Download the Book (PDF): Introduction A nurse in Dubai who wants to send two hundred dollars to her mother in Manila faces a strange fact of modern life. She can stream a film from a server on another continent in a second. She can video-call her mother for free. But the money, which is nothing more than a number in a bank's database, may take a day or more to arrive, and on the global average something like thirteen dollars of it will disappear on the way. If she sends it th

Download the Book (PDF): Introduction A fourteen-year-old is stuck on a problem about the area of a trapezoid. She types the problem into a chatbot on her phone, and within two seconds she has the answer, a tidy derivation, and an offer to explain anything further. She copies the answer into her homework and moves on. The next morning, on a quiz with no phone allowed, she meets another trapezoid and cannot begin. In a different classroom, a boy working on the same topic in a

Download the Book (PDF) Introduction A language model that answers in under a second on a phone, without a network connection, without sending a word of the user's data to anyone, is no longer a research demonstration. In 2026 it is a product requirement. Apple ships a roughly three-billion-parameter model inside its operating systems and exposes it to developers. Google ships Gemma models built to run on phones and single-board computers, and an on-device Gemini Nano through

Download the Book (PDF): Introduction At a signalized intersection in almost any city, a small cabinet sits on the corner. Inside it, a controller decides, many times a minute, which movements get green and for how long. For most of the twentieth century that decision was written in advance: an engineer counted cars on a weekday in spring, worked out a cycle length and a split of green time, and loaded the plan into the box, where it might run unchanged for a decade. The city

Download the Book (PDF): Introduction At noon on a clear day in July, a square metre of farmland in southern Europe receives close to a kilowatt of sunlight. A lettuce leaf in that square metre cannot use most of it. Its photosynthetic machinery saturated hours ago; the surplus energy arrives as heat, drives water out of the leaf and the soil, and forces the plant to spend effort protecting itself rather than growing. Three hours later, as a thunderstorm builds and clouds thi

Download the Book (PDF): Introduction It is eleven at night in the second week of finals. A student has been at her laptop since dinner, working through lecture slides, a shared document of practice questions and a PDF of a textbook chapter that refuses to render at any size larger than a postage stamp. Her eyes burn. The letters swim a little when she looks up at the clock on the far wall, then settle. There is a dull pressure across her forehead, and her neck feels as if it