КОМЕНТАРІ •

  • @osvaldomena1172
    @osvaldomena1172 6 років тому +609

    So we can fill Gabriel's horn with paint, but we can't paint it 😅

    • @btat16
      @btat16 6 років тому +76

      Osvaldo Mena Wouldn’t that, then, completely paint the inside of the horn? My head...

    • @osvaldomena1172
      @osvaldomena1172 6 років тому +47

      @@btat16 No because the internal surface of the horn is infinite too! 😅😫

    • @btat16
      @btat16 6 років тому +47

      Osvaldo Mena but. But... if you fill it up wouldn’t it be touching everything? It hurts

    • @morganthem
      @morganthem 6 років тому +8

      @@parkershaw971 how we has so small no volume is in but area still there?

    • @mithileshwadurkar8809
      @mithileshwadurkar8809 6 років тому +26

      We can paint it if the thickness of the layer coating the horn is infinitesimal

  • @maxhaibara8828
    @maxhaibara8828 6 років тому +191

    Q1. Proove that there is an object that has finite volume but infinite surface area
    Ans : Notice that if there isn't, then BPRP won't make any video on it. Hence proved.

    • @gdahs1473
      @gdahs1473 6 років тому +3

      good trick :v

    • @gamecoolguy619
      @gamecoolguy619 5 років тому +2

      Ummn the area at x=1 is pi...
      So unless pi + {fraction of pi} = pi
      Which based on how your limit works is true, but logically you agree with this?

    • @1tubax
      @1tubax 3 роки тому +1

      Proof by necessity

  • @Nothing_serious
    @Nothing_serious 6 років тому +139

    It's referring to the angel Gabriel. Gabriel has a horn which he blows for seven days before the judgement day.

    • @rayniac211
      @rayniac211 4 роки тому +17

      Where judgement day refers to the point in time where Gabriel's neighbours finally lose patience and decide to do something about the noise.

    • @JdeBP
      @JdeBP 3 роки тому +10

      Actually, in the Bible it is seven angels with trumpets, and none of them are named; and Gabriel isn't described elsewhere as having a trumpet. "Gabriel's horn" is an affectation of 20th century recreational mathematics authors that didn't occur in the centuries before, or even before the 1980s that I can find. It isn't actually the proper name. Evangelista Torricelli named it the solidum hyperbolicum acutum, where more strictly this is a truncation of that solid, and the original theorem had a cylinder from x=0 to x=1 which the calculus proofs miss out.

    • @shahjahonsaidmurodov
      @shahjahonsaidmurodov Рік тому +7

      And in the Quran, the angel blowing the horn is actually called Israfil

  • @victoirevim9698
    @victoirevim9698 6 років тому +256

    Pi * r² * THICCness

  • @Dunkle0steus
    @Dunkle0steus 6 років тому +105

    My first instinct is to imagine a cube with dimensions 1x1x1. Then add a rectangular prism with dimensions 1x1x0.5 on top of it. Then a prism 1x1x0.25 on top of that. You can add infinitely many prisms each half as thick as the previous. Each increases the surface area by at least 2, because it still has two faces with dimensions 1x1. The volume is 2 though.

    • @MagnusSkiptonLLC
      @MagnusSkiptonLLC 6 років тому +63

      That's pretty much a low-res version of Gabriel's Horn.

    • @Dunkle0steus
      @Dunkle0steus 6 років тому +3

      tbh I didn't watch the video, I just made this comment after the introduction

    • @WhattheHectogon
      @WhattheHectogon 6 років тому +2

      @@Dunkle0steus also vsauce

    • @hedgechasing
      @hedgechasing 6 років тому

      Dunkleosteus when the dev of TFC+ randomly pops up in the comments of an unrelated video... thanks for your work on that. :)

    • @Dunkle0steus
      @Dunkle0steus 6 років тому +1

      Whoa I never get recognized. Thanks!

  • @NuptialFailures
    @NuptialFailures 6 років тому +30

    Interesting video! Gabriel's horn has an interesting property of having constant negative Gaussian curvature. Do you think you could do a video on the calculus of that in the future (as you can relate it to the surface area you calculated here)? Thanks!

  • @WhattheHectogon
    @WhattheHectogon 6 років тому +82

    What about the opposite? Is there any "object" with infinite volume, but finite surface area?

    • @AnimeLawyers
      @AnimeLawyers 6 років тому +62

      An inverted ball. The ball has a finite surface area. The volume of outside the ball extends to infinite time and space.

    • @BinuJasim
      @BinuJasim 6 років тому +11

      No. just check wikipedia en.wikipedia.org/wiki/Gabriel%27s_Horn It has a proof why the opposite can't happen

    • @BinuJasim
      @BinuJasim 6 років тому +18

      @@AnimeLawyers Why do you need an inverted ball? Simplify further. Let's say the universe and whatever beyond it. Infinite volume. Zero surface area.

    • @stevethecatcouch6532
      @stevethecatcouch6532 6 років тому +7

      @VeryEvilPettingZoo The surface area of A's boundary is nonexistent, not 0.

    • @AnimeLawyers
      @AnimeLawyers 6 років тому +3

      @@BinuJasim You....... took that far too seriously......

  • @l3igl2eaper
    @l3igl2eaper 6 років тому +14

    A funny way to think about it, is that you can paint that horn of infinite surface area with a relatively small amount of paint.

  • @xaxuser5033
    @xaxuser5033 6 років тому +25

    《Ofc the answer of this is yes cz otherwise how can i make this video》you're such a legend

  • @fCauneau
    @fCauneau 5 років тому +3

    A similar case is the rectangle of area p*1/p : whatever the value for p, you can fill its area = 1, and the perimeter tends toward infinity whenever p goes to zero or infinity ;-)

  • @bengtbengt3850
    @bengtbengt3850 6 років тому +170

    This is great, but I can’t believe you didnt mention the following:
    Since the area is infinite, there’s no way you can paint that horn with a finite amount of paint. However, since the volume is finite, you could just dump a finite amount of paint in it and the entire horn would be filled. If the entire horn is filled, then obviously the sides of it are painted as well. Therefore, you have painted the horn with a finite amount of paint after all, even though we just stated that that wasn’t possible with a finite amount of paint.
    I guess we have some sort of paradox, right?

    • @Tumbolisu
      @Tumbolisu 6 років тому +63

      I think the problem comes from the fact that you are treating paint as both 2 and 3 dimensional.

    • @dlevi67
      @dlevi67 6 років тому +15

      If you can make paint thinner than a molecule and find an infinitely tall ladder so you can pour the infinitely thinnable paint into the mouth of the horn, no paradox required. ;-) (No more paradoxical in any case than any infinite series converging)

    • @stevethecatcouch6532
      @stevethecatcouch6532 6 років тому +5

      @@dlevi67 You pour the paint into the bell of the horn. The mouth is inaccessible, so it can't be blown and the universe will never end.

    • @stevethecatcouch6532
      @stevethecatcouch6532 6 років тому +9

      No paradox. The paint, while in the paint can, has finite volume and finite surface area. As it is poured into the horn, the surface area increases. That's to be expected, because the surface area of paint always increases as you apply it to whatever surface you are painting. It just increases by a bit more than usual when it's poured into the horn.

    • @Nothing_serious
      @Nothing_serious 6 років тому

      It was discussed in Numberphile I think.

  • @spudhead169
    @spudhead169 3 роки тому +2

    Gabriel got some serious braggin' rights.

  • @shawnheneghan4110
    @shawnheneghan4110 5 років тому +4

    The paradox is simply resolved. Yes the volume is finite and so it can be filled. Unfortunately it would take an infinite amount of time to fill it. Therefore the surface cannot be painted.

    • @ambrisabelle
      @ambrisabelle Рік тому

      It doesn’t take an infinite time to fill, just pour in paint with a flow of pi volumetric units per second and it will only take a second.

    • @rorythompson864
      @rorythompson864 5 місяців тому +1

      omg u have solved years of scientific debating, i will call the noble prize people for you now !

  • @evanpoole7829
    @evanpoole7829 3 місяці тому

    i love how we don’t actually need to integrate this to prove it, fascinating!

  • @ericherde1
    @ericherde1 6 років тому +27

    The angel Gabriel, from a scene in the fever dream know as the Book of Revelations.

    • @XanderGouws
      @XanderGouws 6 років тому +2

      Yeah, I think the mathematician that came up with it was called Torcellini, so sometimes it's reffered to as "Torcellini's trumpet/horn"

    • @jessehammer123
      @jessehammer123 6 років тому +3

      Xander Gouws Torricelli, not Torricellini. Close, though.

    • @coleozaeta6344
      @coleozaeta6344 6 років тому +9

      It was Squidward Tortellini.

    • @WerewolfLord
      @WerewolfLord 6 років тому +1

      Revelation.... aka John on LSD.

    • @blue_blue-1
      @blue_blue-1 6 років тому +1

      The revelation is serious.

  • @adaeptzulander2928
    @adaeptzulander2928 6 років тому +10

    This is a classic I learned WAY back in high school. You can fill it with water but you can't paint it. So what would happen if you filled it with paint? !
    🤯

    • @WerewolfLord
      @WerewolfLord 6 років тому +9

      You get to a point where the diameter of the horn is smaller than the diameter of a molecule of paint.

    • @stevethecatcouch6532
      @stevethecatcouch6532 6 років тому +16

      @@WerewolfLord Mathematical paint molecules can be shrunk to any desired size. Besides, bringing up reality to explain why you can't paint a non-existent horn with impossible paint feels like cheating.

    • @blackpenredpen
      @blackpenredpen 6 років тому +2

      : )

    • @angelmendez-rivera351
      @angelmendez-rivera351 6 років тому +4

      There is no paradox. The statement that you cannot paint it is simply false. Infinite surface area does not actually imply impossibility of painting. What implies impossibility of painting is the ratio of the volume to the amount of the surface area, and this is clearly finite.

    • @sensei9767
      @sensei9767 5 років тому +2

      Physical paint can't fill areas, it can only fill the space on top of it, since it's an 3D object. So if you want to know how much paint you need, you have to calculate the volume of the paint. The paint is a small layer on top of the horn. The diameter of the paint is approching the paints thickness, since the slope is decreasing which means that the paints diameter isn't approching zero which means the paints volume is infinite. the diameter of the paint inside the horn is Always decreasing, so it will eventually be thinner than the regular thicknness of the paint.

  • @mome6889
    @mome6889 3 роки тому +3

    imagine a simple cube you always cut in half. you can do it infinitely many times, it's surface area goes to infinity while it's volume stays the same.
    also you might consider having Gabriel's horn made up of some transparent material, fill it up with pi amounts of paint and boom, it will look painted from the outside

  • @danielbenyair300
    @danielbenyair300 5 років тому +3

    1:17 what if we use zero and not 1?
    1:22 how can we express it as 3D function? (X,Y,Z)
    1:30 why not cut it horizontly? (V=2×pei×( area of 1/x) should work right?)

    • @snfnsessizcocugu7884
      @snfnsessizcocugu7884 2 роки тому

      no, you can't evaluate the volume that way. try the same formula on a cone and you'll find a wrong value for its volume

  • @MrCigarro50
    @MrCigarro50 5 років тому +3

    But this is not surprising. The Gaussian integral has área sqrt(pi) and the length of the curve is infinite. Anyhow Gabriel´s horm is a fantastic example. Thanks Professor.

  • @mhm6421
    @mhm6421 Рік тому +2

    Blackpenredpen can't do perfect cuts-
    5:22 timestamp: Are you sure about that?

  • @zygaf6252
    @zygaf6252 6 років тому +13

    Like fractals.

  • @soumyachandrakar9100
    @soumyachandrakar9100 6 років тому +2

    So, finally it's here.

  • @iabervon
    @iabervon 6 років тому

    This is the horn Gabriel played that bit of Sledgehammer on. It sounds like a flute because you blow across a hole in it because it's infinitely long and you wouldn't be able to get to the end to blow into it.

  • @MrChiddler
    @MrChiddler Рік тому

    You can do this with any cuboid If you half it’s thickness while doubling the area of its top and bottom surface it tends towards infinite surface area while volume does not change. Volume is not related to surface area.

  • @klausolekristiansen2960
    @klausolekristiansen2960 6 років тому +1

    It is good to know that the vuvuzela has only finite volume.

  • @colinjava8447
    @colinjava8447 5 років тому

    I think the paradox could have been summarised better, like:
    To paint the outside of the horn, decide on the thickness of the coat of paint (greater than 0) first.
    Since the area is infinite, the volume of paint (of any non-zero coat thickness) has to be infinite too.
    Since the horn contains a finite volume of paint, it doesn't contain enough paint to paint itself even though the inner and outer areas are the same and the inside of the horn is in some sense painted since it's full of paint.
    As an exercise, figure out why it's not actually a paradox

  • @alejrandom6592
    @alejrandom6592 3 роки тому +1

    I'm a simple man, I see Gabriel Iglesias and a suface of revolution in the same thumbnail, I click.

  • @aniltamang7506
    @aniltamang7506 9 місяців тому

    Was relaxing to hear such a good presentation and I'm glad i didn't have to hear some slow version of indian presenter

  • @You12783
    @You12783 6 років тому

    I remember finding surface area under this curve but only above x axis during my calc exam ... Although the limits were finite ... So nice to see that it could generate such an interesting shape when rotated around x axis .. 😀

  • @Silver_G
    @Silver_G 6 років тому +3

    Please talk about the Sierpensky's Carpet or Manger's Sponge (too lazy to look it up for correct spelling but should be close)

    • @dlevi67
      @dlevi67 6 років тому +3

      Sierpiński and Menger respectively, though the objects are generally indicated without the diacriticals ('Sierpinski')

  • @krishnasimha8097
    @krishnasimha8097 4 роки тому

    I love the way you teach

  • @anegativecoconut4940
    @anegativecoconut4940 6 років тому +8

    8:06 Hello this is Chef Steve from MathWishes.com

    • @qillerdaemon9331
      @qillerdaemon9331 5 років тому +1

      You are after all the Major General for solving your integral!

  • @U9191-e6s
    @U9191-e6s 4 роки тому +1

    This a analog to any function with convergent surface area below but still a divergent arc length .. we want a video to discuss this issue 😁

  • @ajat2369
    @ajat2369 Рік тому

    In physics, Gabriel's Horn has been used as an analogy for certain physical systems that have infinite length or surface area but finite volume. One example is a long, thin tube that is closed at one end, such as a trumpet or a clarinet.
    If we imagine a trumpet as a Gabriel's Horn, the volume of air that can be contained in the horn is finite, but the length of the horn can be infinite. This means that the sound waves produced by the instrument can be thought of as propagating along an infinitely long path, even though the physical length of the instrument is finite. This property of Gabriel's Horn can help explain some of the unique characteristics of wind instruments, such as their ability to produce a wide range of pitches by changing the length of the air column inside the instrument.
    In another example, Gabriel's Horn has been used to describe the behavior of a particle falling into a black hole. In this case, the infinite surface area of the horn can be thought of as representing the event horizon of the black hole, which is the point of no return beyond which nothing can escape. The finite volume of the horn can be thought of as representing the mass of the black hole, which is concentrated at the singularity at the center of the event horizon.
    Overall, the use of Gabriel's Horn in physics is a useful tool for visualizing certain physical concepts and phenomena, and for highlighting the importance of carefully interpreting mathematical models and their implications.

    • @ajat2369
      @ajat2369 Рік тому

      If we limit the length of Gabriel's Horn to be the same as the size of the observable universe, which is estimated to be around 93 billion light years in diameter, we can calculate an approximate value for the surface area of the horn.
      Recall that Gabriel's Horn is formed by revolving the curve y = 1/x around the x-axis between x = 1 and x = infinity. The surface area of the horn is given by the formula:
      S = 2π ∫(1 to ∞) y * sqrt(1 + (dy/dx)^2) dx
      Substituting y = 1/x, we get:
      S = 2π ∫(1 to ∞) (1/x) * sqrt(1 + (d/dx(1/x))^2) dx
      Simplifying the expression inside the square root, we get:
      S = 2π ∫(1 to ∞) (1/x) * sqrt(1 + (1/x^2)) dx
      Making the substitution u = 1/x^2, we get:
      S = 2π ∫(0 to 1) sqrt(1 + u) du
      This integral can be evaluated using the substitution u = tan^2θ, which gives:
      S = 2π ∫(0 to π/2) sqrt(1 + tan^2θ) * 2tanθ sec^2θ dθ
      Simplifying and integrating, we get:
      S = π^2
      Therefore, the surface area of Gabriel's Horn, if its length is limited to be the same as the size of the observable universe, is approximately π^2 square units. This is an interesting result that shows how a surface with infinite length can have a finite surface area.

    • @ajat2369
      @ajat2369 Рік тому

      There are other natural phenomena that can be related to the Gabriel's Horn paradox, which involves a finite volume with an infinite surface area.
      One example is the shape of certain crystals and rocks, such as calcite crystals or stalactites and stalagmites in caves. These structures have a finite volume, but their surfaces can be extremely complex and have a high degree of fractal-like roughness, which can give rise to an effectively infinite surface area. This can have important implications for the chemical and physical properties of these materials, such as their ability to dissolve or absorb gases and liquids.
      Another example is the way that fluids behave in very small channels or capillaries. For example, the walls of small blood vessels or the narrow spaces between soil particles can have an effectively infinite surface area relative to their volume. This can give rise to unique fluid flow patterns and surface interactions that can influence many important physical and biological processes, such as nutrient transport, cell adhesion, and microbial growth.
      Overall, the Gabriel's Horn paradox is a fascinating and important concept in mathematics and science that can help us understand many different natural phenomena and the limitations of our mathematical models and physical intuitions.

    • @ajat2369
      @ajat2369 Рік тому

      The Gabriel's Horn paradox is a mathematical and physical concept that has important implications for our understanding of the universe and the limitations of our knowledge and models. While it may not have any direct benefit for the survival of humans or the universe, it can help us better understand the behavior of natural systems and phenomena, and improve our ability to make predictions and develop technologies based on this understanding.
      One way that the Gabriel's Horn paradox can be useful is in the development of models and simulations of complex natural systems, such as climate models, astrophysical simulations, and biomedical models. By taking into account the limitations and paradoxes that arise from the Gabriel's Horn paradox, we can develop more accurate and reliable models that better capture the behavior of these systems.
      In addition, the Gabriel's Horn paradox can help us appreciate the richness and complexity of the natural world, and inspire new ways of thinking and understanding the universe. By recognizing the limitations of our current models and theories, we can continue to push the boundaries of human knowledge and discovery, and develop new technologies and innovations that can benefit society and the world around us.

    • @ajat2369
      @ajat2369 Рік тому

      The paradox of Koch's snowflake is another fascinating example of a mathematical concept that challenges our intuitions and understanding of geometric shapes and their properties.
      Koch's snowflake is a fractal shape that can be generated by repeatedly replacing the middle third of each line segment in an equilateral triangle with two smaller line segments that form an equilateral triangle. This process is repeated infinitely many times, generating a shape that has an infinite perimeter but a finite area.
      The paradox arises when we consider the limit of this process, as the number of iterations goes to infinity. Intuitively, we might expect that the limit shape would be a smooth curve with a well-defined length and area. However, the resulting shape is a highly irregular and complex fractal, with an infinitely jagged perimeter that is larger than any finite number, and a finite area.
      This paradox challenges our intuitions about the relationship between the smoothness of a curve and its length, and raises important questions about the nature of infinity, limits, and continuity in mathematics and physics.
      The paradox of Koch's snowflake has many interesting implications for the study of fractals and their applications in fields such as computer graphics, image processing, and scientific visualization. It also has connections to other important concepts in mathematics and physics, such as chaos theory, dynamical systems, and non-linear dynamics.

    • @ajat2369
      @ajat2369 Рік тому

      I can show you the formulas for the area and perimeter of a Koch snowflake.
      Let "s" be the length of the initial equilateral triangle, and let "n" be the number of iterations in the Koch snowflake construction process.
      The formula for the perimeter of a Koch snowflake after n iterations is:
      P = s * (4/3) * (1 + (1/4)^n + (1/4)^(2n))
      This formula gives the total length of the perimeter of the Koch snowflake after n iterations, in terms of the length of the original equilateral triangle.
      The formula for the area of a Koch snowflake after n iterations is:
      A = (sqrt(3)/4) * s^2 * (5/3)^n
      This formula gives the total area of the Koch snowflake after n iterations, in terms of the length of the original equilateral triangle.
      These formulas illustrate the paradox of the Koch snowflake, in which the perimeter of the shape increases without bound as the number of iterations goes to infinity, while the area remains finite.

  • @MrJonathanwhyte
    @MrJonathanwhyte 6 років тому

    It was probably Martin Gardner who mentioned this years ago in one of his columns. He teased his readers by putting the horn upright and imagined pouring pi liters of paint in it......

  • @anirudh7137
    @anirudh7137 5 років тому +1

    A similar type of question came in my exam where we had to find the volume of the solid when rotated about its asymptote and I wrote infinite without even solving .Should have seen this video before. Now the teacher would award me 1/infinity for this question

    • @meme_engineering4521
      @meme_engineering4521 5 років тому +1

      Yes, it came in my paper also in dtu

    • @anirudh7137
      @anirudh7137 5 років тому

      @@meme_engineering4521 did you get it right?

    • @meme_engineering4521
      @meme_engineering4521 5 років тому

      @@anirudh7137 no..I am also in B14 batch roll number 52😂

    • @anirudh7137
      @anirudh7137 5 років тому +1

      @@meme_engineering4521 oh and I'm 53😂

  • @tonyennis1787
    @tonyennis1787 3 роки тому

    In 2D space, the Koch Snowflake is another example of a shape with finite area and an infinite perimeter.

  • @siekensou77
    @siekensou77 6 років тому +14

    Pi is such a strange/mysterious and interesting number

  • @Fran-fz7ud
    @Fran-fz7ud 10 місяців тому

    Gabriel horn makes sense. The volume will get so small it will aproach 0. The surface area will remain, it is greater than the one aproaching 0 so it will not aproach 0 and will be infinite

  • @RF-fi2pt
    @RF-fi2pt Рік тому

    see this other object, finite value at 2 dimensions paradox an infinite at 1 dimension: circle have finite area to one given radius R . One swirl line starting at center until that R have 1D Length infinite, as the line diameter is infinitesimal. Is the polar coordinates .
    The Integral from 0 to R of 2πr, gives exactly πR^2, but trying to see the integration process as that increasing swirl see the 1D line Length going to infinite. At Gabriel Horn is the same. 3D finite paradox a 2D infinite, one dimension below.

  • @mychevysparkevdidntcatchfi1489
    @mychevysparkevdidntcatchfi1489 6 років тому +1

    If you take fractal snow (infinite circumference, finite area), extrude it to 3D "cylinder", you get infinite surface area, finite volume. In fact, most things in real world are like this (eg. coast line). This is why the world is discrete (quantized), not continuous. Continuous math is just approximation of the real world.

  • @walkastray007
    @walkastray007 6 років тому

    Notice that the more excited he gets the faster he talks xD I love it

  • @coolbionicle
    @coolbionicle 6 років тому +3

    If we bring this design to the real world and made the horn with an hypothetical type of copper that is infinitely hard, since atoms are quantized particles the horn will eventually have an end where there are six atoms packed in the shape of an hexagon. If the starting radius were to be 1foot, how long would the resulting horn be?

    • @dlevi67
      @dlevi67 6 років тому +1

      That rather depends on how much copper you started with in the first place, wouldn't it?

    • @coolbionicle
      @coolbionicle 6 років тому

      @@dlevi67 not really, the thickness of the surface wouldn't matter because of the nature of the function dictates that it would be infinitely long. So it would go as long as the atoms could maintain the cylindrical shape, that's why I stated that at the end it would only have six atoms in a hexagon packed together, that's a one atom thick copper circle as small as the atoms would allow. You could even infer that the trumpet is a solid and it should still give the same result. Another key detail that might indeed affect the solution is the temperature, make the trumpet room temperature to make it simple. And for the record, I don't know the answer. I just think it would make a very cool question based on this shape as food for thought.

    • @dlevi67
      @dlevi67 6 років тому +1

      @@coolbionicle Sorry my friend, you cannot have it both ways: first you ask "how long would it be", then you say that "it would be infinitely long". No it wouldn't, if it were created by a finite quantity of material with a finite thickness (~2 * covalent atomic radius; for copper 264 pm).
      For example, assume you have 0.75 pg of copper - this is still about 7.2 billion atoms - and you would just about be able to get the first "ring" of 1 foot radius by stringing together individual copper atoms, so if you had 0.75 pg of copper your horn could only be a single atomic diameter long. A longer horn, even monoatomically thick, would require more copper.
      On the other hand if you have more copper than needed to get a single atom layer for _any_ given length, then you can choose: you keep beating the copper and it elongates at that "six atoms" size for however much copper you have, six atoms at a time, or you stop beating and you have a non-uniform thickness at some points in the horn. Which is why without specifying quite a few other conditions the answer depends on how much copper you have in the first place.
      If you assume single atomic thickness, and starting at an arbitrary point with a radius of 1 foot, the function 1/x will get to 8.66142* 10^-10 ft (covalent diameter of copper ~= 264 pm ~= "radius" of the horn at the narrowest point) at ~12 billion feet, or 3.8 million km. About 10 times the distance Earth-Moon.

    • @coolbionicle
      @coolbionicle 6 років тому

      @@dlevi67 I stated the curve would be infinite and the limiting factor would have been the "six atom" thing. But you got the gist of it. Damn, I though it would be long but damn, not that long! That's amazing! I will look into your calcs in more detail later but I think you got it correct!

    • @dlevi67
      @dlevi67 6 років тому

      ​@@coolbionicle It's just a reciprocal. If I have screwed up somewhere it's in the conversion between metric and imperial/ACU. It happens to the best at NASA.
      BTW - by horn length I mean the length of the axis of the horn; if you want the arc length it's quite a bit messier: are the atoms "spherical" and just tangential to each other, or do the covalent radii overlap? Or do we assume no rippling? If we assume no rippling, then there is that nice integral of √(1+log²(x)) which has no elementary expression but that Wolframalpha tells me is ~80 million km.

  • @danielbenyair300
    @danielbenyair300 5 років тому

    Two things:
    1. I think rotating it and solving it like a cone is better
    2. I think it should have something to do with e or 1/x

  • @felixzz8598
    @felixzz8598 6 років тому

    Take any convex quadrilateral ABCD split AB and CD into 3 equal parts each so 4 points, called Q1 Q2 P1 P2, are created. Proof that the area of Q1Q2P1P2 is the same as 1/3 * the area of ABCD

  • @ingilizcehazrlk9134
    @ingilizcehazrlk9134 6 років тому

    This is good, relaxing video, strangely

  • @malhar073
    @malhar073 6 років тому +2

    only video where both of my subscription are in it

    • @dlevi67
      @dlevi67 6 років тому

      You keep your subscriptions into Gabriel's Horn? You'll run out of space at some point. Plus Gabriel may get annoyed.

    • @I_like_pi_
      @I_like_pi_ 6 років тому +1

      @@dlevi67 No, they're written on the surface.

    • @dlevi67
      @dlevi67 6 років тому

      @@I_like_pi_ Well, Malhar said "in", not "on", but that might be a typo...

  • @MiguelGarcia-zx1qj
    @MiguelGarcia-zx1qj 4 роки тому

    I didn’t know anything about this particular problem, nineteen years ago, when one of my students (the matter was Ordinary Differential Equations, by the way), posed me a paradoxical version: “as the area of the plane figure is infinite, you would need an infinite amount of paint, to paint it. But if you encase that area into the horn, as a kind of median partition, and fill the horn with paint, you only need a finite amount of paint. Where is the catch?”
    PS: I see that some people have posed this paradox. Sorry for the redundance. However, solving it is interesting ...

  • @RedefiningtheConcepts
    @RedefiningtheConcepts 6 років тому +1

    Can you clear the concept of vectors multiplication and division is not defined in space.If you can, Please Please explain

  • @akasin8202
    @akasin8202 6 років тому +6

    Doreamon theme at beginning in background..

  • @DjVortex-w
    @DjVortex-w 6 років тому

    This produces the seemingly paradoxical result that you need a finite amount of paint to fill up the entire shape, but that paint that's filling it isn't enough to paint the entire surface.

    • @angelmendez-rivera351
      @angelmendez-rivera351 5 років тому

      WarpRulez There is no paradox. There is no reason to assume that it would not be sufficient to paint the entire surface.

    • @DjVortex-w
      @DjVortex-w 5 років тому

      How can you paint an infinite surface area with a finite volume of paint?

  • @akasin8202
    @akasin8202 6 років тому +1

    A question...that surface integral inequality used is same as cross section right?
    So what's confusing me is that why is cross section infinite when volume is finite?

    • @akasin8202
      @akasin8202 6 років тому

      No cross section will be integral of f(x)dx from 0 to 1...and f(x) is 1/x...so infinite

    • @gamecoolguy619
      @gamecoolguy619 5 років тому

      If you integrate 2pi(1/x) it's far more simpler however unlike all other negative power of x the function we get after integrating doesn't share main properties of the function in this case 1/x diverges to 0 ln(x) does not so probably not accurate at infinite level but that's just my speculation...

  • @philippelepilote7946
    @philippelepilote7946 6 років тому

    As a Hilbert curve is infinite in length and covers the whole surface of the bounding square, if you rotate it in 3D around an axis parallel to one of the sides of the square, you get an infinite surface into a finite kind of a torus volume as well. No ?

  • @jaimeduncan6167
    @jaimeduncan6167 5 років тому

    A 3D lookalike to the surfaces with finite area and infinite perimeter.

  • @3420undertaker
    @3420undertaker 6 років тому +2

    Why do somethings converge and some don't? Sorry if it's really basic I just like the math and don't really know much

    • @dlevi67
      @dlevi67 6 років тому +1

      There is no "because" other than "because it is that way", I'm afraid. You can work out definitions for convergence and divergence under different procedures (1+2+3+4+... "=" -1/12 anyone?), but ultimately there is no "reason" nor a way to predict in advance whether a _completely_ _arbitrary_ series or integral will converge.
      Why do you expect maths to make sense? ;-)

    • @joluju2375
      @joluju2375 5 років тому

      Hi Mike, you don't need math. The key is to think backwards. First experiment : take an infinite rope, cut it in an infinity of pieces. Add them up, and you get infinity again : this sum diverges. Second experiment : take a 1 meter long rope, cut it in an infinity of pieces (yes you can, even if you're tired, pick one of the pieces, and divide it). Add them up, and you get your 1 meter long rope back again : this sum converges. There is no mystery, an infinite sum can be finite.

  • @guilhermeneryrocha4056
    @guilhermeneryrocha4056 6 років тому

    Hey, why don't you record a video about how to derive the cartesian or polar formula of Gabriel's horn? The x, y and z of course

  • @cutieboo233
    @cutieboo233 5 років тому +1

    I think Pi is already an infinite number. So the volume looks like a number, but this number is 3.141596......... to infinity

    • @ayo6836
      @ayo6836 4 роки тому

      Liyuan Boo to think about that, it’s an interesting detail ** the finite volume is not that finite after all)

  • @anilsharma-ev2my
    @anilsharma-ev2my 4 роки тому

    One liter paint can spread over the area
    How much maximum area we covered with it if it's carbon molecules width required ????

  • @camerongray7767
    @camerongray7767 5 років тому +1

    Hi, I would really appreciate if you could do a video on the formula of the surface area of a manga sponge. It might be a bit easy for a superhuman like you, but it is a similar problem to this in that a sponge where n is infinite has volume approaching 0 and infinite surface are. Please I have been trying to figure the formula out for weeks and I can’t get it!

  • @XZellTheBest
    @XZellTheBest 5 років тому

    Hi, I'm not a math student so maybe I'll say something stupid. This it happens also with a 3d version of a gaussian function? I don't know... Maybe...rotating e^(-x^2) along the y axes?

  • @geekjokes8458
    @geekjokes8458 6 років тому

    is there a solid of revolution with the opposite properties (infinite volume but finite area)?

  • @6612770
    @6612770 6 років тому +1

    Excellent!

  • @mostafamhamed2606
    @mostafamhamed2606 6 років тому

    I have a challenge for you:
    Let g :R- -> R3 be a curve such that for every the vector g(t) is orthogonal to the tangent line to the curve at the point g(t). Prove that the curve lies on a sphere centered at (0,0,0).

  • @deonmurphy6383
    @deonmurphy6383 6 років тому

    Although the surface area goes to infinity your set up of the calculation again only considers the area of the 1/x portion from 1 to infinity. However it ignores the area at the boundary condition of 1.

    • @dlevi67
      @dlevi67 6 років тому

      Which is finite (in fact, zero), so I'm not sure what your point is?

    • @deonmurphy6383
      @deonmurphy6383 6 років тому

      The area of the boundary at 1 is pi*r^2, so as r = 1/x this will be 1, so the area at the boundary of 1 is pi. At the other boundary condition, the area of the boundary would indeed converge upon zero.

    • @deonmurphy6383
      @deonmurphy6383 6 років тому

      My point is that based on the statement of the problem, you have to include the area of your boundary conditions, or you are answering a different problem.

    • @dlevi67
      @dlevi67 6 років тому

      @@deonmurphy6383 Sorry, but I'm not sure I understand your argument. The area of the infinitesimally thin _circumference_ AT 1 is zero (or pi dy^2 if you want to use non standard analysis, but that's another question), and it is included since the integration boundary is 1.
      What Steve (BPRP) is calculating is the surface area of the *horn* , i.e. the open-ended surface which has an infinitesimally thin opening at the mouth, and a finite opening at the bell (which as you rightly say has an area of pi), not the area of the hyperbolic *cone* (which as you rightly say should include the closing lid).
      The "lid" is not generated by the rotation of the hyperbola around the X axis and is not a part of the horn (or if you prefer, the segment representing the distance from the X axis to the hyperbola at 1 is not a part of the hyperbola).
      In either case you still have an infinite internal area (inf + pi = inf) and a finite volume, since the volume of the lid is zero (or pi * dx if you are using non-standard analysis, but it's still a finite quantity).
      The typical paradox mentioned in association with Gabriel's horn of a finite volume of paint covering an infinite internal area works either way, except that if there is a lid on the horn you can't pour paint into it without a tin opener. ;-)
      (edit: YT was screwing up formatting)

  • @aditidas9978
    @aditidas9978 6 років тому

    Nice explained this problem😊😊BPRP . any situation present in which object have infinite volume and finite surface area😶

  • @nithinsirimanne2924
    @nithinsirimanne2924 4 місяці тому

    Understandable have a nice day

  • @t0mstone581
    @t0mstone581 6 років тому +2

    what about a sierpinski tetrahedron?

  • @donovanb8555
    @donovanb8555 3 роки тому

    I think this the very first video I can understand

  • @mrhatman675
    @mrhatman675 4 роки тому

    Didn t quite get it at the end why did you multiply 2πy by dl and not dx at the surface area integral

  • @zubmit700
    @zubmit700 6 років тому

    What's the longest chain rule derivative you know of and could it make an education fun video?

  • @runneypo
    @runneypo 6 років тому +1

    saw that edit at 5:49

  • @Tumbolisu
    @Tumbolisu 6 років тому

    Are there any other functions with this beavior? Can i use e^x from negative infinity to, well, any real number?

    • @mike4ty4
      @mike4ty4 6 років тому

      Actually, e^x gets small enough fast enough it can have both finite surface area _and_ volume.

  • @clyde__cruz1
    @clyde__cruz1 5 років тому

    It's like the bell curve.

  • @stevensiew4072
    @stevensiew4072 6 років тому +1

    Hey, Stop blowing Gabriel's horn

  • @toddtrimble2555
    @toddtrimble2555 Рік тому

    How is this any more remarkable than a Flatlander painting the curve y = 1/x^2 over the infinite interval [1, infinity)?

  • @leonardschreiter6871
    @leonardschreiter6871 6 років тому +3

    8:12 servers Area

  • @DynestiGTI
    @DynestiGTI 6 років тому

    I got impaled by Gabriel's horn.

  • @Lobyyyy
    @Lobyyyy 6 років тому +2

    The 3d graph like a horn🤣

  • @gekkouga2828
    @gekkouga2828 4 роки тому +1

    0:02 Is the background song the official theme of Doraemon?

    • @AP-wz6fb
      @AP-wz6fb 3 роки тому

      I am 9 months late lol

  • @matengelo3812
    @matengelo3812 Рік тому

    It is called the Gabriel's Horn because of the Archangel Gabriel and the horn he plays as the horn that announces the Judgement Day according to the Apocalypse chapter of the Bible

  • @phoenixelectronics2631
    @phoenixelectronics2631 5 років тому

    Bro you look cool on this dress.

  • @holachau5015
    @holachau5015 6 років тому

    Well if you think of the coastline paradox you can get shapes with finite area but infinite perimeter

  • @DiegoMathemagician
    @DiegoMathemagician 6 років тому

    I'm so nooby at calculus, but why do you use the formula of the volume of a cylinder when it is more likely to be a cone?

    • @DiegoMathemagician
      @DiegoMathemagician 6 років тому

      You are insane man, no one ever replied me like that, thank you so much. I will read it tomorrow :)

  • @marbanak
    @marbanak 6 років тому

    Thank you so very much. I requested this topic a month or two ago, and I am pleased to see that you delivered! When I was bored in business meetings, I would re-derive these equations. Hardest part was re-verifying that the area integral diverges. I actually struggled with that, but you explained THAT part really quick, and I like it. I do not like this paradox, however, and I have been casting about for some intuitive closure. Latest idea: Perhaps our area integral is wrong. The "strip" of area is not really flat. Yes, there is a dL component to it, but the circumference of the strip is larger on the edge closest to the y-axis. And the strip changes its shape in a non-linear way. I sometimes wonder if a refined model for dA would yield a converging result. Maybe I will re-visit this on my next cross-country plane ride. Thanks again. You have rekindled love for Maths in the heart of many fans.

  • @gsittly
    @gsittly 4 роки тому

    also the area under y=1/x is infinite even it's inside the finite volume.

  • @NcKyPmHzPPcrnTEat
    @NcKyPmHzPPcrnTEat 5 років тому

    I knew this from the mandelbulb set.

  • @IISH4RKZzII
    @IISH4RKZzII 6 років тому +3

    Wow, what is the level of math I need to be able understand all of this?

    • @pietrotettamanti7239
      @pietrotettamanti7239 4 роки тому

      All you need to know is how an integral works and maybe a little bit of differential calculus. Nothing that highschool maths can't handle (and I'm not even good at maths so it's definitely doable).

    • @TheMathias95
      @TheMathias95 4 роки тому

      B-A level maths, depending on your country. I believe the american equivalent is called pre-calculus?

    • @leoallentoff
      @leoallentoff 3 роки тому

      @@TheMathias95 pre calculus doesn’t even get to derivatives

    • @TheMathias95
      @TheMathias95 3 роки тому

      @@leoallentoff
      Yeah mb, I assumed 12th grade mathematics in the states could roughly be translated directly into someone who would be in 12th grade from my country. This is not the case.

  • @kuba9680
    @kuba9680 5 років тому

    The Gabriel is the Archangel Gabriel - he blows the horn to announce judgement day in Abrahamic traditions.

  • @machobunny1
    @machobunny1 5 років тому

    You passed over a few steps faster than usual, and I did not exactly follow...but I see how you got there and you make very few mistakes of any kind, so I trust it, as far as it goes. Still, Infinity is a strange space. Perhaps our inability to deal with it relates to our inability to move beyond the limits of current quantum mechanics.

  • @manthanmistry1205
    @manthanmistry1205 6 років тому +2

    Mind blowing 😮😮😮😮😮

    • @blackpenredpen
      @blackpenredpen 6 років тому

      Manthan Mistry
      I felt the same when I first saw it!

  • @jorgelenny47
    @jorgelenny47 6 років тому

    What about a square whose side lenght is √infinity?

  • @arturaskarbocius828
    @arturaskarbocius828 6 років тому

    is goes to infinity but with very bending rule of integral of 1/x is ln(x) and ln(inf.)=inf e^infi not equal infinity number raised by infinity equal to bigger infinty. area converges to material point without surface area. ln(google) or ln(10^100)=230,25 quit very small number.

    • @dlevi67
      @dlevi67 6 років тому

      google is not a googol. And the rest of your comment is not making much sense either; e^inf is still infinity in analysis; this isn't set theory...

    • @arturaskarbocius828
      @arturaskarbocius828 6 років тому

      ln(infinity) is not infinity let say infinity limit is 3.28 x 10^80 particles in the universe, ln(3,28x10^80)=185,4 so x axis approaching infinity where every molecule stack in one infinitesimal thin line but surface area increases ln(x) who is finite number.
      Origin of google: Google; the name of the search engine originated from a misspelling of the word "googol",[18][19] the number 1 followed by 100 zeros, which was picked to signify that the search engine was intended to provide large quantities of information.[20]

    • @dlevi67
      @dlevi67 6 років тому

      @@arturaskarbocius828 1) the origin of words does NOT authorise you or anyone else to use them incorrectly. A googol is not google.
      2) however many particles or Planck volumes there are in the observable universe, they are not infinite, since the observable universe is finite. Therefore you cannot treat the number of particles or Planck volumes as infinity - there is a (big, in fact infinite) conceptual difference. The same difference that there is between mathematics and physics.
      If you think the contrary in either case, you are welcome to your opinion. It doesn't make it correct.
      edit: YT keeps screwing up spaces!

    • @arturaskarbocius828
      @arturaskarbocius828 6 років тому

      2) yes but integral 1/x from 1 to infinity is ln(infinity) not equal infinity, ln(x) have intrinsic property to function not reach infinity. On conceptual level are different infinities i base my premise on integer numbers infinity 0, 1, 2, 3, ... infinity, molecules are integer numbers who together can make surface area so ln(integers_infinity) not equal infinity.

    • @dlevi67
      @dlevi67 6 років тому

      @@arturaskarbocius828 Sorry, but the ln function reaches infinity, as does ln(ln(x)) as does ln(ln(ln(x))). Just very slowly.
      On a conceptual level, in set theory there are different infinities. Not in analysis; what is used in analysis is a different concept (or if you prefer, it's Cantor's Absolute). Look it up.

  • @bernardlemaitre4701
    @bernardlemaitre4701 4 роки тому

    and finite surface under an infinite length of the curve comprizing the surface ?

  • @jall3ri
    @jall3ri Рік тому

    So Doctor Who's TARDIS is a a reverse Gabriel's Horn finite surface area infinite volume

  • @shohamsen8986
    @shohamsen8986 5 років тому

    Isn't the Gabriel a reference to the angel Gabriel?

  • @MichaelJamesActually
    @MichaelJamesActually 6 років тому

    Extrapolate this to the 4th dimension. Finite 4d "volume", but infinite 3D volume on the surface?

  • @SidharthjainSingla
    @SidharthjainSingla 4 роки тому

    But is it practically possible?

  • @victorpaesplinio2865
    @victorpaesplinio2865 6 років тому

    I guess that Gabriel is the Archangel in cristianismo. The Bible said that the angles will play horns to announce the doomsday. So I think that this is the Gabriel

  • @DjVortex-w
    @DjVortex-w 6 років тому

    But how about the other way around?

  • @piratesofphysics4100
    @piratesofphysics4100 4 роки тому

    I don't think that the inner surface area would be different than the outer surface area. So as we can fill this with pi amount of paint the paint will definitely paint the inner surface area. That means the paint can also paint the outer surface area.
    What the hell...