Remember that video about how block collisions can compute the digits of pi? A friend, Adam Brown, just showed that the math underlying this is actually identical to the math behind a very famous quantum search algorithm (Grover's):
Genuinely crazy!
For the most recent video, I had way too much fun simulating the electric field (or rather, the component of that field responsible for radiation) and how it responds to an accelerating electric charge.
The birthday paradox is very famous in probability. If you take 23 people, there's about a 50/50 chance that two of them share a birthday. With 50 people, it's a 97% chance.
We could make many other fun examples to illustrate the same counterintuitive phenomenon (thread).
I have to say, seeing so much of math/science Twitter come to the defense of this video, and the premise of rewarding inquisitiveness rather than mocking inaccuracies, has really made my evening.
The Fourier series video out!
In this animation, each vector rotates at a constant integer frequency. They're added together, tip to tail. The _only_ control you have is the starting position of each, and from that alone, they'll draw almost anything.
With recorded COVID-19 cases (outside china) so eerily matching an exponential, I couldn't resist making a primer on exponential/logistic growth. At least 3 counterintuitive things about this kind of growth seem worth putting into the discussion.
YouTubers often overestimate how much their followers actively await new videos. I bet most followers aren't even aware when it's been a while.
Still, for those of you who are, I want you to know I really am working quite hard on the next video(s?). All will come in due time.
New video: Simulating an epidemic.
What happens when people avoid each other for the most part but still go to a common central location like a store?
What if you can track and isolate cases, but 20% slip through the cracks? 50%?
And much more.
The next chapter about transformers is up on YouTube, digging into the attention mechanism:
The model works with vectors representing tokens (think words), and this is the mechanism that allows those vectors to take in meaning from context.
Take a computer from 1995 and one from today, which one is "old"?
Take the version of you from 1995 and the version from today, which one is "old"?
Some things age into the past, others into the future.
Pretty clever trick. Celcius is the percentage around a semicircle, Fahrenheit gives the angle (plus 32).
This makes for handy intuitive conversions like
25°C = 32 + 45 = 77°F.
50°C = 32 + 90 = 122°F.
Even handier if you're comfortable rounding 32 to 30.
Between 0°C and 100°C are 180°F. This allows for a nice mnemonic to convert between those units using an angle as a guide for °F.
Made possible via
#manim
, thanks to
@3blue1brown
and
@manim_community
!
I remember having way too much fun writing this back in 2017 when I made the Bitcoin explainer.
If someone describes a cryptographic protocol as having "256-bit security", what does that really mean?
New video! Bayes' theorem, and making probability intuitive.
I had fun bringing in some Kahneman and Tversky results to show where human intuition seems to jive with probability, and where it doesn't.
New video! If the answer here does not blow your mind, I don't know what will. In short, how does this number of collisions grow as you increase the mass ratio? E.g., what is it for 1 trillion to 1?
Wow, making Fourier series animations turns out to be super fun. Not exactly original at this point, but so lovely! Any shapes/figures you'd like to see show up in a video?
Early impressions of
@OpenAI
's DALL-E 2. 🧵
All images below were produced by AI, with me feeding it the quoted prompt. I was most curious about how helpful such a tool might be in creative work.
"A sloth playing a guitar, photograph 35mm lens"
Here's the gist of a beautiful argument Archimedes gave for the surface area of a sphere.
In the YouTube video I did on this, I also described another way to relate this area more directly to a sphere's shadow, which I'll copy on the thread below as a progression of puzzles.
Here are the problem-solving tips I went through yesterday. Each may seem simple, but it’s shocking how often they help to get unstuck.
What would you add?
I'm helping to teach a course at MIT this semester with Alan Edelman, David Sanders, and James Schloss (
@LeiosOS
) that intends to blend math and scientific computing
Anyone in the world is free to follow along.
For the most recent video, I had way too much fun simulating the electric field (or rather, the component of that field responsible for radiation) and how it responds to an accelerating electric charge.
It’s here! Quaternions:
“But Grant, 30 minutes seems like a bit much to set aside right now.”
Pssht, don’t give me that, I saw you on Netflix last night.
"Everyone's overreacting, the flu kills way more people each year. Besides, those of us who are young have a low risk even if we do get it."
Do you...hate the elderly?
What happens if you take a grid of 1,000,000 points centered in the complex plane, starting off in a 2π-by-2π box, and repeatedly apply the function z -> exp(z)?
Has anyone ever come across this way of visualizing the convolution of two functions f and g: Look at the graph of the two-variable function f(x)g(y), and consider diagonal slices over the line x + y = k.
The area of those slices represents (f * g)(k).
My TEDx talk has now been posted.
Among other things, I share some thoughts on the question "when will I ever use this" as it comes up in math education.
It begins! Differential equations chapter 1, studying the unsolvable:
If transitioning from the fast-pace of twitter scrolling to a 27-minute video is just not in the cards, please enjoy this strangely calming animation of the three body problem instead.
New video!
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It's an exploration for writing a Wordle solver, with the challenge of not using the official list of Wordle answers (except as a test set), which is really just an excuse for an information theory lesson.
New video!
This is easily the longest one I've ever made. When you find yourself in the mood to settle in with a good puzzle, and a story about two different problem-solving styles, I hope you enjoy it.
In light of the very sad news about Ron Graham's passing, I thought I'd share an interesting tidbit about his famous constant which I only learned recently (thread).
The group of cube rotations is the same as the group of permutations on four objects (S4).
This feels very surprising (to me at least), but becomes more visible when you think of permuting the diagonals of a cube.
Now that the US Open has fully replaced line judges with robots, I propose they take things one step further.
Replace all the ball boys and ball girls with a crew of well-trained golden retrievers. Tennis viewership would go up by a factor of 3, guaranteed.
I realized recently I didn't know why prisms work. Like, why does light slow down? And why would that depend on color?
It turns out, answering the first question with enough detail automatically answers the second, and it's completely delightful.
Suppose that over the last few years, there's been an exponential rise in the amount of opium usage. It's especially prevalent among the youth. You've started to notice as you walk through airports and look at how people twiddle away their time, sneaking the occasional glance…
There's a famous proof for why π shows up in the Gaussian distribution, originally due to Poisson. Despite it being covered well on the internet, I found the prospect of animating it too fun to resist.
But! I wanted to go deeper.
The puzzle below is a famous cautionary tale in math. But there's more to it than just coincidence, and on the YouTube version, we dig into what's really going on.
Full explanation:
Need to create a fake chart that looks like a stock market graph? Happy to go with an overkill solution? Try taking one coordinate from some Brownian motion!
I'm looking for an intern! See the application below.
This may be a little late in the season, but we're flexible for part-time if you have a main gig and still want to help.
Please share it with any undergrads who might be interested.
A little while ago this integral pattern was making the Twitter rounds. It arose in a paper by Jonathan and David Borwein, whose colleague "concluded that there must be a bug in the software" when evaluating.
I made a video to explain what's going on
I'm doing a TEDx talk at Berkeley this February. If you want to come, they gave one of those fancy discount codes for my followers (i.e. you): SPEAKER35
Hope to see you there!
Our first speaker is the incredible Grant Sanderson, founder of
@3blue1brown
, a math-based education Youtube channel with over two million subscribers and over 85 million total views! Sanderson is shaping education in today’s technological age, learn more at TEDxBerkeley 2020! 😍
Emails are funny.
"Dear 3blue1brown,
....<intro>...
I understand that you do not do sponsored videos. Would you be interested in doing a 30-second mention of our AI / Machine Learning / Data Science course?"
Do you understand? I don't think you do.
Pro tip: When
@nattyover
writes something, read it. You'll thank yourself later.
This article on Gödel's incompleteness theorem(s) is one of the most accessible coverages of the topic I've seen that actually captures the substance of the result.
Thanks to the help of some interns, many of my videos have now been adapted into a written/interactive form. The clip below shows an example of one interactive elements made for the neural networks series by
@PullJosh
.
If you have a moment, take a look.
It seems so unnatural to graph periodic functions on a plane, rather than a cylinder since a circular input automatically forces the periodicity. So I made some Fourier series socks, graphing things *properly*.
What are your favorite (potentially long) mathematician quotes? Bonus points if it's not just a pithy restatement of "math is beautiful", but something which changes how you think.
New video!
Learn how asking the right question about Newton's method leads to a hidden Mandelbrot set, in the context of a general primer on holomorphic dynamics.
One neat difference between ChatGPT and previous iterations is its willingness to acknowledge uncertainty or absurdity (e.g. these are less of an issue now )
A funny quirk is it may be _too_ confident in its uncertainty, as in its take on Alice here.
About a month ago when I published this video, recorded cases outside China were ~21k. In it, I mentioned that if you naively projected out the current trend, it'd mean hitting 1,000,000 cases by April 5th.
Just saying.
With recorded COVID-19 cases (outside china) so eerily matching an exponential, I couldn't resist making a primer on exponential/logistic growth. At least 3 counterintuitive things about this kind of growth seem worth putting into the discussion.
I thought it might be fun to do a quick distraction project on the mathematically optimal way to play wordle.
Wrote a little program yesterday which uses a bank of ~13,000 words along with their frequencies in English, tried it today. Not bad!
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"An army's effectiveness depends on its size, training, experience, and morale, and morale is worth more than any of the other factors combined."
- Napoleon