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Comment by boredemployee | Hacker News Reader

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boredemployee·

genuine question: would that amount of digits be useful for any application?

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https://www.jpl.nasa.gov/edu/news/2016/3/16/how-many-decimal...

Thank you for posting this! This is exactly what I was looking for.

TLDR: "For JPL's highest accuracy calculations, which are for interplanetary navigation, we use 3.141592653589793"...Using pi to 15 decimal places, you'd get the distance of Voyager 1 wrong by less than 1cm!

No, it is basically only useful as a programming exercise. You only need like 40 digits to compute the circumference of the universe to the precision of a hydrogen atom.

What is the circumference of the universe?

2.8×10^39 picometers is circumference of the observable part of our universe, roughly. A sole hydrogen atom has a bohr radius of about 25 picometers.

So 40 digits of pi would indeed be in the ballpark for computing anything distance-wise at the circumference of the observable universe down to the hydrogen electron cloud size.

One of the siblings posted a link from JPL about the number of digits they use for their highest precision calculations. In that article they also state that 37 decimals would be sufficient for calculating the cirumference of the observable universe down to the accuracy of the diameter of a hydrogen atom.[0]

[0] https://www.jpl.nasa.gov/edu/news/2016/3/16/how-many-decimal... (Right before the last inline image)

https://github.com/philipl/pifs

but this is a joke hahaha

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