The Mathematically Correct Way to Share a Cake

367,256
0
Published 2024-01-11
Click my trainwell (formerly CoPilot) link go.trainwell.net/UpandAtom-cp to get 14 days FREE with your own personal trainer!

The Cake Cutting Solution www.cse.unsw.edu.au/~haziz/efcakegeneral.pdf

Hi! I'm Jade. If you'd like to consider supporting Up and Atom, head over to my Patreon page :)
www.patreon.com/upandatom

Visit the Up and Atom store
store.nebula.app/collections/up-and-atom

Subscribe to Up and Atom for physics, math and computer science videos
youtube.com/c/upandatom

For a one time donation, head over to my PayPal :) www.paypal.me/upandatomshows

A big thank you to my AMAZING PATRONS!
Jonathan Koppelman, Michael Seydel, Cy 'kkm' K'Nelson, Thorsten Auth, Chris Flynn, Tim Barnard, Izzy Ca, Tate Lyles, Richard O McEwen Jr, Scott Ready, John H. Austin, Jr., Brian Wilkins, Thomas V Lohmeier, David Johnston, Thomas Krause, Lynn Shackelford, Ave Eva Thornton, Andrew Pann, Anne Tan, Nathan Abel, Jeffrey Dutt, Joseph Lamoree, Francisco, Marc-Antoine, Chris Davis, Thomas Urech, chuck zegar, David Tuman, Richard Rensman, Ben Mitchell, Steve Archer, Luna, Tyler Simms, Michael Geer, James Mahoney, Jim Felich, Fabio Manzini, Jeremy, Sam Richardson, Robin High, KiYun Roe, DONALD McLeod, Ron Hochsprung, Aria Bend, James Matheson, Kevin Anderson, Alexander230, Tim Ludwig, Alexander Del Toro Barba, Justin Smith, A. Duncan, Mark Littlehale, Tony T Flores, Dagmawi Elehu, Jeffrey Smith, Alex Hackman, bpatb, Joel Becane, Paul Barclay, 12tone, Sergey Ten, John Lakeman, Jana Christine Saout, Jeff Schwarz, Yana Chernobilsky, Louis Mashado, Michael Dean, Chris Amaris, Matt G, Dag-Erling Smørgrav, John Shioli, Todd Loreman, Susan Jones, Miles Freeman, Bunny Lushington, JRM, Motty Porat, Michael Tardibuono, Yaw Mintah, Carlos Escolar, Anthony Docimo, robert lalonde, Julian Nagel, Cassandra Durnord, Antony Birch, Paul Bunbury, David Shlapak, Kent Arimura, Phillip Rhodes, Michael Nugent, James N Smith, Roland Gibson, Piotr Klos, Joe McTee, Dean Fantastic, Oleg Dats, John Spalding, Simon J. Dodd, Tang Chun, Michelle, William Toffey, Michel Speiser, James Horsley, Brian Williams, Craig Tumblison, Cameron Tacklind, 之元 丁, Kevin Chi, Lance Ahmu, Markus Lindström, Steve Watson, Midnight Skeptic, Potch, Indrajeet Sagar, Markus Herrmann, Gil Chesterton, Alipasha Sadri, Pablo de Caffe, Emily, Colin Byrne, Nick H, Jesper de Jong, Sofia Fredriksson, Phat Hoang, Spuddy, Sascha Bohemia, tesseract, Stephen Britt, KG, Hansjuerg Widmer, John Sigwald, O C, Carlos Gonzalez, Thomas Kägi, James Palermo, Chris Teubert, Fran, Wolfgang Ripken, Jeremy Bowkett, Vincent Karpinski, Nicolas Frias, Louis M, Moose Thompson, Rick DeWitt, Pedro Paulo Vezza Campos, S, Garrett Chomka, Rebecca Lashua, Pat Gunn, George Fletcher, RobF, Vincent Seguin, Michael Brunolli, Shawn, Israel Shirk, Jesse Clark, Steven Wheeler, Philip Freeman, Armin Quast, Jareth Arnold, Simon Barker, Lou, amcnea and Simon Dargaville.

Creator - Jade Tan-Holmes
Script - Alexander Berkes and Jade Tan-Holmes
Animations - Lester Chan
Music - epidemicsound.com

Chapters
0:00-1:42 The Cake Cutting Problem
1:42-3:22 Cut and Choose
3:22-7:29 Last Diminisher
7:29-10:03 Selfridge-Conway Protocol
10:23-11:51 Why the cake cutting problem is hard
11:51-16:28 Aziz-Mackenzie Protocol

All Comments (21)
  • @upandatom
    Click my CoPilot link go.mycopilot.com/UpAndAtom to get a 14-day FREE trial AND 20% off your first month of personalized fitness if you sign up before February 1st!
  • @rustymustard7798
    Meanwhile in real life, Billie wants all the cake, Alex HATES cake but doesn't want Billie to have any. Charlie is completely over all this nonsense, killing his appetite so he tells Alex about Billie's Onlyfans. Now she's begging him not to text her boss the link and crying before throwing the cake in a fit of rage at Charlie, but misses, hitting Doug who was just walking by minding his own business.
  • @chaoscope
    Note to self: do not invite mathematicians to a cake party.
  • As computer scientists, our plan is actually to explain theoretical solutions so confusingly that eventually everyone else will give in and let us have the big piece. It's an optimal solution because I get more cake and you get me to shut up.
  • "Sharing is mathematically difficult" New favourite excuse when my sister asks to share my food. 😂
  • @VaradMahashabde
    "Wedding photo for Mackenzie? Could she not find another pho-OH WAIT A MINUTE"
  • @justklaas4703
    Once I was fed up with my daughters complaining about the size of their slice of cake, and the topping. They thought it was all just so unfair. I had enough of that, so I threatened them to put the cake in a blender and pour each of them a glass. I thought it was a great solution since it fixes the disagreement over who would get the chocolate bit, the strawberry bit and so forth. They declined my offer and accepted the slices given instead.
  • @kentslocum
    3:00 "This is a huge drawback for anyone with more than one friend." It's bold of you to assume I have more than one friend. As someone who has no friends, the optimal sharing strategy is for me to eat the entire cake myself. 😊
  • @kjbunnyboiler
    Having watched this twice now I’ve decided to use the tried and tested methods mothers in families have used for years. Don’t let the kids see the other kids pieces of cake😂
  • @Ed1414One
    People in a birthday: Lets share the cake! Me: Hold up Pulls out my phone to rewatch it
  • @dudifluke1831
    Alex, Billie and Charlie may be happy but Simon definitely got the best deal. :) Good video.
  • @amarug
    This reminds me of an argument I had as an 8-year-old with my parents who cut a small cake in two exact halves, one for me and one for my 2 years younger and much physically smaller sister. I complained that equivalence in absolute size of a cake piece was the wrong metric for fairness, but rather "equivalent satisfaction" should be aimed at and thus, my hypothesis was, that the cake should be divided into the ratio of the sizes of our stomachs, which again could be estimated from our body weights. My parents were not impressed with my hubristic mini-essay of neuroscience and mathematics and just told me to zip it and be glad I have any cake, as many kids don't have cake at all, ever. 😅☠
  • @oguzozgul492
    My identical twin and I used to share coke for instance, so we used to try to fill two glasses equally to the millimeter level accuracy, until we both were satisfied with the equality.. One drop to this, another two drops to that, and repeat. It sometimes took 20 minutes but who cares! Whatever is spilt onto the table, one of us put thier bare feet on it so that the other could not lick it off the table. so for me, it is fairly understandable why an envy free algorithm is so complicated :)
  • @brianw1105
    It would have been hilarious if you and Simon had cupcakes at your wedding!
  • @SilhSe
    ENVY-FREENESS, if only theres such a thing in this world 🥺🥺
  • Hannah Fry did a great video on this years ago on Numberphile. Your video is great too and seems a lot more comprehensive. What motivated you to make this one? EDIT: Oh. The wedding photo! That says a lot, lol.
  • @davidmantiss7105
    This is the first time ever I've seen a scientist made a video about their discover in mathematics. That's wholesome on so manh levels
  • @mroutcast8515
    mathematicians make problems where there are easy solutions - you just buy more cake than friends can possibly eat, everyone is sated and there's like 1/3 still left 😂😂
  • @connecticutaggie
    Nice video. Note: I recall someone defining "fairness" as the condition when all parties are equally dissatisfied. I think that definition might make for an easier solution.😁
  • @suz5191
    this is so cool. I thought this video was gonna be about the better way to cut circular cakes but this is way better