People around the world were celebrating Pi Day on Saturday, and celebrity-scientist Neil deGrasse Tyson joined in the fun on Twitter. Pi Day refers to the mathematical constant Pi, and is marked every March 14 because 3/14 mimics the start of the number. But once a century, there’s a 3/14/15 like there was Saturday , going even further down the never-ending number (which starts 3.1415) and making the people even more giddy.

DeGrasse Tyson simply fit as much of the number Pi as he could into a tweet.

MORE: The Best Pi Day Deals, Freebies and Events

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