xkcd xkcd.com xkcd.com: A webcomic of romance and math humor.Alphabetical Cartogramon May 1, 2024 at 04:00 Doppler Effecton April 29, 2024 at 04:00 Earth Formation Siteon April 26, 2024 at 04:00 Pendulum Typeson April 24, 2024 at 04:00 Alphabetical CartogramDoppler EffectEarth Formation SitePendulum Types