Here’s an experience I’ve had roughly six million times.
- A mathematical topic arises.
- “You know,” I say, “someone has a great tweet about this… somewhere…”
- In order to find it, I am forced to read all of the tweets, ever.
- I am reminded that “all of the tweets ever” is rather too many tweets.
So about a year ago I started a compendium. Tweets, yes, but also videos, apps, memes… anything stimulating or arresting that I can use to embroider my lessons. For a while, this document lived where all important documents live: as a gmail draft. But now I share it as a blog post, and I intend to continue updating it as new ones cross my ken.
NOTE: I will, where convenient, use screenshots and links, because WordPress’s embedded tweets sometimes take ages to load.
NUMBER AND SCALE
A brilliant anagram from Colin Beveridge:
The timeless classic Powers of Ten, arguably the best film of 1977 (suck it, Annie Hall):
The mesmerizing interactive “Scale of the Universe” app (which requires you to enable Flash, but just do it).
Also, this black hole:
An ellipse as the maximum heights of a family of projectiles:
Throwing an object at the same speed but different angles defines an ellipse via its maximum height pic.twitter.com/vQ8NMssCMf— 〈 Berger | Dillon 〉 (@InertialObservr) July 22, 2019
And again, this time for figuring out the scoring system in Australian Rules Football:
Four place mats, arranged to make a quadratic identity at the dinner table:
Polar coordinates on pizza:
Putting sauce on a pizza. pic.twitter.com/Oe9gsZaSjz— MachinePix (@MachinePix) August 28, 2016
GEOMETRY AND TRIGONOMETRY
Volumes of a cylinder, a sphere, and a cone:
Volumes of earth, earth’s air, and earth’s water:
Animated visual proof that any polygon can be rearranged into any other polygon of equal area:
For your trigonometric Halloween, the blood function:
Defining a radian with a wooden model:
Tragic Tweet Delete! -- I thought I would at least add it back : ) We are interested in sending these to folks, especially if you have a maker space and could then make more if you like it. pic.twitter.com/kYUs1jMEEj— MathHappens (@MathHappensOrg) October 1, 2019
Simple harmonic motion:
Beautiful shapes created by simple harmonic motion 🧐 pic.twitter.com/ifsFX4nfN9— Fermat's Library (@fermatslibrary) January 2, 2020
CALCULUS AND DYNAMICAL SYSTEMS
Riemann sums (comparing upper and lower sums as the grid is refined):
A professor solves an optimization problem (“smallest surface area for a given volume”), writes a company that makes cat food to ask why they don’t use this solution, and receives an incredibly thoughtful and interesting reply:
A real-life butterfly effect:
In office hours, sophomore @JackSillin showed me this real world example of the butterfly effect. An unexpectedly strong thunderstorm in Kansas shifted the path of Hurricane Dorian just far enough to spare Florida the worst. I love learning from students @Cornell! pic.twitter.com/P7eqBKH2bQ— Steven Strogatz (@stevenstrogatz) September 10, 2019
The exquisite sensitivity of the double pendulum:
50 double pendulums, whose initial velocities differ only by 1 part in 1000 pic.twitter.com/3b75BDkwF1— 〈 Berger | Dillon 〉 (@InertialObservr) September 30, 2019
PROBABILITY AND STATISTICS
Independence is a delicate and rare phenomenon:
What do probabilistic words really mean?
I see you Anscombe’s Quartet, and I raise you the Datasaurus:
The dangers of using r^2 as an effect size estimate:
The normal distribution in action: