Who cares about topology? (Inscribed rectangle problem)


An unsolved conjecture, and a clever topological solution to a weaker version of the question.
Brought to you by you: 3b1b.co/topology-thanks
Home page: www.3blue1brown.com/

This video is based on a proof from H. Vaughan, 1977. To learn more, take a look at this survey:
pure.mpg.de/rest/items/item_3120610/component/file_3120611/content

— 3blue1brown is a channel about animating math, in all senses of the word animate. And you know the drill with YouTube, if you want to stay posted about new videos, subscribe, and click the bell to receive notifications (if youre into that).

If you are new to this channel and want to see more, a good place to start is this playlist: www.youtube.com/playlist?list=PLZHQObOWTQDPHP40bzkb0TKLRPwQGAoC-

Various social media stuffs:
Twitter: twitter.com/3Blue1Brown
Facebook: www.facebook.com/3blue1brown/
Reddit: www.reddit.com/r/3Blue1Brown

Десятизаходная резьба в два направления.


Смог нарезать с помощью фрезы ( ali.pub/5dps3b ) на токарном станке многозаходную ( десять заходов ) резьбу в два направления, сразу и правая и левая на одном болте.
Музыка от Epidemic Sound (http://www.epidemicsound.com): https: www.epidemicsound.com/referral/13czek/

What does it feel like to invent math?


An exploration of infinite sums, from convergent to divergent, including a brief introduction to the 2-adic metric, all themed on that cycle between discovery and invention in math.
Home page: www.3blue1brown.com/

Music: Legions (Reverie) by Zoe Keating

— 3blue1brown is a channel about animating math, in all senses of the word animate. And you know the drill with YouTube, if you want to stay posted about new videos, subscribe, and click the bell to receive notifications (if youre into that).

If you are new to this channel and want to see more, a good place to start is this playlist: goo.gl/WmnCQZ

Various social media stuffs:
Patreon: www.patreon.com/3blue1brown
Twitter: twitter.com/3Blue1Brown
Facebook: www.facebook.com/3blue1brown/
Reddit: www.reddit.com/r/3Blue1Brown

What they wont teach you in calculus


A visual for derivatives which generalizes more nicely to topics beyond calculus.
Brought to you by you: 3b1b.co/alt-calc-thanks
And by Brilliant: brilliant.org/3b1b
Home page: www.3blue1brown.com

Essence of calculus series:
3b1b.co/calculus

Really nice applet made based on this video by Reddit user Larconneur:
www.geogebra.org/m/rftwacsy

Music by Vincent Rubinetti:
vincerubinetti.bandcamp.com/album/the-music-of-3blue1brown

— 3blue1brown is a channel about animating math, in all senses of the word animate. And you know the drill with YouTube, if you want to stay posted on new videos, subscribe, and click the bell to receive notifications (if youre into that).

If you are new to this channel and want to see more, a good place to start is this playlist: 3b1b.co/recommended

Various social media stuffs:
Website: www.3blue1brown.com
Twitter: twitter.com/3blue1brown
Patreon: patreon.com/3blue1brown
Facebook: www.facebook.com/3blue1brown
Reddit: www.reddit.com/r/3blue1brown

Simulating an epidemic


Эксперименты с SIR-моделью
Главная страница: www.3blue1brown.com
В создании ролика помогли Вы: 3b1b.co/sir-thanks

Моделирование Гарри Стивенсена в Washington Post:
www.washingtonpost.com/graphics/2020/world/corona-simulator/

Моделирование Кевина Симлера в Melting Asphalt:
meltingasphalt.com/interactive/outbreak/

Великолепная визуализация текущего распространения пандемии в каждой стране от Minutephysics и Атиша Батьи:
www.youtube.com/watch?v=54XLXg4fYsc

Если Вы хотите послушать сводку по COVID-19 от математика/эпидемиолога, то я нахожу очень полезной эту лекцию от MSRI:
youtu.be/MZ957qhzcjI

Марсель Салате об отслеживании контактов:
twitter.com/marcelsalathe/status/1242430736944201730

— Эти анимации в большей части сделаны с использованием manim, библиотеки-мешанины на Python с открытым исходным кодом: github.com/3b1b/manim

Исходный код этого видео можно посмотреть здесь: github.com/3b1b/manim/blob/shaders/from_3b1b/active/sir.py

Если Вы хотите её попробовать, я должен предупредить Вас, что это не самый задокументированный инструмент со своими причудами, которые можно было бы ожидать от библиотеки, которую кто-то написал только для себя.

Музыка в начале:
Candlepower от Chris Zabriskie лицензирована под Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/)
Источник: chriszabriskie.com/divider/
Музыкант: chriszabriskie.com/

Остальная музыка от Vincent Rubinetti.
Скачать музыку на Bandcamp: vincerubinetti.bandcamp.com/album/the-music-of-3blue1brown

Слушать музыку на Spotify:
open.spotify.com/album/1dVyjwS8FBqXhRunaG5W5u

Если вы хотите помочь с переводом субтитров или проверкой перевода, уже сделанного другими и ожидающего одобрения, нажмите на шестерёнку в видео, перейдите в «Субтитры», потом «Добавить субтитры». Я очень ценю тех, кто помогает с этим, так как это делает мои видео доступными многим людям.

— 3blue1brown — это канал об анимированной математике во всех смыслах этого слова. Как всегда, если Вы хотите оставаться в курсе новых видео, то подписывайтесь: 3b1b.co/subscribe

Различные соцсети:
Сайт: www.3blue1brown.com
Твиттер: twitter.com/3blue1brown
Реддит: www.reddit.com/r/3blue1brown
Инстаграм: www.instagram.com/3blue1brown_animations/
Патреон: patreon.com/3blue1brown
Фейсбук: www.facebook.com/3blue1brown

Fractals are typically not self-similar


An explanation of fractal dimension.
Home page: www.3blue1brown.com/
Brought to you by you: 3b1b.co/fractals-thanks
And by Affirm: www.affirm.com/careers

Music by Vince Rubinetti: soundcloud.com/vincerubinetti/riemann-zeta-function

One technical note: Its possible to have fractals with an integer dimension. The example to have in mind is some *very* rough curve, which just so happens to achieve roughness level exactly 2. Slightly rough might be around 1.1-dimension; quite rough could be 1.5; but a very rough curve could get up to 2.0 (or more). A classic example of this is the boundary of the Mandelbrot set. The Sierpinski pyramid also has dimension 2 (try computing it!).

The proper definition of a fractal, at least as Mandelbrot wrote it, is a shape whose «Hausdorff dimension» is greater than its «topological dimension». Hausdorff dimension is similar to the box-counting one I showed in this video, in some sense counting using balls instead of boxes, and it coincides with box-counting dimension in many cases. But its more general, at the cost of being a bit harder to describe.

Topological dimension is something thats always an integer, wherein (loosely speaking) curve-ish things are 1-dimensional, surface-ish things are two-dimensional, etc. For example, a Koch Curve has topological dimension 1, and Hausdorff dimension 1.262. A rough surface might have topological dimension 2, but fractal dimension 2.3. And if a curve with topological dimension 1 has a Hausdorff dimension that *happens* to be exactly 2, or 3, or 4, etc., it would be considered a fractal, even though its fractal dimension is an integer.

See Mandelbrots book «The Fractal Geometry of Nature» for the full details and more examples.

— 3blue1brown is a channel about animating math, in all senses of the word animate. And you know the drill with YouTube, if you want to stay posted about new videos, subscribe, and click the bell to receive notifications (if youre into that).

If you are new to this channel and want to see more, a good place to start is this playlist: www.youtube.com/playlist?list=PLZHQObOWTQDPHP40bzkb0TKLRPwQGAoC-

Various social media stuffs:
Twitter: twitter.com/3Blue1Brown
Facebook: www.facebook.com/3blue1brown/
Reddit: www.reddit.com/r/3Blue1Brown

The Essence of How Bitcoin Works (Non-Technical)


A brief intro to the main ideas behind How Bitcoin Works, including how money is transferred, who keeps track of it, and how the whole thing is secured. Want more? Check out my new in-depth course on the latest in Bitcoin, Blockchain, and a survey of the most exciting projects coming out (Ethereum, etc): app.pluralsight.com/library/courses/bitcoin-decentralized-technology
Lots of demos on how to buy, send, store (hardware, paper wallet). how to use javascript to send bitcoin. How to create Ethereum Smart Contract, much more.

1JoLcdC9CAYQ5T4QUARHfXQZyxQBBSFJu9

written script: www.imponderablethings.com/2014/09/the-essence-of-how-bitcoin-works-non.html

Blockchain Technology Explained (2 Hour Course)


Blockchain Technology Course will cover:
— Technology overview
— Blockchain evolution
— Decentralized web
— Distributed organizations
— Distributed ledger
— Smart contracts
— Distributed applications
— Internet of value
— Token economies

****

INTERESTED IN THE STOCK MARKET?
I developed a successful stock market trading model: yuriymatso.com/my-market-model/