speed of light

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.

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.

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.

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.

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.

Cosmo's 22:38 Ocarina of Time speedrun, performed live at AGDQ 2013. The runner uses a complex exploit to skip much of the game.

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.

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.

Admiral Grace Hopper holds up a length of wire to show how far light travels in a nanosecond, about 11.8 inches. She explains how she made the idea concrete to people who could not picture a billionth of a second.

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.

Captain Disillusion's VFXcool episode, led by Alan Melikdjanian, takes a 41-minute nostalgic look at how the visual effects of Flight of the Navigator were made. It covers early computers, motion control, in-camera effects and practical crafts.

A tool-assisted speedrun of Ocarina of Time at Summer Games Done Quick 2022, using TASBot and arbitrary code execution to reach an alternate ending in about 53 minutes. The run is introduced by its creators and followed by an interview.

Douglas Hofstadter lectures at Uppsala University on how analogy and daring thinking drove Einstein's discovery of light quanta. He argues deep insight in physics comes from imaginative leaps rather than rigid logic.

A 39-minute highlights reel of Bill Gates being deposed by David Boies in the 1998 to 2001 United States v. Microsoft antitrust case.

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.

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

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 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.

Summoning Salt traces the speedrunning history of Mario Kart 64's Choco Mountain track and its famous shortcut, through the successive record holders and discoveries. It carries an epilepsy warning for flickering lights.

A short screen recording of the flight simulator Easter egg hidden in Excel 97, with the steps to trigger it. The uploader notes the mouse controls are hard to handle.

Short Airbus footage of its ATTOL project, in which a test aircraft performed a fully automatic, vision-based take-off at Toulouse-Blagnac. The crew ran eight take-offs over several hours.

Microsoft's March 2023 launch highlights for Microsoft 365 Copilot, showing AI features in Outlook, PowerPoint, Excel and OneNote. The demo includes using it to draft a graduation party speech.

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.

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.

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.

Grace Hopper appears on Letterman and uses a foot-long piece of wire to show how far light travels in a nanosecond.

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.

Google's 2010 Chrome ad filmed web page rendering with a high-speed camera, comparing it with a potato gun, a pirate ship and lightning. It presented browser speed as Chrome's key selling point.

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.

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.

A KRAZAM comedy sketch in which Makro walks through the latest Microsoft Office 365 Excel update in a mock stream highlights format.

Casey Muratori's two-hour talk tracing the history of object-oriented programming back to the 1960s and examining how its ideas, and later entity component systems, came about. It is followed by a Q&A.

An animated 11-minute tour of the whole field of mathematics as a single map, showing how pure and applied math and their sub-fields relate to each other.

Microsoft's 2015 concept video imagining how ubiquitous computing, collaboration services and data analytics might change work 5-10 years later.

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.

Chris Granger, creator of Light Table and the Eve language, gives a Berkeley data science lecture on what computation and programming might look like in ten years. He covers the path that led to Eve and ends with demos.

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.

Simon Brown's Agile on the Beach 2019 talk presents the C4 model, a lightweight approach to diagramming software architecture with a shared vocabulary and simple notation.