working backwards

Tom Scott explains why Windows does not let you name a file CON, tracing the reserved device names back to backwards compatibility with DOS.

CGP Grey argues that your brain treats a whole home as one room during lockdown, blurring work, rest and leisure. He recommends creating separate spaces and routines for different activities to stay balanced.

Mark Handley of UCL explains, with simulation visualizations, how early Starlink satellites without inter-satellite links could still give low-latency wide-area communication by hopping via ground relays. He shows it can beat fibre on many long paths.

Branch Education explains how Starlink works, from the ground dish and satellites to phased-array beam steering and data routing. Animations cover how a beam stays connected to a satellite moving at 27,000 km/h.

Numberphile's James Grime introduces quaternions, a type of number beyond the complex numbers, building up from real and complex numbers and explaining why they are useful.

Polylog explains how algorithms can be turned into circuits and encoded as satisfiability problems, which lets you effectively run them backwards. It uses this to motivate breaking RSA, general reductions to SAT, and what P vs NP is really asking.

Historia Civilis traces the history of work and time discipline, comparing modern working hours with those of medieval peasants and the changes brought by clocks and industrialization. It draws on works such as Schor's The Overworked American.

Matt Parker of Stand-up Maths asks whether a country's reported land area accounts for hills and mountains, working through how surface area depends on the resolution of elevation data. It follows up on a question from a viewer and work by researchers who measured it.

Tom Scott visits a rotating house near San Diego and explains how electricity, gas and water keep working on the rotating part. It includes a 3D render of the utility connection system.

CGP Grey asks whether Star Trek-style teleportation would kill you and recreate a copy, working through the philosophy of identity and the Ship of Theseus. It is a short animated explainer.

Paul Irish explains how pointerpointer.com works. It uses a hidden canvas of colored Voronoi regions to look up which photo matches the cursor position.

Tom Scott visits ThyssenKrupp's test tower in Rottweil to see the Multi, a rope-free elevator that uses linear motors to move cabins sideways as well as vertically.

Tom Scott explains why subtitles often differ from dubbed dialogue, covering how translation, timing and reading speed shape each. It features translators and voice talent working in several languages.