Curriculum·Freshman·F101
What a Blockchain Actually Is
The wrong-network send, a failure category documented in wallet and chain support pages rather than one named incident." Whether the funds come back turns on who holds the key on the destination chain.
Lesson 1 opens on
The Paxos fee, September 2023
8 BTC, roughly $520,000. It was reported as the largest fee in dollar terms ever recorded on the network. Paxos attributed it to a bug in its corporate operations software, and analysts suggested the change output had been miscalculated, so the software treated most of the input as fee.
The lessons
- F101-01Ledgers, state, and what "the chain" isDescribe a blockchain as a shared state machine, and say what the blocks and the state each holdabout 30 min · opens on The Paxos fee, September 2023
- F101-02Consensus in plain languageExplain what consensus actually decides, and why ordering is the hard problem rather than validityabout 29 min · opens on Ethereum Classic, August 2020
- F101-03What decentralization buys and what it costsState the single property decentralization actually delivers, and the four costs paid for itabout 31 min · opens on The DAO fork, June and July 2016
- F101-04Nodes, clients, and RPCsDistinguish node, client and RPC provider, and say which one you are actually trusting when you open a walletabout 31 min · opens on The Infura outage and the Geth split, 11 November 2020
- F101-05Block explorers as a literacy skillRead a transaction page and correctly identify status, gas spent, the actual token movements, and who paidabout 31 min · opens on SQUID, November 2021
Labs
F101-L
Trace a simple transfer, a token swap and a failed transaction end to end on three supplied transaction pages: status, what moved, what each cost, who paid, and what the failed one still cost and why. Twenty questions, 18 to pass.