Today, April 15, 2013 is a very memorable day for most Americans - being Tax Day. It is also the birthday of Leonhard Euler, a Swiss born mathematician who is known as probably the most influential and important mathematician of the 18th century. As you know, Google and arguably taxes, rely a lot on math and algorithms.
Here is the Google logo celebrating his life (note, it is animated on the Google home page):
Leonhard Euler is well known for his discoveries in fields as diverse as infinitesimal calculus and graph theory. He was born on April 15, 1707 in Basel, Switzerland and died September 18, 1783 in Saint Petersburg, Russia. The list of things he is known for his tremendous, just see this Wikipedia page. That lis is honestly overwhelming but it goes as basic as coming up with the notion of a mathematical function. For more on his life, read Wikipedia.
Like I said, it is also tax day in the United States of America. The only search engine to make note of that is Dogpile:
Did you pay your taxes yet?