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.

Matt Kulukundis explains how Google designed SwissTable, a fast, cache-friendly hash table, step by step from std::unordered_map. The talk covers open addressing, SIMD probing and the tradeoffs of changing a fundamental data structure.

Dr. Roger Seheult of MedCram reviews the benefits of sunlight beyond vitamin D, covering the solar spectrum, circadian rhythm, melatonin and infrared light. The lecture runs nearly two hours with timestamps.

Technology Connections examines why light bulbs have the lifespans they do, including the real history of the Phoebus cartel. He shows that bulb life trades off against brightness and efficiency rather than being simple planned obsolescence.

Lee Byron of Facebook explains how persistent immutable data structures work and how to use them in React apps with Immutable.js. He covers memoization benefits and avoiding coupling through shared mutable state.

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.

Technology Connections explains why American cars all had the same standardized sealed-beam headlights until 1957. It covers the regulations behind the design and the effect on night visibility.

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.

Matt Kulukundis reviews two years of Abseil's Swiss table hashtable, covering post-release optimizations, lessons from rolling it out across Google, design choices, and what global monitoring revealed.

Malte Skarupke's C++Now 2018 talk on hash table performance, explaining why std::unordered_map is slow and memory hungry and presenting faster designs, including his bytell hash map.

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.

Rick Falkvinge responds to viewer feedback on his earlier Lightning Network video and raises a flaw he says was not previously discussed. The main thread is the network's unsolved routing problem.

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.

AlphaPhoenix shows off a new camera that films at two billion frames per second and uses it to film a laser pointer pulse. He investigates a strange quirk in how the speed of light appears on camera.

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.

Juan Pedro Bolivar Puente explains immutable and persistent data structures in C++ and how they support value semantics. He presents the Immer library, rrb-trees, and a prototype text editor that opens a huge file instantly.

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.

A short concept video of Microsoft's unreleased Courier, a dual-screen tablet designed as a digital notebook with clippings and annotation. It was first leaked by Gizmodo in 2009.

A PyCon 2013 block of Friday evening lightning talks. It includes the debut of Hy, a Lisp dialect that compiles to Python AST, and Solomon Hykes's first public talk on Docker.

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.

An American Airlines training video by Captain Warren VanderBurgh on control malfunctions and flight instrument anomalies. It discusses real incidents such as runaway trim and instrument failures and how crews should respond.

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.

A 2007 Google Tech Talk in which Cliff Click of Azul Systems presents a lock-free concurrent hash table that scales to 768 CPUs. He explains why it is correct by reasoning in a different way than usual happens-before and memory-order arguments.

3Blue1Brown visualizes Feynman's lecture on the refractive index, explaining why light appears to slow down in glass and why the effect depends on color. It builds the idea from waves produced by oscillating charges in the material.

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.

Yannic Kilcher interviews Emad Mostaque, founder of Stability AI, about the company's funding, its mission, and the release of Stable Diffusion. Topics include access to compute, handling harmful outputs, and avoiding the corrupting influence of profit.

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.

MIT Media Lab shows an imaging system capturing a trillion frames per second, fast enough to film light pulses travelling through objects in slow motion.

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.

JPL's David Cummings presents at the 2025 Flight Software Workshop how the team diagnosed and fixed the 2023 Voyager 1 anomaly from billions of miles away. It walks through the flight computer and the memory fix.