what if

Randall Munroe of xkcd answers what would happen if you swam in a spent nuclear fuel pool, and how much radiation you would receive at the surface versus at depth.

PBS Space Time considers whether life could be based on silicon instead of carbon, comparing the two elements' chemistry and why silicon is the most plausible alternative.

Veritasium shows what the world looks like through a UV camera. It covers how pigments absorb UV, how fluorescence works, and how UV imaging reveals sunscreen effectiveness and skin damage.

PBS Space Time examines the Silurian hypothesis, the idea that an industrial civilization could have existed on Earth before humans. It looks at what traces such a civilization might leave in the geological record.

PBS Space Time asks whether dark matter could be made of primordial black holes. It walks through the observational constraints that limit this idea.

ScienceClic visualizes what you would see falling into a black hole, from the approach and the accretion disc to crossing the horizon, in 15 minutes.

A 1937 GM-produced film explaining how the automobile differential lets wheels turn at different speeds around a corner. It uses clear animations and cutaway demonstrations to build the idea from first principles.

Technology Connections explains why humidity matters and compares the main types of humidifiers, including evaporative and ultrasonic designs. It covers how and why you would add moisture to indoor air.

CGP Grey explains jury nullification, a juror's power to acquit despite the law, and why mentioning it can get you struck from jury selection.

Dr. K of HealthyGamerGG argues that gifted kids can be seen as special needs, tracing a path from the gifted label to burnout and perfectionism.

PBS Space Time, together with It's Okay to be Smart and PBS Eons, asks how a universe drifting toward disorder produced something as complex as life. It presents the idea that the laws of physics, through thermodynamics, may actually favor the emergence of life.

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.

A two-minute animation of an Alan Watts talk arguing that life is like music: it is meant to be danced to in the moment, not rushed toward a final goal. It is a short, accessible take on living in the present.

A short explainer on the history and mechanics of public key cryptography and the Diffie-Hellman key exchange. It uses a mixing-paint-colors analogy to show how two parties can agree on a shared secret in public.

An Extra Credits episode on China's Sesame Credit, which gamifies obedient citizenship through a social score. It covers how the system rewards conformity and pressures people through their friends' behavior.

A short explainer on the physiological differences between fasting and simply eating less. It covers ketosis, ghrelin and hunger waves, and the hormonal effects of fasting.

A Vox explainer on how the wildlife trade and wet markets are linked to coronavirus and why new diseases keep emerging in China. It stresses that most people in China do not eat wildlife.

Veritasium takes an IQ test and examines what IQ measures, its history including military use and eugenics, its controversies, and how it correlates with life outcomes. Experts including Cecil Reynolds and Stuart Ritchie contribute.

Ben Felix rebuts common arguments for holding only US stocks, such as past outperformance and international revenue exposure. He supports the case for international diversification with cited academic research.

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.

Kurzgesagt explores the idea that life might have arisen shortly after the Big Bang, when the whole universe was warm enough to be habitable. It discusses what that would mean for the origin and spread of life.

The School of Life sets out principles for making attractive cities, arguing that the art has been lost in the modern world.

A School of Life video arguing that everyone marries someone who is somewhat wrong for them, and that this is unavoidable. It is a four-minute version of an essay by Alain de Botton.

Technology Connections' long closing video in his heat pump series, arguing that adopting heat pumps is well within reach. It explains how they work and what it takes to start using them.

Real Engineering looks at the numbers for running California on renewables, focusing on the large energy storage needed. It argues about the cost of batteries and the role of other sources.

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.

A short Art of the Problem clip explaining Diffie-Hellman key exchange, using a paint mixing analogy for one-way functions and touching on modular arithmetic and discrete logarithms.

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.

minutephysics, in collaboration with the US Census Bureau, explains differential privacy and why the 2020 census adds noise to protect individuals' data. It walks through how statistics can leak private information.

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.

A Vox explainer on how many of the British Museum's treasures were taken during British imperial rule, focusing on the Benin Bronzes and requests for their return.

A guest video by Welch Labs on 3Blue1Brown explaining how text-to-image and video models work. It covers CLIP, shared embedding spaces, diffusion models (DDPM, DDIM), conditioning, guidance and negative prompts.

Steve Mould explains motion amplification and video magnification, techniques that find tiny changes in video invisible to the eye and exaggerate them. He covers the MIT research and industrial uses such as diagnosing vibrating machinery.

A doctor from Medlife Crisis explains in under three minutes why even a rich patient should not simply order every medical test, touching on pre-test probability and Bayesian reasoning. False positives make blanket testing counterproductive.

Wendover Productions explains why drone delivery has not become the future once promised. It covers no-fly zones, costs and the difficulty of the final drop-off.

Practical Engineering explains what a 100-year flood actually means, combining statistics, hydrology and how society treats risk. Grady walks through local drainage infrastructure and the caveats in estimating flood probability.

Stated Clearly explains the RNA world hypothesis, which resolves the chicken-or-egg problem of genes versus enzymes by proposing that RNA once did both jobs. It outlines how evolution could begin with RNA chains alone.

A School of Life short introducing Michel Foucault, who questioned assumed progress in how society treats madness, medicine and sexuality.

3Blue1Brown's first chapter on deep learning explains what neurons and layers are and the math underlying a basic neural network, using handwritten digit recognition with visual animations.

An RSA Animate whiteboard adaptation of Dan Pink's talk on what motivates people at work. It argues that beyond simple tasks, autonomy, mastery and purpose drive performance more than money.