Category: math

Why It’s So Freaking Hard To Make A Good COVID-19 Model

From FiveThirtyEight

Great article, please read it. Be wary of data without context. Always.

Numbers aren’t facts. They’re the result of a lot of subjective choices that have to be documented transparently and in detail before you can even begin to consider treating the output as fact.

How Soon Will COVID-19 Peak?

Difficult to tell, but the sooner social distancing is applied the better. Stay at home.

Each square represents an individual:


uninfected but susceptible to infection


infected in the latent period and not yet infectious


infected and infectious


deceased or recovered


isolated by community screening policies

Daniel Cooney, Vincent Wong, and Yaneer Bar-Yam, Beyond contact tracing: Community-based early detection for Ebola response, PLoS Currents Outbreaks (May 19, 2016). [PDF, arXiv]


New England Complex Systems Institute

Merry X-mas everybody via Reddit

Merry christmas everyone 🥂 including people in the control group 🍸 of course. 🎅


“…The Non-Member State Summer Student Programme represents a unique opportunity for students from around the world, especially from less advantaged countries, to spend their next summer getting involved in some of the world’s biggest scientific experiments at CERN. For most of the students, their summer at CERN will represent a lot of firsts. The first time they will travel abroad, the first time they will work in a fully-equipped physics laboratory, the first time they will meet fellow students from different cultural backgrounds.”

How Julia Robinson helped define the limits of mathematical knowledge:

Inspiring story.

Robinson never thought of herself as a brilliant person. In reflecting on her life, she focused instead on the patience that served her so well as a mathematician, which she attributed in part to a period of intense isolation as a child. At age 9, while living with her family in San Diego, she contracted scarlet fever, followed by rheumatic fever.

Penicillin had just been discovered and was not yet available as a treatment. Instead, she lived at the home of a nurse for a year, missing two years of school.

This is bloody cool. For geeks only.

Scary and creepy math symbols with AMS-LaTeX integration:


The number of all the atoms that compose the world is immense but finite, and as such only capable of a finite (though also immense) number of permutations. In an infinite stretch of time, the number of possible permutations must be run through, and the universe has to repeat itself. Once again you will be born from a belly, once again your skeleton will grow, once again this same page will reach your identical hands, once again you will follow the course of all the hours of your life until that of your incredible death.

What does a black hole look like up close?

A simulation of what a black hole with a disk of gas swirling around it would look, given the bizarre effects of its fierce gravity on the light from the disk. Credit: NASA’s Goddard Space Flight Center/Jeremy Schnittman

Via Bad Astronomy