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Japanese Man Calculates Pi To 5 Trillion Digits On Homemade Computer

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http://www.telegraph.co.uk/science/science-news/7973234/Japanese-man-calculates-Pi-to-5-trillion-digits-on-homemade-computer.html

Shigeru Kondo, a 55-year-old systems engineer for a food company based in northern Japan, easily surpassed the previous record of 2.7 trillion digits, set late last year by a French engineer.

The calculation of the ratio of the circumference of a circle to its diameter - usually abbreviated to 3.14 - took 90 days and seven hours, according to the Kyodo news agency.

The mammoth calculation nearly came to grief on more than one occasion, Mr Kondo said, including one morning when his daughter tripped a circuit breaker when she turned a hair dryer on. The project was saved when the computer switched to an emergency 10-minute back-up power source.

Mr Kondo was also forced to remove casings from the computer and blow cool air onto the machine with fans as the temperature in his home rose to 40 degrees in the hottest Japanese summer since 1946.

Mr Kondo's computer cost Y1.5 million (£11,550) to build and has a hard-drive capacity of 32 terabytes. He plans to apply to the Guinness Book of Records for recognition of his achievement.

Impressive, however the point is what?

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"engineer for a food company based in northern Japan"

they have the most perfectly circular pies in the Universe.

and if you ask for a portion...well thats guaranteed too.

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Thanks.

Listen, I'm normally not this lazy, but I really didn't understand either of those links. Is there an explanation of the method they used to prove it in simple English?

The original question you asked, about it being a recurring decimal, is the same as asking whether it's rational or not (rational = ratio of two integers, like 3/4 or 72934792394/273792478278947982). It's been known for a long time that pi is irrational, so it's not a recurring decimal. Actually proving the pi is irrational is quite tricky (see the links in the earlier post), since if you want to give a precise definition of pi you have to start talking about trigonometric functions like sine and cosine, and then you have to use methods from calculus to prove that it's irrational. The basic idea is to assume that pi is rational and then use this assumption to derive things which contradict known facts about trigonometric functions.

Incidentally, doing long calculations with computers is of no help here. Even if you calculate trillions of digits without repetition, there's always the possibility that it'd start to repeat over a much larger scale.

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Probably so Douglas Coupland can put it in his next book.

JPod devoted 40 pages to Pi near the back which was utterly pointless.

I can't decide if that book was serious or a deliberate cruel parody of what a Douglas Coupland book reads like. Leaning towards genuinely believing its the latter. Look at the evidence; piss taking typographic stuff (like Pi), he appears in the book acting like a tw&t and the plot is pretty much a repetition of several of his other books (OMG, zany boomer parents again). I reckon he is self-aware enough that it was an auto-parody, getting his attack on himself in first.

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I can't decide if that book was serious or a deliberate cruel parody of what a Douglas Coupland book reads like. Leaning towards genuinely believing its the latter. Look at the evidence; piss taking typographic stuff (like Pi), he appears in the book acting like a tw&t and the plot is pretty much a repetition of several of his other books (OMG, zany boomer parents again). I reckon he is self-aware enough that it was an auto-parody, getting his attack on himself in first.

And charge people £13.99 for the priviledge too (I bought it for 20p though and still felt ripped off)

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The original question you asked, about it being a recurring decimal, is the same as asking whether it's rational or not (rational = ratio of two integers, like 3/4 or 72934792394/273792478278947982). It's been known for a long time that pi is irrational, so it's not a recurring decimal. Actually proving the pi is irrational is quite tricky (see the links in the earlier post), since if you want to give a precise definition of pi you have to start talking about trigonometric functions like sine and cosine, and then you have to use methods from calculus to prove that it's irrational. The basic idea is to assume that pi is rational and then use this assumption to derive things which contradict known facts about trigonometric functions.

Incidentally, doing long calculations with computers is of no help here. Even if you calculate trillions of digits without repetition, there's always the possibility that it'd start to repeat over a much larger scale.

Thanks - that's the one line takeaway explanation i was looking for (reductio ad absurdum).

I realise the brute force calculation proves nothing - I was being facetious.

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One for the IT bods - how could he store this number in the computer?

Probably dumping them into text files which can be almost unlimited in size and or length.

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Probably dumping them into text files which can be almost unlimited in size and or length.

Sexy.

Why can't he just be satisfied with knowing pi = circumf/diameter of a circle?

By the way, one for the surveyors: how do you measure the length of a circle's circumference accurately?

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The original question you asked, about it being a recurring decimal, is the same as asking whether it's rational or not (rational = ratio of two integers, like 3/4 or 72934792394/273792478278947982). It's been known for a long time that pi is irrational, so it's not a recurring decimal. Actually proving the pi is irrational is quite tricky (see the links in the earlier post), since if you want to give a precise definition of pi you have to start talking about trigonometric functions like sine and cosine, and then you have to use methods from calculus to prove that it's irrational. The basic idea is to assume that pi is rational and then use this assumption to derive things which contradict known facts about trigonometric functions.

Incidentally, doing long calculations with computers is of no help here. Even if you calculate trillions of digits without repetition, there's always the possibility that it'd start to repeat over a much larger scale.

its 22/7.

end of. Decimals are shite.

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Can I ask what your thought process was upon choosing your user name?

No. But if I let you I'd say I don't remember my thought processes last week never mind 5 years ago.

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its 22/7.

end of. Decimals are shite.

Actually 22/7 is just an approximation, and not apparently that good an approximation given that Pi at 5dp is 3.14159 and 22/7 as you calculator will tell you is 3.14286

So quite a long way from the end of.

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  • 261 Brexit, House prices and Summer 2020

    1. 1. Including the effects Brexit, where do you think average UK house prices will be relative to now in June 2020?


      • down 5% +
      • down 2.5%
      • Even
      • up 2.5%
      • up 5%



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