Gonzalo Ciruelos set out to discover which country was the roundest in shape.
We can define roundness in many ways. For example, as you may know, the circle is the shape that given a fixed perimeter maximizes the area. This definition has many problems. One of the problems is that countries generally have chaotic perimeters (also known as borders), so they tend to be much longer than they seem to be.
For that reason, we have to define roundness some other way. We represent countries as a plane region, i.e., a compact set C⊂R2C⊂R2. I will define its roundness as
That's about where I tune out! Turns out the answer is Sierra Leone. Click through to see lots of mathy thingies on the screen, the runners-up, the least round countries, and the source code. Read the rest
Why does a flat pizza slice flop over unless you bend it into a curve? Thank Gaussian curvature, the 19th century mathematical principle that underpins everything from corrugated cardboard to eggshells to Pringles chips. Read the rest
Brilliant, high-speed math vlogger Vi Hart has revisited the topic of the sizes of infinities. Read the rest
India's Zetatrek citizen science initiative is online workshop starting on 19th July, where science and math hobbyists from all over the world are invited to study the original manuscripts of Sir Isaac Newton. Read the rest
Just in time for you to get the most out of "The Fault in Our Stars," the incomparable, fast-talking mathblogger Vi Hart's latest video is a sparkling-clear explanation of one of my favorite math-ideas: the relative size of different infinities. If that's not enough for you, have a listen to this episode of the Math for Primates podcast.
Chris Mooney of the Inquiring Minds podcast interviewed Jordan Ellenberg about his book How Not to Be Wrong: The Power of Mathematical Thinking, and in a fascinating accompanying post, Mooney investigates whether mathematics are "liberal." His argument is that liberal thought is characterized by "wishy washy" uncertainty and that math professors tend to vote left: Read the rest
Brooke Powers assigned her middle-school math class a probability exercise with no single correct answer and was monumentally frustrated by her kids' inability to accept the idea of a problem without a canonical solution. After a long and productive wrangle with her kids about how critical thinking works and why divergent problem-solving is much more important than mechanically calculating an answer that you could just get out of a computer, she salvaged the exercise and made something genuinely wonderful out of it. Read the rest
I've been writing about Thomas Piketty's magisterial economics bestseller Capital in the Twenty First Century for some time now (previously), and have been taking a close interest in criticisms of his work, especially the Financial Times's critique of his methods and his long, detailed response. I freely admit that I lack the stats and economics background to make sense of this highly technical part of the debate, but I think that Wonkblog's analysis looks sound, as does the More or Less play-by-play (MP3). Read the rest
Here's Randall Munroe's TED talk about his What If? series, in which he answers big, weird questions about baseballs travelling at the speed of light and such, which is also the subject of a hotly anticipated forthcoming book. The talk is a mix of war-stories and insight into what makes Munroe (who is a fascinating dude) tick. Read the rest
In a stirring editorial in the New Scientist, University of Edinburgh mathematician Tom Leinster calls on the world's mathematicians to boycott working for the NSA, which describes itself as the "largest employer of mathematicians in the US" and which may the world's number one employer of mathematicians. Leinster suggests that mathematicians could refuse to work for the NSA, that university heads could refuse to grant professors leave to work at NSA or GCHQ, that national mathematical societies could refuse NSA job-posting ads, and even "expel members who work for agencies of mass surveillance." Read the rest