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Robert Wills of TNMoC explains the Apollo Guidance Computer hardware and software, then walks through the Apollo 11 landing procedure step by step, including the 1202 alarms.

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.

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.

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.

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.

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.

A special lecture from MIT's Private Pilot Ground School in which Lt. Col. Randy Gordon, a fighter and test pilot, describes F-22 flight controls. Topics include thrust vectoring, the pilot command system and how software handles failures.

Trailer for the documentary It's Quieter in the Twilight, shown at the Boston SciFi Film Festival. The film follows the engineers who keep the Voyager spacecraft running.

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.

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.

A NASA and Durham University supercomputer simulation suggesting the Moon may have formed within hours of a giant impact between Earth and a Mars-sized body. It is one of the highest-resolution giant-impact simulations run.

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.

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.

AVweb's Paul Bertorelli explains why general aviation has failed to replace leaded avgas, blaming industry inertia, bureaucratic delay and an exemption that removes the incentive. This is part one of two.

AVweb's Paul Bertorelli explains in part two of a series why general aviation has not replaced leaded avgas. He covers industry inertia, bureaucratic delays and the exemption that lets the industry keep using lead.

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 WSJ report on China's 'dark factories', highly automated plants run by robots with little human presence, visiting Zeekr's EV factory. It covers Chinese labor costs, automation and overproduction in the EV industry.

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

Musician and audio engineer Benn Jordan tries Dolby Atmos as a consumer, covering the theory of immersive audio, its business model, and home theater and headphone listening. He concludes it often falls short of the pitch.

SuperfastMatt looks at how the Tesla Model S retracting door handles were redesigned over time, from many parts to a motor plus sensor, with a focus on engineering and reliability.

Huygens Optics shows how DIY photon sieves shape a laser's wave front, explaining how they differ from zone plates and how aperture count affects the focal point, with time-resolved visualizations of the diffraction.

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

SpaceX's livestream of the Starship SN8 high-altitude test on December 9, 2020. It ascended, did the landing flip with flap control and reached the landing point, but touched down hard because of low header tank pressure.

PBS Space Time explains the proposal to use the Sun's gravity as a giant lens, sending a train of small light-sail spacecraft to the focal point roughly 550 AU out. It covers how such a telescope could image exoplanets in surprising detail and the engineering challenges involved.

Bruce Waggoner of the Voyager team describes how engineers diagnosed Voyager 1's 2023 loss of telemetry and patched its flight software from 15 billion miles away. The talk covers the spacecraft's architecture and the scarcity of old documentation.

A one-minute clip of William Shatner trying to describe the awe of space after a Blue Origin flight while Jeff Bezos sprays champagne.

NASASpaceflight's 24/7 live stream from SpaceX's Starbase in Boca Chica, Texas, showing Starship and Super Heavy development, testing and launches.

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.

Destin Sandlin of Smarter Every Day gives a talk to an aerospace audience, comparing how Apollo was engineered and managed with NASA's Artemis program. He raises concerns about unresolved details, the number of launches and in-orbit fuel transfer needed to reach the Moon, and the loss of institutional knowledge.

Eager Space examines the practicality of putting data centers in orbit, walking through three scenarios with cost calculations and the launch cost reductions that would be required.

Scott Manley examines why SpaceX, Google and others are looking at orbital data centers. He walks through the economics, heat rejection and solar power arguments, with links to the Lumen/Starcloud and Google Suncatcher papers.

Scott Manley surveys the research on whether people can adapt to rotating artificial gravity, from early Soviet centrifuge tests to modern studies. He concludes it is an engineering problem and discusses Coriolis effects and station radius.

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.

Thunderf00t critiques SpinLaunch, the startup that proposes flinging payloads to space with a giant centrifuge. He argues the physics and engineering do not hold up.

EEVblog's Dave Jones critiques Reflect Orbital's plan to sell sunlight to solar farms after dark using orbital mirrors. He walks through the numbers to show the idea does not work out.

An animated Gabbard diagram of objects in low Earth orbit from 1959 to 2021, showing altitude over time. It highlights major debris-generating events and how low-altitude debris decays out of orbit.

Explains the proposed NASA JPL plan to use the Sun as a gravitational lens, sending solar sail craft to its focal region to image an exoplanet's surface. It covers the distances involved, how imaging with the Sun would work and the mission design.