Randall Patrick Munroe (born October 17, 1984) is an American cartoonist, author, and engineer best known as the creator of the award-winning webcomic xkcd. With a background in physics and robotics, Munroe has worked full-time on the comic since late 2006, publishing three times a week to a very large audience. Several of the strips, notably a visualisation of radioactivity levels, were also republished by other outlets. In addition to publishing a book of the webcomic's strips, he has written three books: What If?, Thing Explainer, and How To.