My comments on this draft. 1.  There is no such thing as a pi that varies with the choice of geometry or the size of a circle.  Pi is the mathematical constant 3.14..., and that's it by definition.  Sure, the ratio circumference/diameter can be different, but pi is the ratio in Euclidean geometry.  You do a disservice to your readers by going against the standard usage of the Mathematical community. 2.  I agree with the unnamed mathematician that calculating a gazillion decimal digits of pi is a waste of time.  There's nothing special about radix 10.  Far more interesting would be the continued fraction. 3.  "But thanks to Einstein, we now know that the universe we live in is curved at galactic scales, and there’s no natural way to view it as a 3-dimensional curved hypersurface sitting inside an uncurved 4-dimensional space." Actually, general relativity posits a 4-dimensional curved spacetime, and not a curved 3-dimensional space.  Furthermore, the invariant metric on spacetime has a (3,1) signature rather than the Euclidean (4,0). 4.   Another pi reference: https://smile.amazon.com/History-Pi-Petr-Beckmann/dp/0312381859/ref=sr_1_1?s... From: James Propp <jamespropp@gmail.com> To: math-fun <math-fun@mailman.xmission.com> Sent: Saturday, February 11, 2017 3:10 PM Subject: [math-fun] Draft of my February 2017 blog post Hi, I started writing a new draft titled "Three-point-one cheers for pi !" and would love to get your feedback. I plan on publishing it on the 17th. I can always use more links to content (images or videos) that are likely to interest readers of my essay. I am particularly interested in a link that would present Archimedes' method of calculating the volume of a ball in an accessible way. For that matter, if anyone has risen to Wigner's tacit challenge of explaining to a lay audience why pi is relevant to statistics, I'd love to know about it. Keep in mind that all math-fun feedback goes into one mail-feed, so I won't know whose feedback is whose unless you sign your comment. Also, all substantive suggestions that I use will be acknowledged (unless you specifically ask me not to do this). Please leave your feedback here: https://mathenchant.wordpress.com?p=1471&shareadraft=589f987f95cf7 Title: Three-point-one cheers for pi ! Beginning: Pi, that most celebrated of mathematical constants, leads a curiously double life.  On the one hand, we define it as the ratio of the circumference of a circle to that circle's diameter, and, to the extent that we can imagine a world draped over the armature of a different geometry, we can conceive ... Read more: https://mathenchant.wordpress.com?p=1471&shareadraft=589f987f95cf7 Thanks, Jim Propp