Happy birthday, Einstein! But this is also Pi Day, and a very special Pi Day at that.
Why so special? The date is 3/14/15, the first five digits in the ratio of the circumference of a circle to its diameter.
And—get ready for this—at 26 minutes and 53 seconds after 9 a.m., we will pass a date and time represented by the first 10 digits of π. Very exciting! If you miss it, there will be one more chance at 9 p.m. After that, you’ll have to wait another 100 years for that auspicious moment to happen again, assuming that we will still be writing our Julian calendar dates as we do in America.