The sum of all counting numbers equals WHAT?

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  • Опубліковано 15 лип 2014
  • This is the second half of a lesson, watch the first half here: • Grandi's Series: 1-1+1...
    This is a well-known and hugely controversial result. The "proof" I've demonstrated is not the only way to show it - there are far more sophisticated and convincing ways to do it - but suffice to say that I went through it to raise questions and provoke thought rather than to make a statement about its validity or otherwise! Hope it makes you think.

КОМЕНТАРІ • 4,7 тис.

  • @Majestic469
    @Majestic469 6 років тому +8625

    so basically if someone wanted to give you $1 today, $2 tomorrow, and so on, you shouldn't accept the deal because they would be trying to steal from you.

    • @MrPacoHamers
      @MrPacoHamers 4 роки тому +1054

      That would only be the case if he lives infinitely long and never runs out of money. I would risk that 1/12 dollar on the bet that he wont.

    • @Nathan-tg4gu
      @Nathan-tg4gu 4 роки тому +168

      @@MrPacoHamers Well no, because the value of an infinite stream of cash flows isn't adjusted based on the lifespan of the recipient, as the cash flows can be sold to another party at any point in time.
      That's why the theory of a the price of a stock being equal to the present value of all its future cash flows is rooted in infinite time, not a human lifespan: you can SELL the stock at any time for immediate cash.

    • @zichaozhou1916
      @zichaozhou1916 4 роки тому +74

      happy to be stolen,try hard on me

    • @dangraja5990
      @dangraja5990 4 роки тому +8

      bruh

    • @andywright8803
      @andywright8803 4 роки тому +53

      No. This sum only works in the case where the sum is infinite, meaning it never stops and therefore can never be evaluated.

  • @JoaoRenatoBail
    @JoaoRenatoBail 4 роки тому +6776

    The best part about this videos is my father thinks i'm studying

  • @kevinleugan6037
    @kevinleugan6037 2 роки тому +1090

    Math: Am I joke to you?
    Mathematicians: Yes. An infinite sum of jokes, even.

    • @legend-mayank3078
      @legend-mayank3078 2 роки тому +6

      Ramanujan

    • @Skrimshady
      @Skrimshady 2 роки тому +8

      Odd

    • @seanwilkinson7431
      @seanwilkinson7431 2 роки тому +24

      An infinite sum of jokes is 1/12 of not a joke.

    • @scottwarren4998
      @scottwarren4998 2 роки тому +3

      I know why Eddie cant solve it like Eddie is trying to solve it. And heres WHY: Infinity-1 does NOT equal infinity.
      Hilbert himself said: some infinities are bigger than other infinities.

    • @scottwarren4998
      @scottwarren4998 2 роки тому

      @@WhiteStripesStripiestFan I know why u cant solve it like you are trying to solve it. And heres WHY: 1 minus series-g does not equal 1/2, it equals to infinity. 2 times series-alfa does not equal 1/4, it equals to infinity. Series minus series-alfa does not equal -1/12, it equals to infinity.
      Don't ask me why, u, I dont know yet.

  • @IceMetalPunk
    @IceMetalPunk 3 роки тому +1443

    "It could be wrong, that's fine. Mathematicians are wrong all the time, that's why they're discovering cool new stuff." And this is what makes a great teacher! None of that "you have to be right or you're failing and it's your fault" nonsense we often see (bad) teachers and educational systems do, which only discourages people from wanting to learn more and learn from their mistakes.

    • @eXJonSnow
      @eXJonSnow 2 роки тому +29

      People are wrong all the time because they are just wrong, though, like in this video. Setting the sum of a divergent series to a discrete number is flat out wrong in mathematics. Being wrong doesn't always mean you're on the path to discovering something new.

    • @Leviathan-gp2kv
      @Leviathan-gp2kv 2 роки тому +21

      @@eXJonSnow that's not the point though, it's about trying and proofing you're either right or wrong. That's how you learn and improve yourself. That's why it's allright to be wrong and how you discover cool new things

    • @KamuiAlmighty
      @KamuiAlmighty 2 роки тому +13

      @@Leviathan-gp2kv The guy's a college professor. If you get the answers wrong on his exam, you're going to fail the course. Period. You can be wrong while learning, but when it comes time to apply what you learned, it better be spot-on.
      Encouraging learning and encouraging mediocrity are two very different things.

    • @Leviathan-gp2kv
      @Leviathan-gp2kv 2 роки тому +4

      @@KamuiAlmighty I don't necessarily mean in class. BTW is this college level math!!!??? But I mean even scientists makes mistakes without the mistakes you never come to a breakthrough. No one has is exactly right the first time

    • @scottwarren4998
      @scottwarren4998 2 роки тому

      I have a theory as to why you cant solve it like you are trying to solve it. And heres WHY: 1 minus series-g does not equal 1/2, it equals to infinity. 2 times series-alfa does not equal 1/4, it equals to infinity. Series minus series-alfa does not equal -1/12, it equals to infinity.
      Don't ask me why, u, I dont know yet.

  • @SpecificCorn735
    @SpecificCorn735 4 роки тому +2686

    Anyone gonna talk about the fact that he is writing on a whiteboard that is on a whiteboard ?

    • @asnowowi2497
      @asnowowi2497 3 роки тому +118

      nah, he does it with style so its fine

    • @17smadonna20
      @17smadonna20 3 роки тому +31

      i had a board like that in my class, the whiteboard was on a huge blackboard n it made no sense to me XD

    • @MrAlRats
      @MrAlRats 3 роки тому +139

      He accidentally damaged 1/12th of a whiteboard that belonged to his colleague. He apologised to his colleague and offered to replace the damaged part. His colleague said they will deliver one whiteboard to him on day one, then two whiteboards the next day, three whiteboards the day after and so on. Here we are on day two.

    • @diasteroid
      @diasteroid 3 роки тому +6

      #AustraliaMoment

    • @zanzoun1321
      @zanzoun1321 3 роки тому

      Yeah really 😂😂

  • @quartetoPP
    @quartetoPP 5 років тому +4953

    If you answer that in a calculus II test, your mark will converge to zero.

  • @HNCS2006
    @HNCS2006 3 роки тому +326

    As an English and Maths teacher, I have a big passion for teaching the history of Maths. I always try to humanise mathematics by telling my students the stories of the people behind these theories and results. I feel it makes things more connected for students. Ramanujan's story is a story worth telling. The film "The man who knew infinity" is also a great film for exploring two modes of getting to mathematical results, inspiration or proof.

    • @Onoesmahpie
      @Onoesmahpie 2 роки тому +8

      This has absolutely nothing to do with Ramanujan summation. Woo simply demonstrated that permuting the summands of a divergent series can change the behavior of the series.

    • @quantumgaming9180
      @quantumgaming9180 2 роки тому +2

      I love the same thing (History of Maths)! I am a still a student and until I came upon the stories or the history of the people before us who discovered the things that we are studying today and how they approached them or how they failed and later people throught the time had other points of view of these problems and solved made me love mathematics even more than I used to. I really do believe that to understand and be able to solve a math problem ( famous hard problems especially) a bit of history of how the people before us tried to tackle these and their ideas is really useful.

    • @PurEvil10
      @PurEvil10 2 роки тому +8

      @@Onoesmahpie wtf he literally invented the series. Moreover, his mathematics inventions are what used to study the behaviour of black holes nowadays

    • @babelbabel2419
      @babelbabel2419 Рік тому +6

      @@Onoesmahpie For all your arrogance, you're dead wrong. Changing the order of the terms of a divergent series does not make it convergent using ordinary addition, because it's commutative. The super summation must be used to assign a result to a divergent series. What's shown in the video is a classic Ramanujan super summation.
      Btw, the proof shown in the video is just a trick (used by Ramanujan himself and still excellent to tickle the mind!). A more robust proof is much more complex (Riemann zeta function and analytic continuation get involved). A great deeper explanation is provided by Mathologer: ua-cam.com/video/YuIIjLr6vUA/v-deo.html

    • @ryanchowdhary965
      @ryanchowdhary965 Рік тому +1

      Our history teacher despises mathematics

  • @havardmj
    @havardmj 2 роки тому +442

    Alternative title: Why you can't rearrange a divergent series

    • @russellthorburn9297
      @russellthorburn9297 2 роки тому +11

      LOL. Perfect!

    • @lemonadecitrus4764
      @lemonadecitrus4764 2 роки тому +2

      This is.a.better answer than -1/12: ua-cam.com/video/yjjvAyLgntM/v-deo.html

    • @Onoesmahpie
      @Onoesmahpie 2 роки тому +38

      Exactly I'm not sure why Eddie Woo keeps saying the result is `controversial', it is just a nod to the fact that absolute convergence is a necessary requirement to re-arrange terms. He makes it seem to his students that math is all a big confusing mess where anything can be possible. He does a bad job at explaining this, and in fact seems to be conflating the Ramanujan summation technique with this basic flaw in reasoning.

    • @siriusthegrim
      @siriusthegrim 2 роки тому +20

      @@Onoesmahpie I'm pretty sure the intention is to make the students think.. Sure, he can explain why this proof is wrong but the purpose is to make the students curious.. Why does a seemingly logical proof result in a completely nonsensical answer? By saying that it's "controversial", which must be exactly how it seems to high schoolers that aren't proficient in convergent and divergent series, he is sparking their interest in trying to learn more about it.

    • @Onoesmahpie
      @Onoesmahpie 2 роки тому +4

      @@siriusthegrim I think Eddie is awesome, just pointing out that what he said was technically not true and could have been worded better. I do applaud him for trying to go above and beyond and spark curiosity in students by challenging their intuition and showing how we cannot assume generalizations of specific results hold, and how it is difficult to recognize one's fallacious reasoning sometimes.

  • @ianthai5774
    @ianthai5774 6 років тому +3476

    "have i made you think yet?"
    no but you made me think why is there a whiteboard on top of another whiteboard 🤔

  • @ravenlord4
    @ravenlord4 4 роки тому +2917

    The US government is trying this with the national debt.

    • @nth.education
      @nth.education 3 роки тому +26

      Damn, nice thought, rofl

    • @yinlongyang255
      @yinlongyang255 3 роки тому +8

      hahah....hope they will success

    • @dabeveryday9991
      @dabeveryday9991 3 роки тому +5

      government debt isn't real. its a number on a bit of paper with no relevance in the slightest.

    • @idunnowhattonamemyself9935
      @idunnowhattonamemyself9935 3 роки тому +11

      @@dabeveryday9991 he was joking.................................................

    • @dabeveryday9991
      @dabeveryday9991 3 роки тому +2

      @@idunnowhattonamemyself9935 are you in his brain? How would you know that?

  • @seniorchief6136
    @seniorchief6136 2 роки тому +218

    "Have I made you think yet?"
    And there it is, the missing ingredient in many classrooms. I love that he doesn't push a lesson down their throats. He guides them through the thought process that made other people discover what we know today, in the hopes that these kids will do the same even of it's in other areas in life.

  • @saurabht3540
    @saurabht3540 2 роки тому +70

    I’m out of college for a decade now and I still find his lectures fascinating. I wish I had access to them when I was in school. Thanks and keep uploading these captivating math videos.

  • @bryanshortall787
    @bryanshortall787 4 роки тому +2644

    Long story short: adding, subtracting, dividing, and multiplying both sides of an equation is illegal when dealing with infinity, because: infinity + 1 is still equal to infinity.

    • @Sixsince-dd2eu
      @Sixsince-dd2eu 4 роки тому +302

      Bryan Shortall also you can’t assign a value to a non-converging series (1-1+1-1+1-1+1-1+... does not approach any specific value)

    • @clawsie5543
      @clawsie5543 4 роки тому +143

      @@Sixsince-dd2eu well, you can. Seems like people have a really hard time understanding that it doesn't work with classical definition of a sum of series. You can't even take a sum of infinite series in the first place, because, you know, it's infinite. You need to define first what sum of a series is and then talk about what is possible or not. In classical definition, that result would not work, but you can still assign values to non-convergent series, but you may lose some properties (like linearity). Think of - 1/12 as "generalized sum".

    • @cnoz2378
      @cnoz2378 4 роки тому +16

      @@clawsie5543 Thats when you're assuming that the numbers don't end, which then will be equals to, infinity. But here we are not doing that we are just adding all the numbers up. In fact, thats the point of this theory. This is to prove whether there is an end to numbers or not
      Thats my view on this correct me if Im wrong

    • @clawsie5543
      @clawsie5543 4 роки тому +55

      @@cnoz2378 I don't quite understand what you are saying. The point is that you can't just sum infinitely many numbers, because you can't apply normal algebraic rules. Algebraic rules can be applied only for finite number of numbers. In order to sum an infinite sequence, you first need to define how to do it. If you define it as the limit of partial sums (which is the "classical" definition), then you get that sum diverges towards infinity (what you would expect). But the result -1/12 doesn't mean that the limit of partial sums is -1/12, it is diferent way of summing than classical definition suggest, it is more general way.

    • @sebbes333
      @sebbes333 4 роки тому +9

      infinity < (infinity +1) ;P

  • @avananana
    @avananana 6 років тому +2848

    Everytime the word "plus" and "infinity" comes into the same sentence, mathematics turn weird. I love it.

    • @klavierboy0075
      @klavierboy0075 6 років тому +69

      This comment made me think about infinity, PLUS it`s ridiculous.

    • @JPJustPlay
      @JPJustPlay 6 років тому +5

      Truer words couldn’t have been spoken

    • @user-fz8ng3nk1n
      @user-fz8ng3nk1n 6 років тому +4

      "Infinity" is kind of taking limit

    • @gunansingh7993
      @gunansingh7993 6 років тому +1

      i love it too

    • @Krebzonide
      @Krebzonide 5 років тому +8

      1+1≠∞

  • @devkaul
    @devkaul 3 роки тому +322

    *S. Ramanujan* - "The man who knew infinity"

    • @techie.gaurav
      @techie.gaurav 3 роки тому +5

      Somewhere in heaven he is smiling at us. 🙏🙏

    • @chetia666
      @chetia666 3 роки тому

      Infinity was conceptualized because of zero

    • @bosongod2830
      @bosongod2830 2 роки тому +2

      He probably wrote this to annoy us even after his death lol😂

    • @wolfheart5408
      @wolfheart5408 2 роки тому +1

      @@bosongod2830 will it's definitely useful. So it doesn't matter if it's annoying when it's useful

  • @kallewirsch2263
    @kallewirsch2263 Рік тому +40

    If somebody is interested: Look up the discussion done by "Mathologer".
    In a nutshell: Infinite series need special care or you end up with nonsensical results.
    Infinite series only have a value, if the partial sums converge to a specific value. If they don't then they either have no value or the value is infinte.
    If this converge criterion is not taken into account, then you get nonsenical results.
    As said: Mathologer has discussed that issue. Look it up.

    • @modhere2448
      @modhere2448 Рік тому +1

      I knew you would have ended up seeing that non sense video as UA-cam algo partially favors mathologer very much...
      Please see the video ramanujan summation from channel "singing banana" . you will get a new perspective that mathologer fooled us... Please see it for true knowledge sake.

    • @Auditas
      @Auditas Рік тому

      @@modhere2448 well said.

    • @richardlinsley-hood7149
      @richardlinsley-hood7149 Рік тому +1

      'Approximates to' is not the same as 'equals'. Hence S != 1/4 only approximates to it at infinity.

  • @dearthofdoohickeys4703
    @dearthofdoohickeys4703 4 роки тому +3075

    You may be cool...
    But you’ll never be “writing -1/12 without looking” cool 7:49

    • @DanB-sh3wt
      @DanB-sh3wt 4 роки тому +245

      The way he drew a dot on the board when saying "after all" and striking a pose was truly epic.

    • @shmerox7683
      @shmerox7683 3 роки тому +3

      @@dhruvupreti5120 you can’t

    • @oliverwalsh1598
      @oliverwalsh1598 3 роки тому +1

      @@dhruvupreti5120 show off

    • @tuluaaivao3527
      @tuluaaivao3527 3 роки тому +2

      True finesse

    • @alibabapirce9782
      @alibabapirce9782 3 роки тому

      its 2:15 in the morning and im not sure if i dream or does he realy blow my mind

  • @tarsofelix4414
    @tarsofelix4414 6 років тому +2406

    -1/12 is nature's buffer overflow

    • @VerrixD
      @VerrixD 6 років тому +24

      haha that can be true :D

    • @vedant6633
      @vedant6633 6 років тому +22

      Lol computer science

    • @JorgetePanete
      @JorgetePanete 6 років тому +5

      Verri that*

    • @DavidRomigJr
      @DavidRomigJr 6 років тому +82

      reality.sys is corrupt. Reformat universe?

    • @vishalsigdel9125
      @vishalsigdel9125 6 років тому +1

      No No man the system of numbers was created by human beings. No accuse to god.

  • @willo7734
    @willo7734 Рік тому +29

    Teachers like him are priceless. They can really spark your imagination and send you on a lifelong journey of learning. If every teacher and school was like this the world be a much better place I think.

  • @sreemp
    @sreemp 3 роки тому +31

    Math teacher : Series alpha.
    Back bencher : "Are you serious?"
    Math teacher : "Yes I am serious (laughs)" LOL!

  • @notvoina
    @notvoina 4 роки тому +1482

    Teacher: the test won't be hard.
    The test:

    • @stevethea5250
      @stevethea5250 4 роки тому +14

      This video is why I don't like methmatix

    • @Luca-lz4kg
      @Luca-lz4kg 4 роки тому +32

      @@stevethea5250 methmatix

    • @ncsworld6328
      @ncsworld6328 4 роки тому +7

      @@stevethea5250 lol

    • @turtle_demigod8201
      @turtle_demigod8201 4 роки тому +4

      @@stevethea5250 Were you on Methmatix when making that comment?

    • @stevethea5250
      @stevethea5250 4 роки тому +4

      @@turtle_demigod8201 wish i wuzza methmatix head

  • @sebbes333
    @sebbes333 4 роки тому +688

    "We subtracted something and it got bigger."
    That's clearly a memory overflow error in the reality matrix !

    • @higorss
      @higorss 3 роки тому +3

      Bruh

    • @baptiste2b31
      @baptiste2b31 3 роки тому +14

      That's really funny to say because we can assign -1 to 1+2+4+16 +... +2^n+... making it "when you add 1 to 1111...111 you get 0" that is indeed some kind of "memory overflow"

    • @higorss
      @higorss 3 роки тому +3

      @@baptiste2b31 there isn't a memory overflow. When you say that it exists you're saying that there's no number greater than 1111...111

    • @baptiste2b31
      @baptiste2b31 3 роки тому +10

      @@higorss Of course it's not a "memory overflow" (compturers don't have infinite memory), I'm saying it's "resembles" it.
      First, (my bad, I forgot to precise,) but 1111...111 is considered base 2, then 1111...111 doesn't really "exist", if you want mathematical rigorousness ; what we are dealing with is an application, let's call it S, that associate a value to a sequence :
      to finite sequences it associates the "true" sum, to a converging sequence it associates its sum (therefore S(u_n)=u_0+...+u_n when u_n is finite or converging). We want S to act "like" a sum, therfore we want S to be linear and also we want S(0,...)=S(...).
      This way we can give to some other sequences (the non converging ones) 1 unique possible value that we call "sum".
      So when I write 1111...111, in fact I'm speaking about S(1,...,1,...) that is perfectly well defined mathematicacly and has to be equal to -1 (in order for S to have the proprety of a sum, I can give a proof if you want).
      Then I notice that 1+S(1,...,1,...)=1-1=0. So when you write it as 1+1111...111=0 it "resembles" a memory overflow.
      In conclusion, base 2, modulo 2^n+1, the finite number 1111...111 (with n ones) + 1 = 0. That proprety is called "memory overflow" in computer sciences. My comment is saying that this proprety also appears with infinite sums. So when @Sion mentionned it, it was nice intuition.

    • @alielbadri1965
      @alielbadri1965 3 роки тому +2

      That proofs that infinite divided by 2 not equal infinite.
      When he subtract Sa from S he lost half of the length of Numbers and yet he still compare them by location and asum that it is bigger by four times. Tricky

  • @dhruvsingh34
    @dhruvsingh34 3 роки тому +149

    *EVERYONE* : Video 📹
    *ME 🤔* : White Board on White Board ⬜

    • @jitomatasalad3217
      @jitomatasalad3217 3 роки тому +2

      Oh god you’re right

    • @MrAlRats
      @MrAlRats 3 роки тому +1

      He accidentally damaged 1/12th of a whiteboard that belonged to his colleague. He apologised to his colleague and offered to replace the damaged part. His colleague said they will deliver one whiteboard to him on day one, then two whiteboards the next day and so on. Here we are on day two.

    • @dhruvsingh34
      @dhruvsingh34 3 роки тому +1

      @@MrAlRats I pray you are kidding 😉

    • @qwertyuioph
      @qwertyuioph 3 роки тому +1

      one is likely a projector and the other a whiteboard

    • @WilcoVerhoef
      @WilcoVerhoef 3 роки тому +1

      It's not a projector screen, there's one rolled up above

  • @sujoymitra1012
    @sujoymitra1012 Рік тому +33

    This proof was done by a famous Indian Mathematician Srinivasa Ramanujan (1887-1920). Its applications are in General Physics & Bosonian String Theory. Although it makes me think, I keep wondering can we do such operations with an infinite series? We can do them to finite series but in a never-ending series, it becomes difficult to comprehend. The value of S should be n(n+1)/2 where n is no. of terms & cannot be -1/12 definitely but this feels logical though...

    • @TheFrodoBaggins33
      @TheFrodoBaggins33 Рік тому

      ​@flat_earth_forever thank you "flat earth forever" you missed the point of the proofs (the first series you mentioned the actually does converge to 1/2 btw)

    • @TheFrodoBaggins33
      @TheFrodoBaggins33 Рік тому

      @flat_earth_forever it depends on how you approach it, much like many things in math. By some methods it doesnt converge, by others it does. I think it's much more interesting (and still mathematically coherent) to say it equals 1/2

    • @bramvanduijn8086
      @bramvanduijn8086 Рік тому

      If behaviour of an operation changes it must be because your operation changes, you just didn't notice.
      i.e. infinity is a limit for addition, any attempts to add infinity changes the concept of adding to the point where you're not doing the same thing as you were doing before.

    • @WarpRulez
      @WarpRulez 11 місяців тому +13

      You can do arithmetic operations to infinite series, but only when the series converges. If the series diverges (as the sum of the natural numbers does) doing any operation on it is not valid. What he's showing in this video his hogwash, and you can use the same "tricks" to make the sum equal to whatever you want.
      For example here's a video that "proves" that the sum is equal to -1/8: ua-cam.com/video/6FTwMUL69u0/v-deo.html
      Why would this proof be any more valid than that one? (Answer is: Neither is a valid proof, because most operations done on divergent series are invalid.)

    • @dougaltolan3017
      @dougaltolan3017 11 місяців тому +1

      ​@@WarpRulezThe operations are valid, provided you don't muck about with shifting terms or changing the number of terms.
      In this video calculating 2Sa by shifting and adding is "illegal", as is equating S-Sa to 4S since they have a different number of terms.

  • @EtzEchad
    @EtzEchad 5 років тому +2345

    You can't add and subtract infinite series. If you could, you could prove 1 = 2.

    • @Faisal-os9ks
      @Faisal-os9ks 5 років тому +128

      David Messer just out of curiosity, would you mind showing me?

    • @madsp7417
      @madsp7417 5 років тому +1430

      Faisal S = 1+1+1+1+1+1+1+1+1+... then S+1=1+1+1+1+1+1+1+1... which means S+1=S, which means 1=0

    • @EtzEchad
      @EtzEchad 5 років тому +139

      Priest Plaxis
      That’s simpler. :)

    • @Faisal-os9ks
      @Faisal-os9ks 5 років тому +36

      Priest Plaxis thanks

    • @madsp7417
      @madsp7417 5 років тому +147

      Sahil Naik Yes, but by the same logic 1+2+3+4+5+6+7+8+... equals infinity, which it in fact, does.

  • @saffalife8831
    @saffalife8831 5 років тому +845

    The whole point of this class was to get the students to THINK .....not spoon feed them correct/incorrect answers . Good teacher

    • @GummieI
      @GummieI 5 років тому +20

      And if that is the case cool, that does make for a very good class, BUT it also makes for a horrible youtube video, since we don't get to see that context, meaning he very well can be the start of false information spreading

    • @evolsdog126
      @evolsdog126 5 років тому +59

      Gummiel context is everything. Have a look at the rest of his UA-cam clips and you’ll see that he is always teaching and never spoon feeding. It’d be like taking bits of what Mustafa wrote and claiming that he said “the whole point of this class was to ... spoon feed them correct ... answers.”
      He even ends by telling students to go and research this controversial proof - sounds like he’s trying to peek interest, inspire, challenge and encourage students to “think about solutions”, maybe even realise that even very smart people sometimes make fundamental errors.

    • @GummieI
      @GummieI 5 років тому +4

      Indeed you are right that context is everything here, and as I said that makes for an awesome class, but as a youtube video, it is BAD. You can't expect ppl to watch every single video of his, so they need to be able to stand alone as well, and at that this video does a terrible job

    • @evolsdog126
      @evolsdog126 5 років тому +31

      Gummiel surely you can expect people to watch the entire video and hear him say this is a controversial proof and you should go online and research it. We can’t assume that everyone is an idiot and can’t be bothered watching all of it.

    • @user-rl7wt5yi6r
      @user-rl7wt5yi6r 4 роки тому +4

      @@GummieI he mentioned a lot of times that this is a contradictory topic

  • @sampletexthere7083
    @sampletexthere7083 11 місяців тому +5

    the part i love most about your vids is that it's literally free information. no asking for subs, no hit the like, just raw math and i'm here for it.

  • @KalebC4
    @KalebC4 2 роки тому +24

    This is the cool part about mathematics... scientists are always trying to ask the right questions to find the right answer and expand knowledge, while mathematicians are simply chasing whatever curiosity their nerdiness comes up with, and then recording their results. A lot of important rules in mathematics have come to be, simply because some nerd was like "I wonder what happens if I ____?".

  • @fym4x7
    @fym4x7 4 роки тому +299

    I really like the guy who's always mind blown at some point in every video

  • @SpicyMelonYT
    @SpicyMelonYT 3 роки тому +15

    That one student that kept laughing more than the other students would have totally been me in this class. This is so entertaining to me (educationally). The fact that 1.8 Million people decided to go back to class for math of all things is amazing haha.

  • @krishiv2021
    @krishiv2021 2 роки тому +8

    This is actually called the "Ramanujan Paradox" and was proved by a very well known mathematician in India and I have bean thinking for a long time how to find a loop hole and this is very tiring but whenever I watch a video on this it gets me excited

    • @PubicGore
      @PubicGore 2 роки тому +1

      He proved it? No, doing so he assumed that the common ratio of a geometric series did not satisfy |r|

    • @krishiv2021
      @krishiv2021 2 роки тому

      @@PubicGore the proof wasn't right but it's still named ramanujan paradox so you can't change that but yeah i didn't that the proof was wrong at that time

    • @PubicGore
      @PubicGore 2 роки тому +3

      @@krishiv2021 I never said it wasn't called the Ramanujan paradox.

  • @adloltery
    @adloltery 6 років тому +591

    And the best dad joke award goes to: 0:07

  • @scottpickett1819
    @scottpickett1819 5 років тому +325

    "We subtracted something and it got bigger."
    I want you as my math teacher sometime...

    • @daaaaaaanny
      @daaaaaaanny 4 роки тому +40

      Well technically subtracting a negative makes it bigger

    • @reginaldstubtoe4185
      @reginaldstubtoe4185 4 роки тому

      I want him as my Mohel.

    • @revengeofthenoobs1579
      @revengeofthenoobs1579 4 роки тому +2

      @@daaaaaaanny but he subtracted a positive...

    • @harshithagontu4785
      @harshithagontu4785 4 роки тому

      @Shravan subtracting a positive number from a negative number always leads to large negative number. for example,consider
      -1-(3)=-4.it is possible to get big negative.

    • @turtle_demigod8201
      @turtle_demigod8201 4 роки тому +1

      @@daaaaaaanny, you're twisting the meaning of the word bigger. Try looking at the numbers going higher or lower, the numbers you are suggesting causes it to go lower still, in the technical sense, though the number is "bigger" the fact that it has a "-" next to it causes it to become "smaller" not "bigger". Also adding decimals screw over the entirety of using the words "bigger" and "smaller" due to decimals becoming "bigger" in size yet also becoming "smaller", but not in the same way as negative numbers, and a negative decimal is getting "bigger", while the number itself is getting "bigger". My point is you're wrong due to the English language because there should be a word to describe a number getting "bigger" or "smaller", "higher" or "lower".

  • @manojkumarswain5910
    @manojkumarswain5910 Рік тому +2

    This is Ramanujan Paradox.who was a great Mathematician.proud of u sir.your thought was amazing that make the people to think different.

  • @hasooon7056
    @hasooon7056 3 роки тому +12

    Woo: did I make you think yet?
    Everybody: *SMILES*

  • @plato9070
    @plato9070 5 років тому +459

    This is ramanujan summation, which differs from summation. So the sum of all counting numbers is not -1/12.

    • @Joe-pj6ds
      @Joe-pj6ds 4 роки тому +1

      Bumder

    • @merth.6423
      @merth.6423 4 роки тому +5

      Idk much about this but would the sum of all counting numbers =0 because got their positive and negative counterparts which add up to equal 0

    • @fifthe4908
      @fifthe4908 4 роки тому +18

      @@merth.6423 counting numbers mean positive numbers

    • @capnminus
      @capnminus 4 роки тому +1

      This could also be a Cesaro summation.

    • @agentm10
      @agentm10 4 роки тому +4

      @Stanislav Hronek I think the standard is to use an analytic continuation of the Riemann Zeta function at z = -1. Regardless of how this result is derived (and whether it is flawed or not), nature surprisingly seems to agree to this. In particular, the Casimir force (experimentally measurable) between two infinite plates in vacuum can be derived with this result.

  • @velophil3741
    @velophil3741 4 роки тому +136

    6:04 automatic english subtitles be like "no no, I love you!" "Ohhh I see what you mean"

  • @Lykon
    @Lykon Рік тому +7

    Well, in S_alpha you always leave the last number out, which is an infinitely big number. In general adding/subtracting/multiplying on both sides of an equation breacks down with infinity because it follows different rules (such as 1+infinity infinity, 2*infinity = infinity, etcetera)

    • @bramvanduijn8086
      @bramvanduijn8086 Рік тому

      Exactly, when you look at the set of numbers that addition applies to, infinity is not in it. And arguably neither is zero since the behaviour of adding zero to something is fundamentally different from, for example, adding five.

  • @SonKun89
    @SonKun89 Рік тому +1

    This vedio was coming from no where but it really changed my life 180°. I mean things are not going in the same way that we thought it would be. And now this statement is mathematically approved. Hats OFF to Eddie Woo. Please share more vedios like this they are such an increadible ones !

  • @IronMaidenEE
    @IronMaidenEE 6 років тому +799

    There's a thing called Riemann's Rearrangement Theorem which states that you can't play like that with divergent infinite series

    • @angelmendez-rivera351
      @angelmendez-rivera351 6 років тому +31

      Andrew Sp In the general case, no, but in this particular case it can be done carefully.

    • @orinpemulus1441
      @orinpemulus1441 6 років тому +90

      en.wikipedia.org/wiki/Riemann_series_theorem
      Did you even read anything about it? It only talks about rearranging conditionally convergent series to get other convergent series or divergent series. Nothing specifically about playing with divergent series.

    • @angelmendez-rivera351
      @angelmendez-rivera351 6 років тому +26

      Andrew Sp Also, the rearrangement Theorem does not say you cannot play with divergent series like this. It merely means infinite summation is not closed under any subset of the reals, nor is it commutative or associative. As long as Eddie hasn’t assumed either, this is all perfectly valid

    • @petercottantail7850
      @petercottantail7850 6 років тому +5

      Andrew Sp you do realize wikipedia is not an accurate source, any one can do anything to it, that's why colleges dont allow it as a credible source for papers. which reduces the credibility of this mathematician for suggesting his students go to wikipedia for anything, unless aussie wiki is better or something

    • @IronMaidenEE
      @IronMaidenEE 6 років тому +6

      Peter Cottantail ok you guys are right now stop it with this.

  • @jaygole5073
    @jaygole5073 5 років тому +249

    This was given by S Ramanujan

    • @gaganrocks4858
      @gaganrocks4858 4 роки тому +22

      That's India 🇮🇳

    • @devendrautekar7305
      @devendrautekar7305 4 роки тому +3

      Exactly!!

    • @mithat9398
      @mithat9398 4 роки тому +41

      Bobs and vagene

    • @mayur3301
      @mayur3301 4 роки тому +3

      @@mithat9398 XDDDDD

    • @abijo5052
      @abijo5052 4 роки тому +5

      Ramanujan did use this version one yeah, but more impressively he came up with Ramanujan summation which is why the result is really -1/12

  • @AppyKumari
    @AppyKumari 3 роки тому +2

    Mr. Eddie Woo, if you ever see this.. Thank you so much for your videos. Puts me in a good mood instantly. Love how beautiful numbers re

  • @aryandeopa2801
    @aryandeopa2801 Рік тому +66

    Credits to S Ramanujun for bringing up this amazing theorem… He was a great Indian Mathematician who sent this exact theorem in a letter to a British Mathematician, G H Hardy on January 16, 1913 asking for this theorem to be published under his name.

    • @alokbaluni8760
      @alokbaluni8760 Рік тому +9

      No he didn't wanted this to publish. This proof was just found in his books. This proof is wrong btw and it's been debunked many times.
      Look up about Reimann Zeta function.

  • @charlessnyder1839
    @charlessnyder1839 4 роки тому +61

    “We subtracted something and it got bigger. “ I want you as my accountant! 🤣

  • @joshuamoyer4141
    @joshuamoyer4141 4 роки тому +582

    That awkward moment when you set non-converging series equal to discrete numbers

    • @Antediluvian137
      @Antediluvian137 4 роки тому +35

      Yes, "Ramanujan summation is a technique invented by the mathematician Srinivasa Ramanujan for assigning a value to divergent infinite series"

    • @joshuamoyer4141
      @joshuamoyer4141 4 роки тому +35

      Keep reading the Wikipedia article:
      “Although the Ramanujan summation of a divergent series is not a sum in the traditional sense”

    • @countiblis1867
      @countiblis1867 4 роки тому +58

      ​@@joshuamoyer4141 The standard definition of the summation of a convergent series as the limit of the partial sums isn't a sum in the traditional sense either. A sum in the traditional sense is only defined for a summation of a finite number of integers. You can't start with the definition of addition and derive how the sum over an infinite set of integers should be defined. That definition will be an arbitrary choice, there are many possible choices. Defining it as the limit of the partial sums is one possible definition that has become the standard definition.

    • @davidturner9827
      @davidturner9827 4 роки тому +3

      Correct answer deserves more upvotes...

    • @matthewcrome5835
      @matthewcrome5835 3 роки тому +5

      I hate to be that Grammar Nazi asshole, but *discrete. "Discreet" means secret, "discrete" is the word you're looking for.

  • @burkean
    @burkean 3 роки тому +17

    I have a problem with S-alpha. You "doubled" it by adding it to itself. BUT when you moved it over, you ensured that you are NOT doubling it. In order to pair all the numbers the way you do, there will always be one number left over at the end. Oh, and that missing number is either +infinity or -infinity!
    So you proved that the sum alternates between positive and negative infinity.

    • @SomLata-sq2yj
      @SomLata-sq2yj 2 роки тому +4

      haha same thought

    • @DeJay7
      @DeJay7 2 роки тому

      Of course, no one said that is actual, real proof. It 'looks' really great, just like a video I saw saying π = 4 and the proof definitely 'looks' real but it deceives us. S_a in this case would alternate between 1 and -1, and S would approach infinity.

    • @virendra678
      @virendra678 2 роки тому

      Oh yeah !!

    • @bable6314
      @bable6314 2 роки тому

      There is no end, it's an infinite series.

    • @ssgoko88
      @ssgoko88 Рік тому +2

      Except these series are logically consistent and appear in the real world with these values when you perform quantum experiments

  • @matches7116
    @matches7116 Рік тому +2

    I just discovered this guy, I wish more teachers where like this.

  • @rishabhbothra9573
    @rishabhbothra9573 5 років тому +63

    this result is used in string theory and used in some calculation in quantum physics . this ramanujan infinite series

  • @dammit9128714
    @dammit9128714 5 років тому +49

    "A glitch in the matrix" is all that needs to be said.

  • @douglasburnside
    @douglasburnside Рік тому +5

    I'm 77 years old If I had had this man as a teacher in high school, or even in college, my life today would be totally different. This is an unlikely scenario since I graduated from college 15 years before he was born.

  • @jaswanthmaguluri
    @jaswanthmaguluri 3 місяці тому +3

    This was first explained by srinivasa Ramanujan sir
    Proud to be an indian🇮🇳

  • @gaetantanguay9180
    @gaetantanguay9180 6 років тому +47

    Im actually more impressed by this guy's talent to write on the board with an incredible speed or without looking and the board while writing

  • @ThruThe9
    @ThruThe9 6 років тому +336

    I'd love to view this video's analytics. Most comments here are from the past week and I wonder why.

    • @ThruThe9
      @ThruThe9 6 років тому +23

      Bob McMullan I got here from his 0 to the power of 0 video

    • @Daffyrino
      @Daffyrino 6 років тому +1

      Try socialblade. [C O M]/youtube/user/misterwootube/ :)

    • @abz4852
      @abz4852 6 років тому +2

      within the period of a single second I saw his subscribers increase by 20

    • @ThruThe9
      @ThruThe9 6 років тому

      Michael Rector smart

    • @eric7805
      @eric7805 6 років тому +1

      There was a video (Why 0! is 1) posted to Reddit/r/Math within the past week. It was top that day. A lot of people probably found this channel through that link and are just going through the videos (Like I am)

  • @dinoeebastian
    @dinoeebastian 2 роки тому

    You remind me of my 8th grade history teacher, he was super interesting and was good at teaching, my current math teacher has been going over stuff I've already learned for the entire year.

  • @kavasr
    @kavasr 2 роки тому +2

    He is the best. Wish I had a teacher like him back in school.

  • @TheROYALS678
    @TheROYALS678 4 роки тому +269

    Mom: What are you watching ?
    Me : If u add too many positive numbers u will get negative,..!

    • @OmniscientWarrior
      @OmniscientWarrior 4 роки тому +24

      And not just a negative, but a negative fraction.

    • @BayMacDre415
      @BayMacDre415 3 роки тому +1

      The video was supposed to filter out the retards from passing his course. You fail.

    • @sharpfang
      @sharpfang 3 роки тому +2

      Eh... As every programmer will tell you. But if you get a fraction, you dun bad.

    • @SledgerFromTDS.
      @SledgerFromTDS. 3 роки тому +1

      Omg, this is what I hate the most about
      UA-cam Comments, Its either People
      are believing This Proof or People are
      not believing This Proof or People dont
      know what to say, it's a Massive Mess

  • @GuilhermeDiGiorgi
    @GuilhermeDiGiorgi 5 років тому +168

    Heres something I thought:
    S=1+2+3+4+5+...
    S-S=1+2+3+4+5+...(-1-2-3-4-5-...)
    But hey, dont take that -1 from the 1, take it from the 2, and so on, we get:
    S-S=1+(2-1)+(3-2)+(4-3)+...
    S-S=1+1+1+1+1=infinity
    0=infinity
    ?????
    Infinite sums are scary shit to work with

    • @magicUFO
      @magicUFO 5 років тому +31

      If 1+1+1+...=∞ then 1+2+3+4+...=∞
      ∞-∞≠ because ∞ is not a number

    • @shashwat4920
      @shashwat4920 5 років тому +2

      @@magicUFO correct

    • @JobinPhilipfcbarcelona
      @JobinPhilipfcbarcelona 5 років тому +5

      Well, you'll have to subtract the 1 like all other numbers before going on to step 2.
      Cheers.

    • @kevinpaulsen6103
      @kevinpaulsen6103 4 роки тому +7

      You can’t add or subtract non-converging series’.

    • @akshayrathore7208
      @akshayrathore7208 4 роки тому +8

      @@magicUFO Not correct, It may look like infinity series but it's not. The Sum of all the 1s come out of subtraction will be equal to last number and they both will cancel each other answer will be zero. S-S will remain zero. And if you think that last number to be a very big unimaginable number then dont worry the sum of all 1s will be equal to exact that number.

  • @suriyanarayan8388
    @suriyanarayan8388 3 роки тому

    Food for thought for sure. Wish I had you as my maths teacher. You make math fun

  • @jamesrees8070
    @jamesrees8070 2 роки тому

    I'm in my 3rd year of uni, I have no more math classes, but I still come back to these videos. Wild

  • @shasankshekhar6637
    @shasankshekhar6637 4 роки тому +139

    This was first proved by "S Ramanujan- The Man Who Knew Infinity"
    He was a great Mathematician and today his theories are the basis for the study of Black Holes🙏

    • @SacheeT
      @SacheeT 2 роки тому

      ua-cam.com/video/uhNGCn_3hmc/v-deo.html
      If any one interested in Ramanujan

    • @Whiskypapa
      @Whiskypapa Рік тому +3

      Ramanujan is the absolute goat of maths and for some reason we never learned about him in school. Im 31 now. I first heard about him at 29. It shouldnt be like that. If the guy was from a western country, I’m sure he would be as famous (or more) than Einstein to us.

    • @ryanchowdhary965
      @ryanchowdhary965 Рік тому +2

      @@Whiskypapa GOAT

    • @TheRenegade...
      @TheRenegade... Рік тому

      @@ryanchowdhary965 Then why is he called ram anujan (what do you mean rams are sheep?)

    • @ryanchowdhary965
      @ryanchowdhary965 Рік тому

      @@TheRenegade... greatest of all time (GOAT)

  • @bikkichhantyal1211
    @bikkichhantyal1211 9 років тому +430

    I think we can't write
    1-1+1-1+1-1+.....to infinity= 1/2
    because its non-convergent series.

    • @ryancraigt
      @ryancraigt 6 років тому +32

      Yes it is a divergent series but we arnt taking normal sums, we cant. Hence we are taking a special summation of the series.

    • @angelmendez-rivera351
      @angelmendez-rivera351 6 років тому +43

      The fact that a series diverges does not mean that the sum cannot be evaluated to be a finite number. The limit of f(x) = x^x as x -> 0 = f(x) = 1, yet this by no means implies that 0^0 = 1. The same is true for summation.

    • @friedkeenan
      @friedkeenan 6 років тому +33

      The point of this is to get rid of arbitrary rules and see where that takes us. Why can't we assign a value to a divergent series? Just because it doesn't make sense doesn't mean it's impossible.
      1-1+1-... can be written as
      inf
      Σ((-1)^n)
      n=0
      Well that looks like a geometric series, and we know how to calculate infinite sums with that, so let's try it.
      1/(1-(-1))=1/(1+1)=1/2
      Well that sure looks familiar. And if you're not happy with pure algebra, throw in some calculus and take the limit as the base goes to -1, and you get the same answer. For all intents and purposes, the answer is 1/2. And the final series in this video does indeed equal -1/12. It shows up in physics, which just further confirms it.

    • @angelmendez-rivera351
      @angelmendez-rivera351 6 років тому +2

      I have a link in which expert mathematician Terrence Tao why the argument of convergence vs divergence is not convincing enough to present an objection to the result of the series as equal to 1/2.

    • @angelmendez-rivera351
      @angelmendez-rivera351 6 років тому +6

      terrytao.wordpress.com/2010/04/10/the-euler-maclaurin-formula-bernoulli-numbers-the-zeta-function-and-real-variable-analytic-continuation/#comment-487580

  • @classroom3223
    @classroom3223 Рік тому +11

    This work was by sir ramanujan and is used in the mathematics to explain blackholes.

    • @sjegannath6295
      @sjegannath6295 Рік тому +1

      not this math, the one that is used in black holes is mock theta function but yea he was the one who invented it.

  • @ronaldderooij1774
    @ronaldderooij1774 3 роки тому +5

    Why is this video ending at exactly the moment when it gets interesting?

  • @ge2719
    @ge2719 6 років тому +61

    i think the most confusing part of this video is why is there a smaller white board attached onto a larger whiteboard? and why do i suspect it has something to do with the school ordering new boards to use up a budget so that they get the same budget next year, and ending up buying smaller boards than they already have.

    • @letsbfrank7084
      @letsbfrank7084 5 років тому +2

      Maybe some student didn’t like this teacher and smeared shit on the big whiteboard and instead of cleaning it up because education never gets funded properly they just put another whiteboard over the smeared shit.

    • @Mythraen
      @Mythraen 5 років тому

      If the school ordered a board they didn't need, why would they put it in a classroom instead of a storage room or the dumpster?

  • @saifali9853
    @saifali9853 5 років тому +43

    Why does he have a whiteboard on a whiteboard????

  • @IllusionistsBane
    @IllusionistsBane Рік тому

    All of this is possible if you think of a series not just as an equation but also as a variable in itself - basically, use both ends of the equal sign, not just one. Implicit Differentiation (I call it 'Brute Force Differentiation') taught me this.

  • @alexandrepereira3902
    @alexandrepereira3902 3 роки тому

    Mr Woo, I am a 61 yer old engineer and economist... I have worked in banks all my life... I admire your way of teaching... May God bless you...

  • @Steven-xp6dk
    @Steven-xp6dk 3 роки тому +14

    For those who didn't know, this was formulated by an Indian mathematician Srinivasa Ramanujan

  • @nikheelindanoor3073
    @nikheelindanoor3073 3 роки тому +154

    It makes me sad that he didn't even mention Ramanujan here, while introducing infinite sum series.

  • @alphacikenstudios4447
    @alphacikenstudios4447 3 роки тому

    why did you do that method at the 2s(alpha)? i don't understand it. can you explain it to me

  • @iversonpaulalay5514
    @iversonpaulalay5514 3 роки тому +8

    In the end I was like: WHAT DOES THIS ALL MEAN?! I'M TOO INVESTED IN THIS WHY DID IT STOP THERE?!😂😭

    • @23bhaviklal18
      @23bhaviklal18 2 роки тому +1

      The Mathematician Ramanujan made this theory, he did these research with a chalk in a temple, said that the goddess helped him.

  • @slycordinator
    @slycordinator 5 років тому +9

    When you calculate the sum of Grandi's Series as 1/2, you're conflating the sum of a series with its Cesàro sum (Cesàro mean).
    The sum of an infinite series is the limit of its first n partial sums as n approaches infinity.
    The Cesàro sum/mean is the limit of the average of the first n partial sums as n approaches infinity.
    Those are related but clearly not the same.

  • @nugatschnidde7515
    @nugatschnidde7515 6 років тому +1237

    2+2 is four minous one that is 3 quick mathhhhh

  • @1dash133
    @1dash133 3 місяці тому +1

    8:49 time mark _ "The question is, what does it all mean?"
    It means that when manipulating series of numbers, it is very important to understand exactly what you are manipulating. Seemingly innocent truncating and shifting numbers over have dramatic and unintended consequences, when evaluating multiple series.
    For example, take an equation C = first series of repeating ones. Take the same equation C = second series of repeating ones BUT SHIFT IT OVER ONE PLACE. Now subtract the two equations, C - C = first series - second series. What do you get? 0 = 1. That is the flaw in this video's logic, you can't shift places of values in the series when evaluating multiple equations.
    For me, the bigger mystery is WHY does C = first series NOT EQUAL C = second series? Don't both equations (independently) resolve/converge to the same value? The only answer that I come with is that you have to be very careful when evaluating sets of infinities.
    As for this video, its biggest flaw isn't faulty logic. Arguably, the logic is impeccable. The flaw is a failure to identify the mathematical frame of reference. The playground being discussed is NOT REAL WORLD. Instead, it is something called "Analytic Continuation". It is a logical extrapolation that makes sense within its respective frame of reference. Eddie Loo should make this point clear in his video presentation. (I think maybe that omission is because he assumes that viewers understand this.)

  • @abrahamregha9262
    @abrahamregha9262 3 роки тому

    @
    Eddie Woo
    I think 1+1-1+1-1 is a Divergent series. Its result can be 1 or 0, so it is not convergent. Am I correct?

  • @tanveersingh5423
    @tanveersingh5423 4 роки тому +35

    People here don't know that this result of Ramanujan has helped finding 26 dimensions of string theory and holds everytime.
    It is in the books and is still helping scientist...
    Many tried to prove it wrong cause its absurd...but it just works!!

    • @XxStuart96xX
      @XxStuart96xX 4 роки тому +14

      It is 'wrong' in how it is presented on the board. It is talking about two different things.

    • @kaischmidt7973
      @kaischmidt7973 4 роки тому +5

      He says, that S is EQUAL to -1/12, but it isn't. In order to make this true you have to think of the equal sign as anything BUT "is equal". More like "is associated with"

    • @gorgit
      @gorgit 4 роки тому +1

      You cant add up divergent series and shift the cols... you learn that in the first semester of any math course

    • @yashuppot3214
      @yashuppot3214 4 роки тому +1

      The way its derived here can be replicated but you can set the sum to any value you want, where as using a rigourous formulation, -1/12 would be the only value you could come up woth.

    • @truthseeker9163
      @truthseeker9163 4 роки тому

      Gone Crazy It had been proven, several ways, before Ramanujan.

  • @NaomiAmethyst
    @NaomiAmethyst 6 років тому +436

    I have devised a truly marvelous counter-proof for this, but alas, this comment box is too small to contain it.

    • @gidmanone
      @gidmanone 6 років тому +29

      try harder next time you might win a Nobel laureate with typing fingers of yours

    • @hopp2184
      @hopp2184 6 років тому +130

      gidmanone I don't think you get it... he is referring to Fermats last Theorem

    • @JorgetePanete
      @JorgetePanete 6 років тому +14

      Jacobi Carter this is a parker reply

    • @aakabeer7901
      @aakabeer7901 6 років тому +4

      Hello fermat

    • @majestycrush
      @majestycrush 6 років тому +7

      r/iamverysmart

  • @zero2infinity172
    @zero2infinity172 Рік тому +6

    Credit goes to S. Ramanujan 👍

  • @impossible3795
    @impossible3795 Рік тому +1

    this paradox is known as ramanujan paradox . Here ramanujan is an indian mathematician whose full name is Srinivasa Ramanujan. Proud to had such legend in India.

  • @JuanRojas-om9ec
    @JuanRojas-om9ec 6 років тому +36

    all of those series are (i don't know how to say this in english) "no convergentes" so it's imposible to get a number

    • @11secondsofsummer43
      @11secondsofsummer43 6 років тому +2

      It's not technically possible
      But this is what would happen if it *was*

    • @voltgene9055
      @voltgene9055 6 років тому +3

      En inglés sería así: "Divergent series". Hope it helped ya.

    • @lb9817
      @lb9817 6 років тому

      I think it's called a diverging series or a divergent series

    • @theolast9727
      @theolast9727 6 років тому +1

      Actually the first one(the one he didnt show) is convergent, its telescoping

  • @mattday7337
    @mattday7337 4 роки тому +21

    4:15 "I've got news for you"
    "Oh for God sake"

  • @mdhbigdog
    @mdhbigdog 3 роки тому +3

    Even when I don't fully understand him, he's still interesting and entertaining.

  • @Mohit-gsxr
    @Mohit-gsxr 3 роки тому +2

    This is Ramanujan summation made by the famous Indian mathematician Srinivasa Ramanujan.

  • @SkyFoxTale
    @SkyFoxTale 9 років тому +258

    You can't simply add, subtract, and noodle around with sums that are clearly divergent. It's not controversial, it's against the rules of math. The result -1/12 comes from far more complicated mathematics that involve analytical continuation of the Reimann Zeta function.

    • @easierchutoy7355
      @easierchutoy7355 9 років тому +56

      Yes but it is still based on the idea that 1-1+1-1+1-...=1/2.

    • @michaelbauers8800
      @michaelbauers8800 8 років тому +22

      +Sky Fox I remember being taught otherwise. I remember being told, that you can reorder a divergent series to make it converge. I remember being told a number of times by a number of people. While it seemed a bit hard to believe at the time, this sort of thing shows you can reorder divergent to make it converge. Do you have a math book that says otherwise?

    • @subarnasubedi7938
      @subarnasubedi7938 7 років тому +12

      analytical continuation has the same basis of the proof if this is wrong analytical continuation is wrong

    • @86400SecondsToLive
      @86400SecondsToLive 6 років тому +20

      Dude, the point is: you can reorder series that are NOT absolute convergent in ways to make them converge to any number you can think of.

    • @lameduck1690
      @lameduck1690 6 років тому +7

      There's no math gods. Nobody can tell you that you "can't" do anything, especially not so in mathematics.

  • @timschnitzel
    @timschnitzel 5 років тому +280

    All the lies began with Sg=1/2

    • @tchgs11zdok15
      @tchgs11zdok15 4 роки тому +5

      No actually that is ok as a supersum

    • @doomse150
      @doomse150 4 роки тому +46

      @@tchgs11zdok15 No it's not, the sequence 1 -1 1 -1 diverges to per definition the sum over this sequence diverges as well so you can't assign a value to it

    • @tchgs11zdok15
      @tchgs11zdok15 4 роки тому +12

      @@doomse150 watch mathologer video on this, he explains why most of it is wrong by defention but ultimately could be the answer with the right definition

    • @doomse150
      @doomse150 4 роки тому +19

      @@tchgs11zdok15 What do you mean by "the right definition" if you define stuff the way you want it obviously can work

    • @tchgs11zdok15
      @tchgs11zdok15 4 роки тому +12

      @@doomse150 just watch it, it's like a freaking 40 minute video that addresses everything you can address about this

  • @ashishsagar4417
    @ashishsagar4417 Рік тому

    Hey
    Eddie Woo
    Is it possible that in series S which is equal to -1/12.
    The infinity of what we think of it as a very very large positive number is actually a very very large negative number(-infinity = + infinity). Like our number line is actually a very huge circle which meets with a negative side at very far away from 0.

  • @sabapc81
    @sabapc81 Рік тому +2

    Haven't looked up on the internet yet... But I will.
    But in the meantime, this makes me think that some operations don't work (or are not allowed) on infinite numbers, cause not all infinites are the same.
    It got me wondering... if you have these two series:
    S1 = 1+2+3+4+5+6+7+8+9+...
    S2 = 1+0+2+0+3+0+4+0+5+...
    Are they really the same? One seems to grow faster than the other, so I'd assume the total sum is a larger level of infinite. So you can't really say S1 = S2, nor you can add those two, aligning the numbers however you want and say that S1+S2=2S1 or subtract them and say it's zero and stuff like that. I think that's where we're making invalid operations.
    Anyway... I'm gonna go research now 😂😂

    • @katsurakotaro
      @katsurakotaro Рік тому

      rate of growth doesnt matter, once you say "=" it's instant. 1+0+1+0+1+0 = 1+1+1 = 3

    • @sabapc81
      @sabapc81 Рік тому

      @@katsurakotaro Not sure that makes sense when the list isn't finite.
      Consider these:
      S1(n) = n = 1+2+3+4+5+6+7+8+9+10+...
      S2(n) = n^2 = 1+4+8+16+...
      Would you say that the sum of all n^2 is greater than the sum of all n?
      In fact S2(n) = n^2 could be written like this:
      S1(n) = n = 1+2+3+4+5+6+7+8+9+10+...
      S2(n) = n^2 = 1+0+0+4+0+0+0+8+...
      Under this scenario you could think the sum of all n^2 would be LESS than the sum of all n, since you're skipping a bunch of numbers.

    • @katsurakotaro
      @katsurakotaro Рік тому

      @@sabapc81 s1=s2= infinity, as long as all numbers are positive it will be equal to s1

  • @10_Bit
    @10_Bit 4 роки тому +46

    I remember seeing this on another channel; numberphile

    • @JOhnDoe-nl4wj
      @JOhnDoe-nl4wj 4 роки тому +14

      ya, they got it totally wrong there and it went sorta viral too.. total fuckup

  • @aquibmohd
    @aquibmohd 3 роки тому +57

    Salute to some Indian guy for giving us this. ❤️ Ramanujan ❤️

  • @erickvanpatten673
    @erickvanpatten673 Рік тому +1

    You cannot assign an equal value to the sum that ends in 1/2, it's either 1 or 0, but the sum does not converge at 1/2. Since the sum is not convergent, adding or substracting it does not provide a fixed value. You cannot say that the sum EQUALS 1/2

  • @sakshipatel4054
    @sakshipatel4054 3 роки тому

    Sir can you please say how associative law is applicable to a convergence series

  • @GothicKin
    @GothicKin 6 років тому +217

    "I must have made a mistake, right, right??"
    Absolutely. Two very big mistakes. Firstly you let a non converging sequence have a value. Then you manipulated several non absolutely converging sequences.

    • @9Balrog6
      @9Balrog6 6 років тому +40

      Jacopo Barberis A physician (Hendrick Casimir) had to make a calculation where this S sequence showed up and he decided to try with -1/12, and the answer he got was proven to be right few years later. So I'm not trying to say this makes sense but maybe you should understand that there is things you can't simply understand (Sorry for my bad english btw!) Bye

    • @sebastien5048
      @sebastien5048 6 років тому +54

      The result might be useful in physics, but that doesn't mean this proof is correct. You can get to the right answer with calculation mistakes. Then again, i don't think that's the right answer, if i'm not mistaken you have to define "convergence" in a really specific way to get to "1+2+...= -1/12", so that "=" symbol doesn't exactly mean what we think it means.

    • @reinaldogarciagarcia9065
      @reinaldogarciagarcia9065 6 років тому +5

      Zygo Petalum Right in the spot

    • @duncanw9901
      @duncanw9901 6 років тому +18

      plz don't appeal to authority. That kind of thing is in contrast to the mathematical spirit and removes the core idea of analysis open to all. Simply arbitrarily calling someone stupid and saying they can never understand is kinda low, especially because there is no context on that claim about Casimir's result. I checked the literature and it does appear that he was considering the series in context of the zeta function linked to the observed vacuum energy, which is tied a meromorphic function with interesting pole placement that allowed him to solve one of his integrals (i.e. make the Lesbegue convergent). He was dealing purely with the analytic continuation of the zeta function, not this sum. For which it is unarguably defined at -1 to equal -1/12. But, no, it was not the sum he was working with.

    • @samb443
      @samb443 6 років тому +4

      You can't just act as if naming something is wrong if it doesn't lead to a contradiction. And manipulating series is fine so long as you don't rearrange them, which he didn't. He didn't come to a contradiction, he only came to something unintuitive and the only reason you think it's a contradiction is because you assume the false premise that it is equal to infinity.

  • @foggs2275
    @foggs2275 8 років тому +401

    This has to be the best way i have seen this prof done

    • @Speed001
      @Speed001 6 років тому

      It takes him from 7:10 to 7:54 to show the answer. It took me much less time to figure out that s-3s=4s since s alfa is 1/4 and s alfa is 3 times more than s, 1/4/-3=-1/12

    • @thijsjansen1079
      @thijsjansen1079 6 років тому +84

      Yeah sure, but showing the answer to a question at breakneck speeds doesn't make you a good teacher. If you want to explain something and have it understood, you must make your audience think before you give the answer, the way you thought about the answer while he was still explaining. The fact that he doesn't give away the answers at once makes him such a good teacher.

    • @chhavigupta2802
      @chhavigupta2802 6 років тому +16

      Speed I can't believe ur level of immaturity is so high.

    • @jackkennedy98
      @jackkennedy98 6 років тому +4

      "proof"

    • @archimidis
      @archimidis 6 років тому +2

      HE IS WRONG AND I SHALL PROVE IT
      The problem with is that he (mis)used algebra.
      At 6:14 he cancels out all odd numbers leaving him with infinite gaps
      which add up to 0+0+...=0*infinity0
      Using limits of limits we can assign finite values to
      both 1-1+1-1+... and 1-2+3-4+... but not 1+2+3+...
      Let y=1+x+x^2+...=1/(1-x) when |x|1/2 so 1-1+1-1+...=1/2
      As x->-1 w->1/4 so 1-2+3-4+...=1/4
      As x->1 w->infinity so 1+2+3+...=infinity-1/12
      Q.E.D.

  • @NathanSimonGottemer
    @NathanSimonGottemer 2 роки тому +1

    Technically this is the Ramanujan Summation of the series. Which ends up being a very important concept in its own right because it allows you to analyze divergent series, which is normally impossible due to...well, infinity being what it is.

  • @KamalSingh-wb8ev
    @KamalSingh-wb8ev 2 роки тому +1

    Sum of all counting number .. Does it make any sense??? My question is that is it possible that positive infinity and negative infinity are same point just like plus zero and minus zero are the same point or converges to zero..???

  • @sushantsinghrathore1
    @sushantsinghrathore1 4 роки тому +4

    Sir i loved the way and the things you teach. Can you tell me how you came up with this awesome questions and interesting explanation? So i can tell me school and other head of institutions to refer to that material instead of old curriculum which was taught.

    • @sushantsinghrathore1
      @sushantsinghrathore1 3 роки тому +1

      @JHIGYASU STUDENT wow that's so proud feeling to hear that..
      Can u tell me the resources where I can find interesting contributions of indian mathematicians.

  • @mann079
    @mann079 4 роки тому +3

    Sir I want you in my school as my maths teacher....
    You are great sir..
    I also want to gain this amazing mathematics knowledge..
    Love from India...
    Awesome sir...

  • @sagecarbonell.
    @sagecarbonell. 3 роки тому +1

    Wow, you are really a great teacher, Eddie. So interesting and funny! Time just flew listening to you :D

  • @NidhishwarReddy
    @NidhishwarReddy 11 місяців тому +1

    if i say " are you serious " to my math teacher . then i wont be in the next class

  • @danielpowers2191
    @danielpowers2191 5 років тому +10

    A perfect example of how interesting subject matter nullifies misbehaviour. Excellent work.