Martin Gardner was an American mathematics and science writer specializing in recreational mathematics, but with interests encompassing micromagic, stage magic, literature (especially the writings of Lewis Carroll), philosophy, scientific skepticism, and religion. He wrote the Mathematical Games column in Scientific American from 1956 to 1981, and published over 70 books.
Some good ones, and some less interesting-to-me articles. Harmonic series made a debut in this collection, which show up in a later book in a solution to my favorite problem.
I would love to know what Gardner thought of the state of space exploration and extraterrestrial communication just before his death.