A paywalled paper in the Royal Society's journal Interface argues that the world's underground rail systems are all converging on an "ideal" form. The paper, "A long-time limit for world subway networks," shows that subway systems grow "organically," in response to the needs expressed by the cities above them over the course of decades, and reveal truths about the shape of cities. In Wired, Brandon Keim describes the findings:
Patterns emerged: The core-and-branch topology, of course, and patterns more fine-grained. Roughly half the stations in any subway will be found on its outer branches rather than the core. The distance from a city’s center to its farthest terminus station is twice the diameter of the subway system’s core. This happens again and again.
“Many other shapes could be expected, such as a regular lattice,” said Barthelemy. “What we find surprising is that all these different cities, on different continents, with different histories and geographical constraints, lead finally to the same structure.”
Subway systems seem to gravitate towards these ratios organically, through a combination of planning, expedience, circumstance and socioeconomic fluctuation, say the researchers.
World’s Subways Converging on Ideal Form
Zero-knowledge proofs are one of the most important concepts in cryptography: they’re a way to “validate a computation on private data by allowing a prover to generate a cryptographic proof that asserts to the correctness of the computed output” — in other words, a way to prove that something is true without learning the details.
Retroworks’ $18 decoder rings don’t have much by way of cryptographic robustness (they compare disfavorably to the cipher-wheel wedding rings my wife and I wear!), but they’re not a bad way to introduce the littlies in your life to the idea of habitual secrecy. (via Red Ferret)
This week (and next due to the nature of different release dates for the direct market and the book market) marks the release of the first collection of SHADE THE CHANGING GIRL v.1: Earth Girl Made Easy, which compiles issues 1-6 (previously). It’s a heavy load to recreate a character that giants before you have written. Steve Ditko is a master of the strange. His mind a merry-go-round of experimentation.
The Fader Stealth Quadcopter from TRNDlabs packs incredible flight performance into a package small enough to land on your phone screen, and it’s available now in the Boing Boing Store.The Fader’s six-axis gyroscope module gives it perfect balance in the air. This makes the onboard 720p HD camera all the better for shooting amazing flight […]
Although fully autonomous vehicles aren’t yet allowed on public streets, they are poised to dominate the roads in the not-too-distant future. But before that happens, Apple, Google, Uber, and other companies now investing in self-driving tech are going to need talented developers that can account for the dizzying array of factors at play when a […]
The PiCar-V learning kit comes with everything you need to build a Python-powered robot, and it’s currently being offered in the Boing Boing Store.