How Did Mathematicians Abstract the Idea of Distance? (Introduction to Metric Spaces)

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  • เผยแพร่เมื่อ 24 ก.ย. 2024

ความคิดเห็น • 126

  • @holachau5015
    @holachau5015 18 วันที่ผ่านมา +32

    Great video! Your definition of Q is incorrect though. 1/3 = 0.33333… is rational

    • @pi_squared2
      @pi_squared2  18 วันที่ผ่านมา +23

      Ah you're right! I don't know how that error got through, thank you for spotting that mistake; I've added it as a correction in the caption of the video.

    • @davethesid8960
      @davethesid8960 16 วันที่ผ่านมา +1

      ​@@pi_squared2 You could've also said finite or repeating infinite.

    • @kruksog
      @kruksog 16 วันที่ผ่านมา +8

      ​@@pi_squared2Don't let it frustrate you too much. Making simple mistakes is an essential part of doing something complicated. Keep up the good work.

    • @marigold2257
      @marigold2257 10 วันที่ผ่านมา

      ⁠​⁠​⁠@@pi_squared2you also missed that in a metric space d(x,y)=0 if an only if y=x

    • @7san738
      @7san738 6 วันที่ผ่านมา

      ​@@marigold2257no need for that cuz he showed d(x,x)=0

  • @whoeveriam0iam14222
    @whoeveriam0iam14222 16 วันที่ผ่านมา +39

    Maybe reupload with the music turned down or off

    • @pi_squared2
      @pi_squared2  9 วันที่ผ่านมา +16

      Yes, sorry that it came out like this, I'm quite new to editing and making videos. I'll be reuploading a version of this in the future that is hopefully way better produced not only in the music but the voice-over as well!

  • @redbigapplefloppa302
    @redbigapplefloppa302 18 วันที่ผ่านมา +90

    Why is the music so loud

    • @turtle926
      @turtle926 13 วันที่ผ่านมา +17

      WHAT?

    • @ILSCDF
      @ILSCDF 12 วันที่ผ่านมา +14

      WHY IS THE MUSIC SO LOUD?!

    • @Joshs8707
      @Joshs8707 11 วันที่ผ่านมา

      @@turtle926Are you reta***d?

    • @Joshs8707
      @Joshs8707 11 วันที่ผ่านมา +1

      @@turtle926Hello, u r not okay

    • @turtle926
      @turtle926 11 วันที่ผ่านมา +16

      @@Joshs8707 I CAN'T HEAR YOU

  • @axelsanchez5849
    @axelsanchez5849 18 วันที่ผ่านมา +47

    “As a child I was interested in topology”
    What child knows what topology is lmao I heard the term for the first time as an adult

    • @axelnils
      @axelnils 18 วันที่ผ่านมา +21

      Children with highly educated parents

    • @axelsanchez5849
      @axelsanchez5849 17 วันที่ผ่านมา +5

      @@axelnils I have highly educated parents, they never talked to me about math topics

    • @deltamico
      @deltamico 17 วันที่ผ่านมา +5

      I've heard of it at 16 I think. The thing is yt is good at popularizing math topics in recent years so that's why current young adults might be able to say such thing

    • @jimktrains0
      @jimktrains0 17 วันที่ผ่านมา +6

      It's also possible he meant that topological problems interesting him, but without the formal language. Wondering how different shapes relate to each other and can be turned into each other is something even a young child is capable of thinking about. Things like "how many holes in a straw" and "how many holes are in a coffee cup" aren't unreasonable.

    • @davethesid8960
      @davethesid8960 16 วันที่ผ่านมา +1

      ​@@axelsanchez5849 Well, highly educated is a very broad term. I mean if they're biologists, they won't ever talk about topology.

  • @mr.pumpkinn
    @mr.pumpkinn 17 วันที่ผ่านมา +9

    New incredible math channel is cooking...

  • @Eta_Carinae__
    @Eta_Carinae__ 6 วันที่ผ่านมา +2

    Thinking about it, it kinda feels like Lie Algebras have more in common with a metric than they do with a vector space. The point of disanalogy really is that distances can be negative, and the triangle inequality becomes the Jacobi identity. I mean, given that the determinant - which tracks oriented area/volume/metric scaling under a linear transformation - is a Lie algebra, doesn't that make some sense?

  • @jimktrains0
    @jimktrains0 17 วันที่ผ่านมา +7

    3:50 nit pick: iirc the circle is the boundary, so distance equal to the radius. A disc contains all the points less than the radius. Same with sphere (boundary) vs ball (solid).

    • @pi_squared2
      @pi_squared2  9 วันที่ผ่านมา +2

      You're right, that's a good catch! I'll add that to the description of the video, sorry about the small error and thanks for pointing it out.

    • @renstein8210
      @renstein8210 3 วันที่ผ่านมา +1

      @@pi_squared2 It isn't a small error. You go on to talk about the interior of a sphere, but under your definition, there is no interior. The point/ball that you said was in the interior of the sphere was a part of your sphere. Good that you fixed it. I guess you could fix it by using a slightly different definition of "interior". English is easier to manipulate than math.

    • @renstein8210
      @renstein8210 3 วันที่ผ่านมา

      So, I guess you cleared that up a bit later when you defined interior mathematically...

  • @MrMiguelChaves
    @MrMiguelChaves 13 วันที่ผ่านมา +6

    That music ruined everything

    • @pi_squared2
      @pi_squared2  9 วันที่ผ่านมา +4

      Sorry about that, I'm new to editing and making these videos. I'll be making more with hopefully better audio levels, and plan to re-upload this with better editing in the future as well as my other current vids.

    • @BlackubayEhym
      @BlackubayEhym 4 วันที่ผ่านมา +1

      ​@@pi_squared2keep cooking dude, you got this

    • @tratbagd4500
      @tratbagd4500 2 วันที่ผ่านมา

      ​@@pi_squared2you can reupload again. But great job 👍

  • @torvazz_
    @torvazz_ 20 วันที่ผ่านมา +4

    Super interesting learning about math concepts that I have yet to reach. Love the video, beautifully explained. 🙏

    • @pi_squared2
      @pi_squared2  20 วันที่ผ่านมา

      Glad you enjoyed it!

    • @madallas_mons
      @madallas_mons 16 วันที่ผ่านมา

      ​@@pi_squared2What is the name of the song in the video

  • @MolinaUdofo
    @MolinaUdofo 4 วันที่ผ่านมา +1

    Background noise not loud enough, as I could decipher some of the narration, thank you.

  • @user-wr4yl7tx3w
    @user-wr4yl7tx3w 10 วันที่ผ่านมา +3

    just the music makes the voice a little hard to hear clearly. but great content

  • @stieli5816
    @stieli5816 17 วันที่ผ่านมา +3

    great video with good visual explanation. keep going :)

  • @DiamondMC
    @DiamondMC 20 วันที่ผ่านมา +3

    Got recommended the Quadratic Formula vid just before, and now you post a new vid 👀
    (also no bots can say first now)

  • @akotoy
    @akotoy 19 วันที่ผ่านมา +20

    Nice video, I would recommend trying to explain something like this without using your university level understanding of sets and set operations. Sets and subsets can be described simply in the beginning so it makes it easier for the viewer to understand. Anyways cant wait for your chanel to grow

    • @ValidatingUsername
      @ValidatingUsername 18 วันที่ผ่านมา

      Bound a unit and extend it with scalars

    • @solidpython4964
      @solidpython4964 18 วันที่ผ่านมา +2

      Why are you even doing topology if you don’t know what a set is

    • @akotoy
      @akotoy 18 วันที่ผ่านมา +5

      @@solidpython4964 Tf u mean doing topology? its a youtube video, also who said I dont understand what sets are, I meant for others watching because the set theory was heavy. Also understanding intresting topology topics is possible without set knowledge, sets are just a good language for describing relations that occur in sets

    • @disnecessaurorex4908
      @disnecessaurorex4908 18 วันที่ผ่านมา +2

      I thought sets and subsets were high school topics in most places... And everybody interested in topology will eventually need this kind of knowledge anyway. Cool animations can only go so far.

    • @angeldude101
      @angeldude101 17 วันที่ผ่านมา +2

      I got confused during the proof largely due to the subset symbol being used, which was the ambiguous ⊂. By analogy with

  • @cupatelj52
    @cupatelj52 16 วันที่ผ่านมา +4

    You should turn down the volume of the music, or at least setup the side-chain compression.

  • @7san738
    @7san738 6 วันที่ผ่านมา +1

    nice explanation
    you got a subscriber

  • @sy_ox
    @sy_ox 4 วันที่ผ่านมา

    Music makes the video presentation better not sure why everyone else is complaining. I enjoyed it and I could hear you perfectly fine. I look forward to more of your videos thank you.

    • @pi_squared2
      @pi_squared2  2 วันที่ผ่านมา +1

      Glad you enjoyed it!

  • @DeJay7
    @DeJay7 3 วันที่ผ่านมา

    Honestly, if I'm gonna be real with you, this was not what I expected when I clicked on this. It was certainly intriguing for what it's worth, but for some reason I wanted more of the way that distance is measured? I might be tripping, I'm quite tired honestly, but did anyone else have a different expectation from this title? It's probably closer to the idea of (a metric) space rather than distance, but eh it's kinda the same.

    • @pi_squared2
      @pi_squared2  2 วันที่ผ่านมา +1

      Ah I'm sorry to hear that. For me, it was that mathematicians abstracted distance by creating the definition of a metric space with the distance function relying on 4 key properties outlined in the video. Those 4 properties are what abstract distance, but I apologize if the video was in anyway misleading.

    • @DeJay7
      @DeJay7 2 วันที่ผ่านมา

      @@pi_squared2 Don't stress over it, worst case scenario one could call it "clickbait", which honestly isn't that bad nowadays anyway. As long as the content is there, it's mostly okay!

  • @aniksamiurrahman6365
    @aniksamiurrahman6365 17 วันที่ผ่านมา

    Wow! What a great presentation!

  • @Dunning_Kruger_Is__On_Youtube
    @Dunning_Kruger_Is__On_Youtube 5 วันที่ผ่านมา

    Great video and topology (especially algebraic topology) is awesome.

  • @-MeloTunez_Official-
    @-MeloTunez_Official- 20 วันที่ผ่านมา

    great vid brother as always :D

  • @santiagomartinez3417
    @santiagomartinez3417 5 วันที่ผ่านมา +1

    ¿Where do you actually explain what the title promised? I don't see it anywhere.

    • @pi_squared2
      @pi_squared2  2 วันที่ผ่านมา +1

      Sorry if it felt misleading, the abstraction of distance are the 4 properties listed under the distance function of a metric space. These 4 properties allow you to construct various different possible distance functions, some of them quite different to how we ordinarily measure distance in daily life.

  • @guscastilloa
    @guscastilloa 18 วันที่ผ่านมา +2

    You have earned a new subscriber! Very cool video! !! I'd only suggest to turn down the music a little more when you are speaking because it makes it a little hard to listen to your voice :)

  • @berlinisvictorious
    @berlinisvictorious 9 วันที่ผ่านมา

    I forgot I left speakers on max volume and the music just blasted lol

  • @jakeaustria5445
    @jakeaustria5445 17 วันที่ผ่านมา

    A distance function that only returns 0 is very interesting

  • @-MeloTunez_Official-
    @-MeloTunez_Official- 20 วันที่ผ่านมา +1

    hey brother can you please make a vid explaining basics of sets cuz it is hard to understand what the notation says
    and i have not yet learnt sets so its hard to understand the vids too

  • @geekonomist
    @geekonomist 2 วันที่ผ่านมา

    What is a higher dimension shape? Please use a ruler and a square to demonstrate.

  • @jakeaustria5445
    @jakeaustria5445 17 วันที่ผ่านมา

    Thank You

  • @phillipmetzler7716
    @phillipmetzler7716 8 วันที่ผ่านมา

    Beautiful music, unfortunately, it tends to drown out your voice.
    Maybe try re-releasing the video with the music only 25% as loud.
    Thanks, I appreciate the content

  • @disnecessaurorex4908
    @disnecessaurorex4908 17 วันที่ผ่านมา

    Great video.

  • @SamHolmes-p2p
    @SamHolmes-p2p 16 วันที่ผ่านมา +1

    with the music I can barely hear you talk, awesome video other than that

    • @mrhatman675
      @mrhatman675 15 วันที่ผ่านมา

      The music was dope though

  • @geraltofrivia9424
    @geraltofrivia9424 11 วันที่ผ่านมา

    Great content

  • @BenjaminBrienen
    @BenjaminBrienen 8 วันที่ผ่านมา

    How do I turn off the background music on Math TH-cam? Every video seems to have it...
    Besides that, great video!

  • @mrhatman675
    @mrhatman675 15 วันที่ผ่านมา

    I really like your music

  • @krumpy8259
    @krumpy8259 13 วันที่ผ่านมา

    Now these open balls could have a metric though, so how exactly did we abstracted/generalized metrics spaces? Just by avoiding speaking of Pythagoras theorem?

    • @pi_squared2
      @pi_squared2  9 วันที่ผ่านมา

      The open balls are really just a part within our metric space. The cool idea behind abstraction was the idea that you could describe distance with those 4 properties, which seem quite obvious but are actually enough to help you define objects like open balls and distinguish them from closed balls.

  • @DiamondMC
    @DiamondMC 20 วันที่ผ่านมา +2

    Before this video, I had never heard of topology (in maths), that is very interesting (even if I only understood some of the proofs and notation). Amazing graphics and animations, and explanations.
    Question: What level of study do you learn about topologies in maths/education? I’m starting my 2nd year of college, so I assume it’s University level content?
    Also, could you explain more about the needs/ applications of topology?

    • @pi_squared2
      @pi_squared2  20 วันที่ผ่านมา +2

      Really glad you enjoyed the video, topology is a super interesting area of math! Typically from what I understand it'll be first introduced in the 2nd year of a pure math degree, but you can also get exposed to some of its ideas in a course called Real Analysis in 1st year.
      In terms of the needs/applications, there's a massive variety of subjects within topology, some which seem incredibly abstract and not applicable, while others are quite helpful. For example, topology is used to develop the theory of knots which has been used in quantum mechanics. Topology also plays a role in differential geometry, which is used quite famously to describe General Relativity in physics. As for the more abstract/inapplicable subjects within topology though, there's a rich history in mathematics of things which at first seem totally inapplicable becoming massively applicable/important in the future; so that also might just be the case with a lot of topology!

    • @DiamondMC
      @DiamondMC 20 วันที่ผ่านมา +1

      Ah ok, so I probably won’t come across it in my studies (I plan on studying a Mechanical Engineering degree), but it’s always something I can just research/look up about.
      and wow, interesting applications.

    • @underfilho
      @underfilho 18 วันที่ผ่านมา +1

      Studying mechanical engineering probably wouldnt lead you to topology, topology is an advanced "pure" math subject, generally you'll see it after a course in real analysis, there is also a pure math subject. So it goes to Differential and Integral Calculus -> Real Analysis -> Maybe Analysis on Rn -> Maybe Metric Spaces -> Topology. Of course all of these you'll learn in an undergraduate or graduate course in math.

  • @rowbeartow7376
    @rowbeartow7376 4 วันที่ผ่านมา

    music is too distracting...

  • @r75shell
    @r75shell 16 วันที่ผ่านมา

    Where did you pull out closure? Also, in my opinion, what you're talking about it's not beauty of topology. What you're talking about is basic rules of proofs where you use definitions + axioms + theorems to lead to proof. Beauty of topology is generalization of what we call "distance" to other things which you no longer call "distance" in some cases. For all *metric spaces* you can use term distance. But there are also non-metric spaces with their own "topology", this is where beauty lies. Actually, properties of metric spaces which work for *all metric spaces* is also beautiful but in my opinion non-metric spaces more "mysterious" and thus, more beautiful.

    • @pi_squared2
      @pi_squared2  9 วันที่ผ่านมา

      I do agree that there's a lot more beauty outside of the concepts in this video, this is definitely just an introductory subject in the world of topology. I do think it is still quite cool for a beginner to see the abstract proofs used in this beginner subject. I remember when I first learned about it thought it was really cool and beautiful, even though there is definitely an infinity of more advanced and beautiful topics!

  • @jaydenwilson9522
    @jaydenwilson9522 15 วันที่ผ่านมา

    In general, can it be said that all concepts other than distance itself need to be reified via this foundational magnitude?
    This would imply that there are no units other than length, but only abstractions built on top of this core notion.
    This line of thinking echoes in dimensional analysis and geometrization of physics, where all physical quantities are fundamentally reducible to a foundational unit-typically length.
    In this interpretation, many other physical concepts (such as angles, areas, volumes, and even time) can be seen as derived abstractions built on top of the core concept of distance or length.

    • @pi_squared2
      @pi_squared2  9 วันที่ผ่านมา

      Really interesting idea, I'm not quite sure on whether we need to redefine other concepts, but I can tell you it definitely gets more abstract than this. In the video I just talk about metric spaces, but they fall under a more abstract space which is the topological space, which is defined even without a distance function! If you're curious about these abstractions I also recommend looking into measure theory, where the notion of volume is abstracted.

    • @jaydenwilson9522
      @jaydenwilson9522 4 วันที่ผ่านมา

      @@pi_squared2 When Set Theory is our foundation then everything must be abstracted!
      And yes.... Rubber-sheet geometry was once regarded as Higher Geometry but has substituted its class so that it can turn donuts into mugs..... now mythomagics and mathrobatics are center stage.
      YIKES!

  • @elia0162
    @elia0162 16 วันที่ผ่านมา +1

    the music it is too loud but great vidfeo

  • @remusvang3622
    @remusvang3622 3 วันที่ผ่านมา

    Nice video👌👍

    • @pi_squared2
      @pi_squared2  2 วันที่ผ่านมา

      Thank you so much!

  • @samirikar1
    @samirikar1 18 วันที่ผ่านมา

    Whats your background?

  • @mathunt1130
    @mathunt1130 7 วันที่ผ่านมา

    Slight bug bear of mine, property 3 is unnecessary as it follows from 1,2, and 4 in the following way:
    0=d(x,x)=0.

    • @rielblakcori971
      @rielblakcori971 2 วันที่ผ่านมา

      also he should have included the property 1 as follows: d(x,y) = 0 x=y
      Otherwise we have no metric but a pseudo metric

    • @mathunt1130
      @mathunt1130 2 วันที่ผ่านมา

      @@rielblakcori971 I believe that was encoded as d(x,x)=0.

    • @rielblakcori971
      @rielblakcori971 2 วันที่ผ่านมา

      @@mathunt1130 those are not the same since you can only imply right hand side to left hand side by his definition but no equivalence

    • @mathunt1130
      @mathunt1130 2 วันที่ผ่านมา

      @@rielblakcori971 As I showed, from d(x,x)=0, d(x,y)=d(y,x), and the triangle ineqality, I demonstrated that d(x,y)>=0. From that, we get your condition.

    • @rielblakcori971
      @rielblakcori971 2 วันที่ผ่านมา

      @@mathunt1130 yes but you still didn't show why you get from d(x,y)=0 that this implies x=y, that's the whole point

  • @kcg26876
    @kcg26876 11 วันที่ผ่านมา

    You provide properties of distance as a reduce function but don't define it. How do we rank distances? How do we define a distance of 1 unit?

    • @Xmodg4m3
      @Xmodg4m3 5 วันที่ผ่านมา

      2 elements a and b of the set A are at distance 1 if the distance function outputs the real number 1 when aplied to a and b.
      There is no single function of distance, you can use any function from A to the real numbers that verifies those properties. The set A can be as weird as you want it to be, and different distance functions applied to a and b can output different values.

    • @kcg26876
      @kcg26876 5 วันที่ผ่านมา +1

      @@Xmodg4m3 Agree. There are infinitely many distance functions but the point I'm making is that author *escapes* from bringing any real example of such a function. We can pick 2 arbitrary points A, B on a plain and declare distance of 1 unit. But what property constites distance of 2 between B and C? The qq is how to build such a function.

    • @Xmodg4m3
      @Xmodg4m3 4 วันที่ผ่านมา

      @@kcg26876 A nice thing about math is that most of the time you are not working with concrete things, but with abstractions and generalizations instead. This is a neat thing as it replaces calculation with thinking.
      You are now for example proving things not just about the real space R^3, but about any abstract vector space. This makes so that when you are working with a really abstract and complicated object, but that can be seen as a vector space, you automatically unlock all the vast knowledge humanity has about vector spaces and can apply it right away, whithout needing years of research just for your example.
      He is not fleeing the need to define a concrete distance, as there is no such need to do so. It's just working the way up from a general concept to reach truths that can be applied whenever you try to solve any kind of real life problem involving any kind of notion of distance.

  • @maths.visualization
    @maths.visualization 11 วันที่ผ่านมา

    Can you share video code?

    • @pi_squared2
      @pi_squared2  9 วันที่ผ่านมา +1

      Yes, will be dropping video code for my vids soon in the future!

  • @mikedotexe
    @mikedotexe 7 วันที่ผ่านมา +1

    it would be so much easier if humans ditched mathematical notation and we just used simple programming. 3 lines of JavaScript could convey some of these concepts more intuitively. great video, not trying to bash. it's funny when i finally realize what the set notation is saying and how trivial of a statement it really is when expressed in object.method(parameter) "notation" haha