Dr Sean
Dr Sean
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Can You Solve the 'Hardest Logic Puzzle Ever' in Just 3 Questions?
Head to squarespace.com/drsean to save 10% off your first purchase of a website or domain using code DRSEAN
The logician George Boolos called this the 'hardest logic puzzle ever'! One god always answers truthfully, one always lies, and one always answers randomly by flipping a coin in secret. They understand English, but they always answer "Ja" or "Da". You know these mean "Yes" and "No" in their language, but you don't know which is which. Can you identify each of the 3 gods in just 3 questions?!
Переглядів: 1 403

Відео

Why the Strangest Sums in Math Are Actually Useful!
Переглядів 12 тис.21 день тому
Head to squarespace.com/drsean to save 10% off your first purchase of a website or domain using code DRSEAN What is the point of strange sums like 1 2 3 ...=-1/12 or 1-1 1-1 ...=1/2? These series diverge in the usual sense that we study in Calculus and use throughout most mathematics. But these alternative summation methods actually have physical meaning! Let's explore these weird sums and see ...
The Unsolvable Problem in Every Voting System
Переглядів 1,2 тис.Місяць тому
Head to squarespace.com/drsean to save 10% off your first purchase of a website or domain using code DRSEAN Arrow's Impossibility Theorem tells us every ranked voting system has the potential to make irrational decisions. Let's explore the surprising result, and then prove why every ranked voting system must have this problem! This video is sponsored by Squarespace. 0:00 Introduction 0:34 Arrow...
Why is Pi Everywhere? 5 Levels from Basics to the Unexpected
Переглядів 18 тис.Місяць тому
Head to squarespace.com/drsean to save 10% off your first purchase of a website or domain using code DRSEAN Why does pi show up everywhere, even when there are no circles in sight? Let's explore pi in 5 levels, ranging from geometry to its surprise appearances in complex numbers, calculus, and probability! You can watch pi play Pokémon Sapphire on Twitch here: www.twitch.tv/winningsequence This...
Exploring Bayes' Rule in 5 Levels of Complexity
Переглядів 7 тис.4 місяці тому
To try everything Brilliant has to offer-free-for a full 30 days, visit brilliant.org/DrSean . You’ll also get 20% off an annual premium subscription. Bayes' Rule lets us update probabilities (and our beliefs!) based on new evidence. Let's explore Bayes' Rule in 5 levels, starting with medical testing and trial evidence, and ending with an exploration of the power of Bayesian statistics. This v...
What exactly is e? Exploring e in 5 Levels of Complexity
Переглядів 239 тис.5 місяців тому
To try everything Brilliant has to offer-free-for a full 30 days, visit brilliant.org/DrSean . You’ll also get 20% off an annual premium subscription. What is e? Let's explore the number e in 5 levels of complexity, ranging from compound interest, to representing e in calculus, to simulating e with probability. Small correction: At 11:42, the area is 1/2 xy (1-z)^2 = A (1-z)^2. The left-hand si...
Imaginary Numbers are Not "Imaginary"! In 5 Levels of Complexity
Переглядів 65 тис.6 місяців тому
To try everything Brilliant has to offer-free-for a full 30 days, visit brilliant.org/DrSean . You’ll also get 20% off an annual premium subscription. Imaginary numbers are not "Imaginary"! Despite their name, they are completely solid mathematically, and they are critical for many real-world applications. Let's explore imaginary numbers in 5 levels, ranging from the idea behind calling them "i...
3 Integrals You Won't See in Calculus (And the 2 You Will)
Переглядів 84 тис.6 місяців тому
In Calculus, we usually learn the Riemann integral, or sometimes the Darboux integral in disguise. But there are many problems these integrals can't solve! Like if we want to integrate a function which is discontinuous everywhere, or if we want to integrate with respect to a random process. Let's explore 5 different integrals, starting with the 2 you might see in Calculus, and then 3 more advan...
The Hot Potato Problem Solved 2 Ways - from Algebra to Math Major!
Переглядів 3,6 тис.6 місяців тому
The problem goes like this: you're playing hot potato on a cube. You're at one vertex, and a hungry monster is at an adjacent vertex. You throw the potato to one of the neighboring vertices with equal probabilities. People standing at each other vertex act the same way. What's the probability you feed the monster? Let's analyze this problem two ways - first with algebra, and then as a Markov Ch...
What is 0? From Bee Brains to the Minds of Mathematicians
Переглядів 14 тис.7 місяців тому
To try everything Brilliant has to offer-free-for a full 30 days, visit brilliant.org/DrSean . You’ll also get 20% off an annual premium subscription. 0 lies at the heart of algebraic structures and allows us to do calculus. But what is it? Let's explore 0 in 5 levels ranging from a study on bees' understanding of 0 to algebra, calculus, and beyond. In the last level, we'll see how to rigorousl...
+1−1+1−1+... Explained in 5 Levels from Algebra to Math Major
Переглядів 247 тис.7 місяців тому
What is 1−1 1−1 ...? Let's explore this series in 5 levels, ranging from explorations with arithmetic and algebra to rigorous solutions from Calculus and beyond! 00:00 Introduction 00:18 Level 1 Arithmetic Ideas 01:33 Level 2 Algebra Ideas 03:01 Level 3 Calculus 04:01 Level 4 Cesàro Sum 05:20 Level 5 Abel Sum
Is π Random? Exploring the Elusive Normal Numbers
Переглядів 4,4 тис.7 місяців тому
Is pi random? Pi is fixed and predetermined, but its digits look just like random digits! We'll define normal numbers by exploring why pi's digits look random. Then we'll see what it would mean if pi is a normal number. 00:00 Introduction 00:18 Why do pi's digits look random? 01:02 Normal numbers 03:17 Is pi normal? 04:47 What if pi is normal?
The Hidden Power in Pascal's Triangle
Переглядів 4,2 тис.7 місяців тому
What makes Pascal's triangle so powerful? It has deep connections to the Binomial Theorem and the Central Limit Theorem. And hidden within it are the powers of 2, the Fibonacci sequence, and the fractal Sierpinski's Triangle! Let's explore these patterns and see why they show up in Pascal's Triangle. 00:00 Introduction 00:14 What is Pascal's Triangle? 01:07 Connections to Algebra 04:07 Connecti...
0^0 = 1? Exploring 0^0 in 5 Levels from Exponents to Math Major
Переглядів 24 тис.8 місяців тому
To try everything Brilliant has to offer-free-for a full 30 days, visit brilliant.org/DrSean . You’ll also get 20% off an annual premium subscription. What is 0^0? Let's explore the value of 0^0 in 5 levels, ranging from Euler's definition from the 1700s to Calculus and beyond. This video was sponsored by Brilliant. 00:00 Introduction 00:20 0^0 in the 1700s 01:17 Algebra 03:21 Polynomials 05:02...
Divisibility Tricks in 5 Levels of Difficulty
Переглядів 16 тис.8 місяців тому
To check if a number is divisible by 3, you can add up the digits and see if that number is divisible by 3! Let's explore divisibility tricks like this in 5 levels of difficulty. We'll find divisibility tricks for each number 2-12, and also explore how divisibility tricks work in other bases! Divisibility rules for 2-12 (in base 10), and for working in other bases. 00:00 Introduction 00:19 Divi...
0! = 1 Explained in 5 Levels from Counting to Math Major
Переглядів 434 тис.8 місяців тому
0! = 1 Explained in 5 Levels from Counting to Math Major
This Simple Puzzle Tricks Mathematicians -- Monty Hall Problem in 5 Levels
Переглядів 7 тис.8 місяців тому
This Simple Puzzle Tricks Mathematicians Monty Hall Problem in 5 Levels
Endless Sizes of Infinity, Explained in 5 Levels
Переглядів 24 тис.9 місяців тому
Endless Sizes of Infinity, Explained in 5 Levels
0.99999... = 1 in Five Levels -- Elementary to Math Major
Переглядів 159 тис.9 місяців тому
0.99999... = 1 in Five Levels Elementary to Math Major
Let's Solve the Interview Puzzle that Baffled Me
Переглядів 53 тис.9 місяців тому
Let's Solve the Interview Puzzle that Baffled Me
Negative × Negative = Positive in 5 Levels -- Elementary to Math Major
Переглядів 233 тис.9 місяців тому
Negative × Negative = Positive in 5 Levels Elementary to Math Major
Winning Hexcodle with Binary Search
Переглядів 1,2 тис.9 місяців тому
Winning Hexcodle with Binary Search
A Surprisingly Simple Trick to Solve the Toughest GRE Probability Question
Переглядів 2,3 тис.9 місяців тому
A Surprisingly Simple Trick to Solve the Toughest GRE Probability Question
Dividing by Zero in Five Levels -- Elementary to Math Major
Переглядів 466 тис.10 місяців тому
Dividing by Zero in Five Levels Elementary to Math Major
This Can't Be Right, But Where's the Flaw? Two Envelopes Paradox Explained
Переглядів 2,2 тис.10 місяців тому
This Can't Be Right, But Where's the Flaw? Two Envelopes Paradox Explained
Why don't these cancel out? The square root of x^2 is not always x!
Переглядів 6 тис.10 місяців тому
Why don't these cancel out? The square root of x^2 is not always x!
My Favorite Counting Technique includes ALL of the other Three!
Переглядів 2,5 тис.10 місяців тому
My Favorite Counting Technique includes ALL of the other Three!

КОМЕНТАРІ

  • @kidsvideos4fun
    @kidsvideos4fun День тому

    1:32 if my friend already has some debts and I am removing it then it must result in zero. How it is positive??? 😅😂😂

  • @selahattinaydogan280
    @selahattinaydogan280 5 днів тому

    The following three articles explain that every number is divisible by zero. In doing so, they refute the claims in this video. I recommend reading these articles if you want to learn division by zero from different perspectives. 1.Division by zero in the light of the five fundamental principles - Beş temel ilkenin ışığında sıfıra bölme 2.A study to prove that the denominator can be zero in fractional numbers - Kesirli sayılarda paydanın sıfır olabileceğini kanıtlamaya yönelik bir çalışma 3.The problems created by zero in the division operation, their reasons and an attempt at a solution - Sıfırın bölme işleminde oluşturduğu; sorunlar, nedenleri ve çözüme yönelik bir deneme çalışması

  • @jeremyalm9006
    @jeremyalm9006 6 днів тому

    According to Boolos' original formulation, Random doesn't answer Yes or No randomly, but rather tells the truth or lies randomly, so the original puzzle can be solved in two questions!

    • @notenoughmice
      @notenoughmice 5 днів тому

      Isn't that the same outcome? There's a 50/50 chance of yes/no either way. Be it because the answer doesn't depend on the question and is a 50/50 chance either way or the God randomly decides to answer truthfully (either Yes or No) or to lie (either No or Yes) with the same 50/50 chance

    • @jeremyalm9006
      @jeremyalm9006 5 днів тому

      @ No! Haha, it’s counterintuitive. If the person is, in that moment, is either a truth-teller or a liar, then we can trick them into giving us the information we want in exactly the same way as we do once we have identified a non-random answerer.

    • @notenoughmice
      @notenoughmice 5 днів тому

      @@jeremyalm9006 ah, i think i see what you're getting at

    • @stechuskaktus8318
      @stechuskaktus8318 4 дні тому

      Even if all are telling the truth in a way you understand, how do you discern three people with two questions? There's 3! = 6 possible constellations, with two questions you get a maximum of 2² = 4 different options. You can be lucky and guess right, but other than that, you'd still need a third question.

    • @jeremyalm9006
      @jeremyalm9006 4 дні тому

      @ You get a free “bit” of information by process of elimination. If I know the liar is on the left and the TT is on the right, I don’t have to ask who’s in the middle

  • @S-payanage
    @S-payanage 6 днів тому

    🦦

  • @Österreich-f6m
    @Österreich-f6m 7 днів тому

    And yes. I'm not racist

  • @legobuildingsrewiew7538
    @legobuildingsrewiew7538 7 днів тому

    First!

  • @GokuTheSuperSaiyan1
    @GokuTheSuperSaiyan1 7 днів тому

    I'm about level 4

  • @abdullah.al.noman.z
    @abdullah.al.noman.z 9 днів тому

    20N2024 12:40

  • @manueltran1964
    @manueltran1964 9 днів тому

    OK, you had me at Levels 1 through 4. Level 5 made me cry.

  • @ishwar.9887
    @ishwar.9887 11 днів тому

    From the perspective of quantum mechanics and ancient spiritual wisdom, nothing is everything. so 0 times anything can technically become it. That's what I believe.

  • @IAlreadyHaveAKey
    @IAlreadyHaveAKey 11 днів тому

    Youre about 10 years too late on this video

  • @michapeka2800
    @michapeka2800 12 днів тому

    Love example of group with clock

  • @david-melekh-ysroel
    @david-melekh-ysroel 12 днів тому

    The world where 1+2+3+4+&c = -1/12 is the same where 1+1=0, and it's easier to prove this than to prove that equality. Not talking about modular arithmetic, just regular high school maths.

  • @malvrin
    @malvrin 12 днів тому

    Please do not treat a number as a limit

    • @johnlabonte-ch5ul
      @johnlabonte-ch5ul 10 днів тому

      ??? It is confusing. A number is unique and precise. A limit is a number. So I have to disagree. Please verify if a limit is exactly equal to the number it is defined as. I treat math from a middleschool pov. You might even say I am old-school. The usefull concept of infinity is dangerous, incomplete, inconsistent and imprecise.

    • @Chris-5318
      @Chris-5318 9 днів тому

      Limits are numbers. lim x->oo 1/x = 0. The LHS is a limit, the RHS is a number. What do you think 0 is?

    • @Chris-5318
      @Chris-5318 9 днів тому

      @@johnlabonte-ch5ul Everything is confusing to you. You never say what middle school (that's two words) math your are using. That's because you do not know any middle school math. That's because you are a muppet.

    • @johnlabonte-ch5ul
      @johnlabonte-ch5ul 9 днів тому

      A interesting question from Calculus. A vertical asymtode has a Derivative approaching infinity. Should we say a constant function has no Derivative? approaches 0? or simply 0.

    • @Chris-5318
      @Chris-5318 8 днів тому

      ​@@johnlabonte-ch5ul You are a muppet that has no clue about Calculus. There is nothing interesting about it. A vertical asymptote, by which you mean the function x = constant, does not have a derivative, although it is common practice to say its derivative is +oo or -oo, or infinite, in preference to undefined. In general, the derivative of a function does not approach anything. For a given x value, the derivative is a constant. Your inability to appreciate that is yet another demonstration of how extremely confuse you are about Calculus, especially limits. If a function, f(x) has a derivative at x, then it is given by: f'(x) = lim h->0 (f(x + h) - f(x))/h. It's the expression (f(x + h) - f(x))/h, that approaches the derivative, f'(x) as h approaches 0. That expression is to be regarded as a function of h, not x, because x is being held constant. f'(x) itself is a constant (for the given x) and does not approach anything. e.g., the function f(x) = x^2 has the derivative f'(x) = 2x for a given x. f'(x) is not approaching 2x as h->0 because f(x) is not a function of h. This is all very simple, but as I have remarked before, you are even simpler, and that is why you don't and can't understand it. Be clear the derivative of a function is not approaching the derivative of that function as your stir-fried brain seems to "think" (for the lack of a better word). In particular, a constant function has the derivative 0 - it does not approach 0. Using expressions such as "approaches" or "tends to" are convenient left-overs from simpler times. Thy can be helpful, though. We simply say the derivative of a constant function is 0. I have pointed out to you, quite a few times, that the formal body of the definition of limit does not use phrases such as "approaches" or "tends to". The problem is that the lim notation, along with it's x->a part, is so convenient, that nobody has (successfully) proposed a less misleading notation. The definition is easily enough to clear up any confusion or ambiguity - but you have to learn it and understand it, both being things that you are unwilling and incapable of doing. I am quite sure that, because you are extremely stooooopid, you will not have understood anything I just wrote. I understood it better than you after the very first time that the math teacher introduced it after the "O"-level exams (as it was in the old days).

  • @kdhd100
    @kdhd100 13 днів тому

    1+2+3+.... is infinity not a negative fraction.....

    • @RF-fi2pt
      @RF-fi2pt 8 днів тому

      Mathologer video very well explained what you said , specially because numberphile 9 years ago point this. But as numberphile 9 month ago come with a more physical proof (video the return of -1/12), this of Dr Sean is very clear about solving one physical constraint at Casimir effet, with that strange equality.

  • @JeudyGuzman2
    @JeudyGuzman2 13 днів тому

    I never passed algebra.

  • @Pi_Pithe
    @Pi_Pithe 13 днів тому

    e 13:22

  • @sr6424
    @sr6424 14 днів тому

    This is the best explanation of the -1/12 I’ve seen although some of it is above my intelligence! It’s good to see the example of 1+1+1+1…… This may be a dumb question but I’ll ask it anyway! We have all seen the ‘How to Disprove Pythagoras’ puzzle. The one where you put a a load of steps along the hypotenuse of a right angle triangle’ it doesn’t matter how many steps you put in the sum is always the opposite + the adjacent! E.G. if it is a 1,1,sqrt(2) triangle even with millions of steps the length of the hypotenuse will be 2!

    • @pr0ntab
      @pr0ntab 13 днів тому

      Are you asking why even if the little left and up steps along the hypotenuse of a right angle triangle get closer and closer to the diagonal, they still don't approach sqrt(2) in length as you take the limit, but are still fully 2?

    • @sr6424
      @sr6424 12 днів тому

      @ yes. I understand the maths behind why it will always be 2. Can there be more to it though (similar to the -1/12 conundrum)?

    • @diribigal
      @diribigal 11 днів тому

      @@sr6424 Basically, you have intuition that it's fine to swap the operations of "taking length" and "taking the limit of a curve" and then are confused when the length of the diagonal limit is different from the limit of the lengths of the staircases. The bottom line is that those operations can't always be swapped. In a graduate level real analysis class/book, a number of theorems about when limits can and can't be swapped are studied.

  • @AliceObscura
    @AliceObscura 14 днів тому

    I basically use the level one explanation verbatim when I introduce e to my math students. Since it directly involves money, it is more interesting to most of them and it's a handy way to explain compounding interest at the same time. Two birds with one stone 😂

  • @Steven-v6l
    @Steven-v6l 15 днів тому

    yet another proof that: "repeat this infinitely many times" is not well defined. My favorite example: you have a bag with infinitely many billiard balls (numbered 1,2,3,4 ... etc). Step: remove 1 ball from the bag. Repeat the step infinitely many times. How many balls are left? a) zero -- since you take the next numbered ball each time b) infinitely many -- you only take the even numbers. c) seven -- you only take balls numbered 8 and above. d) anything else. All correct.

  • @RealQinnMalloryu4
    @RealQinnMalloryu4 15 днів тому

    {1n+1n ➖ }+{2n+2n ➖ }+{3n+3n ➖ }+{4n+4n ➖ }+{5n+5n ➖ }+{6n+6n ➖ }+{7n+7n ➖ } {2n^2+4n^2+6n^2+8n^2+10n^2+12n^2+14n^2}={56n^14➖ 1}/12=56n^14/12=48n^14 2^24n^14 2^12n^7^7 2^6n^3^4^3^4 2^2^3n^3^2^2^3^2^2 1^1^3n^1^1^1^1^1^2 3n^2 (n ➖ 3pin+2).

  • @k.chriscaldwell4141
    @k.chriscaldwell4141 15 днів тому

    When mathematicians wander in to philosophy.

  • @steve_x9582
    @steve_x9582 15 днів тому

    Even as a 1st year math student I understood less than 20% of what he said

  • @physnoct
    @physnoct 15 днів тому

    To verify if it's true, put dollar signs on each side!

  • @RobertRobert-d2r
    @RobertRobert-d2r 15 днів тому

    An easier method. lets say 0.9999999.....=x so 10x=9.9999999...... 10x - x = 9x 9.99999999........- 0.999999999....... = 9 9x=9 x=1

    • @johnlabonte-ch5ul
      @johnlabonte-ch5ul 14 днів тому

      This is one of the standard "proofs" that ".99..." is 1. It is a circular algorithm that should end with the exact same value of x as you start with. x=y 10x=10y Subtract x=y or add 9x=9y or 11x=11y x=y The problem is, infinity. Numbers are unique and precise. If you first declare that the formula for the infinite geometric series represented by ".99..." makes it = to 1 in the first place, what are we talking about? No problem. The arithmetic gets messy and doubtful if we use infinity, which by definition is incomplete and imprecise. If we add x=".99..." instead of subtract, we get x=".99..." as we should with the flawed infinite arithmetic. Not very consistant.

  • @dmitry5319
    @dmitry5319 15 днів тому

    Cool. Btw, does it have anything to do with regularisations of sums of functions, in which these are regarded as distributions? (You integrate them against some test functions with good properties, which allows you, say, to integrate by parts and then derivatives of the series converge better, than you can integrate by parts back)

  • @crimfan
    @crimfan 15 днів тому

    Best explanation I’ve seen. Regularization is hugely important.

  • @rainerzufall42
    @rainerzufall42 15 днів тому

    The microwave example is actually very good. Noone would deny, that it takes half the max energy on the food, whatever happens between zero and infinity!

  • @yackawaytube
    @yackawaytube 15 днів тому

    1+2+3+4+...+ = infinity. It's unbounded. You can't group something that doesn't converge to make it meaningful.

    • @tomkerruish2982
      @tomkerruish2982 15 днів тому

      Strictly speaking, 1+2+3+4+... is undefined, as only finite sums are defined with traditional addition. We need to assign a meaning to 1+2+3+4+... first. Of course, the standard way to evaluate an infinite series declares that it diverges to positive infinity. There are meaningful ways (Cesàro, Abel, Borel, Riemann, and likely others) to assign values to some divergent series... for certain values of 'meaningful'.

  • @dimBulb5
    @dimBulb5 15 днів тому

    It is wrong to say 3 + 4 = 2 unless we also say (mod 5) at the end, informing the reader of a non-standard context. So, I think 1 + 2 + 3 + ... = -1/12 is missing some notation to provide this context. Maybe as simple as stating the function maps N -> Q (though the zeta function gets there via complex variables)

  • @bjorneriksson6480
    @bjorneriksson6480 16 днів тому

    off is not minus one, it is plus zero

  • @justingerber9531
    @justingerber9531 16 днів тому

    I don't think it's amazing some function be analytically extended and it has some value (-1/12). It only looks amazing when you put it next to a divergent sum and unfairly use an equals sign.

  • @stanimir5F
    @stanimir5F 16 днів тому

    It could be also -1/8 as shown in the blackpenredpen's video 1+2+3+4+5+6+7+8+9+10+11+...=S 1+(2+3+4)+(5+6+7)+(8+9+10)+...=S 1+9+18+27+...=S 1+9(1+2+3+4+...)=S 1+9S=S 8S=-1 S=-1/8 In general the moment someone calls that the sum is equal to whatever, he has to define what that "equal" means.

    • @RF-fi2pt
      @RF-fi2pt 8 днів тому

      I think the error black red pen try to show is we cannot rearrange terms and write k.S in divergent series . Only at convergent series.

  • @ke9tv
    @ke9tv 16 днів тому

    Of course, in nonstandard analysis, we can say that the standard part of the sum 1+2+3+... is -1/12, separating the standard and nonstandard parts. In some sense what we are saying is that the sum is "an infinite quantity, which we can separate out, minus 1/12." I once used the nonstandard identity 1 + 2 + 4 + 8 + .. = -1 (again this can be established by zeta regularization) in an argument trying to define (for a programming language) the results of bitwise Boolean operations in a system that admitted arbitrary-precision integers. I got there in part by pointing out that it holds (for ordinary binary arithmetic) in any finite word size. From there I could define what it would mean to do AND, OR and NOT among the bits of signed arbitrary precision numbers, using the identity ~x = -1 - x. That identity is meaningless in the reals, but for 2-adic numbers, it's extremely useful!

  • @pjero2005
    @pjero2005 16 днів тому

    Visit mathloger

    • @RF-fi2pt
      @RF-fi2pt 8 днів тому

      Yes mathologer very well explained, specially because numberphile 9 years ago point this. But as numberphile 9 month ago come with a more physical proof (video the return of -1/12), this of Dr Sean is very clear about solving one physical constraint at Casimir effet, with that strange equality.

  • @j-rey-
    @j-rey- 17 днів тому

    Hey nice, you made a video about the -1/12 sum I suggested in a comment on one of your videos several months ago. I had recently watched a then new Numberphile video about a weighting system they made, based on some work that Terence Tao had done, that derived -1/12 from the traditional sum of 1+2+3+etc. using a cosine term in front of each summand. I'm not sure if this video was a response to my comment specifically, but I really enjoyed your take regardless. I've done a lot of applied math at my jobs and during graduate school, so I love seeing how theoretical math can oftentimes be useful in applied math and physics, oftentimes decades after it was deemed "useless."

  • @paparmar
    @paparmar 18 днів тому

    The partial sum of the sequence is n(n+1)/2. If you allow the variable to be all real numbers instead of just non-negative integers, then the formula will give negative values between -1 and zero. Guess what the value of the integral of x(x+1)/2 between x = -1 and x = 0 is. Yep, -1/12!

    • @NotACommunist91
      @NotACommunist91 13 днів тому

      so is that just coincidence, or is there an actual correspondence between both cases?

    • @dlevi67
      @dlevi67 10 днів тому

      @@NotACommunist91 It's not coincidence. One of the best intuitive ways of "seeing" it is on the Wikipedia page of 1+2+3+4+ ...

  • @knutthompson7879
    @knutthompson7879 18 днів тому

    It’s -1/12, you just need to relax what you mean by “sum” and “equals”. Which seems like cheating but we actually do it all the time.

  • @Iddy267
    @Iddy267 18 днів тому

    Yall wanna know why humanity is stuck at a type 0 civilization level? It is because access to knowledge is often locked behind paywalls just like with "BRILLIANT", and learning is controlled by rigid structures. Imagine if education were free and stress-free, where people could learn at their own pace, focused on what genuinely interests them. This freedom would make learning enjoyable, which would foster curiosity, critical thinking, and a much broader skill set across society. Instead, we live in a system where nearly everything, including education, comes at a cost. In Norway, for example, students pay up to 70% of their income just to keep a roof over their heads-it's absurd. If education were truly worth the hassle, it would be accessible to all, without forcing students to jump through financial and structural hoops. With a society more empowered to learn and think critically, we could make significant strides toward becoming a more advanced civilization. All this because people need their greed to be satisfied instead of thinking big as a freaking race.

  • @GARDENER43
    @GARDENER43 19 днів тому

    This is weird because 1+2+3+4+....., is not equal 0 +1+2+3+4+..... 😂😂😂

  • @Blackmuhahah
    @Blackmuhahah 19 днів тому

    In the physics case there is one ingredient missing called "renormalization". This is the "throwing away" of the infinite part of the sum. The regularization mentioned here is more or less identifying which infinities occur. The formal treatment of infinities and when it's ok to throw them away is highly important in past and current theoretical physics and there is no "good" unique way to do it. Some version of this famously appears in classical magnetostatics (maybe even earlier) for the vector potential of an infinite wire. More recently this continues in quantum field theory and general relativity and why they don't "work" together as theories in some technical sense.

  • @brendanward2991
    @brendanward2991 19 днів тому

    In a simulation, everything is possible - even something as incongruous as this.

  • @roland3et
    @roland3et 19 днів тому

    Thanx for this amazing video about the fascinating correlation between the sum of all natural numbers and -1/12! Especially, all these graphical illustrations are impressive! Nevertheless, using the regular equal-sign "=" to describe this relation feels wrong to me, because "+" is (at least in my understanding) the math-symbol for just regular _arithmetic_ summation. Cesàro- and Abel summation, or - all the more - analytic continuation of Riemann's ζ-function is something very different. Therefore, I'd stick with 1+2+3+... ≠ -1/12 Am I wrong? 🙂👻

    • @diribigal
      @diribigal 17 днів тому

      @@roland3et I basically agree. Mathematicians would generally avoid writing that equation because 1+2+... is not specific as to the summation method (and it doesn't use a capital letter Sigma or similar).

  • @perpetgholl5742
    @perpetgholl5742 19 днів тому

    usefull to make view on yt.

  • @frankansari3457
    @frankansari3457 19 днів тому

    There are different ways to calculate this sum - but all end up with -1/12. This is really remarkeble and amazing. Especially because it is completely counter -intuitive.

    • @kazedcat
      @kazedcat 19 днів тому

      It tells you that -1/12 is a characteristic value of the series and not the characteristic of the regularization.

  • @syedabuthahirkaz
    @syedabuthahirkaz 20 днів тому

    A Nice Depiction of Gibbs Peaks : ua-cam.com/users/shortsOGwN3Zb1sXQ?si=44YffkPiUdcCcG6j

  • @peterhall6656
    @peterhall6656 20 днів тому

    Hardy's book "Divergent Series" plumbs the depths of regularization, Norlund, Abel, Cesaro means etc, Tauberian theory and much more.

  • @Qermaq
    @Qermaq 20 днів тому

    3:45 Isn't the Cesaro sum of 1 - 2 + 3 - 4 + ... 0? The partial sums are 1, -1, 2, -2, 3, -3, 4, -4, so every even-positioned term is -1/2, and the others approach +1/2.

  • @BritishBeachcomber
    @BritishBeachcomber 20 днів тому

    -1/12 is an obvious paradox. But all paradoxes are the result of a basic misunderstanding or a misuse of theory. I just ignore the so called proof. Math trickery.

    • @kazedcat
      @kazedcat 19 днів тому

      You can also ignore calculus. Why would adding infinite nothing results into something.

    • @diribigal
      @diribigal 18 днів тому

      @@BritishBeachcomber You're welcome to ignore it, but in doing so you'd be throwing away physics that has real world applications; is that your intent? Should the physicists stop calculating useful values just because you're calling them a paradox?

  • @TheAsaber
    @TheAsaber 20 днів тому

    I don't study math, but rather Latin and Ancient Greek. I love your channel. I've learnt a lot! Your voice being so calm is even ASMR for me hahahahahaha. Keep on the good work! 💪🏻