limits

Not Just Bikes explains how North American speed limits are set and why posted limits matter far less than street design. It argues that drivers follow the road's cues, so safe speeds have to be built into the street.

Kurzgesagt explains why, even with science-fiction technology, most of the universe is permanently out of reach because of cosmic expansion and finite resources.

Veritasium's explainer on Godel's incompleteness theorems and the limits of mathematical proof, tracing set theory, Hilbert's program and the road to Turing and modern computing.

Practical Engineering explains pumped storage hydropower, which makes up most grid-scale electricity storage. It covers how it works and why it fits only certain geographies.

An Isaac Arthur episode on arcologies, self-sufficient habitats that could house whole cities, on Earth or on harsh worlds. It covers how such structures might work and what limits their size.

Sabine Hossenfelder explains that waste heat from ever-growing energy use could eventually boil the oceans in a few centuries, whatever the energy source. She discusses proposed ways to cool the planet.

A filmmaker explains why the Apollo moon landing footage could not have been faked in a studio, based on the video and film technology of the late 1960s. He walks through the limits of cameras, frame rates and effects of the era.

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.

Kurzgesagt asks whether advanced civilizations could have existed on Earth in the deep past and left little evidence. It looks at time as a dimension for searching for alien civilizations and the limits of the geological record.

LegalEagle analyzes Katko v. Briney, the Iowa case about a homeowner whose shotgun booby trap injured a burglar, and the limits on deadly force in defending property.