block pointer rewrite

Sabine Hossenfelder explains how special relativity leads to the block universe, in which past, present and future all exist equally, and asks what that means for whether the past still exists.

Adam Savage shows a set of Mitutoyo ceramic gauge blocks and uses them to explain metrology, the science of measurement. He argues that accuracy and precision work differently than most people assume, which changes how you think about every measuring tool.

WIRED has UCLA professor Amit Sahai explain zero-knowledge proofs to a child, a teen, a college student, a grad student and an expert. Each round goes deeper into the cryptography and why it matters.

Oh The Urbanity! argues that most city dwellers live in dense residential neighbourhoods outside downtown, which can be calm and peaceful. It draws on older, denser parts of Toronto and Montreal.

Technology Connections explains how the simple American drip coffee maker works, including the bimetal valve and bubble-pump heating, and compares the original Mr. Coffee with modern machines.

Veritasium explains why bicycles are stable, arguing that gyroscopic effects are not the answer. The video shows countersteering and an experiment where riders blocked from steering the opposite way cannot turn.

Sabine Hossenfelder explains the delayed choice quantum eraser and argues it does not rewrite the past, as popular accounts claim. She walks through what the experiment actually shows.

2swap explains how he solved the Klotski sliding-block puzzle by mapping its full state space as a graph and visualizing it. The video includes footage of the Guinness world-record solve and links to an interactive graph.

A PBS Space Time episode on fuzzballs, the string-theory proposal for black holes that replaces the singularity with a tangle of strings. It explains why black holes seem to both have to exist and break known physics.

Linus Tech Tips breaks down the company's income streams, including sponsors, YouTube Premium, merch and other products. It gives percentages for each revenue source.