- 🤯 🚀 🧶 Software woven into wire: Core rope and the Apollo Guidance Computer. “Much of the core rope wiring (address inhibit wires, set, reset, etc.) was the same for all core rope modules. Two women passed a needle back and forth through the cores to create this wiring. The needle was hollow and contained the necessary length of wire.”
- 🤩 🛵 🚲 🇯🇵 Small vehicles of Tokyo. “A slim cataloguing of the rich diversity of small vehicles that help shape street life in the world’s largest city”
- Good 🧵 by manvir singh on the pre-colonial Tlaxcallan republic. People often assume that the only states of pre-colonial Mesoamerica were despotic kingdoms. What’s rarely appreciated, however, is that one of the main rivals of the Aztec Empire—a city-state called Tlaxcallan—was a republic ruled by an assembly of commoners & nobles.
- 🐦 🐵 🐝 🦑 🧠 Animals Count and Use Zero. How Far Does Their Number Sense Go? “The intelligence of corvids like ravens and crows is well known. Recently, crows were even shown to have a numerical ability seen in few other species so far: a grasp of the concept of the empty set — the numerosity zero.”
- 😬 🌎 ∿ Jet stream 🧵 by Jeff Berardelli. You often hear us talk about the wavy jet stream. Here’s a good illustration of how this manifests in extreme weather, connecting the Europe flooding to the Heat Dome in the US West. Some scientists have found a connection between climate change and a more amp’d - wavy jet.
- Nice 🧵 explaining Markov 🔗 In this thread, I’ll help you understand Markov Chains. In life, and in investing, we often come across situations where luck/chance plays a major role. And Markov Chains are often a great way to model and analyze such situations. (Via Some anders.)
- 🔴 Inside Mars, NASA’s InSight Mission Mapped Surprises Down to the Core. “Like Earth’s, Mars’s mantle is far thicker than its crust. But the rigid part of the upper mantle, which on Earth forms the base of ever-shifting tectonic plates, is perhaps twice as thick on Mars, maybe more. ”
- 🇻🇪 🗺 How the World’s Slums Can Get Back on the Map. “More than 1 billion people live in these areas of the world’s cities, according to the United Nations, and their numbers have been growing as urbanization trends continue. But severe information gaps keep much of this landscape hidden: Unlike formal areas, slums might not have their streets, services and buildings mapped on platforms such as Google Maps.”
Note — Aug 22, 2021