it might not be obvious to those who do not write the date as month/day/year, but today's date is 3.14 for those of us that do! pi day.
while reading the rest of this post, feel free to listen to this slightly mesmerizing little pi song.
pi is the ratio of any circle's circumference to its diameter, which is also equal to the ratio between a circle's area (pi*r^2) and its radius (in flat, euclidean space).
some people will celebrate today by eating pies.
today is also considered by many to be talk like a physicist day. what do you get when you cross talk like a pirate day with talk like a physicist day?? the punch line from a comic by brightly wound:
if you (d/dt) something then you are taking the derivative with respect to time. you are asking how the thing changes with time, which you call its rate. so (d/dt) of pi, or d*pi/dt, is finding the rate of pi, or pi-rate! hardy-harrrrrrrrr. ok, i'll stop now.