light table

Veritasium explains why the one-way speed of light has never been measured, only the round-trip speed, since measuring it requires synchronized clocks that assume the answer. It explores the implications for relativity.

A PBS clip in which Richard Feynman explains the strange nature of light and electromagnetic radiation. He conveys how little of it we actually see and how radio waves are present everywhere.

DIY Perks shows how to turn old or smashed TVs and monitors into realistic artificial window lights, using the backlight and Fresnel lens to simulate distant daylight.

Technology Connections experiments with filtering white and colored LEDs to make holiday lights look less garish. He explains why narrowband LED strings look harsh compared with incandescent bulbs.

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.

A 1994 video from Knight Ridder showing a concept for a tablet newspaper with a rounded-corner rectangular touchscreen. It was reposted by Matt Novak of Paleofuture.

A short look at CoeLux, an artificial skylight that recreates the scattering process that makes the sky look blue, producing a convincing illusion of distant sun and depth.

A SIGGRAPH 2013 demo from Douglas Lanman and NVIDIA of near-eye light field displays, which allow much thinner head-mounted displays that still show accurate focus and depth cues.

A short video of a Microsoft Surface multimedia coffee table, with a pointer to making a homemade multi-touch screen. It shows the original touch-table concept.

A 2017 video arguing that banks and Blockstream steered Bitcoin toward the Lightning Network. It is partisan commentary from the Bitcoin Cash side of the scaling dispute.

Technology Connections complains about the harsh, overly blue color of modern LED Christmas lights and tries more fixes for them. It follows earlier videos by the same creator on holiday lighting.

Technology Connections explains how LED traffic lights, which do not melt snow, drew complaints and were blamed for accidents. He uses it to illustrate the 'but sometimes' fallacy against new technology.

Professor Mike Merrifield of Nottingham explains in a mostly uncut conversation why light travels slower in glass. He treats light as a wave and describes how the material's electrons produce secondary waves that combine to slow it.

A Microsoft Flight Simulator Feature Discovery episode in which CEO Sebastian Wloch explains the new aerodynamics simulation for the 2020 release.

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.

Technology Connections explains why single-hose portable air conditioners are inefficient and often a poor choice compared with window units. It details how the single hose pulls in warm outside air and wastes energy.

Mathologer shows how times table diagrams on a circle produce cardioids and other curves connected to the Mandelbrot set. He explains the patterns and links to a tool for making your own diagrams.

Fermilab's Don Lincoln explains why light travels slower in water and glass. He knocks down common wrong explanations such as absorption and re-emission, then gives the wave-mechanics reason tied to refractive index.

ScienceClic explains why nothing can go faster than light by treating motion through space and time together, so everything moves at the speed of light through spacetime. It uses animated visuals to cover relativity basics in 12 minutes.

The Slow Mo Guys visit a lab with a camera capable of filming at 10 trillion frames per second, fast enough to see light travel. They show the setup and the resulting footage.

Half as Interesting explains why airlines flew empty 'ghost flights' out of Heathrow to keep their landing slots under use-it-or-lose-it rules.

DIY Perks builds a realistic artificial sun for dark winters, using a powerful water-cooled LED, a satellite dish reflector for near-parallel rays, and a scattering layer to mimic the blue sky. The video explains the optics behind why most lamps do not look like sunlight and shows the build and its results.

A short clip showing a person touching an active table saw blade with a finger and walking away unharmed, thanks to SawStop's system that stops the blade within milliseconds of skin contact.

A BBC Earth clip from Super Powered Owls in which the team uses sensitive sound equipment to compare owl flight with other birds. It shows why owls fly almost silently.

A woodworker shows how his table saw accident happened, why it happened and how to avoid a similar one. He describes severe hand lacerations from a blade contact.

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.

First part of a six-part recording of the 1973 Lighthill debate on AI, where Sir James Lighthill's critical report on AI research was contested by figures including McCarthy and Michie.

Dave Jones of EEVblog tears down an Esinomed Infoview medical tablet computer built around an 800MHz AMD Geode board, exposing extremely shoddy construction and design.

A full piano performance of Beethoven's Piano Sonata No. 14, the Moonlight Sonata, with all three movements: Adagio sostenuto, Allegretto and Presto agitato.

A five-minute lightning talk from React.js Conf 2016 by Elie Rotenberg on protecting the DOM from tampering. It shows how React tree obfuscation (react-armor) can shuffle class names, tags and tree structure to defeat CSS-selector-based ad blocking.

A five-minute demo of a live ClojureScript game editor by Chris Granger. It is based on Bret Victor's demo from the Inventing on Principle talk, with code changes reflected instantly in the running game.

A man with no flight instruction and only desktop flight simulator experience attempts to take off and land a Cessna 172, with a commercial airline instructor aboard who gives no help. The flight came out of a prop bet.

Periodic Videos visits a fluorine expert to show how reactive the element is in action. It also includes a discussion of fluoride and tooth enamel.

Inventor Mary Lou Jepsen demonstrates using red light and sound to see inside the body and brain, aiming at tumor detection and neural activity measurement, and potentially a cheaper wearable MRI replacement.

A CNN segment showing William Shatner emotionally describing his Blue Origin suborbital flight to Jeff Bezos right after landing.

Highlight clip from the 2021 Free Expression Awards honoring YouTube CEO Susan Wojcicki. The video became notable for its overwhelmingly negative like/dislike ratio.

Asianometry explains the EUV light source inside ASML's lithography machines, where lasers hit falling tin droplets twice to produce 13.5 nm light. It walks through the engineering of the droplet generator, the pre-pulse and main laser, and the plasma that results.

A five-minute lightning demo of VisiData, a terminal tool for exploring and manipulating data. It uses two months of NYC 311 complaint data to drill down, plot points on a virtual map and save selected rows.

Wendover Productions explains why Boeing's efficient 787 beat Airbus's giant A380, contrasting hub-and-spoke with point-to-point routes. It covers the economics of long-haul flights.

Veritasium explores planned obsolescence, from the Phoebus lightbulb cartel to printers and phones. It explains how companies deliberately shortened product lifetimes and why products aren't better.