But what is a Fourier series? From heat flow to drawing with circles | DE4

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  • เผยแพร่เมื่อ 2 ธ.ค. 2024

ความคิดเห็น • 4.2K

  • @pablotano352
    @pablotano352 5 ปีที่แล้ว +7963

    After listening to a lot of teachers, I have to say that you are simply the best explainer I know. Probably one of the greatest teachers of all time. By explaining complex and powerful ideas in such a beautiful and simple way, your work will surely have a big impact on the life of future scientists and engineers. Keep it going man, you are doing an amazing job!

    • @fygarOnTheRun
      @fygarOnTheRun 5 ปีที่แล้ว +185

      I have to subtract e to the i times pi from this comment

    • @aryamanmishra154
      @aryamanmishra154 5 ปีที่แล้ว +13

      where did you do your PhD from?

    • @Ludix147
      @Ludix147 5 ปีที่แล้ว +34

      He truly is very good at what he does! You can tell that he has a good understanding of when his explanations are good, and you can tell he takes a lot of time to get to that point.

    • @gaeb-hd4lf
      @gaeb-hd4lf 5 ปีที่แล้ว +5

      Completelly agree

    • @wengeance8962
      @wengeance8962 5 ปีที่แล้ว +38

      I didn't do a PhD in physics and I think the same

  • @HotDogMarchant
    @HotDogMarchant 5 ปีที่แล้ว +2272

    I’m in the process of writing my thesis for a PhD in theoretical physics and I’ll be completely honest, I cried at how elegant this explanation is. Thank you for helping someone who feels they’ve lost a lot of passion for maths and physics after years of hard work, realise that they still have the capacity to really care about these subjects. Truly thank you.

    • @joynew1914
      @joynew1914 4 ปีที่แล้ว +70

      I really admire those who study mathematics and theoretical physics.

    • @austinconner2479
      @austinconner2479 4 ปีที่แล้ว +33

      What made you lose passion along the way? I just finished my thesis for a PhD in math and I'm still excited about the math itself. Worst parts of academia are still stuff outside the math (grant writing, etc..)

    • @NovaWarrior77
      @NovaWarrior77 4 ปีที่แล้ว +2

      Oh man. Happy for you sir.

    • @ashutoshsamantaray2572
      @ashutoshsamantaray2572 4 ปีที่แล้ว +22

      @@thesickbeat ya i am annoyed by these type of comments but then i feel bad abt promoting for some1 to not speak what they want

    • @vutruongquang3501
      @vutruongquang3501 4 ปีที่แล้ว +7

      It's been 11 months, how are you going George ? I will you're all good and healthy ^^

  • @lightyearahead
    @lightyearahead 5 ปีที่แล้ว +5793

    Math is even more beautiful when someone teach like this.

  • @lol12313
    @lol12313 ปีที่แล้ว +632

    As I begin my journey to get a physics degree, I can't help but look back and thank you for all the content you've made. Truly inspiring and educational stuff :)

    • @colummahony3364
      @colummahony3364 ปีที่แล้ว +35

      Such a generous guy, thanks for supporting this stuff on TH-cam

    • @spongbong0
      @spongbong0 ปีที่แล้ว +11

      please give me tips as I also would like to have a degree in physics

    • @lol12313
      @lol12313 ปีที่แล้ว +15

      @@spongbong0 im innately a curious person, so physics is a pathway for me to understand how things work. Im particularly interested in how things work on a fundamental level and look forward to learning about relativity and QM in depth.
      For me, choosing physics is like following a passion; for you, i dont know what physics might be, so take some classes and find out!?

    • @spongbong0
      @spongbong0 ปีที่แล้ว +3

      @@lol12313 I've expressed my feelings in that exact same way once. 🤣 I see we have similar feelings

    • @Aaaarussss
      @Aaaarussss ปีที่แล้ว +1

      ​@@lol12313 I want to be an astrophysist please give me some tips on how to get good at physics I practice questions daily but I don't know what else to do

  • @DennisDavisEdu
    @DennisDavisEdu 5 ปีที่แล้ว +3017

    Grant, you have the unique trifecta:
    1. Intelligence to understand these complex topics.
    2. Ability (and willingness!) to explain them clearly.
    3. Technical chops to animate and edit your explanations.
    Nothing you do is easy but it is all appreciated by a wide audience.

    • @Sweet-Vermouth
      @Sweet-Vermouth 5 ปีที่แล้ว +44

      Agreed. He is easily one of the best, if not THE ABSOLUTE BEST

    • @randomdude9135
      @randomdude9135 5 ปีที่แล้ว +47

      Thanks for adding chops and trifecta to my vocabulary.

    • @alex_evstyugov
      @alex_evstyugov 5 ปีที่แล้ว +14

      That is not a unique trifecta by any stretch of imagination.
      Many have it, and more to the point everyone can.
      *You* can have that trifecta.
      If you don't, that's your own choice.

    • @whitewalker608
      @whitewalker608 5 ปีที่แล้ว +3

      A lot of Stanford/MIT/UCB etc Computer science graduates have all 3.

    • @PrimerBlobs
      @PrimerBlobs 5 ปีที่แล้ว +74

      There's also a strong instinct for visual beauty, a tendency toward warm communication, and memory/empathy for what it's like to not know the concepts yet, which are what make 3b1b really stand out, IMO

  • @AG-lm5uf
    @AG-lm5uf 5 ปีที่แล้ว +1634

    I dropped out in 10th grade 25 years ago and your videos have inspired me to go back to school.

    • @mjolnirforsworn
      @mjolnirforsworn 5 ปีที่แล้ว +66

      It's never too late!

    • @Userjdanon
      @Userjdanon 5 ปีที่แล้ว +32

      u just dont learn that in school but in uni. indeed, hes a great lecturer

    • @ronaldjensen2948
      @ronaldjensen2948 5 ปีที่แล้ว +35

      Amir, I'm about your age and just finishing a bachelor's degree... If I can, you can... And one of my favorite math teachers is also named A. Ghoreishi. :)

    • @skydragon3857
      @skydragon3857 5 ปีที่แล้ว +6

      How do you go back anyways idk how it works

    • @ronaldjensen2948
      @ronaldjensen2948 5 ปีที่แล้ว +16

      @@skydragon3857 Look for a local college/university, visit their web-site and find the apply button... Also, look for non-traditional student services for help, advice and support.

  • @spudzzy0373
    @spudzzy0373 4 ปีที่แล้ว +4975

    I’m imagining students watching this and furiously taking notes while I’m here at 2am thinking “oooh circles make shapes”

    • @paulgoogol2652
      @paulgoogol2652 3 ปีที่แล้ว +236

      Most average students: "well it is 3am for me"

    • @Wilker_uwu
      @Wilker_uwu 3 ปีที่แล้ว +28

      i'm bad at math ;-;

    • @MrParry1976
      @MrParry1976 3 ปีที่แล้ว +26

      well it is 3 am right now here

    • @abicol6010
      @abicol6010 3 ปีที่แล้ว +47

      This video came out while I was taking my intro diff EQ class. Didn't see it till now at 3am. Would have been helpful at the time since my Prof gave zero context for how these equations work and how they can be applied.

    • @ishworshrestha3559
      @ishworshrestha3559 3 ปีที่แล้ว +2

      Ok

  • @legovd1018
    @legovd1018 3 ปีที่แล้ว +2275

    Somehow this wound up in my recommended, and I’ll be frank here. I’m in 10th grade and am nowhere NEAR the level of algebra and calculus comprehension required for this, but you explained this complex subject so well and fluently and thoroughly that even I managed to roughly understand some of the concepts! Excellent work, and keep it up!

    • @foxphire0093
      @foxphire0093 3 ปีที่แล้ว +107

      I (a Junior Electrical Engineering Student) went through the same experience time and time again. But, remembering these after a time of learning is a great way to see how far you have come with understanding and knowledge; I did that as I was watching this because I’m going over Fourier Series right now in my Signals and Linear systems class, and I said to myself “wow, I’ve learned a lot, I actually understand where these are coming from!” when I watched this last year, I had no idea where things were coming from, but after learning about the fundamental concepts and applying them, the fog cleared and I actually recognized things. All of this to say, always go back to videos like this to see what you recognize to see what you now know - it’s the joy of learning.

    • @andiehammettz4u265
      @andiehammettz4u265 3 ปีที่แล้ว +25

      Agreed. How in the world did I just receive that when I'm mathematically illiterate yet artfully wired?

    • @foxphire0093
      @foxphire0093 3 ปีที่แล้ว +20

      @@andiehammettz4u265 Because there is an art to mathematics, art comes from mathematics in the end as it describes everything in the universe

    • @andiehammettz4u265
      @andiehammettz4u265 3 ปีที่แล้ว +7

      @@foxphire0093 but when I draw I'm not thinking of a formula. The creativity is not pre formulated outside of how the parts relating to the whole. Form AND function.

    • @will8070
      @will8070 3 ปีที่แล้ว +5

      i’m a sophomore too and i’ve just been watching a bunch of his random videos and i watched this one like a couple weeks ago lol

  • @alpineblob
    @alpineblob 5 ปีที่แล้ว +627

    This is pure gold for an engineering student like myself. I hope you one day get the recognition you truly deserve for illustrating the ideas this beautifully and clean. Thank you.

    • @FilippoSolari
      @FilippoSolari 5 ปีที่แล้ว +19

      same for me... as an engineering student, i've never fully understood the math behind Fourier, limiting myself to apply it mechanically. I know what an FFT and the Fourier series are built for and their importance in signal processing, but the math behind them remains for me some sort of magic even after Math III exam.
      This, damn this is totally mind blowing.

  • @eunhyoukshin7777
    @eunhyoukshin7777 5 ปีที่แล้ว +258

    Joseph Fourier must be so proud to have a Fourier-portrait of himself

    • @gcewing
      @gcewing 5 ปีที่แล้ว +32

      And when it's built up from frequency components one at a time, it kind of looks like he's developing from an embryo!

  • @blacklegend2304
    @blacklegend2304 5 ปีที่แล้ว +719

    That must have been some hard-core editing
    Thanks for the great content

    • @Schattengewaechs99
      @Schattengewaechs99 5 ปีที่แล้ว +57

      Animating ≠ Editing

    • @giacomo.delazzari
      @giacomo.delazzari 5 ปีที่แล้ว +134

      Doing something like this with video editing software is almost impossible. Each of his videos is entirely produced by a Python program that uses a library he wrote (which is also open source IIRC). I guess that is the only sane way to create videos like this.

    • @nuklearboysymbiote
      @nuklearboysymbiote 5 ปีที่แล้ว +24

      @@giacomo.delazzari still pretty insane

    • @pointerish
      @pointerish 5 ปีที่แล้ว +43

      Hard-core coding instead.

    • @fygarOnTheRun
      @fygarOnTheRun 5 ปีที่แล้ว +18

      @@giacomo.delazzari yep, it's online: github.com/3b1b/manim

  • @mkoyama
    @mkoyama ปีที่แล้ว +339

    I am a Math Ph.D holder who's been both teaching and researching the Fourier related field and, HOLY CRAP this is one of the best visual explanation I've seen. I will definitely distribute a reference to this channel wherever I will go.

    • @roncho
      @roncho 11 หลายเดือนก่อน +4

      mr Grant is a genius teacher!!!

    • @ByronMacleod-r9p
      @ByronMacleod-r9p 8 หลายเดือนก่อน +1

      The mathematics for Alfred Hitchcock, cartoon drawing, is about the same as a diamond Anvil.

  • @Necron3145
    @Necron3145 5 ปีที่แล้ว +1975

    that list of immortal mathematicians is imcomplete
    it doesn't have you in it

    • @48956l
      @48956l 5 ปีที่แล้ว +19

      Link one research paper this guy has published..?
      Do you even know his name without looking it up lol

    • @shivakumargujjari
      @shivakumargujjari 5 ปีที่แล้ว +119

      @@48956l so you really thought he genuinely wanted 3b1b's name in it? Really?

    • @48956l
      @48956l 5 ปีที่แล้ว +24

      Shiva Kumar ya and ur name belongs on the immortal dumbasses list

    • @faridmammadov5989
      @faridmammadov5989 5 ปีที่แล้ว +14

      That, I guess, would be an overestimation but I have to admit that he knows what he is doing

    • @anders5611
      @anders5611 5 ปีที่แล้ว +44

      Because he's not a mathematician, he's an educator.

  • @3blue1brown
    @3blue1brown  5 ปีที่แล้ว +287

    To those asking about the software behind these animations, take a look at 3b1b.co/faq
    If you want to play with these animations, I might actually recommend looking at the video by The Coding Train, since the code he shares is probably easier to get started with, and the video itself involves walking directly through his implementation: th-cam.com/video/Mm2eYfj0SgA/w-d-xo.html

    • @gabriellord9214
      @gabriellord9214 5 ปีที่แล้ว +6

      Please could you explain FFT (fast Fourier Transform?) It's used in audio manipulation and so on, which I'm super interested in... I don't know whether this video covers it (only just started watching haha 👍😊)
      Cheers 😊

    • @randomdude9135
      @randomdude9135 5 ปีที่แล้ว

      Thankyou for your contributions and efforts. 😊

    • @gabriellord9214
      @gabriellord9214 5 ปีที่แล้ว +1

      Ahah! ~5:50 makes a whole lot of sense! It's possible to think of sounds as sums of various sine waves! So it all fits! Enjoying the video! Thanks 3B1B 😊

    • @TheCodingTrain
      @TheCodingTrain 5 ปีที่แล้ว +17

      Thanks for the shout out! The video you reference just shows the basic fourier series for a square wave. I also have these three follow-ups which show how to draw a path with epicycles. The demo is here: editor.p5js.org/full/ldBlISrsQ/ Code: editor.p5js.org/codingtrain/sketches/ldBlISrsQ And these three videos show how to write the code!
      thecodingtrain.com/CodingChallenges/130.3-fourier-transform-drawing.html
      thecodingtrain.com/CodingChallenges/130.2-fourier-transform-drawing.html
      thecodingtrain.com/CodingChallenges/130.1-fourier-transform-drawing.html

    • @thefantasicm_2407
      @thefantasicm_2407 5 ปีที่แล้ว

      Your work is awesome man :-)

  • @biubiuty
    @biubiuty 5 ปีที่แล้ว +965

    Your visualization skills alone deserve a Nobel prize :O

  • @Skymaster.47
    @Skymaster.47 ปีที่แล้ว +92

    The global academic ecosystem needs more people like 3Blue1Brown to teach Maths to students.

    • @vmajed7103
      @vmajed7103 10 หลายเดือนก่อน +1

      can't you just say "students" instead of all you wrote at the beginning?

  • @saurabhjoglekar
    @saurabhjoglekar 5 ปีที่แล้ว +380

    Whoever first invents a time machine, please go back in time and show Fourier this video. Absolutely amazing!

    • @dexter2392
      @dexter2392 5 ปีที่แล้ว +33

      Fourier would be proud.

    • @chupetaparabose1
      @chupetaparabose1 5 ปีที่แล้ว +62

      @@dexter2392 Or , he will create the fourires series because of the video

    • @vinayakchaturvedi8006
      @vinayakchaturvedi8006 5 ปีที่แล้ว +38

      @@chupetaparabose1 Maybe he made this series because of this comment :3

    • @FiasaPower
      @FiasaPower 4 ปีที่แล้ว +39

      Imagine how he visualised this inside his head back in 1800s.

    • @VeronicaGorositoMusic
      @VeronicaGorositoMusic 4 ปีที่แล้ว +15

      @@FiasaPower I was wondering the same... What a genius could imagine this?
      Amazing minds.

  • @leeschmalz6365
    @leeschmalz6365 5 ปีที่แล้ว +924

    "Taylor made polynomial" and then not acknowledging the pun, I love it

    • @vinayakchaturvedi8006
      @vinayakchaturvedi8006 5 ปีที่แล้ว +17

      Hahaha I caught it too xD

    • @connorconnor2421
      @connorconnor2421 5 ปีที่แล้ว +15

      3:45

    • @c4stmiranda902
      @c4stmiranda902 4 ปีที่แล้ว +6

      I dont get it. Can you plz explain.:(

    • @Max-bz8ev
      @Max-bz8ev 4 ปีที่แล้ว +41

      @@c4stmiranda902basically, you can express many functions locally as an infinite polynomial or power series called a *Taylor* series.

    • @markenangel1813
      @markenangel1813 4 ปีที่แล้ว +6

      @@c4stmiranda902 he has another video about Taylor series:
      th-cam.com/video/3d6DsjIBzJ4/w-d-xo.html

  • @ErikRyde
    @ErikRyde 3 ปีที่แล้ว +1011

    After watching this for the 1000th time, I finally had the key intuition necessary to code my own Fourier Transform. As a musician, nothing makes me happier than having my own little Fourier transform now. I just want to thank you for these videos, they’ve completely resparked my joy for math.

    • @dracovet777
      @dracovet777 3 ปีที่แล้ว +12

      So you've coded your very own Melodyne?

    • @ErikRyde
      @ErikRyde 3 ปีที่แล้ว +51

      @@dracovet777 Sort of lol. Melodyne is way more intense than my algorithm. Since I wrote this I've managed to optimize it using some linear algebra I just learned, but it's still just a basic fourier transform and not anywhere close to an fft

    • @sidewinded1
      @sidewinded1 3 ปีที่แล้ว +3

      Could you tell me how you coded it? I would love to try!

    • @ErikRyde
      @ErikRyde 3 ปีที่แล้ว +21

      @@sidewinded1 ok so I use python’s numpy library. Long story short I take the inner product of 2 vectors which are representative of the functions you get in the Fourier series. The fancy stuff is making it all compact so I can use it wherever I need to, I basically made that all into a lambda function. I know this isn’t the worlds best explanation but all I’m trying to say is it boils down to how much linear algebra you know.

    • @punkt3260
      @punkt3260 3 ปีที่แล้ว +1

      Nothing makes you happier? No wife?

  • @lynethebat
    @lynethebat 10 วันที่ผ่านมา +1

    i don’t understand a thing about this video but your voice is just so soothing and it makes me want to keep watching

  • @charleshoots4720
    @charleshoots4720 5 ปีที่แล้ว +48

    I'm a seismologist and even I don't understand Fourier theory at this level of ease and intuition. You took one of the most complicated concepts in science and made it so beautiful and intuitive.

  • @nandospm
    @nandospm 5 ปีที่แล้ว +116

    I am an electronic engineer. I took a dozen of courses about Fourier series and transform. I work with spectral analysis on daily basis and this video blew my mind

    • @0xFDFA
      @0xFDFA 3 ปีที่แล้ว +1

      Same here, though I only apply dfft occasionally in my professional life.

  • @krishnapandit8190
    @krishnapandit8190 5 ปีที่แล้ว +91

    Okay. Grant Sanderson is the best math youtuber hands down. It's surreal that you can relate to so many concepts with just the Fourier series.

  • @helmanfrow
    @helmanfrow 2 ปีที่แล้ว +70

    It's amazing to see all these concepts described with animated drawings. I find it even more amazing that generations of people were able to learn and apply the concepts well before the advent of moving pictures. To really internalize these ideas and visualize these things in your mind must be an amazing experience.

  • @alexandre.hsdias
    @alexandre.hsdias 5 ปีที่แล้ว +58

    In all my years at college, I've never seen such a stunning presentation about Fourier series. I can't help but say thank you . This is in a total different level of explanation...

  • @raquibkhaneee
    @raquibkhaneee 4 ปีที่แล้ว +77

    I took courses on signal & system and digital signal processing before TH-cam was founded. I wish I was born later so I could take advantage of the best explainers like you and the best of visual presentations like this. The timings of items you throw on the screen, the sequence, the connections, and the visual ques you use is beyond precision, beyond exact. This is a God-mode representation of Fourier series in terms of rotating circles! Take a bow!

    • @foxphire0093
      @foxphire0093 3 ปีที่แล้ว

      I’m in Signals right now and watching this definitely helps my overall understanding of why things happen as opposed to just accepting it and moving on

  • @maxlopalegz5500
    @maxlopalegz5500 4 ปีที่แล้ว +343

    This video is being recommended to me by my university maths department!
    All the best from Berlin! Awesome work

    • @Jagdpilot
      @Jagdpilot 3 ปีที่แล้ว +18

      Digitalisierung be like

    • @AR-vb4xy
      @AR-vb4xy 3 ปีที่แล้ว

      Wie geht es deutschen Hochschulen?

  • @ducanhdinh8574
    @ducanhdinh8574 2 ปีที่แล้ว +15

    I've never known what even is a "differential equation", and I'm definitely never studying this kind of advanced maths in college. However, this is one of the best youtube series I've ever seen, and this super well-articulated, extremely elegant video has prompted me to express my utmost appreciation for your content, Mr. Sanderson. Truly the best Maths channel in the world.

  • @aforslow
    @aforslow 5 ปีที่แล้ว +219

    I've finished a 5-year degree of applied physics, but I gotta say that I never quite fully understood why the Fourier series works. A big reason for that is that there's so many things to learn that you mostly learn the 'how' instead of the 'why'. It makes for quick gains of knowledge, but it simultaneously makes for quick losses of knowledge, as it really is the 'why' that makes for the building blocks of knowledge in the long run.
    Your channel, and especially this video, masterfully compresses the 'why' into its central components and makes for quick and stable gains of knowledge. In the long run, you will have helped creating a much more efficient, robust and accessible education for everyone. Great job, and keep going!

    • @aforslow
      @aforslow 5 ปีที่แล้ว +5

      conacal rubdur it’s a very broad engineering degree (I should probably have written Engineering physics, as that’s its real name), so you can get into most engineering things (except for chemistry, I guess) if you choose the right specialization (i.e. Master’s degree). I myself am working with software development and machine learning!

    • @aforslow
      @aforslow 5 ปีที่แล้ว +1

      conacal rubdur Yes, it is computer science! I’d say that more and more engineers go into this field nowadays, despite coming from quite different backgrounds in their bachelor’s. As you might realize, my Engineering physics degree was quite different from what I’m working with now. Basically, my first 3 years (i.e. bachelor’s) consisted of lots of heavy maths and physics, which has given me a solid mathematical foundation to understand most research papers I read on AI and other subjects. In your case, I’d say that most engineering degrees give a good mathematical foundation, though (except maybe for chemical engineering; I don’t know how complicated maths needs to be there), so it’s probably more important to choose a bachelor’s that you could feel motivated for, rather than choosing something that could boost your career.
      Anyways, owing to your list of subjects, I’d say that mechanical or aerospace engineering would probably be the best bet! I think bachelor’s = undergrad, so you have to decide on your bachelor’s before you get into college. Don’t worry though; the math you learn in one field is often used in the next (such as fourier series), so choosing one specialization doesn’t mean you can’t change your mind in the future! :)

    • @aforslow
      @aforslow 5 ปีที่แล้ว +1

      conacal rubdur Yeah, I’d go for mechanical engineering in that case, since it’s broader and, who knows, maybe you’ll find something else that’s more interesting there, and then it’s nice to know that your broad education gives you better opportunities to specialize in that if you want!
      I have no idea what the chances of landing the jobs you’re listing are, and I’d definitely say that it depends on where you are. Engineers are pretty popular on the job market though, so finding a job shouldn’t be that hard.
      Regarding the major, I’d say that it also depends on where you are. I’ve heard that in U.S. it’s pretty common to do a bachelor’s work for a while, and then get back to a master’s. Many here hope that the company offers a paid master’s, since doing it on your own very likely costs more than you get back from a future career. In Europe, however, the situation is very different, as we don’t have to pay for each semester. Therefore, we often do a bachelor’s and master’s consecutively, without a break, in order to actually finish our degree. I myself would reason that if I started working after my bachelor’s, I wouldn’t wanna go back to school once I’ve settled into this new lifestyle of getting paid and not having a constant feeling that I have to study. People are of course different, but if you’re in Europe, I’d recommend bachelor’s + master’s in one go, since you then finish everything in one go, and it feels like you continuously improve your lifestyle!

    • @aforslow
      @aforslow 5 ปีที่แล้ว +1

      conacal rubdur well, location matters in the sense that your society works differently than in Europe. For you, it costs a whole lot more for each additional semester you study; whilst in Europe, you don’t have that much to lose to study a couple more years. Regarding your question about applying for jobs all over US, I don’t know what’s best, since I don’t live there and don’t know anything about the costs of travelling or how valuable it is to move for jobs there. If it had been me, though, I would have started out looking for jobs nearby, since it’s simpler!

    • @aforslow
      @aforslow 5 ปีที่แล้ว +1

      conacal rubdur Yes, that sounds good! Those unemployment rates are very low, so you shouldn’t worry about that. Additionally, if I were to worry about unemployment after graduation, I would take into consideration how easy my job is to automate, since that is a trend that will accelerate. For most engineers, though, I’d say they’re pretty safe!

  • @abdulhamidwalidabdulhamid2353
    @abdulhamidwalidabdulhamid2353 3 ปีที่แล้ว +554

    I have an exam tomorrow on Fourier Series and I can tell that no Instructor in my college managed to make me understand it this way.
    Despite the fact that they all have PhDs but its always the way of explanation that matters.
    Your teaching skills are on another level

    • @toxickid2456
      @toxickid2456 3 ปีที่แล้ว +7

      Bruh ok, did i ask?

    • @toxickid2456
      @toxickid2456 3 ปีที่แล้ว +3

      @Santino EGL ik, and urs not

    • @eigenrauflinog9069
      @eigenrauflinog9069 3 ปีที่แล้ว +10

      @@toxickid2456 no one cares what you think

    • @toxickid2456
      @toxickid2456 3 ปีที่แล้ว +3

      @@eigenrauflinog9069 Who asked?

    • @Coolgiy67
      @Coolgiy67 3 ปีที่แล้ว +3

      That’s what I’m saying all their phd’s are literally useless. Most of them suck so much at teaching, theirs this graduate kid who only has his bachelors and he explains stuff better and seems to have a better understanding of the material then our PhD having Profesor

  • @japanlovescali
    @japanlovescali 4 ปีที่แล้ว +59

    I feel privileged to discover this channel even before my college begins

    • @santiagos4290
      @santiagos4290 3 ปีที่แล้ว

      Just luck + time

    • @aravndhanr7241
      @aravndhanr7241 3 ปีที่แล้ว +3

      Yes you are. Make the most of it. Enjoy learning. Very happy for you

  • @jiemin3065
    @jiemin3065 5 ปีที่แล้ว +99

    10:08, a beautifully wordless proof of e^-ix + e^ix = 2 cos(x). Thank you for this!

    • @squibble311
      @squibble311 4 ปีที่แล้ว +3

      i actually didnt think about that, ur a smart guy

    • @alberto3071
      @alberto3071 4 ปีที่แล้ว +2

      If you're interested, you can prove 2isin(x)=e^ix-e^-ix just by looking at the difference vector of the ones shown. It's modulus is 2sin(x) and is vertical thus the vector is 2isin(x).

  • @Qsdd0
    @Qsdd0 5 ปีที่แล้ว +549

    3:45 Fourier-made, not Taylor-made. :P

    • @NightOmegaX
      @NightOmegaX 5 ปีที่แล้ว +50

      I'm a little upset that I got beaten to this

    • @AlienValkyrie
      @AlienValkyrie 5 ปีที่แล้ว +17

      Damn you, I already made that joke on the patreon draft. Don't you go stealing my puns!

    • @lukasmiller8531
      @lukasmiller8531 5 ปีที่แล้ว +6

      I usually hate puns, but this one...

    • @Mayank-mf7xr
      @Mayank-mf7xr 5 ปีที่แล้ว +10

      if you look at it , taylor series is a similar idea of breaking down a function ( must satisfy some conditions first ) to an infinite sum of its derivatives , each amped up a certain amount .

    • @VikeingBlade
      @VikeingBlade 5 ปีที่แล้ว +15

      I thought that was an actual mistake while watching it, then realized tailor-made

  • @josvanderspek1403
    @josvanderspek1403 3 ปีที่แล้ว +56

    I'm taking a masters course on Fourier Analysis right now, and rewatching this video just now shows me that the level of (even technical!) essence he manages to address without introducing new jargon is astonishing. Especially considering how long-winded definitions of things like even Cauchy sequences and limits actually are! Around 9' he's actually talking about _Cesàro convergence,_ for instance, something I never saw in a bachelors course. And yet he doesn't miss it! And _still_ he acknowledges that he swept some things under the rug!
    This is a great man.

  • @skyclaw
    @skyclaw 2 ปีที่แล้ว +66

    I’m sure I’m not the only fully trained mathematician who watches 3B1B purely out of appreciation for his teaching style.

    • @MetapeterUndMetagreta
      @MetapeterUndMetagreta 2 ปีที่แล้ว +4

      Not only the style but this incredible calm and... special voice. If someone would exactly do what he did with a normal or "bad" voice: No one would listen to him/her. (crazy thesis)

    • @jameshakai1662
      @jameshakai1662 ปีที่แล้ว

      ​​@@MetapeterUndMetagreta Personally, I never considered his voice. But what's important to me is his clear and easily understandable speech. TH-cam is filled with videos explaining university level mathematics that I could never listen to for the sheer fact that I can't understand the accent. I really appreciate the effort, but a strong accent immediately makes me click away

  • @renedekker9806
    @renedekker9806 4 ปีที่แล้ว +27

    It is the ultimate high praise to your teaching skills that a video on a complex mathematical subject like this, gets 2.6 million views. Absolutely brilliant.

    • @midouar4859
      @midouar4859 3 ปีที่แล้ว

      10 million views 😅

  • @KianaMaillet
    @KianaMaillet 4 ปีที่แล้ว +12

    Physics student here!! Thank you so much for everything you do, your content is SO valuable to me and many other students, I've even had 2 professors send us your videos for better understanding. You are a blessing!:)

  • @elkalajeer710
    @elkalajeer710 5 ปีที่แล้ว +808

    Guys I think I got it
    Those at the start are circles

    • @vampyricon7026
      @vampyricon7026 5 ปีที่แล้ว +9

      Hugh Dennis answering Picture of the Week on Mock the Week:
      "That's Boris Johnson."

    • @chaossspy6723
      @chaossspy6723 5 ปีที่แล้ว +27

      Actually they are circumferences

    • @drone_better7757
      @drone_better7757 5 ปีที่แล้ว +7

      @@vampyricon7026 Oh, no. I'm not brave enough for politics.

    • @spacejunk2186
      @spacejunk2186 5 ปีที่แล้ว +8

      Whats a circle?

    • @jonperkins4460
      @jonperkins4460 5 ปีที่แล้ว +1

      👏👏👏👏👏👏👏👏👏👏👏

  • @miriammcfarlane6972
    @miriammcfarlane6972 ปีที่แล้ว +5

    You do such a good job of explaining this. It's been nearly 50 years since I learnt this kind of maths, so I'm a bit rusty on some of it, but I still get the general idea and could rewatch it...plus it's so calm and soothing to watch the drawings happen! 😊

  • @halbeard2996
    @halbeard2996 5 ปีที่แล้ว +153

    Every youtube science channel recently: draws these fourier shapes with a couple of arrows on screen
    3Blue1Brown: hold my beer

    • @eunhyoukshin7777
      @eunhyoukshin7777 5 ปีที่แล้ว +14

      When a mathematical genius is also a programming genius:

    • @user-uu1nw1bl9j
      @user-uu1nw1bl9j 5 ปีที่แล้ว +8

      @@eunhyoukshin7777 This dude has a greater mathematical insight than I ever dream to have, but even though I don't know what he does outside these videos, to call someone a genius for explaining subjects you already encounter in your first year of studying physics or mathematics is a little bit too much.

  • @veljko100able
    @veljko100able 5 ปีที่แล้ว +159

    Please make video about Laplace transform and (or) Z transform, I am sure there a lot of others confused by that topic. And I haven't seen better person to explain it to us

    • @Schattengewaechs99
      @Schattengewaechs99 5 ปีที่แล้ว

      Yes, that would be a very interesting topic!

    • @thomas.02
      @thomas.02 5 ปีที่แล้ว +11

      i believe he mentioned in an earlier video that he will explain them in a later video of this series

    • @diarya5573
      @diarya5573 5 ปีที่แล้ว

      Yes! I have so much trouble visualising those

    • @veljko100able
      @veljko100able 5 ปีที่แล้ว +3

      @@thomas.02 oh that's nice, I am looking forward to it!

    • @porschepanamera92
      @porschepanamera92 5 ปีที่แล้ว +1

      Laplace transforms are for example beautifully used in structural dynamics. It would be nice to see something like that visualised indeed. Not an easy topic to study from text books only lol

  • @DonArmadillo
    @DonArmadillo 5 ปีที่แล้ว +187

    3b1b Has allowed me to find beauty (and even a little love for maths) a subject I previously (and kind of still hate/dislike). I've went from barely passing to acing my college math exams, much thanks to the conceptually and visually (yet incredibly accurate) descriptions Grant has given. The overview stipped of the detailed theoretical information is priceless. So much respect to you! Please join his patreon!

    • @denelson83
      @denelson83 5 ปีที่แล้ว +20

      I'd say he Grant-ed you the insight you needed.

    • @sadkritx6200
      @sadkritx6200 3 ปีที่แล้ว +4

      @@denelson83 Who Grant-ed you the permission to make such puns?

    • @GammaFZ
      @GammaFZ 3 ปีที่แล้ว +4

      @@sadkritx6200 joe

    • @ishworshrestha3559
      @ishworshrestha3559 3 ปีที่แล้ว

      Kk

    • @GammaFZ
      @GammaFZ 3 ปีที่แล้ว +1

      @Aaditya Sabharwal you know

  • @ivoryas1696
    @ivoryas1696 6 หลายเดือนก่อน +2

    0:40
    Honestly... it's one of those things that I wasn't sure I'd _ever_ be able to *_truly_* wrap my head around... Like not only _integer_ but *_constant,_* and yet they interfere with eachother in sufficient volume to mess with the image?
    But honestly thinking about it, it's a rather sensible logical conclusion of a tool so powerful... regardless of how non-obvious it is...

  • @0xFDFA
    @0xFDFA 3 ปีที่แล้ว +135

    I'm an electronic engineer amoung other degrees, and I've mastered the math back in the day and used dfft on quite a few occasions proffesionally but this was a wonder to watch and made me look at it from a new fresh angle. This video should be part of every curiculum that includes fourier transform. The part about how the Fourier got the idea in the first place was especially worthwhile for me. Thank you

    • @JohnRobenault
      @JohnRobenault 2 ปีที่แล้ว +5

      Exactly. It's like I've been doing the math blindly, but this gives me an opportunity to actually see what I've been doing.

    • @absoultethings4213
      @absoultethings4213 2 ปีที่แล้ว

      Uii

  • @ammyvl1
    @ammyvl1 4 ปีที่แล้ว +86

    4:19 the people are (in order) Pythagoras, Euclid, Archimedes, Fermat, Newton, Leibniz, Bernoulli(?), Euler, Fourier, Gauss, Riemann, Cantor(?), Noether(?), Ramanujan,
    Gödel, Turing.
    Just for reference, I put a ? besides the ones that may be wrong.

    • @hwg5039
      @hwg5039 4 ปีที่แล้ว +18

      No Taylor, Lagrange, Descartes and Pascal? Damn...

    • @dimitrisdimitriadis4913
      @dimitrisdimitriadis4913 3 ปีที่แล้ว +3

      Shamefully missing Thales among the immortals as well. Video dropped from 10/10 to a 9.5/10 just for that.

    • @MarioMicheli
      @MarioMicheli 3 ปีที่แล้ว +1

      Yes, that is Emmy Noether

    • @GammaFZ
      @GammaFZ 3 ปีที่แล้ว +6

      I thought that fat dude was JS Bach

    • @ishworshrestha3559
      @ishworshrestha3559 3 ปีที่แล้ว +2

      Ok

  • @Mayank-mf7xr
    @Mayank-mf7xr 5 ปีที่แล้ว +73

    i earlier told how your essence series are in sync with my courses in college ...
    i studied calculus in 1st sem ... just as your series rolled in .
    i studied linear algebra in 2nd one ... longside your your series on it .
    i have to study differential equation for 3rd sem and guess what ... you put out what i exactly need .
    my core course contains ' fourier series and special function ( gamma , bessel and so on )' and you just bring this gem .
    i am so lucky .

    • @Abdega
      @Abdega 5 ปีที่แล้ว

      Wish I was, I always just miss them :/

  • @AbsAnubis
    @AbsAnubis ปีที่แล้ว +1

    Awesome content

  • @dancingbubbles1126
    @dancingbubbles1126 5 ปีที่แล้ว +7

    The calmness of your voice, the music in the background, and the fluidity of the animation make watching this really soothing. It's also beautiful.

  • @trevorjohn3632
    @trevorjohn3632 5 ปีที่แล้ว +7

    I have been using Fourier analysis in my work for over 50 years and I was taught the old way in terms of transforms between frequency and time domains. I guess I understand the principles, techniques and math really well, or at least I thought I did until I saw this. This visualisation is truly mind blowing. What a fantastic video and all done in less than half an hour!

  • @shivamsoni5894
    @shivamsoni5894 5 ปีที่แล้ว +40

    You make me love math.After watching one video I go out to relate everything in nature and i almost never fail to find a relation . Math to me now feel like a suject of great wisdom and it is more of a skill when practised for enough times can improve your understanding in it thank you man !

  • @SketchMonkey-hy8jl
    @SketchMonkey-hy8jl หลายเดือนก่อน

    I can't thank you enough for making this video. I might have watched it a hundred times before I could make sense of the maths behind this beautiful art but when you do understand it, it's so rewarding. People like you willing to teach is why internet still healthy.

  • @volvocineseries5839
    @volvocineseries5839 5 ปีที่แล้ว +409

    "ah shit, here we go again"
    -me about to spend the next indefinite amount of time pondering maths

    • @saeidakbari4788
      @saeidakbari4788 5 ปีที่แล้ว +4

      LOL That's me exactly! :D

    • @PauloConstantino167
      @PauloConstantino167 5 ปีที่แล้ว +1

      wow. congrats on your world changing comment

    • @nolan412
      @nolan412 5 ปีที่แล้ว +3

      Begins grinding gears.

    • @planktonfun1
      @planktonfun1 5 ปีที่แล้ว

      there goes sleeping

  • @PaulPaulPaulson
    @PaulPaulPaulson 5 ปีที่แล้ว +74

    4:19 Which one of them is you?

    • @manioq1447
      @manioq1447 3 ปีที่แล้ว

      He didnt *INVENT* (at least i think) anything!

  • @vanster
    @vanster 4 ปีที่แล้ว +34

    I rarely write comments on TH-cam, but right now I am so overwhelmed by your visualization and explanation that I cannot remain silent. I think you are a genius at explaining things like this. Thank you very much for what you are doing.

  • @rahevar3626
    @rahevar3626 3 หลายเดือนก่อน +1

    I was in 8th grade when this video came out. over the years I would stumble upon this video and watch and understand it as much as I could up to the point I would understand the math(because I wasn't even aware of some of the topics existing) and end the video there. Now after 5 years, I can proudly say that I have completed the full video fully understanding it, and also making a program similar to what is shown in the video. Thank you for sharing such amazing knowledge with us.

  • @SabinCivil
    @SabinCivil 5 ปีที่แล้ว +3240

    What an amazing explanation, this video deserves 10 million views!

    • @pardeepgarg2640
      @pardeepgarg2640 4 ปีที่แล้ว +90

      Not 10 million but 20 million

    • @epicmoofish3726
      @epicmoofish3726 4 ปีที่แล้ว +87

      Aight, hold on lemme watch 6.5 million times

    • @VineFynn
      @VineFynn 4 ปีที่แล้ว +5

      Does everyone really need to know what a fourier series is

    • @Shoya_Ishida_69
      @Shoya_Ishida_69 4 ปีที่แล้ว +7

      No , it deserves 10000000000000 Trillion views and 10000000000000000000000000000000Trillion subscribers

    • @Sciencedoneright
      @Sciencedoneright 4 ปีที่แล้ว +5

      @@jerryboy9652 even more... 10000 BILLION VIEWS

  • @Mau365PP
    @Mau365PP 5 ปีที่แล้ว +42

    Explanations like this 20:09 are the reason I love this channel

    • @benjaminglass2694
      @benjaminglass2694 5 ปีที่แล้ว +9

      My jaw dropped when I got there. I've been looking for a way to understand that concept for years.

    • @eunhyoukshin7777
      @eunhyoukshin7777 5 ปีที่แล้ว +4

      Yeah its much better than just stating orthogonality of sinusoidals

    • @janv.8538
      @janv.8538 5 ปีที่แล้ว

      True

    • @Mayyouknow
      @Mayyouknow 5 ปีที่แล้ว

      same here!

  • @sergiucimpoi8497
    @sergiucimpoi8497 3 ปีที่แล้ว +25

    The first time I visited this channel, I was: "How on Earth did he make 3.5mil followers?"
    Now: "How on Earth does he only have 3.5mil followers?"
    I guess, even for a non math head, this would be a pleasure to watch.
    Keep them flowing!

    • @sethdon1100
      @sethdon1100 2 ปีที่แล้ว

      He now have more subscribers (followers) than Numberphile.

  • @antoniojpan
    @antoniojpan ปีที่แล้ว +4

    The work and genius that goes into making this video make it a true piece of art.

  • @randomdude9135
    @randomdude9135 5 ปีที่แล้ว +1596

    That moment when Rotating vectors draw better than you 😑

    • @shizotypical
      @shizotypical 5 ปีที่แล้ว +63

      Such is the power of math

    • @kenzostaelens1688
      @kenzostaelens1688 5 ปีที่แล้ว +12

      i feel your pain

    • @halbeard2996
      @halbeard2996 5 ปีที่แล้ว +130

      Maybe you're not rotating enough when drawing something

    • @DarthZackTheFirstI
      @DarthZackTheFirstI 5 ปีที่แล้ว +29

      thats not true. he used svg data which was taken from a picture drawn before. he just followed the tracks. so the artist was first and then the program ;P

    • @ariat3381
      @ariat3381 5 ปีที่แล้ว +58

      @@DarthZackTheFirstI you killed this poor little joke, how dare you!

  • @johncao6516
    @johncao6516 5 ปีที่แล้ว +230

    0:25 That's the Nail and Gear of HELLO INTERNET!

    • @changyang1230
      @changyang1230 5 ปีที่แล้ว +23

      I was pleasantly surprised when I saw it too! Great Easter egg!

    • @changyang1230
      @changyang1230 5 ปีที่แล้ว +36

      And hello Tims!

    • @coryman125
      @coryman125 5 ปีที่แล้ว +38

      Probably my favourite thing about "this side of TH-cam" is how often people will reference each other's channels in odd ways like this. Came looking for a comment about it as soon as I saw it :P

    • @doktorcool3740
      @doktorcool3740 5 ปีที่แล้ว +6

      Yes - this Tim noticed it too and was delighted! :-)

    • @greghmn
      @greghmn 5 ปีที่แล้ว +10

      Crazy how we can sometimes detect symbolic styles subconsciously. I wasn’t sure what that logo was at first, thinking it was either for CGP Grey or one of Brady’s channels. Guess I was right on both. Maybe the gear was a giveaway.

  • @ethancooper4154
    @ethancooper4154 5 ปีที่แล้ว +20

    This is actually the greatest channel on TH-cam

  • @williamdeng5966
    @williamdeng5966 3 ปีที่แล้ว +29

    This is sick! As usual, painfully clear explanations, and the exercises at the end really helped me to solidify my understanding and to get a feel for the beauty of Fourier series! I couldn't even believe I was actually expressing a discontinuous step function as an infinite sum of trig functions! Thanks for all your hard work Grant, and I'm looking forward to the lecture on the Laplace transform!

  • @翔_shaun
    @翔_shaun 3 ปีที่แล้ว +18

    Just want to say you have no idea how inspiring and influential you are to every person that is interested math. Definitely not being the only one, I am greatly delighted, encouraged, and motivated by you on the journal of learning math. Thank you for your contribution, thank you, thank you, thank you.

  • @leopoldsimmons4804
    @leopoldsimmons4804 5 ปีที่แล้ว +996

    friend: how well can you draw?
    me: how many arrows you got?
    friend has left the chat

    • @zionj104
      @zionj104 5 ปีที่แล้ว +1

      100th like

    • @thawng9346
      @thawng9346 4 ปีที่แล้ว +1

      jemma??

    • @NovaWarrior77
      @NovaWarrior77 4 ปีที่แล้ว +3

      Thi is why you and I have no friends. 😢

    • @felixalexander8986
      @felixalexander8986 4 ปีที่แล้ว

      lol

    • @evariste1686
      @evariste1686 4 ปีที่แล้ว

      beautiful! But how do you add colour and shade to the last arrow? In that sense the arrows don't draw as the points are invisible until....

  • @jezza10181
    @jezza10181 11 หลายเดือนก่อน +5

    Your explanations beat anything by any other content creators... You are literally god level.

  • @satishreddy3668
    @satishreddy3668 3 ปีที่แล้ว +1

    Thanks!

  • @breezyashell
    @breezyashell 5 ปีที่แล้ว +79

    being a visual learner I never really understood Fourier series. This is amazingly helpful!

    • @steve-o6413
      @steve-o6413 5 ปีที่แล้ว +2

      Your not alone...

    • @Cuasimodo2372
      @Cuasimodo2372 5 ปีที่แล้ว +2

      Everybody is a visual learner, you just gotta think hard to visualize what formulas mean

    • @steve-o6413
      @steve-o6413 5 ปีที่แล้ว

      Abstract thinkers (3D) use more visual than Straight thinkers (2D)...

    • @Carofdoom1126
      @Carofdoom1126 5 ปีที่แล้ว +2

      Seriously 3B1B had reached math education immortality

    • @steve-o6413
      @steve-o6413 5 ปีที่แล้ว

      Taking 2D Concepts and turning them into 3D Concepts is what this Video is about at least in my mind. Left Brain Right Brain...

  • @FerroNeoBoron
    @FerroNeoBoron 5 ปีที่แล้ว +100

    You were expecting trigonometric functions but it was I, complex exponential!

    • @randomaccessfemale
      @randomaccessfemale 5 ปีที่แล้ว +8

      Euler's equation is just so fundamentally beautiful. It is superior.

    • @alexeie.6187
      @alexeie.6187 5 ปีที่แล้ว +1

      @@randomaccessfemale superior to what?

    • @vinaytanwar7840
      @vinaytanwar7840 4 ปีที่แล้ว

      *Evil sound plays in background*

    • @xtdycxtfuv9353
      @xtdycxtfuv9353 4 ปีที่แล้ว +6

      trigonometric functions’ bizarre adventure

    • @johnjackson9767
      @johnjackson9767 4 ปีที่แล้ว

      Twas i!

  • @aaron41
    @aaron41 5 ปีที่แล้ว +23

    Fourier and Laplace were basically the only two things I got out of higher level calc. I love your animiations by the way!

    • @MubashirullahD
      @MubashirullahD 5 ปีที่แล้ว

      I studied them but don't remember anything :(

  • @midasredblade236
    @midasredblade236 2 ปีที่แล้ว +1

    third year of University, i had to study this and MY GOD the book (combined with my course teachers *nonexistent* teaching skill) made me feel like i was reading hieroglyphs...... *thank* *you* *Grant* *Sanderson* thanks a million...no thanks a billion for making this so easy to understand

  • @spider_plantt
    @spider_plantt 4 ปีที่แล้ว +4

    this is an amazing video! i'm an engineering intern working with magnetic excitation loops and this explains fourier series so neatly! absolutely amazing visuals and a great explanation for a difficult topic to cover--well done!

  • @csag7803
    @csag7803 4 ปีที่แล้ว +5

    You make the most beautifully constructed and animated video's I have ever seen on youtube. Thank you for this blessing! Much love from the Netherlands. :)

  • @Shougun2007
    @Shougun2007 5 ปีที่แล้ว +12

    I have no idea what any of this means. But it's so beautifully explained and satisfying to watch, that I can't.... stop.... watching

  • @because-strudels
    @because-strudels ปีที่แล้ว +2

    What an elegant and clear explanation. And the effectiveness of your visuals CANNOT be understated! Fantastic video

  • @GaleAnders
    @GaleAnders 5 ปีที่แล้ว +5

    I LOVE THIS !!!
    My brain has never felt more alive.
    Don't ask me to repeat it all, but the way you explain this actually enabled me to stop the video here and there, and (sort of) predict what you were going to say next.
    I WANT MOOOOORE !!!

  • @baskirmani
    @baskirmani 4 ปีที่แล้ว +17

    This was breathtaking.
    I have been becoming hopeless about the world, but now I'm going to see myself as a tiny sine wave contribution to a universal pattern so complex, I'll never see it. And yet: my tiny little contribution matters to the whole.
    This video might just have brought order and hope to my life.
    Thank you.

  • @justcarcrazy
    @justcarcrazy 5 ปีที่แล้ว +136

    3:45 Taylor-made? I thought we were discussing the Fourier-series?

    • @each1teach1
      @each1teach1 5 ปีที่แล้ว +5

      cheeky. very cheeky.

    • @trevormurray8817
      @trevormurray8817 5 ปีที่แล้ว +3

      Nice.

    • @rtravkin
      @rtravkin 4 ปีที่แล้ว +3

      take a complex Taylor series, and restrict it to the unit circle--and you get a Fourier series (with only "positive" modes-counterclockwise rotation).

  • @gabemathews1216
    @gabemathews1216 3 ปีที่แล้ว +2

    You are seriously the missing link in my education. The way you explain mathematical concepts is unmatched and it gives me so much more perspective and appreciation for whatever I'm studying at the time. Thank you!

  • @mariannanezhurina7399
    @mariannanezhurina7399 5 ปีที่แล้ว +16

    “Pure mathematics is, in its way, the poetry of logical ideas.”
    Albert Einstein

  • @edwinwing4567
    @edwinwing4567 3 ปีที่แล้ว +13

    I truly enjoyed seeing this generalization. It had never dawned on me to use a 2-d curve as input to the DFT. Way to go.

  • @JonTingvold
    @JonTingvold 5 ปีที่แล้ว +24

    18:56: "The trick is to first multiply f(t) by something that makes that vector hold still-sort of the mathematical equivalent of giving a smartphone to an overactive child."

    • @derdimi927
      @derdimi927 4 ปีที่แล้ว +1

      This one just completely killed me xD

  • @PBlague
    @PBlague 3 ปีที่แล้ว +1

    I watched this a few months back and although it was really cool I didn't understand enough... but now that I see how it is working and you were able to bring that image into the circle initial constants it was just soooooo satisfying... I've been watching your content for so long and you amaze me every time, keep on doing what you're doing.

  • @DeadalusX
    @DeadalusX 5 ปีที่แล้ว +172

    me in the beginning of video: "Time to get smarter!"
    me halfway through: "Oh look the circles! it draws da picture! :O"

  • @PitiNasri
    @PitiNasri 5 ปีที่แล้ว +7

    I love how after he explains a concept, i think "Ah, i already heard about that but i can see why i never saw an illustration of the phenomenon: it's so complex !" and then he just proceed to brute-force an complex animation that explain efficiently what the idea is about.

  • @shubhamsehgal2336
    @shubhamsehgal2336 4 ปีที่แล้ว +26

    I am a young web developer with poor mathematical skills but I always got fascinated how those .svg files actually draw figures. Although I don't understand anything but seeing arrows moving in circular motion creating a pictures got me goosebumps.
    Knowledge is power🙏

  • @熊ちゃん-h7t
    @熊ちゃん-h7t 3 ปีที่แล้ว +4

    As a high school student who hasn’t (officially) taken vector calculus yet, this explanation of Fourier series was incredibly well done for someone like me to understand it. The whole series about differential equations has been an adventure opening doors unknown to me in the realm of mathematics, and I’m excited to see what else is out there!

    • @EliteCubingAlliance
      @EliteCubingAlliance 2 ปีที่แล้ว +3

      I am also a high school student! I just finished my freshman year but I understand this as well. I am actually going to college for calculus next year, but I actually have already studied it. My introduction to calculus was 2 years ago and I learned it through this youtube channel! I am very happy now that I am more advanced that I have that basic intuition of the math so that whenever I do calculus 1 next year, I won't be confused. When I am an adult, I am definitely going to support this guy because his way of teaching is incredible!

  • @bhargavjoshi275
    @bhargavjoshi275 3 ปีที่แล้ว +5

    I just cannot appreciate enough how good the animations are in these videos! MASSIVE respect!!

  • @trymbruset3868
    @trymbruset3868 5 ปีที่แล้ว +5

    Brilliant video! I was never taught why multiplying by the exponential factor inside the integral was done, and where the reasoning for doing so comes from, but seeing it represented in this way makes it completely intuitive! Wonderful explanation

    • @MM3Soapgoblin
      @MM3Soapgoblin 5 ปีที่แล้ว

      It's a basic principle of orthogonal functions, although he made an interesting visualization of it here. You were never taught that with Fourier series? Was that in undergrad or graduate?

    • @trymbruset3868
      @trymbruset3868 5 ปีที่แล้ว

      @@MM3Soapgoblin Well we were exposed to it very briefly in Calc II or III, and then again in real analysis, but it was never really emphasized or used in any way after being introduced, so I just noted that it was a thing, sort of like a change of variables deal. This was during undergrad, and I never once encountered it in a graduate course, though to be fair I was studying the more theoretical side of things, focusing on topology, measure theory, algebra and mathematical logic.

    • @MM3Soapgoblin
      @MM3Soapgoblin 5 ปีที่แล้ว

      @@trymbruset3868 Huh, interesting. We spent a whole week on orthogonality to setup up the foundation for Fourier (and other) series expansions. It was the first week of our first class in the graduate physics program at UCCS.

  • @mankritsingh4058
    @mankritsingh4058 2 หลายเดือนก่อน

    I was cramming hard to get my brain to recall this stuff, and thankfully found your video again.
    This is so beautiful and intuitive that everything instantly clicked! Ever grateful for your videos

  • @shambosaha9727
    @shambosaha9727 5 ปีที่แล้ว +39

    You now have a Taylor-made solution... you had me

  • @23chenriheng46
    @23chenriheng46 5 ปีที่แล้ว +49

    "by using the power of the spin, one can unlock many more possibilities than previously thought possible" -gyro zeppeli

    • @iantaakalla8180
      @iantaakalla8180 4 ปีที่แล้ว +4

      The Spin can draw, but only if it manipulates enough vectors. Thus the stand “Ball Breaker 3 Leaves” or “Tusk Act 3: Leaves” would be able to draw with great precision.
      Perhaps if I was being original, I guess the stand would be “Photograph” since it can accurately copy drawings like a photograph copies real life by reflections.

    • @yash1152
      @yash1152 3 ปีที่แล้ว

      timestamps?

    • @GammaFZ
      @GammaFZ 3 ปีที่แล้ว +6

      did not expect a jojo reference in a civilised clean place like this

    • @Jamie31166
      @Jamie31166 3 ปีที่แล้ว

      @@iantaakalla8180 IS THAT A FUCKING JOJO REFERENCE?!?!

  • @drorfrid
    @drorfrid 5 ปีที่แล้ว +25

    4:15 List of Immortals:
    Pythagoras - Euclid - Archimedes - Fermat
    Newton - Leibniz - Bernoulli - Euler
    Fourier - Gauss - Riemann - Cantor
    Noether - Ramanujan - Gödel - Turing
    Corrections (My Opinion):
    Pythagoras does deserve to be on the list, but not only for his theorem. Although historically ambiguous, he still did other discoveries other than his theorem, like the theory of proportions.
    Archimedes is... mainly a physicist. He did contribute to math, but not enough to be in the "Immortals of mathematics"
    Newton and Leibniz deserve to be glued together so they're both half in. Newton is a genius, but Physicist.
    Euler deserves to be there twice.

    Ramanujan is Ambiguous. He is my favorite mathematician, but he didn't really contribute much. but he is definitely worth mentioning.
    Turing is like Archimedes, not deserving to be on this list because he did something else.
    forgot - Galois, Hilbert, Lagrange
    possibly forgot - Jacobi, Erdős, Poincaré, Descartes, Cauchy, Weierstrass

    • @drorfrid
      @drorfrid 5 ปีที่แล้ว

      @@sasmitvaidya I'm jewish and I know you are too, but I'm still afraid when a german becomes angry at me

    • @Gunth0r
      @Gunth0r 5 ปีที่แล้ว +2

      Klein, Poisson, Gauss

    • @HamzaFouads
      @HamzaFouads 5 ปีที่แล้ว

      Maxwell, Friedrich Bessel, Laplace, Gauss, Kant

    • @khwajawisal1220
      @khwajawisal1220 5 ปีที่แล้ว

      you mentioned Poincare so why not jorge Perelman the guy who has solved 1 out of the 7 million dollar prize questions, he gave the proof that Poincare conjecture holds true in any dimensions.

    • @amolinas194
      @amolinas194 5 ปีที่แล้ว +1

      Laplace?
      He is like everywhere

  • @bowtangey6830
    @bowtangey6830 2 ปีที่แล้ว +6

    If I remember the history correctly, the Fourier series idea was first suggested by Daniel Bernoulli (son of Johann and nephew of Jakob. Euler's father and Johann had both roomed in Jakob's house in Basel when the father and Johann were both students at the University of Basel when Jakob taught. -- Daniel is the Bernoulli of "Bernoulli's Principle" in fluid flow). He was studying it in connection with not the Heat Equation, but the Wave Equation as a model for a plucked string (like a guitar string). He proposed in a letter to Euler that any realistic initial configuration could be written as a sum of sine waves. Euler replied both showing how the coefficients of the sine terms could be calculated, but also criticizing the concept. He noted that a simple initial configuration would be pulling the string out at the middle, giving the string (endpoints fixed) a v-shape. That shape is not differentiable at the vertex, but all sine functions used in the proposed sum are differentiable everywhere. So, he stated, the idea could not work in the generality that Daniel suggested. The idea was out. When Fourier first presented his results in a paper of heat propagation to a Paris committee in 1807, the paper was rejected. On of the committee members, Joseph Lagrange (a protégé of the now-dead Euler) specifically criticized the notion that any function could be represented by Fourier's trigonometric series.

    • @bilkishchowdhury8318
      @bilkishchowdhury8318 5 หลายเดือนก่อน

      Dividing complex motion into simpler harmonies is an idea as old as time

  • @ranadeep7462
    @ranadeep7462 5 ปีที่แล้ว +4

    Amazing explanation. It made Fourier series way more interesting than the ones in books

  • @akshaysriram8559
    @akshaysriram8559 3 ปีที่แล้ว +18

    Can we take the time to think of other math videos in general overall : their content, explaination, and surprisingly most importantly -their video effects and animations on their content.....
    I mean 3b1b takes that to a different level. With his beautiful and precise animations he helps you dive deep into whatever he explains and it's really satisfying
    You should really be recognised for that .

  • @OrigamiPie
    @OrigamiPie 5 ปีที่แล้ว +27

    0:32 Where's all the love for the mighty Nail and Gear?

    • @andycheng4436
      @andycheng4436 5 ปีที่แล้ว +1

      OrigamiPie Flaggy Flag

    • @Vionalli
      @Vionalli 4 ปีที่แล้ว +4

      The mighty Nail and Gear has flown in space, and now in 3Blue1Brown...

  • @evannall9786
    @evannall9786 2 ปีที่แล้ว +1

    I googled one question for my geometry homework and I've been getting recommended this

  • @jordanhildebrandt3705
    @jordanhildebrandt3705 5 ปีที่แล้ว +4

    Brilliant work! Your knowledge of the subject is amazing, your teaching ability is phenomenal, and I can't even figure out HOW you made the visuals on this video. Good show!!

    • @rigille
      @rigille 5 ปีที่แล้ว +1

      He wrote a program called "manim", it's on GitHub ^^

  • @LetniTaboryTJSokolMartineves
    @LetniTaboryTJSokolMartineves 4 ปีที่แล้ว +5

    I have been teaching FT in this way for years, and I must say that - based on everything I know - this is the most accessible way for students to really *understand* it.