video thumbnail 21:04
Why is there no equation for the perimeter of an ellipse‽

2020-09-05

[public] 1.31M views, 75.0K likes, 875 dislikes audio only

channel thumbStand-up Maths

Jane Street are still offering amazing internships: https://jane-st.co/SUM-internships

A Podcast of Unnecessary Detail is out now: https://festivalofthespokennerd.com/podcast/ Come for the Unnecessary Detail, stay for the A Podcast Of.

These are my approximation equations:

perimeter ≈ π[53a/3 + 717b/35 - √(269a^2 + 667ab + 371b^2)]

perimeter ≈ π(6a/5 + 3b/4)

If you can do better, submit it to Matt Parker's Maths Puzzles.

https://www.youtube.com/watch?v=qJSHdJX6gB0

https://www.think-maths.co.uk/ellipsepuzzle

This was my pervious video featuring ellipsoids:

/youtube/video/l51LcwHOW7s

You can buy the ellipse from this video on eBay. I've written on my two new equations and signed it. All money goes to charity (the fantastic Water Aid).

https://www.ebay.co.uk/itm/363096345270

Bonus content and a deleted scene are available on my Patreon.

https://www.patreon.com/posts/41274351

Huge thanks to all who sent in a recording of them singing "A total ellipse of the chart." Sorry I could not include everyone. These are the people in the video:

Helen Arney

Steve Hardwick

Victoria Saigle

Andrew McLaren

Fractal

Macey

Sören Kowalick

It all started because of a request I put out on twitter.

https://twitter.com/standupmaths/status/1301252952930299904

CORRECTIONS:

- So far the only times (I've noticed that) I say "eclipse" instead of "ellipse" are 5:01 and 05:26 which was just after talking about my wife who is a solar physicist. So I think we split the blame 50/50.

- It seems everyone but me recognised the Root Mean Square. I think I only associate that with current for some reason! Thanks all.

- Let me know if you spot any other mistakes!

Thanks to my Patreons who meant I could spend about a week trying to find approximations for the length of ellipses. "Are you still working on that?" Lucie would - rightfully - ask over the weekend. "I'm going the extra mile for my patreon people!" I would reply. Here is a random subset of those fine folks:

Benjamin Richter

Louie Ruck

Matthew Holland

Morgan Butt

Rathe Hollingum

Jeremy Buchanan

Sjoerd Wennekes

Barry Pitcairn

James Dexter

Adrian Cowan

https://www.patreon.com/standupmaths

As always: thanks to Jane Street who support my channel. They're amazing.

https://www.janestreet.com/

Filming and editing by Matt Parker

Additional camera work by Lucie Green

VFX by Industrial Matt and Parker

Music by Howard Carter

Design by Simon Wright and Adam Robinson

MATT PARKER: Stand-up Mathematician

Website: http://standupmaths.com/

US book: https://www.penguinrandomhouse.com/books/610964/humble-pi-by-matt-parker/

UK book: https://mathsgear.co.uk/collections/books/products/humble-pi-signed-paperback


Intro
/youtube/video/5nW3nJhBHL0?t=0
Elliptical terms
/youtube/video/5nW3nJhBHL0?t=54
The email
/youtube/video/5nW3nJhBHL0?t=255
Better approximations
/youtube/video/5nW3nJhBHL0?t=433
My lazy approximation
/youtube/video/5nW3nJhBHL0?t=683
Infinite series
/youtube/video/5nW3nJhBHL0?t=838
Jane Street internships
/youtube/video/5nW3nJhBHL0?t=972
Tan of a prime
/youtube/video/5nW3nJhBHL0?t=1083
Stand-up Maths I do mathematics and stand-up. Sometimes simultaneously. Occasionally while being filmed. (It's quite the Venn diagram.) Principle channel supporter: Jane Street https://www.janestreet.com/ http://standupmaths.com http://twitter.com/standupmaths
/youtube/channel/UCSju5G2aFaWMqn-_0YBtq5A
The Genius Geometry of the James Webb Space Telescope 187,159 views
/youtube/video/os0a5au_3Mo