It Took 2137 Years to Solve This

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Published 2024-04-30
⬣ LINKS ⬣
⬡ PATREON: www.patreon.com/anotherroof
⬡ CHANNEL: youtube.com/c/AnotherRoof
⬡ WEBSITE: anotherroof.top/
⬡ SUBREDDIT: www.reddit.com/r/anotherroof
⬡ TWITCH: www.twitch.tv/anotherroof

⬣ ABOUT ⬣
Despite being easy to state, the problem of constructing regular polygons confounded the Ancient Greeks. It took over 2000 years to make progress, and in this video we’ll trace a path through history to learn what innovations allowed more polygons to be constructed.

⬣ TIMESTAMPS ⬣
00:00 - Introduction
01:47 - Ancient Constructions
08:14 - What the Ancient Greeks Lacked
11:20 - From Geometry to Numbers
16:28 - From Numbers to Equations
21:58 - From Equations to the Complex Plane
31:48 - Gaussian Periods
36:10 - Final Construction

⬣ INVESTIGATORS ⬣
Nothing for you here. Sorry!

⬣ REFERENCES ⬣
Euclid's constructions mentioned at 3:50:
Perpendicular lines: aleph0.clarku.edu/~djoyce/elements/bookI/propI11.h…
Duplicate angles: aleph0.clarku.edu/~djoyce/elements/bookI/propI23.h…
Alternate angles: aleph0.clarku.edu/~djoyce/java/elements/bookI/prop…
Parallel lines: aleph0.clarku.edu/~djoyce/elements/bookI/propI31.h…
Parallelogram properties: aleph0.clarku.edu/~djoyce/elements/bookI/propI34.h…

The Thirteen Books of Euclid’s Elements. T. L. Heath (1908)

J. Derbyshire: "Unknown Quantity: A Real and Imaginary History of Algebra" Joseph Henry Press (2006)

Al-Kamil treats irrational quantities as numbers in their own right
H. Selin, U. D'Ambrosio: "Mathematics Across Cultures: The History of Non-Western Mathematics" Springer (2000)

Al-Mahani’s definition of rational and irrational
M. Galina: "The theory of quadratic irrationals in medieval Oriental mathematics" Annals of the New York Academy of Sciences 500 (1987) 253-277.

Al-Khwaizmi quadratic equations
Al-Jabr - Al Khwarizmi

Sridhara’s method
D. E. Smith: “History of Mathematics” Vol 2 Dover (1925)

Tombstone story
C. W. Dunnington: "Carl Friedrich Gauss: Titan of Science" Hafner Publishing (1955)

⬣ CREDITS ⬣
Intro music by Tobias Voigt. Other music by Danijel Zambo and Apex Music.

Image Credits
Euclid
cdn.britannica.com/46/8446-050-BC92B998/Euclid-woo…
Arithmetica
upload.wikimedia.org/wikipedia/commons/3/3b/Diopha…
Al-Jabr
upload.wikimedia.org/wikipedia/commons/2/25/Bodlei…
Gauss
upload.wikimedia.org/wikipedia/commons/e/ec/Carl_F…
Heptadecagon Construction
upload.wikimedia.org/wikipedia/commons/d/d1/Regula…
Gauss Tombstone
upload.wikimedia.org/wikipedia/commons/2/26/Grave_…

All Comments (21)
  • @AnotherRoof
    COMMON COMMENTS AND CORRECTIONS! 1. At 44:30 I say: "the next one is 257 which is one more than 256, 2^7" but of course 256 is 2^8. Terrible mistake on my part! 2. A few have asked whether I should be saying "primes of the form 2^(2^m)+1" when discussing Gauss's method. This is right but I deliberately omitted this to address it in the sequel -- I say that the method works on primes of the form 2^m+1 which is correct, it just happens that m must be a power of 2 for it to be prime. 3. 41:39 alpha_2 is incorrect: the coefficient of root(17) should be negative. 4. Regarding "transferring lengths" because the compass is supposed to "collapse" when picked up: Euclid proves (Book 1 Proposition 2) that you can move a line segment wherever you want. Originally I was going to show this, but I cut it to avoid an awkward complication so early in the video. It's proved so early in Elements that a collapsing compass can be treated as a non-collapsing one that it isn't worth worrying about! 5. Regarding the 15-gon, many have pointed out that since 2/5-1/3=1/15 we can just draw that arc and we're done. All who point this out are correct but I was presenting Euclid's proof. Like I said about the square, there are easier ways but that's how Euclid does it! 6. Regarding "2137": My patrons and I had no idea about the meme in Poland when we named the video! It's a fun coincidence -- the number comes from Elements being written ~300BCE and Wantzel publishing his paper in 1837. Obviously only an estimate as we don't know exactly when Elements was written!
  • @SKO_EN
    2137 is a very special number indeed
  • @KatMistberg
    It surprised me how long that problem took to solve, didn't realize you were THAT old
  • @EebstertheGreat
    So many Poles in chat, it's like the ℘-function up in here.
  • @VieneLea
    Imagine my disappointment when I clicked on the video an realised the 2137 number was chosen just randomly, without acknowledging it's holiness
  • @deldrinov
    I'm imagining Euler going back in time and explaining complex numbers to Euclid and only hearing "wow, I never thought about it this way, this is so wrong yet so intuitive"
  • @mironhunia300
    Another Roof has managed to harness the power of polish memes to bring in more people to learn about math.
  • @Wielorybkek
    jan paweł drugi konstruował małe wielokąty
  • @tylerduncan5908
    16:34 funny to me that diophantus accepted that rational numbers exist, and we use his name to refer to equations with integer solutions.
  • @user-bs2bh2kw7n
    Pan kiedyś stanął nad brzegiem Szukał ludzi gotowych pójść za Nim By łowić serca słów Bożych prawdą O Panie, to Ty na mnie spojrzałeś Twoje usta dziś wyrzekły me imię Swoją barkę pozostawiam na brzegu Razem z Tobą nowy zacznę dziś łów Jestem ubogim człowiekiem Moim skarbem są ręce gotowe Do pracy z Tobą i czyste serce O Panie, to Ty na mnie spojrzałeś Twoje usta dziś wyrzekły me imię Swoją barkę pozostawiam na brzegu Razem z Tobą nowy zacznę dziś łów Dziś wyjedziemy już razem Łowić serca na morzach dusz ludzkich Twej prawdy siecią i słowem życia O Panie, to Ty na mnie spojrzałeś Twoje usta dziś wyrzekły me imię Swoją barkę pozostawiam na brzegu Razem z Tobą nowy zacznę dziś łów
  • @lapiscarrot3557
    46:41 "You may now perform a poly-gone" that pun coming back at the end cracked me up