Weekly links for June 3

Global flight paths in pictures by Michael Markieta.

How crackers crack passwords, via metafilter.

Why do cicadas breed in prime year intervals?

From John Geer, better estimation when perfection is unlikely – a derivation of the Laplace succession rule. This underpins Geer’s Deciding Data, an aggregator of data science news; here’s how it works.

From Quora, how do you explain Bayes’ theorem in simple words?

Upstart is a company that allows people to invest money in young people in exchange for a share of future income. Say what you will about their business model, they have an interesting blog.

From the New York Times “Wordplay” blog, is it better to walk or run in the rain?

From Marginal Revolution, do Lacanians understand the third derivative?

American Heritage did an article a few years ago on girl computers (who were instrumental in the World War II effort); the documentary “Top Secret Rosies” on the same subject is available on Netflix streaming.

Jordan Ellenberg estimates that he has a quarter million friends of friends on Facebook. Edward Frenkel writes on credit card security and cryptography for Slate. (What’s this doing in the same paragraph? Well, Jordan Ellenberg is Slate’s usual math contributor.)

Barry Mazur on the nature of evidence in mathematics, perhaps best accompanied by these notes by Mazur on plausibility.

Gerhard Woeginger has a collection of 98 papers which attempt to settle P vs. NP, if you’re into that sort of thing.

Khan Academy has lots of data on learning, something I wished I had back when I was teaching. Via Y Combinator.

The Guardian asks which times tables are hardest and easiest for children; results are surprisingly noncommutative.

Nate Silver asks why can’t Canada win the Stanley Cup?

Burr Settles text-mines the difference between “geek” and “nerd”.

Andrew Gelman asks about the statistical properties of referral chains.

Ben Frederickson examines the distribution of user ratings.

Ian Stewart, writing for the New Statesman, puts forward the idea that mathematics is a third intellectual culture bridging the gap between the arts and the sciences.

Science &ecute;tonnante explique pourquoi 1 + 2 + 3 + … + = -1/12. (In French.)

Prices in virtual economies are as hard to manage as real life ones, says Zach Seward at Quartz, in reference to the game Dots a few weeks ago he put out a the ultimate Dots strategy guide.