# March 14th is Pi Day

As you probably know from math class, “π (sometimes written pi) is a mathematical constant that is the ratio of any Euclidean circle’s circumference to its diameter. π is approximately equal to 3.14. Many formulae in mathematics, science, and engineering involve π, which makes it one of the most important mathematical constants.” Pi is such a fascinating number that it has its own holiday. Pi Day is celebrated on March 14th, which also happens to be the birthday of Nobel Prize-winning physicist, Albert Einstein (March 14, 1879).

- PIDAY — A brief history of Pi, activities and links from the Exploratorium.
- Pi Day — Learn about Pi and see some cool Pi-inspired designs
- How to Celebrate Pi Day — Fun and creative ideas for celebrating Pi on its big day
- The Joy of Pi — Lots of interesting facts about Pi and links to great resources about this special number
- 50 Interesting Facts about…Pi — Impress your friends with these facts and figures about Pi
- A chronology of Pi — A timeline of mathematicians and the number of places to which they were able to calculate Pi
- Where is your birthday in Pi — Find out where in Pi your birthday is found.
- Ask Dr. Math : About Pi — All about Pifrom Dr. Math and the Drexel Math Forum

## Albert Einstein

Albert Einstein is widely recognized not only as one of the greatest scientists, but as one of the most creative and influential thinkers, in history. He developed the ground-breaking Theory of Relativity and won the Noble Prize for Physics in 1921. For his accomplishments, he is considered the “father of modern physics.” Albert Einstein was born on March 14, 1879.

- Reading List — Biographies of Einstein for children and young adults

- Biography — A brief biography from Nobelprize.org
- Albert Einstein.biography — A more extensive biography of Einstein with images and videos from Biography.com
- Einstein — An online exhibit from the American Museum of Natural History.
- Einstein: Image and Impact — An digital exhibit about Einstein by the AIP Center for the History of Physics
- Albert Einstein Online — A compilation of lots of great links to information about Einstein’s life, his work, his writings, images and more
- Numberplay: Einstein’s Riddle — “The following classic, which has appeared in a variety of incarnations over the years, was supposedly given its original form by Albert Einstein.” Can you solve it?
- How to Understand E=MC2 — The famous equation explained in seven steps from WikiHow