Security News > 2022 > March > Happy #PiDay – even if you aren’t in North America!

If you're interested, the quickest way to "Know" Pi to seven significant digits is in the form 355/113, which comes out at 3.14159290, a mere 0.0000085% higher than the more precise 3.14159265.

Why does Pi come out at close to 3.14, instead of, say, 3, or 4 or something easier to remember and more natural, in the mathematical sense of a whole number?

The length of each side of the inner square - to work this out for yourself, you can use Pythogoras's theorem, as shown above - is 1/√2, which is slightly more than 7/10, so its perimeter is slightly more than 2.8.

By using polygons with more and more sides in our diagram, rather than squares, we could produce better and better approximations of non-curved figures that home in more and more closely on from above and below, corralling it into an ever-narrower range of possible values.

The current record is close to 63 trillion decimal digits, which took Swiss academics more than 100 days on a "Computer" that was apparently equipped with 1024 gigabytes of RAM and more than 600,000 gigabytes of disk space.

PS. The cybersecurity connection here is this: never assume that apparently impracticable or difficult calculations, whether that's churning out Pi to ever more decimal places, or cracking passwords and cryptographic codes, will retain their difficulty forever.

News URL

https://nakedsecurity.sophos.com/2022/03/14/happy-piday-even-if-you-arent-in-north-america/