Constructing a four-point egg

January 30, 2024 10:51 PM

Tony Finch illustrates the steps needed to construct a four-point egg, and, as a bonus, offers an interactive egg.
posted by Lirp (16 comments total)

Note: everyone needs a egg
posted by aubilenon at 11:34 PM on January 30 [1 favorite]

good egg
posted by clew at 11:38 PM on January 30

finally, after all these years of static, non-interactive eggs
posted by DoctorFedora at 12:40 AM on January 31 [1 favorite]

Tony Finch's website is awesome.
posted by Cardinal Fang at 4:19 AM on January 31 [1 favorite]

Oooh, points as in "coordinates on a Cartesian plane," not points as in "that's going to be a mighty uncomfortable chicken."
posted by Panjandrum at 5:47 AM on January 31 [4 favorites]

"Take that, Moss!"
posted by Wetterschneider at 5:49 AM on January 31

A “four-point egg” sounds like sportscaster jargon from a game I really don’t understand. “Of course, Brian, we saw McMillan score a four-point egg last time these two teams faced one another.”
posted by ricochet biscuit at 5:55 AM on January 31 [8 favorites]

that's beautiful
posted by seanmpuckett at 6:52 AM on January 31

Huh - seems I'd inadvertently used Moss's Egg construction for making a 3d-printed egg. I knew it as a Persian architectural dome construction from Gereh & Arc by Sayed Akbar Helli, pub. Kashan (Iran) 1986, p.25. It's slightly too pointy.

I'm a little disappointed that Tony's using 𝜏 for angles. 𝜏 is, was and ever more shall be the time constant. End of.

I did roll down a whole mess of egg curve constructions after I found 7SEGG-CHAN, a whimsical (if rather hard to read) egg-shaped 7-segment numeric LCD font that's part of the DSEG Font Family. It uses Yamamoto's Equation of Egg Shaped Curve of the Actual Egg is Found.
posted by scruss at 7:24 AM on January 31 [5 favorites]

I see that some people are still trying to make tau happen.
(posted just before reading the previous comment oops)
posted by 3j0hn at 8:15 AM on January 31 [2 favorites]

I should also add that while geometric eggs are all well and good, there was a lot of action recently in trying to a derive universal formula for the eggs of all birds where the parameters are only physical measurements of the eggs. I wrote up a summary of some of the conversation around that new egg formula ( published first at https://nyaspubs.onlinelibrary.wiley.com/doi/10.1111/nyas.14680 ) with comparisons to some older, simpler formulas in an interactive notebook document https://learn.maplesoft.com/doc/aexk4qbkm0/egg-formulas (it should work in Firefox, despite the warning screen). The physical parameter-based formula is really ugly, but the prettier formulas all require numerical fitting to parameters that are not directly physical.

I hadn't seen Yamamoto's egg formula that scruss posted when I made that document, but it seems Yamamoto is mostly interested in approximating a chicken egg with an easy to compute with formula.
posted by 3j0hn at 9:04 AM on January 31 [3 favorites]

This is delightful.
posted by cortex at 10:32 AM on January 31

3j0hn, you are the egg-man
posted by scruss at 1:32 PM on January 31 [3 favorites]

These have been trying times.
posted by zamboni at 7:29 PM on January 31

Egg!

Oh this reminds me, I saw an amazing tessellated fleur-de-lys pattern in a fresco in Assisi that I’ve been wondering ever since how to recreate with straightedge and compasses. Looks like he has a software I can play with.
posted by lokta at 5:20 AM on February 1

Oh he does not — but he does live nearby!
posted by lokta at 5:23 AM on February 1