Saving 4M books from landfill
I share the same obsession as archive.org.There were library books that for one reason or another made an impression on me as a kid.  Sadly of course those old books have been rotated out of the system.Books that replaced them didn't impress me. (Though perhaps as I have aged I am less impressionable?)There were some great science and chemistry books for kids when I was young — to be replaced with "grossology" books.I liked the books that showed future automobiles, spacecraft but I understand why those are dated. I'm not sure I have seen anything that has the same sense of optimism to replace them though.Or maybe I just prefer the early space-art illustration and concept art in those books done by artists wielding gouache long before CG made everything look bland and lifeless.In any event I tracked many of these books down on eBay and purchased them. (So often "DISCARD" stamped inside the front cover, a library card pocket inside the back cover.)Because I am worried that I am becoming a hoarder I was inclined to instead scan many of the books I had collected and then return the original to the sea of used books.I have uploaded to archive.org everything I scanned.And I am happy to have in fact also found many other cool books there that I had assumed were going to be lost to time (thinking now about "The Boy Mechanic" bookstore example).