block size

3Blue1Brown explains the math and mechanics behind Bitcoin visually: ledgers, digital signatures, proof of work and the blockchain, building up a decentralized payment system from first principles.

A short Vox video on Barcelona's superblocks, an urban design approach that closes interior streets to through traffic to return space to pedestrians.

A visual scale comparison of stars and cosmic objects, from planets up to some of the largest known stars, set to music. It is meant to convey the vastness of the universe.

CGP Grey explains the elegant ratio of A4 and the metric paper sizes, then zooms out across scales from the Planck length to the observable universe.

Sabine Hossenfelder explains how special relativity leads to the block universe, in which past, present and future all exist equally, and asks what that means for whether the past still exists.

Tom Scott explains why electronic voting is a bad idea. Elections must be trusted by everyone and attacks on software scale in ways attacks on paper do not, so open source or blockchain fixes do not solve it.

Adam Savage shows a set of Mitutoyo ceramic gauge blocks and uses them to explain metrology, the science of measurement. He argues that accuracy and precision work differently than most people assume, which changes how you think about every measuring tool.

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 scene from The Big Short in which Jared Vennett pitches credit default swaps on mortgage bonds to a hedge fund team, using a Jenga tower to illustrate collateralized debt obligations.

Not Just Bikes explains how SUVs and light trucks have grown in size and share of US sales, and why that is dangerous for pedestrians, cyclists and city life. He covers the regulatory loopholes, such as fuel economy rules and the chicken tax, that favored them.

WIRED has UCLA professor Amit Sahai explain zero-knowledge proofs to a child, a teen, a college student, a grad student and an expert. Each round goes deeper into the cryptography and why it matters.

A two-minute clip of Andreas Antonopoulos explaining why a 51% attack on Bitcoin would not destroy it and what such an attack would cost. It is a succinct take on mining security.

Oh The Urbanity! argues that most city dwellers live in dense residential neighbourhoods outside downtown, which can be calm and peaceful. It draws on older, denser parts of Toronto and Montreal.

A short How to ADHD explainer, featuring Brendan Mahan, on why simple tasks can feel impossible for people with ADHD. It introduces the 'wall of awful', a pile of past failures, shame and anxiety that builds up in front of a task and blocks starting it.

Vsauce's Michael Stevens takes viewers past infinity using transfinite numbers, ordinals and cardinals, with input from mathematician Hugh Woodin. It is a fast-paced, mind-bending tour of different sizes of infinity.

A short video from the trafficwaves.org site showing how traffic jams and standing waves form, including the fight between cheaters and blockers at an exit-lane backup. It also touches on how individual driving behavior affects the flow.

FortNine looks at the data on why newer pickup trucks with tall, blunt grilles kill so many pedestrians, cyclists and motorcyclists. It argues that lowering hood height would substantially cut fatalities.

Veritasium explains why bicycles are stable, arguing that gyroscopic effects are not the answer. The video shows countersteering and an experiment where riders blocked from steering the opposite way cannot turn.

A short clip from Carl Sagan's Cosmos in which he explains how Eratosthenes measured the circumference of the Earth using shadows in two Egyptian cities. It is a clear, visual account of an ancient scientific feat.

Numberphile's James Grime explains Cantor's result that some infinities are bigger than others, including why the reals outnumber the integers. It is a short, accessible introduction to countable and uncountable infinity.

Wes Bos breaks down the techniques behind the McMaster-Carr website's speed: server-rendered HTML, prefetching, CDN and service worker caching, preloading, critical CSS and fixed-size images. He also notes its old-school jQuery and YUI JavaScript.

Not Just Bikes takes on the common excuse that a country is simply too big or spread out for good transit and walkable cities. The video argues that city density and short everyday trips matter, not national size or overall population density.

A PBS Space Time episode hosted by Gabe Perez-Giz on the nature of spacetime and whether space and time are fundamental. It builds up reference frames and causality in a short, dense format.

An Isaac Arthur episode on arcologies, self-sufficient habitats that could house whole cities, on Earth or on harsh worlds. It covers how such structures might work and what limits their size.

2swap explains how he solved the Klotski sliding-block puzzle by mapping its full state space as a graph and visualizing it. The video includes footage of the Guinness world-record solve and links to an interactive graph.

Not Just Bikes argues that oversized American fire trucks and fire department requirements push cities toward wide roads and dangerous street design. He compares this with the Dutch approach to emergency response.

Not Just Bikes looks at the tiny microcars such as the Canta seen around Amsterdam. It discusses how they serve people with mobility issues, can use bike paths under certain rules, and where they fit in a 21st century city.

Tom Scott visits Penistone to explain the Scunthorpe problem, showing why naive web and profanity filters block innocent words.

CaspianReport explainer arguing that Russia's geography, especially its vast size and indefensible Moscow core, shapes its political behavior. It frames Russian security thinking through the lens of geographic determinism.

An 8-minute explainer on the Lightning Network and how it relates to Segwit, Bitcoin and Litecoin. It covers how off-chain payment channels route payments to scale blockchain transactions.

Vsauce explores math through card tricks and big numbers, including an animation of how enormous 52 factorial, the number of deck orderings, really is.

Kurzgesagt explains black hole stars, a hypothesized kind of giant star with a black hole at its core that could be a route to early supermassive black holes.

A short Techquickie explainer on why laptop webcams are much worse than phone cameras. It covers sensor size, image processing, and the interface differences between laptops and phones, with input from a Logitech engineer.

A Veritasium video on the asteroid threat, with UCLA's Dave Jewitt explaining detection efforts and how different asteroid sizes compare in damage.

Gamers Nexus benchmarks how the amount and application method of thermal paste affect CPU cooling. It compares pea-sized dots, thin spreads and large blobs with Thermal Grizzly Kryonaut.

Not Just Bikes looks at traffic in the Bahamas to show that a small country can be just as car-centric as a big one. He ties it to land use, car dependence and how dedicated transit lanes help.

Linus Tech Tips breaks down the company's income streams, including sponsors, YouTube Premium, merch and other products. It gives percentages for each revenue source.