Comment on How do people calculate pi to the hundredth+ decimal place?
qt0x40490FDB@lemmy.ml 1 day ago
One thing to be aware of is the if you actually made a circle and measured its radius and circumference you wouldn’t get pi. Not because your measurements would be off, but because the universe does not follow the assumptions mathematicians used to define pi—namely Euclidean geometry. Pi is mathematical, not physical. If a the real circles and real diameters don’t give you pi that is a problem for the universe, not a problem for mathematics.
bjoern_tantau@swg-empire.de 1 day ago
Wat?
qt0x40490FDB@lemmy.ml 1 day ago
The universe is non-Euclidean, so no circle made in the actual geometry of the universe actually has the ratio of pi between its circumference and diameter.
Is that the part you are confused about, or did I write something else badly?
bjoern_tantau@swg-empire.de 1 day ago
The universe being non euclidian needs some extraordinary evidence.
qt0x40490FDB@lemmy.ml 1 day ago
Overly snarky response: Uhhhm. Have you been asleep since, what, 1915 or something? We have extraordinary evidence, and everyone has accepted it, in so far as I know.
Less snarky response: the path on which light moves is the universes instantiation of a straight line. It is “the (locally) shortest path between two points”, the same definition you learned in geometry class. Yet in our universe, two straight lines can intersect each other twice. This is because our universe has at least some local curvature, meaning it is non locally non Euclidean. In order to have a mathematically perfect circle you would need to live in a universe without any matter or energy, and with certain other properties.
rmuk@feddit.uk 1 day ago
It’s true! I just drew a circle and measured it. Turns out π≈5.