Pi and the size of the Universe - Numberphile
Pi is famously calculated to trillions of digits - but Dr James Grime says 39 is probably enough. All our Pi videos: http://bit.ly/W4oDN1 More links & stuff in full description below ↓↓↓...
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JAMES GRIME: We love pi, of course. Everyone loves pi. But one of my favorite pi facts is-- and I think it's fun. You only need 39 digits of pi to be able to measure the circumference of the observable universe within the width of one hydrogen atom. And that's all you need. Shall we write out the 39 digits? So the 39 digits of pi. It's 3 point-- now, 3 counts as one of the digits. So it's now 38 decimal places. Let's do the 38 decimal places-- 1 4 1 6 5 9 7 9 3 2 7 4 2 0. -He didn't memorize that, everyone. There you go. Show them what you did, just in case. JAMES GRIME: Wolfram Alpha app, never leave home without it. -You're not a pi memorizer, James. JAMES GRIME: No, I'm not. And that's another thing al...
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JAMES GRIME: We love pi, of course. Everyone loves pi. But one of my favorite pi facts is-- and I think it's fun. You only need 39 digits of pi to be able to measure the circumference of the observable universe within the width of one hydrogen atom. And that's all you need. Shall we write out the 39 digits? So the 39 digits of pi. It's 3 point-- now, 3 counts as one of the digits. So it's now 38 decimal places. Let's do the 38 decimal places-- 1 4 1 6 5 9 7 9 3 2 7 4 2 0. -He didn't memorize that, everyone. There you go. Show them what you did, just in case. JAMES GRIME: Wolfram Alpha app, never leave home without it. -You're not a pi memorizer, James. JAMES GRIME: No, I'm not. And that's another thing al...
