WEBVTT - What Is Pi?

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<v Speaker 1>Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff,

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<v Speaker 1>Lauren bog Obam here. The number referred to as PIE

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<v Speaker 1>has mesmerized mathematicians for four thousand years. It's the rarest

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<v Speaker 1>of mathematical constants and unfailingly accurate ratio that's also never ending.

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<v Speaker 1>The digits of pie have been calculated out more than

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<v Speaker 1>twenty two trillion decimal places without ever repeating. That makes

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<v Speaker 1>it an irrational number. The definition of pie is simple.

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<v Speaker 1>It's the ratio of a circle's circumference, that is, the

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<v Speaker 1>length around the circle divided by its diameter, or the

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<v Speaker 1>length across the circle. But what's remarkable is that, no

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<v Speaker 1>matter the size of the circle you're measuring, that ratio

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<v Speaker 1>of circumference to diameter will always equal three point one

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<v Speaker 1>four one five nine, two six, five, three, five, eight, nine, seven,

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<v Speaker 1>et cetera, usually shortened to three point one four. Divide

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<v Speaker 1>the circumference of a tennis ball by its diameter and

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<v Speaker 1>you get three point one four. By the circumference of

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<v Speaker 1>the planet Mars by its diameter, and you get three

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<v Speaker 1>point one four. Divide the circumference of the known universe

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<v Speaker 1>by its diameter. You get the point Pie is critical

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<v Speaker 1>to several basic calculations in geometry, physics, and engineering, including

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<v Speaker 1>the area of a circle, which is pie times the

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<v Speaker 1>square of the radius, and the volume of a cylinder,

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<v Speaker 1>which is pie are squared times the height of the cylinder.

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<v Speaker 1>When the ancient Babylonians attempted to measure the precise area

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<v Speaker 1>of circles back in nine b c E, they assigned

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<v Speaker 1>a value to pie a three point one to five.

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<v Speaker 1>The ancient Egyptians came up with three point one six

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<v Speaker 1>zero five. The Greek mathematician Archimedes, working in the third

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<v Speaker 1>century BC, and the Chinese mathematician Zoo Changza, working in

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<v Speaker 1>the fifth century c E, are co credited with calculating

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<v Speaker 1>the most accurate approximations of pie, before calculus and supercomputers

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<v Speaker 1>gave us a more definitive answer. Then, in seventeen o six,

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<v Speaker 1>the self taught Welsh mathematician William Jones assigned the Greek

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<v Speaker 1>letter P to this magical number without end, possibly because

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<v Speaker 1>P is the first letter of the Greek words for

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<v Speaker 1>periphery and perimeter. The symbol's use was later popularized by

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<v Speaker 1>eighteenth century Swiss mathematician Leonard Euler, but wasn't adopted worldwide

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<v Speaker 1>until nineteen thirty four. The fact that pie can be

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<v Speaker 1>found everywhere, not only in circles, but in arcs, pendulums,

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<v Speaker 1>and interplanetary navigation, and that it's infinitely long has inspired

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<v Speaker 1>a cult following that includes plenty of geeky tattoos and

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<v Speaker 1>even its own national holiday. National Pie Day was officially

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<v Speaker 1>recognized by the United States Congress in two thousand nine,

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<v Speaker 1>but the definitely not square roots of the holiday can

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<v Speaker 1>be traced back to eight and a man named Larry

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<v Speaker 1>the Prince of Pie Shaw. Shaw was a beloved longtime

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<v Speaker 1>employee at the Exploratorium, a science museum in San Francisco, California,

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<v Speaker 1>and came up with the idea of Pie Day on

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<v Speaker 1>a nineteen eighty eight staff retreat following the death of

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<v Speaker 1>Exploratory and founder Frank Oppenheimer. The date for celebration and well,

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<v Speaker 1>because the first digits of pie are three point one

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<v Speaker 1>four March fourteen, or three fourteen. Even better, March fourteenth

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<v Speaker 1>is also Albert Einstein's birthday, making Pie Day a nerd

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<v Speaker 1>double header. The first Pie Day celebration was nothing more

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<v Speaker 1>than Shaw and his wife handing out slices of fruit

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<v Speaker 1>pie and tea at one pm one f nine being

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<v Speaker 1>the three digits following three point one four, but the

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<v Speaker 1>holiday quickly gained fame in the Bay Area. Shaw eventually

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<v Speaker 1>built the Pie Shrine at the Exploratorium, a circular classroom

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<v Speaker 1>with a circular brass plaque at its center. Every Pie

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<v Speaker 1>Day celebration at the Exploratorium ended with a colorful parade

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<v Speaker 1>led by Shaw blasting his boombox with a remix of

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<v Speaker 1>Pomp and Circumstance set to the digits of Pie and

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<v Speaker 1>circling the Pie Shrine exactly three point one four times.

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<v Speaker 1>The parade ended with the singing of Happy Birthday to

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<v Speaker 1>Albert Einstein. The Prince of Pie passed away in twenty seventeen,

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<v Speaker 1>but the annual Exploratorium party continues, as do Pie Day

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<v Speaker 1>celebrations the world over. Popular ways to celebrate include baking

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<v Speaker 1>a pie or some kind of circular treat, and holding

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<v Speaker 1>pie recital contests. The current world record for memorizing and

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<v Speaker 1>reciting the most digits of pie was set by Hiresh

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<v Speaker 1>Kumar Sharma of India in twenty fifteen, when he recited

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<v Speaker 1>a staggering seventy thousand and thirty digits in seventeen hours

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<v Speaker 1>and fourteen minutes, but it's okay to start somewhere below that.

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<v Speaker 1>Producer Tyler says that at one point back in the

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<v Speaker 1>day he had about a hundred and fifty memorized, but

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<v Speaker 1>right now can do around eighty three point one two, six, five, eight, nine, seven, four, six,

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<v Speaker 1>two six, four three three eight, three two seven, nine,

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<v Speaker 1>five zero two eight, four, one six, nine, three nine seven, zero,

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<v Speaker 1>five eight, two zero, nine, seven four and four for

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<v Speaker 1>five nine, two, three, zero, seven, eight, one six, four zero,

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<v Speaker 1>six three six y. Today's episode was written by Marshall

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<v Speaker 1>Brain and Dave Ruse and produced by Tyler Clay. For

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<v Speaker 1>more on this and lots of other curious topics, visit

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<v Speaker 1>hastaff works dot com. Brainstuff is a production of I

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<v Speaker 1>heart Radio. For more podcasts for my heart Radio, visit

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<v Speaker 1>the iHeart Radio app, Apple Podcasts, or wherever you listen

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