It's PiDay.

This is Scientific American Science Quickly, I'm Jeff DelVasio.

Well, another 3.141592653589793238462, you get the idea.

Day is upon us.

If that special day in March, when we collectively celebrate the irrational number represented by the Greek symbol Pi,

in its simplest definition, Pi is the ratio of a circle circumference to its diameter.

Pi shows up everywhere in mathematics.

In 1960, our illustrious then-mathematical games columnist, Martin Gardner, quoted mathematician Augustus de Morgan,

speaking of Pi as this mysterious 3.14159, which comes in at every door and window and down every chimney.

Pi shows up outside of its circular home in the motions of springs and pendulums, in probability and in our 365-day calendar.

It shows up in nature everywhere, there's a circle or a spiral, like in planets in DNA.

Pi even shows up in the bends of rivers, relating to their sonuosity specifically.

The existence of Pi has also led to mass baking on March 14th and defeats the discounts.

Humans have known about the existence of Pi for at least the last 4,000 years.

But in the last few hundred years, we have been trying to increase the precision of our calculations of the digits of Pi.

In 1949, the electronic computer Anyak was used for 70 machine hours to calculate Pi to more than 2,000 decimals.

Just last year, Google Cloud calculated it to 100 trillion digits.

And along with the risk to calculate Pi has come a parallel contest of trying to memorize its unending string.

Today, on Science Quickly, we talked to someone who's created another way to honor and to try to remember the digits of Pi through a song.

Devin Powell is a science writer and a creator of Science Multimedia, and he joins us today.

Thanks, Jeff.

What humans have managed to memorize incredibly long sequences of Pi decimals?

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