reference frames

A PBS Space Time episode hosted by Gabe Perez-Giz on the nature of spacetime and whether space and time are fundamental. It builds up reference frames and causality in a short, dense format.

Matt Parker explains the history behind NTSC television running at 29.97 frames per second rather than 30, tracing it to the backward-compatible addition of color. He walks through the arithmetic behind the odd ratio.

Veritasium visits NIST to explain Standard Reference Materials, the carefully characterized items such as peanut butter used to calibrate instruments and keep measurements consistent. It covers why they exist and why they are expensive.

Robert Miles explains reward modelling, in which an AI learns what humans want from their preference comparisons instead of a hand-written reward function. He walks through the 2017 paper on deep reinforcement learning from human preferences.

Tom Scott tours the rotating room artificial gravity facility at Brandeis University's Graybiel lab. It shows how humans cope with rotation-based gravity and the odd effects such as Coriolis forces.

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 short animated simulation comparing how Multics and Unix were developed, showing why Unix's small composable programs and pipes gave it a efficiency advantage. It frames Unix as a moonshot achievable by a small team.

Kurzgesagt makes a selfish case for improving the world, arguing that helping people far away raises prosperity and innovation for everyone, including yourself. The animated video frames this as egoistic altruism and positive-sum cooperation.

Practical Engineering explains what a black start is: restarting a power grid after total collapse. It shows why most plants need outside power to start and why rebuilding a synchronized grid is delicate and high-stakes.

A five-minute CGP Grey explainer arguing that a phone is effectively an extension of your mind, and that any backdoor or master key into encrypted devices will inevitably be abused or leaked. It frames the encryption debate as locks that are either unbreakable or absent.

Joseph Everett argues, drawing on the book The Salt Fix, that most people benefit from more rather than less salt, and reviews studies on sodium, potassium and blood pressure.

Martin Donald explains the Wave Function Collapse algorithm using Sudoku-like constraint solving and shows how he implemented it with Blender and Godot. It links demos and reference articles.

Veritasium debunks common climate change myths in under seven minutes, with references to NASA and published research. Topics include CO2 sources, sea ice and 1970s predictions of cooling.

A Wendover Productions explainer arguing that major airlines make much of their profit from loyalty programs and co-branded credit cards rather than flying. It frames airlines as quasi-banks that sell points in bulk, using United's pandemic-era loan as a hook.

Animator Noodle explains why frame interpolation does not make animation better, covering timing, easing, smear frames and using the wrong tool for the job. A pinned correction says the video is partly outdated given later AI developments.

Smarter Every Day uses high-speed and Schlieren photography to show how a whip crack is a supersonic shockwave formed at the tip. It references academic papers on whip physics.

Part 1 of Smarter Every Day's three-part series on manipulating the YouTube algorithm. It features Renee DiResta and examples of how social media platforms can be manipulated.

Kurzgesagt examines how AI-generated content is flooding the internet, from video and music to news and books. It looks at how this makes verifying what is real harder.

Kurzgesagt's animated explainer on CRISPR gene editing, covering how the technology works and what it could mean for curing disease, designer babies and aging. It frames genetic engineering as an irreversible change coming to humanity.

A Numberphile video in which physicists Tony Padilla and Ed Copeland show a seemingly astounding result that 1+2+3+4+... equals -1/12. The argument is informal and has drawn criticism for glossing over what the result actually means.

PBS Space Time explains how spacetime geometry and light cones determine the order of events and what can cause what. It visualizes causality in special relativity.

CaspianReport explainer arguing that Russia's geography, especially its vast size and indefensible Moscow core, shapes its political behavior. It frames Russian security thinking through the lens of geographic determinism.

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 rides a boat across the Los Angeles reservoir covered in 96 million black plastic balls. He explains why they were really introduced, which was not primarily to reduce evaporation.

A PBS Space Time episode asking whether time began at the Big Bang. It explains that the Big Bang is not what most people were taught and what 'start' of the universe really means.

A Veritasium video on survivor bias, explaining how an observed sample can be incomplete and skewed. It uses examples such as bombers and famous success stories.

Mick West shows new night-vision reference footage indicating the Navy's supposed flying pyramid UFO is just an out-of-focus light, likely a plane near LAX, rendered triangular by bokeh. He identifies other lights as Jupiter and stars.

CGP Grey investigates why the name Tiffany spiked in popularity and then faded, with help from onomastics experts. It is a short, playful look at how names spread.

A Kurzgesagt animation on longtermism, arguing that because the future could hold trillions of people, our actions' effect on future generations may be what matters most.

Kurzgesagt explains the skyhook, a rotating cable with a counterweight that could catapult spacecraft from Earth orbit toward deep space. It covers why it would make space travel cheaper and more efficient.

Not Just Bikes visits Paris to see how Mayor Anne Hidalgo's policies are turning it into a '100% cyclable' city. It looks at the changes that took space from cars for bikes and people.

An animated Sprouts video presenting Dietrich Bonhoeffer's argument that stupidity is more dangerous than evil, because reason cannot reach stupid people. It frames stupidity as a social and moral phenomenon.

Not Just Bikes reflects on five years in the Netherlands and tours small towns and cities, from Haarlem to Veenendaal. It argues that good urbanism with walkable streets, bike infrastructure and transit is found almost everywhere there, not just in Amsterdam.

Vsauce asks whether music will ever run out of new melodies. It counts the possible note combinations and discusses how common chord progressions and remixing affect originality.

Scott Manley tells the story of a computerized telemetry system built to sit at the heart of a nuclear test device in place of the plutonium pit, designed to transmit data in the microseconds before it was destroyed.

A short video telling how Xerox PARC invented the graphical user interface and how Steve Jobs's 1979 visit influenced Apple's Lisa.

Half as Interesting explains why the Eiffel Tower's night-time lighting is under copyright, which makes publishing photos of it at night legally problematic.

Tom Scott visits an eHighway test in Lubeck, Germany, where electric trucks with pantographs draw power from overhead wires. He explains how this could electrify road freight.