of Lists, Fourth Edition, 2000 [PDF]? Nyet. Poor Randall, saddled with a list that doesn’t include the word “science”! (Typing “science” into the SimpleWriter kicks it back as a not-top-10-100s word; it’s allowed by the three lists named above.)

Oddly, all three lists above include “paragraph,” but not “rock” (Wiktionary). Two out of three like “France” (GitHub). I thought for sure everyone would like “melody,” but not Wiktionary. And I thought for damn sure everyone would like “women,” but not Wiktionary. (To be fair, Wiktionary likes at least one woman, but doesn’t seem fond of a gang of 'em.) At least the Wiktionary list lets me ask, "What’s up with [Wiktionary]?