math and computer science, bad term, :boost_ok: 

An interesting example of Brouwer's fixed point theorem: I think the tummy button of the snowman on the girl's PJs lines up with her own tummy button.

Real-world analysis: for any ε>0, there is a dog δ such that δ's whiskers are within ε of my toast.

The toddler has started using the words 'maybe' and 'probably'. Time to inoculate her against frequentist interpretation.

In these days in which "exponential growth" has such ominous connotations, we are pleased to announce our new paper which includes fast-growing functions in a much lighter setting. Fusible numbers and Peano Arithmetic. . Joint work with @jeffgerickson and @alreadydone

A color contrast checker that offers alternatives if your color combination has not enough contrast. It would be cool to chose if you want to change background or foreground though but it's still very nice to get suggestions

@ColinTheMathmo red looks darker for me, so no problem. Not sure if it's a problem for people with the deuteranopia (missing blue receptors)


A little something that may help... 320 Random Acts of Maths: pocket-sized problems, teasers, curios, provocations, inspirations, etc. For downloads, inc. solutions and slides:


OERu joins forces with COL, UNESCO (IITE) and ICDE to establish an #OER support group to assist institutions transitioning to online learning during the #COVID19 crisis. Please join our #OER4Covid support group:

A variant of the classic 15-puzzle, where the puzzle is coiled around a cylinder. Unlike the original, this version is solvable because of the extra connection between the first and sixteenth squares of the frame. YouTube:

@ColinTheMathmo The root of it was "how can I get my friends to show me cool bits of maths?"

@ColinTheMathmo did you follow the math-offs in 2019 and 2018?
A "pitch" is just an essay or a video or a paragraph about some interesting maths. Like a Big MathsJam talk in a blog post.
The competition element is just to provoke interest - doesn't mean anything, really. Readers will be asked to vote for the pitch that made them go "Aha!" the loudest.

@ColinTheMathmo cool!
A technical note: the camera seems to keep adjusting focus. There's an app called Open Camera ( that lets you lock the focus while recording

A problem of mine appeared in the lastest Mathematics Magazine:
Suppose \(\pi\) is a permutation of \(\{1,2,\ldots,2m\}\). Consider the (possibly empty) subsequence of \(\pi(m+1),\pi(m+2),\ldots,\pi(2m)\) consisting of only those values which exceed \(\max\{\pi(1),\ldots,\pi(m)\}\).

Let \(P(m)\) denote the probability that this subsequence never decreases, when \(\pi\) is a randomly chosen permutation of \(\{1,2,\ldots,2m\}\). Evaluate the limit of \(P(m)\) as \(m\to\infty\).

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