Today is Albert Einstein’s birthday (born March 14, 1879). Einstein is one of those scientists who is as famous for being famous as he is for his actual scientific achievements. His face and name are attached to a variety of things that have nothing to do with physics: videos for toddlers, an African grey parrot, a movie with Walter Matthau (which has as little relation to the real Einstein as the Counting Crows song “Einstein on the Beach” has to the Phillip Glass opera of the same name), etc. He is cited as an archetypal genius.

Much of this is for good reason: Einstein is one of the founders of modern physics. He formulated the theory of relativity, both the special theory  of relativity (which describes motion at very high speeds and energies) and the general theory (an elegant theory of gravity, replacing the force of Newtonian physics with a geometrical description). He won the Nobel Prize in 1921 for his photon theory of light, which elegantly explained the photoelectric effect, how shining light on metals produces electric currents. Along with Indian physicist Satyendra Nath Bose, he discovered a type of statistics for certain particles which led to a new state of matter called Bose-Einstein condensates, first created in a laboratory in 1995.

Einstein’s intuition was very powerful and his mathematical ability strong (despite his self-deprecation on the subject). Where he ran into trouble was in thinking that his intuition was always right, and this led him to spend a lot of time pursuing theoretical dead ends. That’s not a criticism: after all, theoretical physics is more dead ends than clear pathways, and even the most brilliant minds can get trapped by false leads. And of course he wasn’t a perfect man in his personal life.

Ultimately, Einstein’s legacy is huge: he started or facilitated the start of the major branches of physics in the 20th century. His geometrical thinking about general relativity led to innovations in particle physics—specifically the Yang-Mills theory, which underlies our understanding of the nuclear forces. Even though he was slow to come around on cosmology and the expansion of the universe, there’s no question his theories are what enabled cosmology to move out of philosophy departments into the realm of science. For his contributions across so many areas of physics, we remember him today. Happy birthday, Albert Einstein.