here together

Isaac Arthur examines Dyson spheres and swarms, including common myths and misconceptions. He covers uses such as interstellar travel, black hole generation, and computing large enough to simulate universes.

Matt Parker on Numberphile explains the strange properties of spheres in higher dimensions, such as how they poke out of their bounding boxes. It uses Pythagoras to build intuition for 4D and beyond.

A Kurzgesagt animated explainer on how humanity could build a Dyson sphere, a swarm of structures capturing the sun's energy. It covers using Mercury's materials and a step-by-step construction approach.

A 21-minute animation showing how a sphere can be turned inside out without creases or tears, known as sphere eversion.

Huygens Optics shows through a laser interference experiment that the question of a photon's size is really about coherence length. It argues that photons exist as energy exchanges between radiation and matter, not as little particles in free space.

A short, sarcastic Half as Interesting video about a tiny freight railway in Canada built to exploit a shipping regulation loophole. It explains how a track just 100 feet long counted as a railway.

Not Just Bikes introduces the "stroad", a street-road hybrid common in the US and Canada that fails at both jobs. He contrasts it with Dutch design, where each road has a single purpose, and covers cost, danger and ugliness.

3Blue1Brown visualizes high-dimensional spheres to explain a surprising puzzle about how a sphere fits in a box as dimensions grow. It builds geometric intuition for counterintuitive properties of high-dimensional space.

Sabine Hossenfelder explains how the greenhouse effect actually works, given that infrared is mostly absorbed low in the atmosphere already. She walks through why more CO2 still warms the surface.

Tom Scott-style exploration by suckerpinch (Tom7) of generalized anagrams where letters can be broken into pieces, called anagraphs, with a whimsical computational approach.

Veritasium asks people where a tree's mass comes from, then explains that most of a dry tree's mass originates from carbon dioxide in the air. It combines street interviews with a short explanation of photosynthesis.

An RSA Animate summary of Iain McGilchrist's lecture on the divided brain, arguing the brain's two hemispheres attend to the world differently and that this has shaped culture and society.

Isaac Arthur examines the Dyson Dilemma, the puzzle of why we see no Dyson spheres or megastructures if growth-oriented civilizations should build them. He covers detectability and whether such structures could hide.

Vox's Joe Posner, with help from 99% Invisible, explains why bad doors are everywhere. It covers Don Norman's long-running complaint about doors and the idea that good design should not need instructions.

Not Just Bikes tours Houten, a Dutch town designed around cycling, explaining how its layout makes most trips by bike safe and easy. It also promotes a book about the town.

Not Just Bikes reflects on five years in the Netherlands and tours small towns and cities, from Haarlem to Veenendaal. It argues that good urbanism with walkable streets, bike infrastructure and transit is found almost everywhere there, not just in Amsterdam.

Tom Scott visits an eHighway test in Lubeck, Germany, where electric trucks with pantographs draw power from overhead wires. He explains how this could electrify road freight.

Joseph Everett, with Dr. Frank Mitloehner, argues that eating less meat will not do much for the climate. He covers beef's water footprint, land and feed use, and methane.

Technology Connections' long closing video in his heat pump series, arguing that adopting heat pumps is well within reach. It explains how they work and what it takes to start using them.

Not Just Bikes explains, using Urban3's property-tax analysis, why car-dependent suburbs generate less tax revenue than they cost to maintain, so dense urban cores effectively subsidize them. It is part of a Strong Towns series.

Veritasium explains the effort to redefine the kilogram, which was still defined by a physical artifact, and how a near-perfect silicon sphere from the Avogadro project helps. It also covers the history of the unit's odd naming.

Tom Scott explains the design of the British BS 1363 plug and socket, including fuses, shutters and safety features, and why he thinks it beats other plugs.

Guitarist Jim Lill methodically tests what in an electric guitar affects its tone, swapping parts on a partscaster and even trying a 2x4 body. He finds that wood and construction matter far less than people assume.

Not Just Bikes shows how traffic calming is built into streets across the Netherlands, from city centres to villages. Street design naturally slows cars and makes roads safer.

Zack Freedman gives advice on why makers fail to finish projects, including scrapping bad ideas, showing work publicly and writing a plan that keeps projects fun. It is aimed at hardware DIY but generalizes.

Tom Scott argues that grammatical gender is a silly concept and that the singular 'they' is an established gender-neutral pronoun. The description carries later corrections and reflections he added in 2019.

Veritasium explores why the number 37 turns up so often, drawing on Tom Magliery's collection of 37 sightings and a poll of about 200,000 people asked to pick a random number. It covers how humans choose numbers and why 37 stands out.

Kurzgesagt introduces the Fermi paradox: with so many stars and planets, why do we see no sign of aliens? It sets up the question and what it might imply for our own future. It is part 1 of 2.

Sabine Hossenfelder explains why she thinks faster-than-light travel may not be ruled out. She argues that the standard objections from special relativity are inconclusive.

Verge Science's pilot of its Trial & Error series follows amateur scientist Jon Larsen on a hunt for micrometeorites. It shows how tiny space rocks can be found on rooftops and confirmed under a microscope.

Wendover Productions explains why American towns, retail and buildings increasingly look alike, covering zoning pressures, corporate standardization and cheap construction types like 5-over-1 buildings.

Asianometry explains that the worst of the 2021-22 chip shortage sits in trailing-edge semiconductors, not the leading-edge chips usually covered. It covers why those older-node fabs are so hard to expand and fix.

Sabine Hossenfelder explains why hydrogen is a poor answer for decarbonization, covering how most hydrogen comes from fossil fuels, the efficiency losses of green hydrogen and reliance on rare metals in fuel cells.

Wendover Productions explains the wave of supply shortages in 2021, arguing the causes go beyond COVID. It covers how just-in-time manufacturing was applied, container imbalances and the chip shortage.

Kurzgesagt explains the black hole bomb and how far-future civilizations might extract energy from spinning black holes, including Dyson-sphere-style ideas.

Tom Scott explains why hold music sounds worse than it used to, tracing it to old telephone exchanges and the audio compression applied by modern switches. It is a short visit to the Milton Keynes Museum.

Technology Connections explains how a home can act as a thermal battery by pre-cooling or pre-heating when electricity is cheap or abundant. He shows how this shifts load off-peak and eases strain on the grid.

Stand-up Maths explains why the perimeter of an ellipse has no simple closed-form equation, showing the infinite series and presenting approximation formulas.

Numberphile talks with Grant Sanderson of 3Blue1Brown about a darts puzzle with a shrinking bullseye. Solving it takes the volumes of high-dimensional spheres, and the answer turns up Euler's number.

Isaac Arthur explains the Matrioshka Brain, a hypothetical computer or artificial mind powered by an entire star using nested shells. It covers how such megastructures relate to Dyson spheres and superintelligence.