faster than light

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.

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.

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.

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.

Engineering Explained examines new research suggesting corn ethanol in US gasoline may emit as much or more carbon than gasoline. It covers the Renewable Fuel Standard and why ethanol was assumed to be a green fuel.

A PBS Space Time episode explaining why faster-than-light travel is equivalent to travelling back in time, using relativity and Minkowski diagrams for different observers.

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.

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.

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.

Veritasium recounts a $10,000 bet with a UCLA physics professor over whether a vehicle can travel downwind faster than the wind. He presents the professor's reasoning and demonstrations, including one without aerodynamics.

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.

aGameScout explains rolling, the third major NES Tetris playstyle, in which players tap the back of the controller to move pieces faster than hypertapping. It covers how the technique works and where it comes from.

Sciencium examines the Mpemba effect, the claim that hot water freezes faster than cold water. It walks through experiments and a published paper questioning the effect.

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.

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.

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.

PBS Space Time introduces Miguel Alcubierre's warp drive, explaining how spacetime itself could be warped rather than moving a ship through it, and whether it is physically possible.

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.

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 investigates whether a wind-powered vehicle can travel directly downwind faster than the wind, driving the Blackbird craft himself. The video explains the physics behind a claim some physics professors dispute.

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 Technology Connections video weighing LED streetlights against high pressure sodium lamps, covering efficiency, color, cost and light pollution. It is a follow-up to his earlier explanation of why street lights are orange.

Real Engineering explains why biofuels, especially corn ethanol, are a poor energy source, looking at energy inputs, efficiency and carbon cost.

Tom Scott investigates moire-effect beacons, called Inogon leading marks, a Swedish invention from the 1980s that shows different patterns depending on the viewer's position. He visits one used to mark an undersea cable and tracks down its history.

Technology Connections explains how RGB light and color work, from hue and saturation to color vision and how objects appear under different lighting. It uses a studio setup with colored lights to demonstrate the effects.

Wendover Productions explains why modern airliners fly no faster than they did decades ago, covering the economics of speed and fuel efficiency, and why supersonic travel faded.

3Blue1Brown, in collaboration with minutephysics, introduces the math of superposition and quantum states using polarized light. It builds up the quantum behavior of photons as a simple counting and probability problem.

Technology Connections tests how quickly gas, induction and standard electric stoves boil water, with CO2 measurements and a discussion of the advantages and disadvantages of each.

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.

Joseph Everett, with Dr. Frank Mitloehner, argues that eating less meat will not do much for the climate. He covers beef's water footprint, land and feed use, and methane.

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.

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.

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.

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.

A Veritasium video that follows the principle of least action from Bernoulli and Newton to quantum mechanics, asking whether light takes all possible paths at once. It includes experiments showing quantum waves.

Technology Connections explains how an ordinary tank water heater works, including twin-element designs, and why it is cleverer than it looks.

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

Technology Connections takes apart a 1940s Sunbeam Radiant Control toaster. It senses the toast's own browning and lowers and raises it automatically using purely mechanical parts and no electronics.