Happy Birthday, Albert Einstein! And Happy Pi Day! Today's date, 3/14/15, represents the first 5 digits of π, the ratio of the circumference of a circle to its diameter. AND, at 9:26 and 53 seconds, we will pass a date and time represented by the first 10 digits of π = 3.14159265358979323846264338327950288, which makes it a once-a-century Pi Day. I am going to celebrate by having a piece of pie for breakfast. And at 9:26:53 pm, I might have another.