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?
From your measurement of pi, we can deduce that you live in an anti-de Sitter space, so all the string theorists will now be sending you emails to test out their theories.
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.
Meh, spacetime curvature has so little effect that it actually does come down to measurement accuracy. And if you go to the scale of the whole universe it is flat as far as we currently know.
Now I wonder how LISA will handle curvature changes due to sun, earth and moon moving around, or if they won’t make enough of a difference.
qt0x40490FDB@lemmy.ml 2 days 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 2 days ago
The universe being non euclidian needs some extraordinary evidence.
rmuk@feddit.uk 2 days ago
It’s true! I just drew a circle and measured it. Turns out π≈5.
qt0x40490FDB@lemmy.ml 2 days ago
From your measurement of pi, we can deduce that you live in an anti-de Sitter space, so all the string theorists will now be sending you emails to test out their theories.
qt0x40490FDB@lemmy.ml 2 days 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.
bjoern_tantau@swg-empire.de 2 days ago
Meh, spacetime curvature has so little effect that it actually does come down to measurement accuracy. And if you go to the scale of the whole universe it is flat as far as we currently know.
Now I wonder how LISA will handle curvature changes due to sun, earth and moon moving around, or if they won’t make enough of a difference.