Complex Fibonacci Numbers?

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  • เผยแพร่เมื่อ 1 มิ.ย. 2024
  • Huge thanks to Jane Street! www.janestreet.com/join-jane-...
    Check out Ben Sparks's GeoGebra files.
    Binet formula 2D complex output: www.geogebra.org/m/twvvzpga
    3D imaginary output of Binet formula: www.geogebra.org/m/z6dy9cj5
    3D plot of absolute output of Binet formula: www.geogebra.org/m/pb7hmxyd
    My four-part series on Numberphile videos about Fibonacci Numbers (from 2014) starts here.
    • Brady Numbers - Number...
    Here is me going on about the square root of five (Numberphile 2018).
    • Lucas Numbers and Root...
    This was the Fibonacci puzzle video from Matt Parker's Maths Puzzles.
    • MPMP: The 1 Million Ba...
    Read a whole bunch about "Generalized Fibonacci Sequences and Binet-Fibonacci Curves".
    arxiv.org/pdf/1707.09151.pdf
    The zero I found was at -9.14202391817 + 2.80064954276i and you can see the exact form here: www.wolframalpha.com/input/?i...
    Try it for yourself and put the Binet Formula (((1+sqrt(5))/2)^n - ((1-sqrt(5))/2)^n)/sqrt(5) in the Wolfram roots calculator: www.wolframalpha.com/widgets/...
    This site has everything you'll ever need to know about Fibonacci Numbers.
    www.maths.surrey.ac.uk/hosted-...
    Buttercup - The original buttercupchallenge
    • Buttercup - The origin...
    CORRECTIONS
    This was a long video and in hindsight there are a few things I wish I had phrased better. Here they all are:
    - I misspoke around 01:13 when I said "negative one, zero" as it is clearly "negative one, one, zero".
    - At 07:53 I mean the negative values -5 to 0. I said it a weird way.
    - My language at about the 1D input to 2D plot from 09:17 is a bit sloppy. The real values going into the Binet function are not the horizontal axis shown; the plot onscreen is solely the output.
    - I say "axis" when I mean "plane" or even "complex plane". The big flat thing.
    Let me know if you spot anything else!
    Thanks again, as always, for Jane Street being my principal sponsor.
    www.janestreet.com/
    Thanks to my Patreon supports who do support these videos and make them possible. Here is a random subset:
    Loren Thomas
    Richard Dickins
    Barry Salter
    Susan Moury
    Sarah Gerweck
    Ulrich Kempken
    Piotr
    Gary Martin
    Euler
    Daniel DeJarnatt
    Support my channel and I can make more videos:
    / standupmaths
    Filming and editing by Matt Parker
    Music by Howard Carter (excluding Buttercup)
    Design by Simon Wright and Adam Robinson
    MATT PARKER: Stand-up Mathematician
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  • บันเทิง

ความคิดเห็น • 2.3K

  • @Dodgerific
    @Dodgerific 3 ปีที่แล้ว +2203

    I like the Fibonacci series where you start with 0, 0. Its easy to remember

    • @jetison333
      @jetison333 3 ปีที่แล้ว +199

      I can even calculate any item in that sequence in my head ;)

    • @NStripleseven
      @NStripleseven 3 ปีที่แล้ว +82

      The formula for a term in the sequence is the simplest I’ve ever seen

    • @darthgeeek
      @darthgeeek 3 ปีที่แล้ว +40

      Math truly is amazing

    • @cmyk8964
      @cmyk8964 3 ปีที่แล้ว +51

      Ah yes, the sequence that correctly predicts the exciting things that happens in my life

    • @minerforstone4136
      @minerforstone4136 2 ปีที่แล้ว +34

      I love how you choose the simplest possible sequence and it's "golden ratio" is undefined

  • @3blue1brown
    @3blue1brown 3 ปีที่แล้ว +4749

    Whoa.

  • @BH-2023
    @BH-2023 3 ปีที่แล้ว +701

    Well, I mean... the Fibonacci sequence was discovered thinking about the ideal procreation of rabbits, and it's pretty hard to have a negative rabbit mate with a positive rabbit

    • @themathaces8370
      @themathaces8370 2 ปีที่แล้ว +122

      That's what mathematicians do... Extending simple ideas to random dimensions...

    • @jayfredrickson8632
      @jayfredrickson8632 2 ปีที่แล้ว +112

      You can but then they mutually annihilate and you get a huge explosion

    • @reubenmanzo2054
      @reubenmanzo2054 2 ปีที่แล้ว +66

      They say opposites attract, don't they?

    • @fders938
      @fders938 2 ปีที่แล้ว +70

      Don't even get started with imaginary and 4D rabbits

    • @mr_waffles_the_dog
      @mr_waffles_the_dog 2 ปีที่แล้ว +1

      All you have to do is swing the rabbits around your head at a moderate fraction of the speed of light, and you get a handy anti-rabbit

  • @punpcklbw
    @punpcklbw 3 ปีที่แล้ว +1874

    The moments when his amazed face perfectly merges with himself are really trippy. Nice touch =P

    • @niccy266
      @niccy266 3 ปีที่แล้ว +53

      It's called the buttercup challenge, he links it at the bottom of the description

    • @ryla22
      @ryla22 3 ปีที่แล้ว +13

      It made me look up the song
      Really good song

    • @tomppeli0
      @tomppeli0 3 ปีที่แล้ว

      @@niccy266 1

    • @mrss649
      @mrss649 3 ปีที่แล้ว +2

      Lol yes

    • @flisboac
      @flisboac 3 ปีที่แล้ว +4

      Kinda freaks me out, tho

  • @robspiess
    @robspiess 3 ปีที่แล้ว +4818

    Fun fact: Phi (1.618) is really close to the ratio between miles and kilometers (1.609) which means you can use adjacent Fibonacci numbers to quickly mentally convert back and forth between them.
    For instance: 89 miles is nearly 144 km (it's actually 143.2), or 21 kilometers is roughly 13 miles (13.05).
    You can even shift orders of magnitude to do longer distances! e.g., 210 miles is around 340 km (multiplying 21 and 34 by 10) which is close to the actual answer of 337.96 km.

    • @witerabid
      @witerabid 3 ปีที่แล้ว +197

      🤯

    • @nuklearboysymbiote
      @nuklearboysymbiote 3 ปีที่แล้ว +251

      OH MY GOD

    • @Kebabrulle4869
      @Kebabrulle4869 3 ปีที่แล้ว +130

      I use this trick all the time, it’s so useful

    • @jonathanfeller
      @jonathanfeller 3 ปีที่แล้ว +249

      I find it easier to just do x+(x/2)+(x/10)

    • @XMarkxyz
      @XMarkxyz 3 ปีที่แล้ว +156

      Finally a good way to do it quickly, but I still think the imperial units are hideous, just a little less than what I thought before

  • @NyscanRohid
    @NyscanRohid 3 ปีที่แล้ว +2223

    φ : Let's see what's at the end of this infinite sum...
    φ : π!?
    π : Hey.
    φ : What are you doing in complex space?
    π : I work here. It's my job to be here at all times.

    • @weckar
      @weckar 3 ปีที่แล้ว +298

      π : I was here long before you got here, and will be here long after you leave.

    • @mr.champion7304
      @mr.champion7304 3 ปีที่แล้ว +98

      *rational numbers in geometric sequences intensifies*

    • @FourthDerivative
      @FourthDerivative 3 ปีที่แล้ว +141

      "Wait, it's all pi?"
      "Always has been"

    • @sharpfang
      @sharpfang 3 ปีที่แล้ว +127

      C'mon. You've messed with complex numbers. How are you *not* expecting a π there? Also, mandatory e, this time wearing the disguise of 'ln'

    • @lucyf6516
      @lucyf6516 3 ปีที่แล้ว +17

      sharpfang dude most people don’t intuitively know that pi has something to do with the complex plane lol. I’m sure you’re very smart. Here’s a gold star ⭐️.

  • @asailijhijr
    @asailijhijr 3 ปีที่แล้ว +624

    Missed opportunity: you could have had your amazed face trace the path of the graph shown on the screen at the time.

    • @jamesthomas3871
      @jamesthomas3871 3 ปีที่แล้ว +32

      I think he tried. It was awfully close, wasn't it?!

    • @arranmcgown2386
      @arranmcgown2386 3 ปีที่แล้ว +7

      I thought he was going to

    • @pronounjow
      @pronounjow 3 ปีที่แล้ว +21

      He sure Parker Squared that one!

  • @dragoncurveenthusiast
    @dragoncurveenthusiast 3 ปีที่แล้ว +293

    I have to say, I'm a tiny bit disappointed that his amazed face didn't follow the graph. It even pointed at his face!
    6:45

  • @haydenhoes12
    @haydenhoes12 3 ปีที่แล้ว +894

    this aint no sit down maths. we standin up now

    • @Vaaaaadim
      @Vaaaaadim 3 ปีที่แล้ว +30

      Rise up gamers

    • @volodyadykun6490
      @volodyadykun6490 3 ปีที่แล้ว +41

      I think Matt isn't stand-up comedian, he's sitting all the video, he's more of sit-down comedian

    • @thecuriousgorilla6005
      @thecuriousgorilla6005 3 ปีที่แล้ว +2

      Calm down Nolan

    • @standupmaths
      @standupmaths  3 ปีที่แล้ว +106

      Ha. I’m filming in a small room at home during the lock-down.

    • @demonking86420
      @demonking86420 3 ปีที่แล้ว +11

      He's doing the Parker Square equivalent for standing up (dead meme I know)

  • @brandonfrancey5592
    @brandonfrancey5592 3 ปีที่แล้ว +97

    I was waiting for the line, "And so I contacted Ben yet again and for some reason he blocked me and stopped responding to my e-mails."

  • @brian554xx
    @brian554xx 3 ปีที่แล้ว +321

    I've always preferred the 0, 1 start. With these numbers often found in nature, adding a moment of creation feels profound.

    • @rarebeeph1783
      @rarebeeph1783 2 ปีที่แล้ว +23

      it also feels even simpler than a 1, 1 start, like if you had to enumerate all the possible starts, you'd start something like "(0, 0); (0, 1)"

    • @KarstenJohansson
      @KarstenJohansson ปีที่แล้ว +12

      I think both are found in nature. In some spiraled plants, there is a gap in the center which is effectively 0. Others have something in the center which is effectively 1. Until your comment, I'd never considered that. I'm pretty sure that the vast majority of fib-nth() functions consider the 1st nth to be 0.

  • @claytrav2153
    @claytrav2153 3 ปีที่แล้ว +349

    The line looks like my Doctors Signiature

    • @georgplaz
      @georgplaz 3 ปีที่แล้ว +6

      underappreciated comment!

    • @AlanTheBeast100
      @AlanTheBeast100 3 ปีที่แล้ว +12

      Looks like my doc's prescription for ... well anything and everything.

    • @Darqice
      @Darqice 3 ปีที่แล้ว +6

      I'm actually thinking of trying to align my signature to this plot just for my internal giggles :D Would also make a nice company logo.

  • @HugoBDesigner
    @HugoBDesigner 3 ปีที่แล้ว +904

    The synchronized "Matt Parker's Maths Puzzles" cards were... _chef kiss_

    • @standupmaths
      @standupmaths  3 ปีที่แล้ว +128

      thankyouverymuch

    • @caster-
      @caster- 3 ปีที่แล้ว +12

      I hadn't even noticed! Very nicely done!

    • @Danilego
      @Danilego 3 ปีที่แล้ว +22

      6:49 this is so oddly satisfying

    • @Nate9273
      @Nate9273 3 ปีที่แล้ว +3

      MammamiaDasAhSpicyMeatball

    • @hecko-yes
      @hecko-yes 3 ปีที่แล้ว +2

      a channel after my own heart

  • @brianwestley6985
    @brianwestley6985 3 ปีที่แล้ว +445

    The Fibonacci convention was huge this year -- it was as large as the previous two put together.
    ThankyouladiesandgermsI'llbehereallweektrythechicken

    • @zaraak323i
      @zaraak323i 3 ปีที่แล้ว +8

      Tipyourwaiters!

    • @quesoestbonne
      @quesoestbonne 3 ปีที่แล้ว +4

      @Idiot Online Wondering Aloud 👏, 👏, 👏👏,👏👏👏,👏👏👏👏👏,👏👏👏👏👏👏👏👏,👏👏👏👏👏👏👏👏👏👏👏👏👏.....

    • @stevemattero1471
      @stevemattero1471 3 ปีที่แล้ว +2

      Wait there's a fibonacci CONVENTION??? When and where!?

    • @demonking86420
      @demonking86420 3 ปีที่แล้ว +4

      Oh get the heck out, I just got that

    • @Lawrencelot89
      @Lawrencelot89 3 ปีที่แล้ว +26

      @@stevemattero1471 Location: just add the coordinates of the locations of the last two conventions. Time: just add the dates of the previous two conventions to get the new date.

  • @sxygrandpa8061
    @sxygrandpa8061 3 ปีที่แล้ว +241

    The Binet formula for the Lucas sequence is actually simpler than the Fibonacci sequence: (ϕ)^n + (-1/ϕ)^n = nth Lucas number

  • @derrickmelton5844
    @derrickmelton5844 3 ปีที่แล้ว +383

    This reminds me of an experiment I did with Conway's life. I started wondering what would happen using the standard life rules with a bounded game, but set a cutoff for how many steps the game would iterate. I then took the union of each iteration of the previous game to create a seed for a new game, and continued to repeat the process.
    I mainly was doing this to see if you could use GOL to generate interesting height maps when I found an interesting property. For some reason if my iteration value was 2 meaning 2 distinct steps after the initial state to create a new input, the mean value of my bounded inputs approached pi. When they surpassed pi they would eventually trend back down to pi.
    I have no idea why pi arose because I am not that skilled at math, but I still wonder why that generation of inputs for a board state would trend towards it. The most I discovered was that method of generation retained symmetry if it existed in the initial board state meaning a blob in the very center would create symmetry along the diagonal, horizontal, and vertical axes.

    • @av3stube480
      @av3stube480 3 ปีที่แล้ว +40

      Okay I lack the mental capacity to imagine what you did but I'm really interested in why would Pi appear there...

    • @adityaekbote8498
      @adityaekbote8498 2 ปีที่แล้ว +21

      Yo idk what you are saying but that looks exciting let us know if you find anything

    • @creativenametxt2960
      @creativenametxt2960 2 ปีที่แล้ว +3

      Interesting.
      Would you provide more details?

    • @pranavkondapalli9306
      @pranavkondapalli9306 2 ปีที่แล้ว +18

      you did an experiment with 'Conway's life' lmao what
      PS: ik what GoL is

    • @trickytreyperfected1482
      @trickytreyperfected1482 2 ปีที่แล้ว +16

      @@pranavkondapalli9306 wow, I didn't even notice that first read through. That's an unfortunate typo for OP to make.

  • @hexeddecimals
    @hexeddecimals 3 ปีที่แล้ว +176

    Now I want to see a 3b1b style animation of the 2d inputs moving around to their 2d outputs

    • @fibbooo1123
      @fibbooo1123 3 ปีที่แล้ว +12

      One of the “results” of the 3b1b videos is exponentiation moves complex numbers around in circles- so presumably like that? But maybe not since there are 2 exponentiations being added

    • @volodyadykun6490
      @volodyadykun6490 3 ปีที่แล้ว +11

      Also just all the colours ordered as inputs mapping to their outputs

    • @violetsteele350
      @violetsteele350 2 ปีที่แล้ว

      He commented on this vid. You could comment on his commeng

  • @Rubrickety
    @Rubrickety 3 ปีที่แล้ว +395

    To explore this further would clearly require a large investment of time and effort. I suggest you apply for a Grant. Sanderson, ideally.

    • @pamdemonia
      @pamdemonia 3 ปีที่แล้ว +35

      I see what you did there and I approve!

    • @anirudhranjan7002
      @anirudhranjan7002 3 ปีที่แล้ว +12

      For those who don't know, Grant Sanderson is the host of 3Blue1Brown

    • @anuwamy969
      @anuwamy969 3 ปีที่แล้ว

      @@anirudhranjan7002 he already comment

  • @connorconnor2421
    @connorconnor2421 3 ปีที่แล้ว +8

    5:34 this excites me uncontrollably
    it's impossible not to smile

    • @tony_yt5967
      @tony_yt5967 2 ปีที่แล้ว +2

      “Ofc you’re dividing it by the sq root of 5, big fan!”😂😂made me happy made me smile nice 👍🏽

  • @PLASMATIER
    @PLASMATIER 3 ปีที่แล้ว +45

    The positive only values look like a growing spiral from the side, while the negatives create a spiral we serve head-on. If you used them as different POV, you could maybe plot out the tips of leaves or the sharp bits of a pinecone. It's really neat..

  • @davidgrupp7662
    @davidgrupp7662 3 ปีที่แล้ว +262

    Can we just take a moment to appreciate the editing involved for the amaze face

    • @Woe_YT
      @Woe_YT 3 ปีที่แล้ว +13

      Its actually pretty simple, you just cut a still from a frame of the video and then move it to the time and place in the video in reverse. It is a cool effect though.

  • @duskyrc1373
    @duskyrc1373 3 ปีที่แล้ว +272

    Heh, that random pi at the end. That's something I love about maths, if you're ever hungry you never have to go far to find a delicious pi.

    • @vblaas246
      @vblaas246 3 ปีที่แล้ว +7

      I want to know why though. Is it because every periodic system has a (circumpherence/2r)*dt relation? What about an 'oval', it can always be projected back to a circle right? Giving you a pi in every periodic system somewhere?

    • @TheBasikShow
      @TheBasikShow 3 ปีที่แล้ว +19

      V Blaas I’m not sure exactly why this particular pi shows up, but complex analysis is absolutely riddled with pi so it isn’t that surprising. In particular, this function is made of exponentials, and complex exponentials are inextricably linked with pi.

    • @ottolehikoinen6193
      @ottolehikoinen6193 3 ปีที่แล้ว +2

      2/5ths make it sound he could've used τau and get rid of the pesky 2.

    • @wilddogspam
      @wilddogspam 3 ปีที่แล้ว +1

      @@ottolehikoinen6193 2/5 * 1/π =4/5 * 2/τ though.

    • @criskity
      @criskity 3 ปีที่แล้ว +2

      @@TheBasikShow I remember when I took Complex Analysis in college, the answer to the exercises we did was almost always pi. If not, it was zero, 2pi, or pi/2.

  • @jacobwolf5640
    @jacobwolf5640 3 ปีที่แล้ว +49

    Very interesting, that plot of the Binet sequence appears to spell out 'Jeremy Bearimy'...

    • @pedrosso0
      @pedrosso0 2 ปีที่แล้ว

      Jeremy Bearimy you say?

  • @StrangeIndeed
    @StrangeIndeed 3 ปีที่แล้ว +5

    1:34 I just love Matt's humor, where he randomly does stuff, never addresses it, etc. Plz never change

  • @HipNerd
    @HipNerd 3 ปีที่แล้ว +47

    The ‘face’ bits were great. Nice effect.

  • @bacon.cheesecake
    @bacon.cheesecake 3 ปีที่แล้ว +115

    I've always been a fan of the 0, 1 start, glad to see it got some recognition

    • @andymcl92
      @andymcl92 3 ปีที่แล้ว +12

      I too like that start, although the 1,1 makes most sense with the origin story (breeding rabbits).

    • @OscarCunningham
      @OscarCunningham 3 ปีที่แล้ว +11

      @@andymcl92 In the 1st generation you have one pair of young rabbits and no mature rabbits. So in the 0th generation you must have one pair of mature rabbits and one pair of young antirabbits. Then the mature rabbits give birth to the young pair we see in the 1st generation, but there are no mature rabbits left in the 1st generation because the antirabbits grow up and annihilate them.

    • @Chris_Cross
      @Chris_Cross 3 ปีที่แล้ว +3

      But to me, it doesn't seem like it should work. The reason there is the two "1"s is because there's nothing before it.
      So if you start at 0, there's nothing before it, so you put another 0. "0, 0". But then, if you try to make the sequence by adding the two previous numbers to get the next, it just becomes and infinite string of "0"s.

    • @peglor
      @peglor 3 ปีที่แล้ว +7

      I like to start with two zeros - makes the maths much simpler...

    • @crustyoldfart
      @crustyoldfart 3 ปีที่แล้ว +2

      Why not make it completely general and start with the integers A,B ? So the series progresses A,B,A+B,A+2*B,2*A+3*B,3*A+5*B.... And we see that adjacent Fibonacci numbers occur in the coefficients. We can legitimately make A,B anything we chose including +ve and -ve values chosen at random.

  • @DavidDyte1969
    @DavidDyte1969 3 ปีที่แล้ว +24

    That was really sweet. I saw the title and started trying to imagine an equation describing a curve like that, with zeroes where the Fibonacci numbers are. Didn't realize that such an elegant parameterized version already existed.

  • @clockworkkirlia7475
    @clockworkkirlia7475 3 ปีที่แล้ว +44

    This is just such a cool maths revelation, with an amazing payoff and one of the absolute best editing jokes I've ever seen. That's pi outta pi from me, even if I apparently can't read 3d plots very well.

  • @SeptimusBlyth
    @SeptimusBlyth 3 ปีที่แล้ว +107

    19:44 Here comes Matt’s π day calculation 2021.

    • @twojuiceman
      @twojuiceman 3 ปีที่แล้ว +12

      I thought the same thing. Use that absurd formula for area under the curve to calculate pi

  • @qwertyuiopzxcfgh
    @qwertyuiopzxcfgh 3 ปีที่แล้ว +48

    "What a stupid idea! Who wants a video about Fibonacci numbers at 3 in the morning!?"
    Matt Parker: "Oh boy, 3 AM!"

    • @soupisfornoobs4081
      @soupisfornoobs4081 3 ปีที่แล้ว +4

      Now me at GMT+2, knowing sleep is a social construct

    • @alexandermcclure6185
      @alexandermcclure6185 หลายเดือนก่อน

      Literally anyone awake at 0300 just wants something to do.

  • @DjImpossibility
    @DjImpossibility ปีที่แล้ว +5

    Gosh darn it, now I want to look at Fibonacci quarternions!

  • @andrewholaway4113
    @andrewholaway4113 2 ปีที่แล้ว +41

    I love that you've made a living of messing around with interesting numbers and sharing it with us. I used to do things like this on my TI-86 graphing calculator, but never got far enough to make these kinds of incredible graphs (it was far beyond my mathematical understanding). Thanks for sharing your passion!

  • @Chlorate299
    @Chlorate299 3 ปีที่แล้ว +108

    Find someone who looks at you with the same excitement that Matt gets around numbers.

    • @georgplaz
      @georgplaz 3 ปีที่แล้ว +7

      with detached heads floating in space? no thanks!

  • @mangusto666
    @mangusto666 3 ปีที่แล้ว +120

    You could utilize time representing one variable. An animated 3D graphic may be used to visualize a 4D equation.

    • @himanbam
      @himanbam 3 ปีที่แล้ว +15

      You can kinda already do that with his program by sliding the complex input value.

    • @sherlock_norris
      @sherlock_norris 3 ปีที่แล้ว +13

      Or you can colorcode the complex plane and then color it according to the complex output.

    • @elvis_mello
      @elvis_mello 3 ปีที่แล้ว +5

      That seems like something a physicist would do

    • @buddyclem7328
      @buddyclem7328 3 ปีที่แล้ว

      Yes! I want to see this!

    • @davidpalomino9138
      @davidpalomino9138 ปีที่แล้ว

      While this does work in theory, it's not going to be like what most may imagine. Since the full plot is a 2D manifold embedded in 4 spacial dimensions, a 3D cross section would just be a 1D manifold embedded in 3 spacial dimensions.

  • @DerKlappspaten
    @DerKlappspaten 3 ปีที่แล้ว +64

    6:44 actually looks like an inwards spiral beeing (exponentially) accelerated to the right

    • @PiercingSight
      @PiercingSight 3 ปีที่แล้ว +5

      That was my thought too. Could help explain why pi shows up a few times. The Fibonacci numbers may just be a 1d slice of a 2d projection of a 3d spiral.

    • @mryellow4633
      @mryellow4633 2 ปีที่แล้ว +3

      Wow interesting observation. Meanwhile the negative numbers in the Binet formula formed an actual spiral 7:09. If the positive inputs can be described as an "inward spiral" then the negative numbers would be an outward spiral.

    • @kylecow1930
      @kylecow1930 2 ปีที่แล้ว +3

      Yeah it is!!, the (-phi)^-n term acts as a spiral exponentially decresing in radius and the phi^n acts to push the centre of the spiral to the right exponentially

  • @mosconirmg
    @mosconirmg 3 ปีที่แล้ว +12

    When I learned Fibonacci sequence in 99 (i was 15), I tried to extended backwards, but I lacked the math to understand this whole "bi infinite" sequence.
    Watching this video was a real time travel to the past.
    Nice work!

  • @scanerang
    @scanerang 3 ปีที่แล้ว +84

    3Blue1Brown has a nice way to represent 4D graphs. What he does is draw the transformed gridlines of the input space. It's like what you did with the graph with the real number line as input.

    • @olmostgudinaf8100
      @olmostgudinaf8100 3 ปีที่แล้ว +17

      Did no one think of using colour for the 4th dimension?

    • @MPSpecial
      @MPSpecial 3 ปีที่แล้ว +1

      He also used colour gradients in another video (about finding the zeros of a complex function I believe)

    • @f.p.5410
      @f.p.5410 3 ปีที่แล้ว +3

      Those graphs don't always look good, and they can even be more confusing for non-injective functions.
      Watch 3b1b video on Riemann's zeta, the map looks cool but it doesn't tell you anything about the function. You can't really recognize slopes and shapes, it's a mess.
      Unfortunately, this function looks like the kind of function which would be too messy to represent as a grid mapping.

    • @f.p.5410
      @f.p.5410 3 ปีที่แล้ว +3

      @@olmostgudinaf8100 Yes, and it's really useful from a topological perspective. For example, a Klein bottle is quite intuitive if you colour the overlapping part because you can see the neck part moving in the "colour dimension".
      It's less useful for complex functions because you can't really see slopes. It's hard to tell if a colour is shifting at a parabolic/exponential rate. It's still used a lot through a plotting technique called domain colouring, but it's still not a perfect way to plot complex functions. There isn't a perfect way unfortunately, you'll always have some drawbacks.

    • @teamupleft7097
      @teamupleft7097 3 ปีที่แล้ว

      What about two overlapping 3d surfaces attached to the 2D complex plane? Like the thumbnail for this video but with one real surface and one imaginary surface.

  • @sacielo
    @sacielo 3 ปีที่แล้ว +27

    The "other" thing I loved about this was the "how we got there" story. A great example of the mindset to approach problems scientifically and what to look for :)

    • @OH-pc5jx
      @OH-pc5jx 3 ปีที่แล้ว +2

      Yeah I really liked this video start to finish - but I *really* wish he’d done a domain colouring/colour wheel plot!! I find them so much more intuitive

  • @BrodieEaton
    @BrodieEaton 3 ปีที่แล้ว +15

    Matt just looks so happy, and it makes me happy. This is actually a really cool find! Well done!

  • @Poldx
    @Poldx 3 ปีที่แล้ว +4

    6:50 - next level videoediting - I love it

  • @TheNefari
    @TheNefari 3 ปีที่แล้ว +66

    i just realised that the curve that goes through 1 twice is actually a spiral/cone looked at from the side :D

    • @Microtherion
      @Microtherion 3 ปีที่แล้ว +3

      I think it could even be described as an 'epicycle'.
      (Oy, Ptolemy: no! I respect your attempt to maintain the geometric integrity of our planet's immediate locality, but if you was to come round here, and start arranging *my furniture* into a highly idiosyncratic theological exegesis, I would say - 'Ptolemy, nooo! Outside now! You are not in the bustling multicultural milieu of ancient Alexandria. This is Lambeth. Now get your pharaonic physog out of my impromptu courtyard knees-up, you stripy antediluvian muppet!' Etc). :)

  • @eldabys
    @eldabys 3 ปีที่แล้ว +293

    playing buttercup while he does the amazed face... LMAO

    • @zozzy4630
      @zozzy4630 3 ปีที่แล้ว +16

      Started reading through the comments hoping someone had already ID'd the song for me. Thank you

    • @ALZlper
      @ALZlper 3 ปีที่แล้ว +4

      @@zozzy4630 You mean Darude Sandstorm?

    • @Rabbit-the-One
      @Rabbit-the-One 3 ปีที่แล้ว +3

      @@ALZlper I think he does indeed mean Sandstorm by Darude.

    • @colinsanders3124
      @colinsanders3124 3 ปีที่แล้ว +2

      @@ALZlper The song is Buttercup by Jack Stauber

    • @colinsanders3124
      @colinsanders3124 3 ปีที่แล้ว +2

      @@zozzy4630 th-cam.com/video/e2qG5uwDCW4/w-d-xo.html

  • @yukelalexandre8885
    @yukelalexandre8885 3 ปีที่แล้ว +1

    Hell yes! Been thinking about this for two years but couldn’t visualize it without the tools!

  • @usageunit
    @usageunit 3 ปีที่แล้ว +15

    Can't wait to see the quaternionic version of this video!

    • @angeldude101
      @angeldude101 2 ปีที่แล้ว +2

      Quaternions don't really add much beyond more complex planes (which is very useful when doing 3D rotations). The dual and split-complex numbers on the other hand do have some interesting behavior, but neither can act as a square root of -1.

  • @fozzzyyy
    @fozzzyyy 3 ปีที่แล้ว +40

    90% of the budget for that amazed face effect at 6:47
    Edit: I stand corrected 7:28
    btw for plotting complex functions, I've been trying for a while to make a program the plots the path of f(x + ti) in 3D where t is just the time. This could be a 4D plot

  • @mr.neverspeaks7884
    @mr.neverspeaks7884 3 ปีที่แล้ว +201

    I “enjoy” math and this is WAY out of my understanding of math ,but I just love the content. Thank you!

    • @Ragnarok540
      @Ragnarok540 3 ปีที่แล้ว +15

      I was going to say this is not complex at all but yeah, is a bit complex. Get it? Is easy, thought, except for the 4D visualization part.

    • @sebastianjost
      @sebastianjost 3 ปีที่แล้ว +8

      @@Ragnarok540 4d visualization can be done a lot better when using colors.
      I've explained that in this comment section before so I won't do it here again.
      But if you search, you will find how it's done.

    • @carrotfacts
      @carrotfacts 3 ปีที่แล้ว +6

      @@Ragnarok540 For someone who watches math youtube videos for fun, it's quite difficult. Glad you get it so easily, though

    • @tirocska
      @tirocska 3 ปีที่แล้ว +3

      @@carrotfacts Could you explain which part(s) you find difficult? Just curious.

    • @andrewosborne1447
      @andrewosborne1447 3 ปีที่แล้ว

      I mean, all he did was say “here’s a solution to a recursion. It’s continuous on C”.

  • @chrisxd146
    @chrisxd146 2 ปีที่แล้ว +6

    It's insane how often pi shows up in any level of math. Funnily enough it's the first example I given when helping students to better understand infinite series and what they're useful for (alongside Euler's identity).
    Very cool video that I wish I wouldn't have waited so long to watch.

  • @tekkorb778
    @tekkorb778 3 ปีที่แล้ว +24

    I never expected that the graph of the negative positions of the fibonacci seqeuence would give a fibonacci spiral, amazing!

  • @GunganWorks
    @GunganWorks 3 ปีที่แล้ว +13

    The amazed face absolutely cracked me up!!!

  • @Yazoocxi
    @Yazoocxi 3 ปีที่แล้ว +92

    Matt! You are already in python. Take a look at the library "matplotlib" it can do zoomable/movable 3D plots directly from python.

    • @vibacourtney-battista6918
      @vibacourtney-battista6918 3 ปีที่แล้ว +1

      What software could I code an interactable fractal zoom using python?

    • @RubenMoor
      @RubenMoor 3 ปีที่แล้ว +3

      Seems crazy to me to rely on excel when you have matplotlib - or at least I wouldn't admit it 😬

    • @andrewosborne1447
      @andrewosborne1447 3 ปีที่แล้ว +3

      Matplotlib, pandas, numpy.

    • @ThaiNguyen-bl1pi
      @ThaiNguyen-bl1pi 3 ปีที่แล้ว +3

      Ruben Moor you underestimate the obsession of Matt with Excel

  • @eekee6034
    @eekee6034 2 ปีที่แล้ว +3

    That first graph made me the most excited I've been about math, *ever!* :D

  • @lovingfoe1444
    @lovingfoe1444 3 ปีที่แล้ว +6

    This guy went insane. Really maths “y”. Imaginative. I love how he opens he mouth to show his excitement.

  • @romajimamulo
    @romajimamulo 3 ปีที่แล้ว +29

    What I would do is the way 3blue1brown did the display of the Zetta function: start with a grid in the complex plane, and animate distorting it

  • @gordonwiley2006
    @gordonwiley2006 3 ปีที่แล้ว +204

    The way Matt's goodbye face's hand was animated was wigging me out for some reason. Does not tarnish the good maths though.

    • @MCAndyT
      @MCAndyT 3 ปีที่แล้ว +20

      Really kept my attention while he did the sponsored portion. Very clever, that one...

    • @fennecfoxfanatic
      @fennecfoxfanatic 3 ปีที่แล้ว +12

      That animation kept me on my toes! More intense than the bouncing dvd logo

    • @gordonrichardson2972
      @gordonrichardson2972 3 ปีที่แล้ว +5

      Gordon Wiley Tom Scott did a video on green-screen perspective errors being creepy.

    • @kuromurasakizero9515
      @kuromurasakizero9515 3 ปีที่แล้ว +8

      it seemed like it was both timed to the beat of the music and slightly off at the same time. Methinks he learned a new editing trick and enjoyed it a lot :)

    • @partywumpus5267
      @partywumpus5267 3 ปีที่แล้ว

      @@kuromurasakizero9515 definitely looks like he's having a fun time with it

  • @ChuckHenebry
    @ChuckHenebry 2 ปีที่แล้ว +1

    Love the various faces. Nice video editing!
    The goodbye face kept me watching all the way through the Jane St. promotional-a first for me. Nice audience hook, Matt!

  • @lmitz
    @lmitz ปีที่แล้ว +2

    I like how at 1:35 it is perfectly synced between the text in the previous video and the current video

  • @Turcian
    @Turcian 3 ปีที่แล้ว +131

    Matt: Uses Python for computing the values
    Also Matt: Uses Excel to plot the values computed using Python
    We need to talk about Matplotlib. Or should I call it Mattplotlib?

    • @silverzero9524
      @silverzero9524 3 ปีที่แล้ว +26

      Mattdoesntplotlib

    • @MaxDiscere
      @MaxDiscere 3 ปีที่แล้ว +4

      Matplotlib sucks, excel is far better if you want to be fast

    • @trueriver1950
      @trueriver1950 3 ปีที่แล้ว +3

      @@MaxDiscere
      Agreed Excel is great for a fast and dirty first look.
      But it's no good at all if you want to be able to zoom, change point of view, etc

    • @iabervon
      @iabervon 3 ปีที่แล้ว +2

      Mattplotlib will give you graphs that are interesting and look good, but if you happen to look at them diagonally one of the ways, they don't quite add up. Also, some of your numbers appear in two places for some reason.

    • @pascalschetelat7198
      @pascalschetelat7198 3 ปีที่แล้ว +1

      Wow, lots of people here need to learn to use matplotlib which is arguably both faster and and more powerful than excel. Plus it is interactive and give nice looking graphs

  • @TheSpacecraftX
    @TheSpacecraftX 3 ปีที่แล้ว +11

    It hit me near the end how good of a job you've done of editing this. The virtual plot that you're actually pointing to points on like a weatherman. Also I suspect you just learned how to do the face thing and it's really cool.

  • @surrealdynamics4077
    @surrealdynamics4077 3 ปีที่แล้ว +4

    I love your videos! I don't really understand the complex maths involved, and I don't think I ever will get to. But maths really spark an interest and curiosity in me, I love to learn more and take a peek into this otherworldly stuff!

  • @mistec34
    @mistec34 3 ปีที่แล้ว +2

    I love your enthusiasm, my dude. Keep learning, growing and challenging yourself and others! :)

  • @ImDoubleDelight
    @ImDoubleDelight 3 ปีที่แล้ว +82

    "A third" incorrectly stated as 0.333, yet time stamped at 03:33 is some fine trolling... 🧐

    • @i_booba
      @i_booba 3 ปีที่แล้ว +9

      That's some fine detective work also, dang.

  • @KarstenJohansson
    @KarstenJohansson 3 ปีที่แล้ว +24

    6:29 this is the shadow of a spiral (3D onto 2D plane). Then the next part of the video shows a spiral, which is still a shadow of the spiral, but seen from a fairly easily guessed angle in 3d space.

    • @timh.6872
      @timh.6872 3 ปีที่แล้ว +9

      That's a good catch! It does look like a projection of a decaying helix.

    • @atomictraveller
      @atomictraveller 3 ปีที่แล้ว +2

      i saw nonlinear damped mass spring (have a vid on using quadrature osc to appx sine and cosine)
      s0 = 1.f; s1 = 0.f; // init
      s0 -= w * s1; s1 += w * s0; // loop .. where w = angular frequency 2 * pi * hz / samplerate

  • @jamesbra4410
    @jamesbra4410 3 ปีที่แล้ว +3

    Very informative, lots of effort put in. Some of the best math content I've seen.

  • @YuVW
    @YuVW 3 ปีที่แล้ว +11

    I can't believe you did all of this teasing and then didn't show the plot across the line containing the zeroes

  • @gustavofb3
    @gustavofb3 3 ปีที่แล้ว +31

    If the surface have not a name yet
    It could be named "the Parker's Blanket"

  • @nicolaom
    @nicolaom 3 ปีที่แล้ว +196

    I’m wondering what are the properties of the loop that the two 1’s form... I don't know why, but it was the part that I found the coolest

    • @theot1692
      @theot1692 3 ปีที่แล้ว +38

      I wonder what the area of the loop is

    • @richardpike8748
      @richardpike8748 3 ปีที่แล้ว +21

      @@theot1692 I was about to say this lol. I also wonder the area of the loop. And if you wanted to go deeper I guess you could also do analysis of curvature, length, etc... never know what you might find.

    • @gajbooks
      @gajbooks 3 ปีที่แล้ว +26

      The real question is does the loop shrink in the complex plane, and if so where does it reach zero size?

    • @richardpike8748
      @richardpike8748 3 ปีที่แล้ว +7

      @@gajbooks volume of the loop? o_o

    • @hwliebenberg5487
      @hwliebenberg5487 3 ปีที่แล้ว +2

      I dont think the line crosses the x axis at all, I believe that from the point of perspective where you looking from the X/Y axis vantage point it looks like it crosses the x-axis, but it doesn't, it loops around it, just like a inverse spiral if looking from the vantage point of Z/Y axis. (I dont know, it just looks like it)

  • @dianedong1062
    @dianedong1062 3 ปีที่แล้ว +2

    Beautiful! I never thought about using anything other than positive real numbers in the Fibonnaci sequence until today.

  • @plaustrarius
    @plaustrarius 3 ปีที่แล้ว +2

    Was able to graph the 2D slice with real inputs, working on the complex input/complex output graphs
    excellent project thank you Matt!!

  • @bentbliley
    @bentbliley 3 ปีที่แล้ว +11

    In regards to where Fibonacci starts, I’d always been taught it starts 0 1.

    • @ComradeTiki
      @ComradeTiki 3 ปีที่แล้ว +3

      Zero indexing... nice.

  • @DemoniteBL
    @DemoniteBL 3 ปีที่แล้ว +5

    I love how excited Matt is about everything.

  • @nymalous3428
    @nymalous3428 ปีที่แล้ว +1

    Coincidentally, I just taught my class graphing complex numbers on the complex plane yesterday... and today I get this recommendation.

  • @DhaTennisKid
    @DhaTennisKid 3 ปีที่แล้ว +2

    Loved the 3D representation of a 4D concept, super cool
    Would love to see a follow-up video with bigger graphs!!!

  • @parodysam
    @parodysam 3 ปีที่แล้ว +6

    First time I’ve seen e, pi, and phi all together like that

  • @WilliametcCook
    @WilliametcCook ปีที่แล้ว +5

    I was surprised at how easy it is to graph in Desmos:
    \frac{\left(\phi^{t},0
    ight)-\frac{1}{\phi^{t}}\left(\cos\left(t\pi
    ight),\sin\left(t\pi
    ight)
    ight)}{\sqrt{5}}
    Set your preferred boundaries for _t_
    Or, if you want animation, restrict _t_ to [0,1] and replace every instance of _t_ with _at_ for some variable _a_

  • @TheArunster
    @TheArunster 3 ปีที่แล้ว +2

    This is so awesome. Love the energy and passion. ❤️

  • @KaiCrafted
    @KaiCrafted 3 ปีที่แล้ว +1

    I really enjoyed the graphics/effects this video, along with the content 👍

  • @jony7779
    @jony7779 3 ปีที่แล้ว +20

    You give "domain coloring" a try next time you want to visualize functions of complex numbers.

  • @Czxvkq
    @Czxvkq 3 ปีที่แล้ว +7

    That equation at the very end reminds me of Euler's Identity. You could call it Parker's Identity!

  • @criskity
    @criskity 3 ปีที่แล้ว +1

    That loop in the graph is mind-blowing!

  • @rashmi9733
    @rashmi9733 3 ปีที่แล้ว

    This is one of the awesome channel in you tube and I love it and learn from it.
    Thank you so much sir.

  • @MaximusMuleti
    @MaximusMuleti 3 ปีที่แล้ว +3

    This was one of the coolest Fibonacci maths I've ever seen!!!

  • @aliasalias2131
    @aliasalias2131 2 ปีที่แล้ว +4

    Nice new point of view, thank you :).
    Also, by the way, in the log abs plot, you can see the two binet terms as two planes, which I find constructive.
    Remark: Personally I like to plot the abs and use colors for the output phase, to keep it 3d. It distracts a little bit from the phase, but often you don't really need it, and e.g. with the log abs you can see the zeros and poles quite well.

    • @MajikkanBeingsUnite
      @MajikkanBeingsUnite 2 ปีที่แล้ว

      That sounds awesome! 😸 It will both show the angle and make it 🌈rainbow, which automatically boosts the awesomeness of a mathematical plot by about omega!
      Sadly, no version of Geogebra I've ever tried can make multicoloured outputs 😿 so it's gonna have to be a new file, not an updated version of this particular interactive.

  • @ataraxianAscendant
    @ataraxianAscendant 2 ปีที่แล้ว

    ok i really like the buttercup challenge thing you had going on, I've been listening to a lot of jack stauber recently and I thought it was really cool to see one of his songs appear in one of your videos!

  • @scottytremaineplays9461
    @scottytremaineplays9461 2 ปีที่แล้ว +2

    This should have been in my complex analysis module.
    Also, the limit of the integral of the Binet function - mind blown 🤯

  • @alyssaburgueno5963
    @alyssaburgueno5963 3 ปีที่แล้ว +7

    You’ve likely already heard of it, but you could also look at the 5-adic interpolation of the Fibonacci numbers; this yields a 5-adic continuous function in fact! Really cool stuff. Unfortunately, I think you‘d run into the same difficulty (or more) getting a visualization of the result.

  • @tomadams7553
    @tomadams7553 3 ปีที่แล้ว +6

    That amazed face to 'Buttercup' 🤣

  • @SaintOf007
    @SaintOf007 3 ปีที่แล้ว

    Very nice video! The most common fun fact I relay to lay person about my graduate studies is relating chaos theory, winding numbers, and the golden ratio, all as an explanation as to why we see the golden ratio appear everywhere in nature. It would be amazing if you could do a nice video about that. You do such a good job at your teaching, I bet you would do a great job and it is a very fascinating bit. Thank you, I'll keep watching 👍

  • @switch1e
    @switch1e ปีที่แล้ว +1

    This is so cool. Thank you for making this video

  • @helloworld-ru9tz
    @helloworld-ru9tz 3 ปีที่แล้ว +4

    This video just tells us how amazing Matt Parker's editing and programming skills are.
    6:45 and 7:24

  • @revenevan11
    @revenevan11 3 ปีที่แล้ว +3

    9:00 you could use a 3d plot with the input complex n being the 2d surface of the x-y plane, and the z axis being one output, and then either use some color gradient for the other output instead of a 4th dimension, or animate the 3d plot over time as the 4th dimension so that we could get some idea of how it changes as you slide along that 4d axis. I've done a bit of this sort of sliding through the 4th axis by animating with 3d slices to show simple 4d objects like hyperspheres in wolfram mathematica, but my trial has expired for that and I haven't gotten around to learning python yet to do it myself. Loved this video!!!
    Edit: you (and Ben) did some stuff like this, I just commented too early lol.

    • @revenevan11
      @revenevan11 2 ปีที่แล้ว

      Re-watching this video, I'm realizing how close I was to pushing back into the negative numbers when I was learning about the fibonacci sequence! (Basically, as a kid, I realized that 0, 1, 1.... was more of the fundamental starting point, so when I wrote my fibonacci generator on my TI-84, I started with 0 and 1 😁)

  • @belladoralastname6096
    @belladoralastname6096 3 ปีที่แล้ว

    This is one of my favorite channels specifically because I think this is the only person I've ever seen excited as I get for math

  • @kyrilcouda
    @kyrilcouda 3 ปีที่แล้ว +1

    6:45 Liked and subscribed just for that meme. Good job, Matt :D

  • @jeremy.N
    @jeremy.N 3 ปีที่แล้ว +8

    Hey Matt, looks great. However, you should try taking the logarithm of the absolute value, when plotting, since the fibonacci series is an exponential series and thus diverges quite fast. That would also help showing the zeroes and the "waves" you can see in the function.

    • @joshcork2201
      @joshcork2201 3 ปีที่แล้ว +2

      This works when the output is large, but for small values, log is a very large negative number. Furthermore log is undefined at 0.

  • @djpeterson7479
    @djpeterson7479 3 ปีที่แล้ว +8

    "Oh look! I made it spin!"
    Poker face, Matt. Just pretend you meant to do that.

  • @matthewsaulsbury3011
    @matthewsaulsbury3011 3 ปีที่แล้ว

    Wow! That's amazing and cool! Those are neat looking graphs! 👍🏼😀

  • @nbee4981
    @nbee4981 3 ปีที่แล้ว +1

    I was taking a course regarding the Laplace Transform , lo, about 40+ years ago, and, as a part of it, the prof introduced the notion of "difference equations" (cf. "differential equations") and the difference equation analog of the LT called the "Z Transform". As he went into the idea, I realized that you could use the Z transform to redefine a Fibonacci sequence as a function of the two initial values (this was a variable Fib sequence, not just the uniform standard one) and the "n-th" value you wanted -- that is, rather than have to calculate all the intermediate numbers, you could get the n-th term by simply plugging in N, F-sub-0 and F-sub-1.
    And, in fact, this was the subject for the next day's class/lesson. I always love it when I see where the class is going ahead of time.
    Not sure if that can be turned into a segment, but you might enjoy looking over it either way.
    Transforms are pretty cool things. And the LT is actually pretty primitive, being one of the first tools invented to manipulate, analyze, and understand the concepts of differentials.

  • @jasonpatterson8091
    @jasonpatterson8091 3 ปีที่แล้ว +34

    You said "deposit" in your presentation of that puzzle. That implied positive numbers only. I don't know how many other people considered negatives and discarded the idea as outside the rules as presented, but I did. I'm still bitter about the bonus points.

    • @theadamabrams
      @theadamabrams 3 ปีที่แล้ว +4

      I could have written this exact comment word for word!
      "Deposit" means a strictly positive number. I even looked up the word at the time because, like others, I thought of the negative answer and then determined that it was not a valid solution (and I did notice Matt's use of the word "integers", but he also explicitly used the word "deposit").
      I'm okay with giving equal points for the answer involving negatives, but it seems insulting to give *additional* points for an *_incorrect_* answer.

    • @DukeBG
      @DukeBG 3 ปีที่แล้ว +4

      Same. I was offended by Matt saying that the rest of the people didn't consider the negative numbers. I considered and actually emailed about them, but did not enter it in the answer box because I didn't want to lose points.

    • @Huntracony
      @Huntracony 3 ปีที่แล้ว +1

      @@DukeBG In MPMP: if it goes in the answer box and it works, it is valid. Though, I also didn't try it because I thought positive only was implied.

    • @DukeBG
      @DukeBG 3 ปีที่แล้ว

      @@Huntracony Yeah, now we know that and we'll act accordingly in the future. But I'm still going to be cross about "not considered" wording here.

    • @Huntracony
      @Huntracony 3 ปีที่แล้ว +1

      @@DukeBG Rightfully so.

  • @stephenamy9879
    @stephenamy9879 3 ปีที่แล้ว +55

    I liked this so much that I clicked "like" n times, n being an odd number

  • @josephyoung6749
    @josephyoung6749 3 ปีที่แล้ว

    that curve at the 6 and a half minute mark looks so nice, almost like cursive... well done!

  • @patrickmestabrook
    @patrickmestabrook 3 ปีที่แล้ว

    LOVED this video my dude! Thank you!