coin flips

A two-minute animated introduction to Bitcoin from 2011, explaining it as a peer-to-peer digital currency. It was widely shared in Bitcoin's early days as the standard newcomer explainer.

3Blue1Brown explains the math and mechanics behind Bitcoin visually: ledgers, digital signatures, proof of work and the blockchain, building up a decentralized payment system from first principles.

A two-minute clip of Andreas Antonopoulos explaining why a 51% attack on Bitcoin would not destroy it and what such an attack would cost. It is a succinct take on mining security.

Andreas Antonopoulos answers a question about how to secure your Bitcoin. He covers holding your own keys, backing up the 12 to 24 word seed phrase, and the tradeoffs of custodial accounts, phone wallets and hardware wallets.

Andreas Antonopoulos answers a Bitcoin Q&A question about energy consumption in mining. He argues that mining is arbitrage for the cheapest electricity, drives investment in renewables, and that the traditional financial system has hidden externalities.

An 8-minute explainer on the Lightning Network and how it relates to Segwit, Bitcoin and Litecoin. It covers how off-chain payment channels route payments to scale blockchain transactions.

Lindybeige gives an hour-long history of English coinage and the problems of maintaining a trustworthy currency. It ends with an explanation of why the pounds, shillings and pence system worked so well.

Veritasium explains how cosmic rays and other particles flip bits in computer memory, with examples including a Belgian election count error, plane incidents and game glitches. It is inspired by a RadioLab episode on bit flips.

Numberphile with Simon Pampena on how humans misunderstand randomness, including coin-flip sequences, run lengths and the gambler's fallacy.

A step-by-step animated explanation of how SHA-256 works, from padding and message schedule to the compression function and final hash, with source code for the animations.

Episode 4 of Mike Maloney's Hidden Secrets of Money, explaining how currency is created through a chain of IOUs among the Treasury, banks and the Federal Reserve. It covers bonds, Fed checks, debt, taxes and fractional reserve lending, from a gold-and-silver advocate's viewpoint.

Ward Cunningham explains the history and intent of the debt metaphor, which he coined while refactoring the WyCash product. He says debt means code reflecting an incomplete understanding of the problem, not sloppy programming.

CGP Grey's short animated argument for abolishing the US penny, covering its cost and history.

Veritasium explains the Dzhanibekov effect, also called the tennis racket theorem, where a spinning object flips unexpectedly about its intermediate axis. The video gives an intuitive account of the underlying rotational dynamics, drawing on Terry Tao's explanation and the original papers.