More on the sphere | Algebraic Topology 4 | NJ Wildberger

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  • Опубліковано 27 гру 2024

КОМЕНТАРІ • 26

  • @KipIngram
    @KipIngram 2 роки тому +8

    This is a spectacular lecture - I've had an "interest" in topology for a long time, but I could never really get my ahead around how it was relevant to other, more "practically interesting" areas of math. But Dr. Wildberger just made that make sense to me, right around the half-hour mark. I feel like a new brick just settled into place in my "knowledge wall," and I always just love that feeling. 🙂

  • @jonwolfe7054
    @jonwolfe7054 7 років тому +12

    These lectures are very clear and engaging. Many thanks to A/Professor Wildberger for sharing these with the world!

    • @brendawilliams8062
      @brendawilliams8062 3 роки тому

      Dr Wildbergeris awesome. He can guide you to your personal mathmatical niche. Absolutely a genius.

  • @ChristinaPhillipsartist
    @ChristinaPhillipsartist 12 років тому +1

    Totally hooked, what a wonderfully rich subject. Feel privileged to be able to sit this course from the UK, thank you to the Prof and to UNSW

  • @brendawilliams8062
    @brendawilliams8062 3 роки тому

    Thankyou Dr Wildberger

  • @KipIngram
    @KipIngram 2 роки тому

    11:30 - Ok, I was also having initial trouble seeing that connection between the circle on the sphere and that "vertex" point. But Dr. W's response to the audience question was well done and now I see - I hope the questioner does too. The key thing was when he pointed out that if I was looking at the sphere with my eye at the vertex, the part of the sphere I could see would like inside a circle on its surface. "Click."

  • @area51xi
    @area51xi 3 роки тому +1

    17:35 to 17:38 gave me chills.

  • @Chalisque
    @Chalisque 7 років тому +4

    Enjoying the lecture series. One humorous comment is that the early part of this (esp around the 10m mark) could easily have the speech distorted, fake subtitles added, and reshared as 'Lecture on the Theory and Construction of Death Stars'... (I guess that's what happens if you grow up watching Star Wars)

  • @Styhn
    @Styhn 13 років тому +2

    I like these lectures a lot, thanks for uploading them.

  • @monoman4083
    @monoman4083 7 років тому +1

    Great explanations; Thanks Professor.

  • @alistairfrancis6511
    @alistairfrancis6511 11 років тому +1

    I'm not sure i understand why there are 2 layers; is it that one layer is "z" and the other "z^2"? or that they represent the 2 complete revolutions made by z^2 with one revolution of z? and why is it okay to make slits? it doesn't seem like a continuous transformation.
    Thanks.

  • @oldsachem
    @oldsachem Рік тому

    Is NJ laying the mathematical schema of quantum wormhole?

    • @pseudolullus
      @pseudolullus Рік тому

      Do you mean AdS/CFT? It's veery distantly related, although the dualities between different surfaces/spaces are important and somewhat similar.

  • @arekkrolak6320
    @arekkrolak6320 7 років тому

    You say s2 + point in infinity. Does it matter which point? Because previous video said about line in infinity, which suggest there is more than one possibility...

  • @vivaelche05
    @vivaelche05 13 років тому

    Hello Prof. Wildberger, I was wondering if you had a syllabus of some sort for this course. And i was also wondering what you thought of the book on Algebraic Topology by Allen Hatcher to be used as a companion to these lectures.

  • @fallingmasonry
    @fallingmasonry 8 років тому +1

    29:29 Riemann Death Stars

  • @hechen236
    @hechen236 9 років тому

    awesome lecture, I guess I've learnt something.

  • @y2536524
    @y2536524 11 років тому +1

    hi professor,
    i want to ask why only (1,0) is the exceptional case instead of (k,0) for all k .why is the other points already included in the 1D subspace

    • @Anthony-db7ou
      @Anthony-db7ou 5 років тому +3

      y2536524 it is the line through the point from the origin. It can be scaled by any complex number. Hope that helps. (Just realized I’m 5 years late but fuck it)!

  • @njwildberger
    @njwildberger  12 років тому

    Certainly the first statement is correct. However it is not so clear what you mean by the last two... but I think roughly your intuition is okay.

  • @drscott1
    @drscott1 2 роки тому

    👍🏼

  • @Rawae3
    @Rawae3 12 років тому

    It's amazing that Zero is going to infinity : it's a matter of rotation
    wow
    life Cann't be more Simple, or may be more complicated !

  • @aron8999
    @aron8999 5 років тому +1

    Ogres are like power maps on the Riemann Sphere

    • @brendawilliams8062
      @brendawilliams8062 3 роки тому

      It seems the 9 and 10 do better than the 3 on an layered onion 🧅 to me.

  • @brendendurham9116
    @brendendurham9116 10 років тому

    a debonair mathematician