react conf

Historia Civilis explains the origins and governing system of the Iroquois (Haudenosaunee) Confederacy. It covers the Great Law and the league's surprisingly intricate legal and political structure.

Tom Scott explains why confetti and snow wreck video quality, using interframe compression and bitrate. He demonstrates it live by changing the quality on screen.

A Veritasium video that runs the 2-4-8 rule-guessing puzzle on people to show how they test only examples that confirm their hypothesis. It uses this to illustrate confirmation bias and falsification.

A SciShow episode in which Hank Green introduces five of the most dangerous chemicals, from lethal toxins to substances that explode on contact. It is an entertaining overview of extreme chemical hazards.

Thunderf00t presents high-speed camera footage of alkali metals such as sodium and NaK reacting with water. The footage shows that the explosion is not caused by hydrogen ignition, as the usual explanation says. It is a Coulomb explosion driven by electrons leaving the metal.

PBS Space Time explains Roger Penrose's conformal cyclic cosmology, in which the far future of our universe becomes the big bang of the next. It explores what could come after the universe ends.

ACS Reactions investigates why Mexican Coke, supposedly cane sugar sweetened, tested as having glucose and fructose, explaining that sucrose breaks down in acidic soda.

An animated 44-minute summary of Ray Dalio's book Principles for Dealing with the Changing World Order. It lays out the Big Cycle of rising and declining nations, covering debt cycles, internal conflict, and shifts in global power over the past 500 years.

CGP Grey's quick, witty explainer on the differences between the United Kingdom, Great Britain and England, and the countries that make up the UK.

Every Frame a Painting analyzes how Jackie Chan stages action comedy, with nine principles such as starting from a disadvantage, using the environment, clear shots, and keeping action and reaction in the same frame.

Veritasium explores the Prisoner's Dilemma and Axelrod's tournaments, showing why tit-for-tat and forgiving strategies win in repeated games. It extends the ideas to cooperation in evolution and conflict.

PBS Space Time argues that the speed of light is better understood as the speed of causality, the universal limit on how fast cause and effect propagate. Light travels at that speed because it is massless, but the limit itself is a property of spacetime.

CGP Grey explains how traffic jams come from human driving behavior such as tailgating and reaction delays, and how leaving gaps and smoothing speed would reduce congestion. It also touches on self-driving cars.

Numberphile interviews cryptographer Ron Rivest about end-to-end verifiable voting. He explains how homomorphic encryption and receipts let a voter confirm their ballot was counted without being able to prove how they voted to anyone else.

Yuta explains what Japan's 99% conviction rate actually means, noting that prosecutors drop cases unless confidence is very high. He argues that the number is widely misunderstood and cites his sources.

Huygens Optics explores the idea that space is a non-linear elastic medium, and uses simulations to show how wave energy might be confined locally into particle-like objects. It touches on inertia, the Schwinger limit and the vacuum as a medium.

Veritasium examines research suggesting science explainer videos like Khan Academy's make students feel they understand while tests show they have not learned, because misconceptions go unaddressed. It suggests how to partly fix this.

Geoff Cumming uses a simulation to show how wildly the p value varies from one replication to the next because of sampling variability. He argues for estimation and confidence intervals over null hypothesis significance testing.

A short excerpt from Frans de Waal's TED talk showing a capuchin monkey fairness experiment in which two monkeys are paid unequally, one with cucumber and one with grapes. The shortchanged monkey reacts angrily.

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.

Technology Connections explains the difference between power (watts) and energy (watt-hours) and why confusing them leads to errors. It runs about 52 minutes and uses everyday examples.

CGP Grey explains why airport codes are inconsistent and sometimes confusing, from their origins in old weather station codes to the quirks that cause mistakes. He builds the story around a single typo that sent a flight to the wrong continent.

Not Just Bikes explains how Dutch traffic lights use early detection, transit priority and conflict-free design to cut waiting. The aim is to move as many people as possible rather than as many cars.

Veritasium's Derek Muller spends an hour in a silent, dark anechoic chamber at BYU to test the claim that 45 minutes is the most anyone can bear. He reports on his experience and other people's reactions.

Randall Munroe of xkcd answers what would happen if you swam in a spent nuclear fuel pool, and how much radiation you would receive at the surface versus at depth.

A short BicycleDutch episode showing how Dutch protected intersections continue cycle paths through the junction without needing extra street width.

Scott Manley explains the nuclear salt water rocket, Robert Zubrin's concept of a rocket fueled by a rapid nuclear reaction in uranium salt dissolved in water. He covers its extraordinary performance and the dangers of managing it.

A short BicycleDutch episode showing how Dutch junctions with protected cycle paths are laid out. It argues these are proven, non-experimental designs that make intersections safer for cyclists.

Technology Connections explains how touch lamps work and traces them back through patents to the 1950s, far earlier than most people assume.

An animated map showing the borders and populations of European countries for every year since 400 BC. Vassal states and colonies are excluded from population counts.

A short CGP Grey explainer on why 'Holland' is wrong as a name for the whole country of the Netherlands. It covers the country's provinces and its constituent territories.