Cantor's Infinity Paradox | Set Theory

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  • čas přidán 6. 06. 2024
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    Cantor sets and the nature of infinity in set theory.
    Hi! I'm Jade. Subscribe to Up and Atom for new physics, math and computer science videos every two weeks!
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Komentáře • 1,6K

  • @upandatom
    @upandatom  Před 5 lety +235

    I see there is a lot of confusion over the first proof of the uncountability of the Real numbers. This is my fault. I was unclear and didn't provide the whole proof. I have made a video explaining it from start to finish in detail. Sorry for the confusion. czcams.com/video/_qyDBUpAGuo/video.html

    • @getowtofheyah3161
      @getowtofheyah3161 Před 5 lety +5

      Up and Atom Mathemtics PhD student who has taken axiomatic set theory. Lots that needs to be corrected in your video.

    • @monad_tcp
      @monad_tcp Před 5 lety

      oh, now it makes sense

    • @pat6595
      @pat6595 Před 5 lety

      Jade, do you think there will be a Theory of Everything?

    • @daredevil016
      @daredevil016 Před 5 lety +3

      Hey Jade 👋 , Since we know that there are infinite no. between any two real no. then what is the no. just next to zero(0) ?Or a no. i.e. just bigger than zero(0)?? If there are infinite no.ahead of it ,what no. it would be ??? Btw I m high school student from India , if there is any mistake in my question that I have mentioned ,please lemme know & please give your valuable opinion on this ...anyways new subscriber love your videos ,your way of explaining it ,keep making videos this help me alot in learning ...sorry for too long comment 😅.

    • @AgentOccam
      @AgentOccam Před 5 lety +2

      @@daredevil016 there's no number "just next to" zero, in real number terms. Assume the phrase "just next to" refers to the only number, call it x, larger than zero, of which it is true that you can't define a number that's less than x but still greater than zero.
      Can you do this with the natural numbers? Yes. For example, 3 has exactly one number that can be x, namely 4. No number that meets the definition of a natural number can be less than 4 and yet greater than 3. So in those terms, 4 is "just next to" 3.
      So in that sense, 1 is the number "just next to" 0. But there's no number in the real numbers, say, that can meet that definition.

  • @palrob1714
    @palrob1714 Před 5 lety +280

    I love how goofy your drawings are. They look very endearing.

    • @therayven3147
      @therayven3147 Před 3 lety +2

      @Joe Tonner amen to that...

    • @aurelienyonrac
      @aurelienyonrac Před 3 lety +7

      I love here drawings. It takes a pure soul to draw like that. I hope she uses them in all of here video 😍

  • @dubber889
    @dubber889 Před 4 lety +188

    mathematician comes to a bar, asking for a 1 litre of beer and then asking half of it, and half of it, and then half of it. The bartenders then said, "You should know your limit".

    • @savagenovelist2983
      @savagenovelist2983 Před 4 lety +27

      ryuzaki Can you not even tell the joke correctly?
      An infinite number of mathematicians walk into a bar: The first one asks for a shot, the second one for half a shot, the third for a third of a shot...
      At some point, the bartender hands them two shots and says: “Know your limits.”

    • @bigmichael6156
      @bigmichael6156 Před 4 lety +3

      @@savagenovelist2983 what if 64 mathematicians go to a chinese restaurant. Asked what they whant to eat. First one said: 1 grain of rice, please. the second : two grain third whants four next whants eight and so on?
      Chef : we must collect rice harvest for ten years to serve the last.

    • @Spacetauren
      @Spacetauren Před 4 lety +7

      @@savagenovelist2983 Actually the sum (for n from 1 -> infinity) of 1/n diverges to infinity. It would be more like :
      An infinite number of mathematicians walk into a bar: The first one asks for a shot, the second one for half a shot, the third for a fourth of a shot, the fourth for an eight of a shot...
      At some point, the bartender hands them two shots and says: “Know your limits.”

    • @desmondroberts6034
      @desmondroberts6034 Před 3 lety +4

      @@savagenovelist2983 Why wouldn't the bartender say in impatience: 'Here - knock yourselves out'

    • @HarshPatel27
      @HarshPatel27 Před 3 lety +2

      @@bigmichael6156 That's a version of the famous Indian tale of 'rice on a chess board' czcams.com/video/71yuH365Rug/video.html

  • @legoharry100
    @legoharry100 Před 5 lety +202

    "My infinity is bigger than your infinity." - Thanos

    • @jeromedavies2408
      @jeromedavies2408 Před 3 lety +3

      Indeed, is the Infinity Gauntlet enumerable or non-enumerable?

    • @lukasvozak7698
      @lukasvozak7698 Před 3 lety +1

      Don't wanna destroy 69 likes :(

    • @AnnoyingMoose
      @AnnoyingMoose Před 2 lety +1

      Thanos is just an imaginary irrational.

    • @samgordon9756
      @samgordon9756 Před rokem

      "You call that big? As if." --He Who Remains (Kang)

    • @michaeleckert7692
      @michaeleckert7692 Před rokem

      He really needed somehelp poor guy thought 2× meant something hell he didn't even push an octave

  • @giwrgos_kakep5020
    @giwrgos_kakep5020 Před 3 lety +56

    "You can't really count all the natural numbers, you die at about 3 billion" - instant subscribe

  • @hexenex
    @hexenex Před 2 lety +8

    Please, don't apologize for the length of the video. It is extremely fascinating and informative. And, infinite, of course!

  •  Před 5 lety +16

    Ah great video! It reminds me the first years of my engineering with calculus and algebra and their demonstrations. I could find the beauty of some demonstrations, and some other nasty ones... There were some challenges of course, but at the end finding the order in the chaos was part of the joy too. Thanks for the explanation, that I'm sure has hard work behind.

  • @dcryan
    @dcryan Před 3 lety +3

    Loving your videos! 👏 You really know how to break a topic down into bite size pieces. You‘re able to take comprehensive topics and make them more approachable and less daunting.

  • @linkon_
    @linkon_ Před 5 lety +6

    Thank you for explaining such a complex topic so easily. It takes some time to grasp the content of the video, but still explained effectively. 🙌👏👍

  • @equesdeventusoccasus
    @equesdeventusoccasus Před 5 lety +3

    Excellent work. It feels like this could be the start to a new series you could post along side your other videos as time permits. I'd be happy if it was.

  • @rish1459
    @rish1459 Před 5 lety +1

    Another lovely video. I love how you show a proof by induction without getting into the guts of how to prove by induction! Brilliant.

  • @impowerzone
    @impowerzone Před 2 lety +2

    Your expiation of the topic was amazing. I was struggling with some of the concepts while learning discrete mathematics for my data science course but you made it fun and easy to understand, please keep going your work is useful in many ways :) thanks for making the video.

  • @SpencerTwiddy
    @SpencerTwiddy Před 5 lety +6

    Cool vid as always👍🏼 here's a quick video topic suggestion: the Anthropic Principle. It might be a bit philosophical but I hear about it a lot from leading physicists, and think you would probably have an interesting and unique way of explaining it. Thanks!

  • @SahilBansal17
    @SahilBansal17 Před 5 lety +91

    In the proof at 04:22, in the first line, it must be suppose a/b = sqrt(2).

    • @ShaneClough
      @ShaneClough Před 5 lety +2

      a/b sqrt(2) = 1 is essentially the same as a/b = sqrt(2), if you divide through by sqrt(2) you get a/b * 1/sqrt(2) = 1. Taking the reciprocal of both sides then leaves you with b/a sqrt(2) = 1, and because a and b are just arbitrary integers, you can use them interchangeably leaving you with a/b sqrt(2) = 1.

    • @blazedinfernape886
      @blazedinfernape886 Před 5 lety +26

      @@ShaneClough what are you saying????
      The supposition itself is wrong it should be a/b =sqrt2
      Not a/b = 2

    • @1PUREROSE
      @1PUREROSE Před 5 lety

      Shane Clough thanks

    • @itisdevonly
      @itisdevonly Před 5 lety +3

      Yeah, I got really confused by the proof until I realized the first line was supposed to say sqrt(2) rather than 2.

    • @Scubadooper
      @Scubadooper Před 4 lety +2

      Surely it doesn't take much to edit the video and correct the proof.
      If you've still got it put a square root sign in on the very first line, if not rewrite it!

  • @mau_lopez
    @mau_lopez Před 4 lety +1

    Fantastic video, really enjoyed it. I found all the explanation a lot simpler than other explanations I've seen before. Thanks a lot for this video Up and Atom! Cheers!

  • @russellcannon9194
    @russellcannon9194 Před 4 lety +1

    Wow. Wow! WOW! Very well done. Thank you so much for making this video. I have known for a long time that some infinities are larger than others, but whenever I tried to explain this to my skeptical friends, I would fail miserably. The explanation you provide here is so elegant and succinct that all I need do is recommend this video to my friends as THE proof. Thank you so very much. A true measure of genius is not in what one knows but in the ability one possesses to successfully explain a complex concept in a way that can be apprehended by those who struggle with it. You are a genius. Vey well done. Cheers, Russ

  • @prbroussard
    @prbroussard Před 5 lety +14

    Yeah! Always fun to hear about Aleph null and Aleph one

    • @danielspivak3926
      @danielspivak3926 Před 5 lety +2

      Saying that the size of R is aleph one is the same as the continuum hypothesis. You're thinking of beta null and beta one.

  • @aspiringcloudexpert5127
    @aspiringcloudexpert5127 Před 5 lety +5

    Yay, a new Up and Atom video!

  • @xpkareem
    @xpkareem Před 4 lety +2

    He didn't drive himself insane thinking about numbers, he was always going to go insane, he just spent his time waiting to go insane thinking about numbers.

    • @dru4670
      @dru4670 Před 3 lety

      This sounds more plausible for some reason

  • @theultimatereductionist7592

    Order density of a set (between any two x & z in the set there exists a y in the set such that x < y < z) implies automatically an infinite set. But, you need the additional & independent axiom of the least upper bound property to make the set uncountable. Both Q & R have order density but only R has the LUB property.

  • @perrzzz
    @perrzzz Před 4 lety +5

    Wow, yours presenting is beyond amazing!

  • @haisontrinh727
    @haisontrinh727 Před 5 lety +5

    I'm glad that you made a video about Cantor's work, he is one of my idols, thank you so much. However, you forgot to mention the relation between cardinality of natural numbers and real numbers (c=2^ℵ0) and its proof, the Continuum hypothesis, which drove him insane. These are the real fun parts (except for insane part, poor Cantor!).

    • @wienerfotograf
      @wienerfotograf Před 10 měsíci

      Cantor was wrong, in my opinion all infinities are the same. I can prove it if you want.

  • @mininao
    @mininao Před 5 lety

    Woah this is awesome ! I've tried a bunch of times to understand the different "sizes" of infinity and this is the first time i really get it ! Thank you so much !

  • @garybrisebois2667
    @garybrisebois2667 Před 4 lety +1

    Thanks for posting this Jade. I have loved this subject since I first studied it almost forty years ago. I learned that the Real numbers were uncountable (the term we used) and therefore a "stronger infinity" than the natural numbers. I had never realized that the transcendentals were the downfall of the countability of the Reals, I thought it was all the Irrationals. I would love to see the proof regarding that! Anyhoo recently, in the past few years, I looked into Strengths of Infinitude further, and learned that with dimensionality you can find infinitudes stronger than the Reals: the number of line segments on a line is Stronger than Reals, the number of curves on a plane is still stronger than that, the number of shapes in 3-space still stronger, and so on! This means that there is AN INFINITUDE of INFINITY STRENGTHS! Blew my mind. Thanks again, came here from Tom Scott :)

    • @wienerfotograf
      @wienerfotograf Před 10 měsíci

      So you could also say that Cantor was wrong and all infinities are the same. They are Infinite!

  • @therealEmpyre
    @therealEmpyre Před 5 lety +167

    I see an issue with the first proof you showed for real numbers not being enumerable. You said they are not enumerable because there are infinitely many other real numbers between any two real numbers, no matter how close they are. This is true, but the same is true for rational numbers, which have been proven to be enumerable, so that is not a proof that real numbers are non-enumerable.
    The diagonal proof is convincing, though.

    • @terryendicott2939
      @terryendicott2939 Před 5 lety +10

      Since there is a rational number between any two reals, one can pick two distinct transcendental numbers and put an infinite number of rationals between them. So by the first "proof", does this mean that there are more rationals than transcendentals? The second argument has one small omission. The decimal representation of rational numbers is not necessarily unique. For example .50 = .499999999999999999999999999999999999999999999999999999999999999999.... This actually does not affect her proof, but should be mentioned and shown that it won't.

    • @therealEmpyre
      @therealEmpyre Před 5 lety +3

      @@terryendicott2939 I didn't say that there is a rational number between any two reals, or at least I didn't mean to say that. There are infinitely many rational numbers between any two rational numbers (not between any 2 real numbers). That makes them very densely packed, and yet I know that the irrationals, and more specifically the transcendentals, are much more densely packed still. I was not arguing against what she was trying to prove, just against that specific proof as she described it.

    • @terryendicott2939
      @terryendicott2939 Před 5 lety +2

      @@therealEmpyre I know you did not say that between any two reals is a rational. I did. If this were not true rulers would not work. I just wanted to point out that the argument used could provide a "proof" that a set with cardinality of the continuum would be "smaller:" than the integers. Just a small variation of your observation.

    • @therealEmpyre
      @therealEmpyre Před 5 lety +2

      @@terryendicott2939 I think you are wrong about there being a rational number between any 2 reals numbers, but it is just beyond my level of expertise to explain why. I am sorry that I can be of no further help.

    • @dan_rust_maths
      @dan_rust_maths Před 5 lety +14

      @@therealEmpyre Between every two distinct real numbers exist infinitely many rational numbers. Let x < y be two real numbers. Let n be such that (1/10)^n < y-x. Such an n must exist as y-x is strictly positive (and then use Archimedes' property). Now Let z be the number you get by only taking the first n+1 decimal places of y (if y has a trailing sequence of 0s in its decimal representation which begins before the n+1st position, then we can do a similar trick with x by taking the first n+1 decimal places and then adding (1/10)^(n+2) ). It should be clear that z is rational as it has only finitely many non-zero digits. Clearly z is strictly less than y, and by our choice of n, it can easily be shown that z is strictly greater than x. To get infinitely many, just take larger and larger ns in the above argument.

  • @juddgoswick2024
    @juddgoswick2024 Před 4 lety +4

    Jade's enthusiasm is transcendental. For a formal proof, watch her videos!

  • @katelikesrectangles
    @katelikesrectangles Před 4 lety

    This is the first time I've heard this stuff and felt like it made any kind of sense. Thank you so much!

  • @lectrix8
    @lectrix8 Před 5 lety

    This is one of my favorite topics in pure math. I love your presentation. Very succinct!

  • @AlexKnauth
    @AlexKnauth Před 5 lety +21

    Wait the “proof by continuum” thing at 7:43 : why doesn’t that also imply that the rational numbers are non-enumerable?
    If the rational numbers are enumerable, and this proof technique seems to contradict that, is the proof technique invalid?
    Or, does it not actually apply to the rationals because of something I’m not seeing?

    • @JiveDadson
      @JiveDadson Před 5 lety +1

      the diagonalized number is not rational.

    • @AlexKnauth
      @AlexKnauth Před 5 lety +2

      @@JiveDadson Yes, I know. That's how I know the Diagonalization proof doesn't work for the Rationals. But what about the "continuum" proof? Does that rely on any properties of the Reals that Rationals don't also share?

    • @stevethecatcouch6532
      @stevethecatcouch6532 Před 5 lety +7

      @@AlexKnauth The continuum proof is not sound. Her assertion that you get stuck at alpha(v) and beta(v) is unsupported. Nothing about her list of omegas prevents finding a number on the list that falls between alpha(v) and beta(v).

    • @DarwinsStepChildren
      @DarwinsStepChildren Před 5 lety +5

      Her written explanation doesn't explain the "proof by continuum" very well. Even using the phrase Real Numbers is a bit confusing, because Real numbers include natural, integers, and rational numbers, AS WELL AS, irrational and transcendental. The proof by continuum only applies to the irrational and transcendental numbers. Technically, she should have said "irrational & transcendental" in place of "Real Numbers". Also a bit confusing is that the proof by continuum explains something intuitive. Some scientific proofs explain something(s) that is/are new, and unknown through experience. Take the age of the earth. It doesn't matter how much experience one has on earth, the age of the earth is not intuitive, in fact, the only way Homo sapiens can understand the age of the earth is via the scientific proof. However, take something like gravity, it is intuitive to Homo sapiens, as well as some other species, that if you drop an object, it will fall towards the center of the earth. This intuition comes with experience. Most Homo sapiens, when shown Newton's or Einstein's equation for gravity, after asking what it explains and being told it explains why a stone thrown in the air will eventually hit the ground, will say they already knew this and didn't need a mathematical equation to tell them. Even given this, gravity can't be explained through intuition, and requires mathematical proof to "exist", or be used in mathematical equations. The proof by continuum is similar. The important aspect for ANY infinite set is whether or not it can be paired with the Natural Numbers. Given alpha and beta, the fact that there is an infinite number of numbers between the two is irrelevant. Take alpha to be zero, and beta to be one. There are an infinite number of rational numbers between them. That isn't important. What is important is whether they can be matched with another Natural Number. There is 1/10, 1/100, 1/1000, etc. between 0 and 1; however, 1/10 "could" be matched with 10. 1/100 could be matched with 100, and 1/1000 could be matched with 1000, and so on and so forth. The important aspect of proof by continuum is that the irrational and transcendental numbers cannot be matched with the Natural numbers. The video's author does say this ~ 8:50. Take pi, a transcendental number, what natural number pairs with pi? None, again this is intuitive because the number goes on forever with no repeating pattern. NOW, PROVE Pi HAS NO NATURAL NUMBER TO PAIR WITH. This is where the proof by continuum comes into play. Take alpha to equal Pi, and take Beta to equal Pi plus one. There will be an infinite number of numbers between Pi and Pi plus one that CANNOT BE PAIRED WITH ANY Natural number, and it is this fact that PROVES that Pi is an irrational/transcendental number, and cannot be enumerated, and is therefore contained in a "different" infinity than the enumerated natural, integer, and rational numbers.

    • @meetjoshi9853
      @meetjoshi9853 Před 4 lety

      @@DarwinsStepChildren Thank you so much man. You cleared all of my doubts

  • @zbyszekz77
    @zbyszekz77 Před 5 lety +5

    Great video, maybe part II about continuum hypothesis and Godel incompleteness theorem?

    • @upandatom
      @upandatom  Před 5 lety +4

      yes i so want to cover the incompleteness theorem. just gotta wrap my head around it first

    • @TheDecguy
      @TheDecguy Před 5 lety

      I was waiting for Godel to show up.

    • @omerresnikoff3565
      @omerresnikoff3565 Před 5 lety

      Which one of Gödel's three incompleteness theorems?

  • @ahmedaly4328
    @ahmedaly4328 Před 5 lety +2

    Such an enjoyable concept to think about! Thanks and keep up the good work, Jade :)

    • @emmapasqule2432
      @emmapasqule2432 Před 2 lety

      Hi Mr Aly! I think you operated on me at the Austin hospital back in 2021, I had my gallbladder removed. Thank you Mr Aly! I hope that you are well. I always tell people that "Ahmed" is the best surgeon in Melbourne!! Best wishes, Emma Pasquale.

  • @douglaspackard3515
    @douglaspackard3515 Před 4 lety

    Your enthusiasm is contagious! Love the videos

  • @NotHPotter
    @NotHPotter Před 5 lety +150

    All of set theory's talk of alphas, betas and omegas is Greek to me.

    • @jesse2535
      @jesse2535 Před 5 lety +3

      its literaly greek my baby

    • @aspiringcloudexpert5127
      @aspiringcloudexpert5127 Před 5 lety +7

      @Kat Cut It's a pun on an English idiom.

    • @Blox117
      @Blox117 Před 5 lety +1

      i am the alpha!

    • @sharpnova2
      @sharpnova2 Před 5 lety +1

      honestly it's clearly greek to her as well. her first proof of the uncountability of the continuum is completely wrong and in fact could apply to the rationals as well which are provably countable. this video is littered with potentially harmful errors and generalizations.

    • @BlackJar72
      @BlackJar72 Před 5 lety +3

      It could really use some alephs.
      (Just google "aleph infinity.")

  • @GMPStudios
    @GMPStudios Před 5 lety +44

    And this my folks, is what you need to know to understand limits in calculus.

    • @NotHPotter
      @NotHPotter Před 5 lety +2

      Hehe, and the limits of calculus.

    • @stevec7819
      @stevec7819 Před 5 lety +3

      @@NotHPotter Weierstrass function

    • @NotHPotter
      @NotHPotter Před 5 lety +2

      @@stevec7819 well played

    • @GMPStudios
      @GMPStudios Před 5 lety

      @Ian M But DC has a lot of limits xD

    • @hybmnzz2658
      @hybmnzz2658 Před 3 lety +1

      Hell no. That is so different. Limits are about the arbitrarily large. Whether you are talking formally or informally.

  • @dnlwood32
    @dnlwood32 Před 2 lety

    Absolutely love the enthusiasm. I watch so many science videos and enthusiasm certainly makes them more watchable.

  • @englishiseasy6092
    @englishiseasy6092 Před 4 lety

    I love the way you explain the most complex and even boring things ever and I keep watching it over and over and over again. ❤❤❤

  • @kaushikgupta9490
    @kaushikgupta9490 Před 5 lety +6

    4:40 Hippasus, is that really you ? 😂😂😂

  • @markhaus
    @markhaus Před 5 lety +33

    Reading about mathematicians you begin to wonder if going too deep into maths awakens the “Great Old Ones” and drives you insane

    • @soutrikgun9133
      @soutrikgun9133 Před 4 lety +4

      I love the craft of the comment

    • @Raison_d-etre
      @Raison_d-etre Před 4 lety

      No.

    • @reikiorgone
      @reikiorgone Před 4 lety

      only awakens one to their spirit essence... the singularity

    • @Raison_d-etre
      @Raison_d-etre Před 4 lety

      @@reikiorgone No need for that hypothesis.

    • @reikiorgone
      @reikiorgone Před 4 lety

      @@Raison_d-etre that's an a priori assumption... Love ya!

  • @elyepes19
    @elyepes19 Před 5 lety +2

    Thanks for the video and the topic!
    A great intro to it is on the book "A Journey Through Genius" by W. Dunham, over there there are other ideas like quadrature of circle (impossible because of transcendental numbers), also the summation of 1/(n^2) = (pi^2)/6 (why pi, a transcendental, here?) with n going to infinity, and many more related to this video, and in line with the spirit of the Up and Atom channel

  • @thomaswright7325
    @thomaswright7325 Před 3 lety +1

    Props on the Charles Petzold quote. 'CODE' is in my top 5 most important books I've ever read.

  • @bernard2735
    @bernard2735 Před 4 lety +4

    Actually Euclid uses the word ‘ἄλογος’ (alogos - literally ‘irrational) in The Elements.

  • @Dudleymiddleton
    @Dudleymiddleton Před 5 lety +3

    You make brain-melting mathematics sooo sweet! :)

  • @bogdanchisalescu7739
    @bogdanchisalescu7739 Před 5 lety +2

    videos so nicely made, so evocative, keep up the good work !!!! :))

  • @zakirorrahman9007
    @zakirorrahman9007 Před 5 lety

    Great explanation really . Especially the set theory part and the proof great explanation.Superb!

  • @JJ-kl7eq
    @JJ-kl7eq Před 5 lety +22

    The SPCA is going to be interested in your sets where you draw lines between the forks and the dogs.
    Is there a dark side to you we need to know about?

    • @Blox117
      @Blox117 Před 5 lety +2

      whats wrong with eating dogs?

    • @robinw77
      @robinw77 Před 5 lety

      @@Blox117 there's nothing necessarily wrong with that, but sticking forks in living dogs is cruel :-)

    • @fakegay68
      @fakegay68 Před 5 lety

      I hope it has nothing to do with hunger.

  • @GMPStudios
    @GMPStudios Před 5 lety +6

    Infinity War!

  • @ffhashimi
    @ffhashimi Před 5 lety

    Well explained; I hope you create a video on the diffrence between Cardinal and Ordinal numbers, It's always pleasure to watch your videos .

  • @ctso74
    @ctso74 Před 5 lety

    Great video, again. Cantor was certainly a character, from his philosophical endeavors to his Baconian theories.

  • @taht-qrm6696
    @taht-qrm6696 Před 4 lety +3

    8:41 what i drew on my math exam paper

  • @alefdias4468
    @alefdias4468 Před 5 lety +4

    I love how passionately you talk about how exciting number theory and set theory are... I am graduating in engineering and people don't really see the beauty in math, just its usefulness, which makes me a little sad when helping people understand, let's say, calculus and the amazing things that make my eyes shine do not excite them in any way

    • @upandatom
      @upandatom  Před 5 lety +3

      I know right?! I think it's because it's very abstract and when we learn about it its uses aren't emphasized. Oh well :(

    • @alefdias4468
      @alefdias4468 Před 5 lety

      @@upandatom , exactly! I really enjoy talking about math, I like it not only for how useful it can be, I just find so much beauty in it! So much pleasure in simply understanding and visualizing the concepts, it is simply amazing! I wish I could show math to other people through my eyes... It is so hard to explain why you find so much beauty in something(showing people things they don't see is probably hard in any situation). I really enjoy learning and understanding things, and the ones I like the most are in math... So general, so logic, like e and π transcend our meanings based in our daily uses of numbers, math transcends our reality!(and can still predict things about it, even abstractly on a completely different dimension, sometimes literally).

  • @pranaynarvariya8342
    @pranaynarvariya8342 Před 2 lety

    After class, this video has cleared some doubts my doubts. Thanks a lot.😊

  • @ChrisDart-cerebratorium
    @ChrisDart-cerebratorium Před 4 lety +1

    I love your videos. You make these concepts so much easier to understand especially with your animations. The only catch I have is that the sound quality is a little muffled. The higher frequencies seem to be missing. Is there a way you can fix this?

  • @JakubH
    @JakubH Před 5 lety +12

    doesn't the argument starting at 7:42 hold also for just the rationals?

    • @iVideoCommenter
      @iVideoCommenter Před 5 lety

      No, because a rational is defined by the division of two integers, which are defined by finite successors of 0.

    • @Eulercrosser
      @Eulercrosser Před 5 lety +3

      Yes, you are correct. The argument breaks down at 8:09 when she says "suppose you get stuck" and assumes that you will get stuck without ever proving it (which cannot be proved when you've assumed that you have a complete list).

    • @AlexKnauth
      @AlexKnauth Před 5 lety

      Jakub Homola +1 You’re talking about the “proof by continuum” thing at 7:43, right? I have the same question.
      Is there something I/we’re missing that makes it apply to the reals but not the rationals?

    • @JakubH
      @JakubH Před 5 lety +1

      @@Eulercrosser about that "get stuck", I think she assumed that for contradiction to prove that you can always find numbers between a' and b'. She than found other numbers in between, creating that contradiction.

    • @JakubH
      @JakubH Před 5 lety +2

      @@AlexKnauth yeah, she later said "this is the infinity of the continuum", but that doesn't seem right to me, since that argument also applies for rationals

  • @AyushGupta-rb4hb
    @AyushGupta-rb4hb Před 5 lety +3

    "Some infinities are bigger than other infinities"- Fault in our stars

  • @stephenpuryear
    @stephenpuryear Před 5 lety +2

    Jade, thanks for taking a run through this topic. It's fascinating but a lot of work. David Wallace, "Everything and More" is another resource, if you, like me, need an artifact to hold in your hands while you wrestle with these ideas. Thanks also for your link to "The Annotated Turing". I trust your recommendations and will give it a look.

  • @stevesloan6775
    @stevesloan6775 Před 4 lety

    That was trippy!
    I love the your work.

  • @MisterrLi
    @MisterrLi Před 4 lety +4

    Thanks for your little introduction on infinity. It is hardly a complete one, however, the nature of infinity is a little bit richer than this. When talking about infinite sets mathematically, there are many ways to express them. Cantor created one of the methods, in which he equals all infinite sets that are listable. It is however easy to see that therer are other possible ways to do it. You can treat all infinite sets together as a whole (as one concept, traditionally "∞"), where every infinite set is bigger than every finite set, and that's probably the most common and simple definition of an infinite set used in real analysis. Then there are the Cantorian hierarchy of transfinites, starting with finite numbers, then countable infinite numbers, then bigger and bigger levels of infinite sets, one level constructed from the smaller one below it. Yet another definition of infinite sets actually separates different countable infinities, like the set of all natural numbers and the set of all natural number squares. Nothing is wrong with Cantor's system, there are just many different ways to express infinite sets and their relations, and some ways do it more precise than Cantor did. The pairing up method doesn't work for this more precise definition of infinity, so instead nonstandard analysis numbers are used. These numbers have better precision compared to the usual real numbers and can also express infinite sets, so they make it easier to express and compare infinite sizes of sets. What system to use depends (as always) on your need; how much precision that is asked for and which tool will work best on the task at hand, not which system that is the best in every situation.

  • @cakeisamadeupdrug6134
    @cakeisamadeupdrug6134 Před 5 lety +13

    0.00000000000...1 == 0
    Hehe I usually teach the sum of an infinite series via the medium of Harry Potter tbh. Assuming each Horcrux splits Voldemort's soul perfectly in half, obviously.

    • @alefdias4468
      @alefdias4468 Před 5 lety

      Hahaha, I think I will use it too in calculus 2 to show intuitively the convergence of infinite series, seems much more interesting to divide a soul than a square...

    • @superfluidity
      @superfluidity Před 5 lety +3

      Not really. '0.00000000000...1' is just a meaningless string of symbols. It doesn't represent any number. You can't have an infinite string of zeroes and then a 1, since there's no end to the infinite string and so nowhere to put the 1.

    • @alefdias4468
      @alefdias4468 Před 5 lety

      @@superfluidity I think math is more about the abstractions we make, not about what kind of strings of symbols represent what, I see the "infinite" zeros after the comma as the idea of approaching a limit, the more zeros you put in between, the closer you get to zero, so, if to put a "methematical rigorosity", we can use the accepted limit version, is the same as saying that, as n goes to infinity, Lim [1/10^n]=0. To get more geometrical, it is about the number line, frontiers between numbers get really blurry when the continuous real line is explored... Many funny things happen when exploring the in-between of the numbers, the irrational and the transcendental ones are really interesting...

    • @cezarcatalin1406
      @cezarcatalin1406 Před 5 lety

      If the number of 0 is a quasi-infinite number, you just described the first rational number above 0.

    • @FactoryofRedstone
      @FactoryofRedstone Před 5 lety +1

      @@cezarcatalin1406 If you take lim(n->infinity)(1/10^n) you don't get a number above 0 you get 0. And what it means that they are infinite non-enumerable is, that there is no 1st number above 0, or above anything. For saying there is a 1st number, you need to be able to count (list) them, but there isn't.

  • @troyc382
    @troyc382 Před 3 lety

    Great video, thank you for the beautiful, amazing humour in math, definitely subscribed now! 😊❤️👍

  • @CarlosGonzalez-rg6ht
    @CarlosGonzalez-rg6ht Před 3 lety

    Absolutely fantastic video! Thanks very much.

  • @mrnarason
    @mrnarason Před 5 lety +14

    "a set is a group" lol
    There is a reason mathematicians use the specfic wordy definition, "a set is a collection of elements".

    • @heimdall1973
      @heimdall1973 Před 5 lety +1

      Describing a set as a group, collection, whatever else you can think of, is just playing with words, not defining a set.
      Mathematicians *do not* define a set. They describe sets by telling us their properties and properties of set membership. (A few such properties are given as axioms, others are proven.) So a set is just an abstract object. For example, having an object x, there is a unique "set", let's call it A, such that x is "a member of" A and any object that is not x is not "a member of" A. Such "set" we also describe as {x}, but {x} is a distinct object from x.
      By the way, a group is another mathematical term (it describes a set with a binary operation defined on it, satisfying certain properties).

  • @Msaber2012
    @Msaber2012 Před 4 lety +6

    Number theory is infinitely interesting 🙃

  • @lex33122
    @lex33122 Před 5 lety

    This is awesome! Very well presented.
    I'm totally engrossed by the philosophical side of maths. Thanks again for a great video!

  • @pattyfromtoledo
    @pattyfromtoledo Před 5 lety

    Love the quote at the end!

  • @geo3043
    @geo3043 Před 5 lety +7

    I didn't understand the first proof: why can't you do the same thing with fractions?

    • @AlexKnauth
      @AlexKnauth Před 5 lety +1

      geo froid You’re talking about the “proof by continuum” thing at 7:43, right? I have the same question.
      Is there something I/we’re missing that makes it apply to the reals but not the rationals?

    • @pierreabbat6157
      @pierreabbat6157 Před 5 lety +1

      You'll get an irrational number as the limit of the two sequences.

    • @geo3043
      @geo3043 Před 5 lety +1

      The problem for me is that it seems to be supposed that there is a finite quantity of numbers (in the list of omegas) between alpha and beta. But that's not true, even whith only fractions. You can always find an infinity of fractions between two numbers, no matter how close they are. So, with the infinite list of fractions, you would always be able to take a closer number of alpha by going further on the list. Therefore, the closest number of alpha does not really exist on the list.

    • @geo3043
      @geo3043 Před 5 lety

      @@hojasrayadas thank's for the answer, i'll have to look at the way this list is constructed to fully understand.

  • @neurodivergent4life
    @neurodivergent4life Před 5 lety +3

    Jade's friend recieves a call:
    - Hey! Guess what! My infinite is bigger than yours!! ........ Ha!!
    - *Sigh*... It's 3am, Jade, go to bed...

    • @upandatom
      @upandatom  Před 5 lety

      how did you know about this conversation?

    • @neurodivergent4life
      @neurodivergent4life Před 5 lety

      @@upandatom "I was there, I’m everywhere. Isn’t it beautiful world when everyone lives together, maybe it’s just me.
      Maybe it is I who lives with everyone. You are never alone.
      My name is...
      ... Alexa!"
      Happy Halloween. Lol

    • @thatellipsisguy8984
      @thatellipsisguy8984 Před 4 lety

      And that folks, is why the French husband is tired...

  • @nickyork8901
    @nickyork8901 Před 7 měsíci

    Brilliant explanation, so clear - and entertaining at the same time.

  • @thedrewsky4915
    @thedrewsky4915 Před 3 lety +1

    recently I was looking at what concepts and basic theorems I would need to learn if I were to take a certain major for college and cantor's principle was listed under it. I watched three videos before finding this one and left them completely clueless with what the heck cantors theory was even remotely about. Thank you so much for explaining it, now I at least know what I am getting myself into.

  • @quahntasy
    @quahntasy Před 5 lety +23

    Who is here before 100 views?
    You sir are greater than infinity.

    • @garyk3478
      @garyk3478 Před 5 lety +3

      I am! After I discard the other 2,106 views as outliers, anyway.

  • @matthewalan59
    @matthewalan59 Před 5 lety +5

    You are infinitely adorable. I guess I am going to have watch all your videos.

  • @monsieurr33fer
    @monsieurr33fer Před 5 měsíci

    Just found your page and it's brilliant!! Thank you

  • @raphipik
    @raphipik Před 3 lety

    Creepy how Google/CZcams knew I was reading that exact book and recommended this video! But super good recap of chapter 2 and made it easier to understand :)
    Thanks Jade

  • @ericlondon5731
    @ericlondon5731 Před 4 lety +3

    I wish you had been my math teacher in high school. I would have hung on every syllable to every word and found a reason to stay after class. I actually had an old cranky dude who hated being there and let everyone know, daily.

  • @gJonii
    @gJonii Před 5 lety +11

    Your first proof for non-enumerability of reals seems to work equally well on rational numbers. Meaning, it's wrong

    • @MikeRosoftJH
      @MikeRosoftJH Před 5 lety +4

      The proof is incomplete as stated. There are actually three different cases: a) the two sequences a(n) and b(n) are finite; b) the sequences are infinite and have the same limit; c) the sequences are infinite and have a different limit. In either case there is some real number not in the sequence. (For details, see the linked video in the pinned comment, or the Wikipedia article "Georg Cantor's first set theory article".)
      You can apply the proof (or the better-known diagonal proof) to a sequence containing all rational numbers, but the resulting number must be irrational.

  • @Echo3_
    @Echo3_ Před 4 lety

    I don't know how you learn this. I have a hard time keeping up, but it is soo alluring to watch you talk about it with ease ;)

  • @dru4670
    @dru4670 Před 3 lety

    Started from your recent video then came back to watch this. Really love it. Am a sophomore engineering student 🤗.

  • @keniangervo8417
    @keniangervo8417 Před 5 lety +4

    This was better explained than from a teacher

    • @richardaversa7128
      @richardaversa7128 Před 5 lety +1

      She is a teacher! In fact her audience of students is probably larger than any college professor or high school teacher's.

  • @TheHernanNoguera
    @TheHernanNoguera Před 5 lety +9

    "Yeah, the Greeks didn’t like irrationals"
    **throw a man off a cliff because, you know... numbers**

    • @darkwater234
      @darkwater234 Před 4 lety

      Well played! Greeks were suppose to be the architects of reason and wisdom and yet they rage quit math and killed some poor dude.

  • @smileifyoudontexist6320

    You have a great take on Learning teaching various subjects Fun!

  • @Snowflake_tv
    @Snowflake_tv Před 5 lety

    Thnx for the link!

  • @Valdagast
    @Valdagast Před 5 lety +4

    Oh yeah? Well, my transcendental number can beat up your algebraic number!

  • @letheology
    @letheology Před 5 lety +5

    Not George Cantor (pronounced like jorj). Georg Cantor, pronounced like Gay-Orc.

    • @richardfarrer5616
      @richardfarrer5616 Před 5 lety +1

      Gay-Org, I would say.

    • @letheology
      @letheology Před 5 lety

      @@richardfarrer5616in German final stops are unvoiced. but yeah, maybe an English speaker should say gay-org

    • @richardfarrer5616
      @richardfarrer5616 Před 5 lety

      @@letheology Interesting. I hadn't really considered it. I've done a quick survey of Internet sites though and www.howtopronounce.com/german/georg/ agrees with me in spelling, although their examples are closer to your suggestion. Meanwhile forvo.com/word/georg/ has one which is definitely Gay-orc, while another is completely unvoiced with Gay-or. I can safely say that, when watching a video on infinity, I did not expect to learn something about German pronunciation.

  • @amphibiousone7972
    @amphibiousone7972 Před 5 lety +1

    Great Job!

  • @6612770
    @6612770 Před 5 lety

    Very nicely done!

  • @picodev5597
    @picodev5597 Před 5 lety +3

    well done.
    about the cantor's diagonal it's not correct to "add 1" becaus if you add the carries to the digit to the left you' wont be sure to not get a precedent nimber. Usually it's easier to create the new number by using 8 if the original digit is not 8 and 1 instead. Any digit but 9 could be used ti avoid the .99999=1 problem.

    • @zeon137
      @zeon137 Před 5 lety +2

      Not really, it's actually any operation mod9

    • @pierreabbat6157
      @pierreabbat6157 Před 5 lety

      I'd add 5 mod 10 (or 2 mod 4 etc.; as long as the base is at least 4, it works).

  • @brandonnicholson2633
    @brandonnicholson2633 Před 5 lety +3

    The idea that one infinity can be bigger than another is built on the mistaken idea that infinity is a number, and therefore, has a size and can be measured. But it's not a number at all, so we shouldn't assume that we can treat it as one. Infinity breaks a lot of basic mathematical laws, because it's not a number, and so it isn't bound by those laws. Infinity doesn't belong to the set of all numbers so Cantor's theory has a very fundamental flaw.

    • @Lonly82Wolf
      @Lonly82Wolf Před 5 lety

      Yes, only a closed set can be compared to another closed set to see if one is bigger than the other, but when talking about infinity it is not a closed set it goes on forever, because of this infinity can't be bigger or smaller than infinity, if they are both infinity then they are the same size infinite size.

    • @gidi5779
      @gidi5779 Před 5 lety

      Infinity is not assumed to be a number and it surely is not treated that way. When one says "one set is bigger than the other" they mean there exists a surjection from it to the other. Also, I am not aware of any "mathematical law" that is "broken" by infinity

    • @gidi5779
      @gidi5779 Před 5 lety

      @@Lonly82Wolf What do you mean by closed set?

    • @Lonly82Wolf
      @Lonly82Wolf Před 5 lety

      @@gidi5779 I mean a closed group of numbers, that you can count.

    • @Lonly82Wolf
      @Lonly82Wolf Před 5 lety

      @@gidi5779 Although it seems logical the idea to compare infinits, by comparing their parts they go on for ever, if they have no end they are the same size infinite.

  • @deletedaxiom6057
    @deletedaxiom6057 Před 5 lety

    Where were you 3 years ago? When I learnt this I was a bit confused but fascinated.
    Nice video, clear, to the point and entertaining.

  • @dhritimanbora6675
    @dhritimanbora6675 Před 2 lety

    Great content! 👍 I would like to point out that natural numbers always starts with 1. As soon as we include 0, it becomes a set of whole numbers.

  • @hanks.9833
    @hanks.9833 Před 5 lety

    Excellent video 👌👏
    To demystify the transcendentals look up Liouville numbers.

  • @jonthecomposer
    @jonthecomposer Před 5 lety

    I've always liked concepts inside mathematics. It's really interesting hearing people talk about it. To me, it's like a pure form of logic with its own world of idiosyncrasies. It seems the more you know about how numbers are and behave, the more you realize you know very little. I loved the documentary on Andrew Wiles and how he proved Fermat's last theorem. And although I didn't understand much of the inner workings, I did understand the concepts that allowed him to prove it. Just the fact that he could even begin to relate "this with that" in such a strung out manner to even see what he was trying to go for, is just mind blowing to me. No wonder it took him years! Anyway, I digress. I just enjoy learning. Sometimes the biggest ideas come from the most humble beginnings.

    • @upandatom
      @upandatom  Před 5 lety +1

      totally agree with this. and I didn't know there was a documentary about andrew wiles, I'll have to check it out!

  • @chrisdengerd9363
    @chrisdengerd9363 Před 4 lety

    You are teaching me alot thank you.

  • @vitaliset
    @vitaliset Před 4 lety

    the funny part about this video is that i coincidentally saw that right before i study about infinity for my exams. Really helped to sort out some shenanigans that was going on that chapter of our course

  • @jeremyellis4047
    @jeremyellis4047 Před 5 lety

    Thank you for posting these videos. It is refreshing to be reminded of the absurdity of the world we live and constantly don't pay attention to. One way I try to make sense of the continuum is like this: The Number Line is an infinite line. Each number in order can be assigned a position. Between each number we can place all of the other numbers that fit in their own places. The trick though is to fit the numbers like 0.(infinity)1, 0.9(infinity)9, etc., those we can say are at a right angle in the plane of the Number Line, extending to infinity on their own number line, simply beginning where the two line are intersecting. This brings me to the irrational numbers. Now I did not think of this on my own, but was rather told by Numberphile here on youtube: they can be easily represented as a 3D line curving out of the XY Plane and into XYZ. So once you add imaginary numbers to your Plane of the Continuum, you have a 3 dimensional representation of all possible numbers that we know of so far. At least until you decide to see the universe as a point represented as 1 and add 1 to it.

  • @coreybray9834
    @coreybray9834 Před 3 lety

    We note first that the squares of N are contained as a proper subset within the set N. So, if N mapps to the squares of N, and the squares of N maps back to the squares of N in N, then the set N must have a Cardinality that is larger than its own Cardinality, a clear contradiction. This arises from the fact that we did not exhaust N in our second mapping, but only exhausted a subset of N.
    In fact, if we use the standard definition for an infinite set, we run into some serious and blatantly overlooked problems.
    For all m in Z^+, there exists an element m+1 in Z^+, such that m < m+1 in Z^+. This set Z^+ is endless by construction, because for every m in Z^+ we know we always have one larger value m+1. But, at no time do we everfind, when building Z^+ that the transition from m to m+1 is ever a leap from the finite to the infinite. There is always a finite distance of +1 that exists between all values m and m+1 in Z^+. Consequently, the set is both endless and finite everywhere, not endless and infinite. Anyone doubting this result is encouraged to identify the value for m, such that m+1 is no longer finite.
    Also, notice that mathematicians argue that infinity = infinity + 1 = infinity + 2 and so on, but if all these steps equal infinity, then the very idea of magnitude, as well as the fundamental theorem of arithmetic, breaks down at infinity. But, the concept of magnitude and the fundamental theorem of arithmetic never breaks down in the case of m < m+1, because m and m+1 cannot possibly be represented as the same unique product of primes to their powers as with the earlier case where all the above forms of infinity equal each other. So, Z^+ is not an infinite set, because all values of m and m+1 in Z^+, such that m => 2, will never have the same magnitude, nor the same unique prime factorization.

  • @digitig
    @digitig Před 4 lety

    I already knew Cantor's infinity paradoy. I just like watching Jade.

  • @joelrivardguitar
    @joelrivardguitar Před 2 lety +1

    Good video. If I remember correctly the first infinity is w (omega) or Aleph-null/Aleph 0 and the next one is Aleph 1. Infinity and the Mind by Rudy Rucker is one of my favorite books ever.

  • @Logical-Sense
    @Logical-Sense Před 5 lety

    It wasn't so long, the presentation made time fly by.

  • @omerresnikoff3565
    @omerresnikoff3565 Před 5 lety +1

    It's actually even easier than that, since Cantor proved that the power set can't have a bijection (pairing) onto the original set, therefore the power set of the reals is even a bigger number. More complex mathematics as the use of the von Neumann-Bernays-Gödel (NBG) set theory allows you to see that the cardinal of the reals is the next infinite cardinal after the enumerable, that is, there is no posible intermedium cardinal; this is called the continuum hypothesis and Gödel has a great article concerning it and the uses of the axiom of choice (AC)

  • @billf7585
    @billf7585 Před 3 lety

    I'm fascinated by this topic, the cardinality of the continuum, and all the strangeness it leads to. Its relatively easy to prove that any open interval has the same cardinality as all real numbers. Another interesting related topic is the Continuum Hypothesis, also advanced by Georg Cantor, who believed it to be true. It states that there is no set whose cardinality is strictly between that of the natural numbers and that of the reals.

  • @carlhopkinson
    @carlhopkinson Před 5 lety +1

    I took Set Theory in college and it was the most mind warping course I ever didn't drop.