Michael Hartl

I’m Michael Hartl—author, educator, and entrepreneur. I’m founder of Learn Enough to Be Dangerous, an education company dedicated to teaching the single most valuable skill you can learn in the 21st century. Learn Enough is an outgrowth of the Ruby on Rails Tutorial, an introduction to web development that Wikipedia founder Jimmy Wales once called his “favorite book.” I’m also (in)famous as the founder of Tau Day and author of The Tau Manifesto, which have inspired an international movement dedicated to the proposition that “pi is wrong.”

I’m a graduate of Harvard College and have a Ph.D. in Physics from Caltech, where I studied black hole dynamics and was an award-winning instructor in theoretical and computational physics. I’m also an alumnus of Y Combinator, the entrepreneur program that has produced companies such as Dropbox and Airbnb. (Alas, my own Y Combinator startup was neither Dropbox nor Airbnb.)