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No altcoins. No tokens. No "crypto." Other coins have other sites. We have one.
The Bitcoin School
For people who want to understand Bitcoin. Not flip it.
Plain language. Sourced chapters. Live on-chain data from a real node. Huge glossary, Rabbit Holes, and one opinionated Journey from "what is money?" to running a full node. No altcoins, no affiliate links, and no signup needed to read any of it.
From the glossary
Hosting a Bitcoin node or service over Tor, hiding real IP addresses and enhancing privacy/censorship resistance.
Read full entryNew on the site.
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Rabbit Hole · 14 min
Quindecillions: Why Nobody Can Stumble on Your Bitcoin
After a vanity address search, readers ask whether the address already had coins in it and how many wallets the search found on the way. Every Bitcoin address is a drawer. There are about 1.5 x 10^48 of them, 57 million hold coins, and no search on record has landed on a funded one by chance. The same arithmetic is why nobody has to register a key before using it.
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Rabbit Hole · 15 min
Which Coins Does Your Wallet Spend?
Your wallet does not have a balance. It has a bag of coins, and every payment starts by choosing which to spend. What that choice costs today, what it costs later, what it tells a chain analyst, and how the reference wallet decides, with four algorithms and one score.
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Rabbit Hole · 15 min
Use It Once: Why Reusing a Bitcoin Address Is Dangerous
One bitcoin in four sits at an address that was spent from and then paid again. What a reused address gives away, to whom, why it keeps happening eighteen years after the whitepaper said not to, and how to stop without rushing.
No bullshit.
No price predictions. No affiliate-bait. No fear marketing. Every chapter cites its sources, and the live on-chain numbers come straight from a full Bitcoin node.
Have fun.
Interactive, opinionated, well-crafted. Rabbit-hole vibes. Built by Bitcoiners for people who want to actually understand.
Down the rabbit hole.
All rabbit holesCustody and Privacy
How do I hold it safely and privately?
- Mt. Gox to FTX: The Custody Graveyard
- Privacy on Bitcoin: What Works and What Doesn't
- Use It Once: Why Reusing a Bitcoin Address Is Dangerous
Hard Questions
The strongest objections, including where the critics are right.
- Quantum and Bitcoin
- Bitcoin and Energy
- Rat Poison, Tulips and a Pet Rock: Everything Bitcoin's Been Called (so far)
Corrected in public.
All corrections-
Dividing two weeks by 2,015 gives 600.3 seconds, while blocks at constant hash rate average about 600.6 (Wuille). Bitcoin Inquisition has enforced BIP-54 on signet since February 2026. Two hours was a precaution after testnet4 exposed pool software that stamped blocks from its own clock, and under a sustained attack it costs about three seconds a block (599.9997 against 596.7211 seconds in Wuille's simulation). Testnet3 carries a time warp Greg Maxwell planted on purpose in July 2012; the 2024 storms were the minimum-difficulty bug. The discovery is now dated: ArtForz, BitcoinTalk, 12 September 2011.
What was wrong -
29.0 covers the time warp rule; the negative-window rule reached Bitcoin Core's templates in 32.1 (PR #35949, October 2026). Two hours was a precaution, at a cost of about three seconds a block under a sustained attack.
What was wrong -
Since Bitcoin Core 28.0 (PR #29623) the node warns when its outbound peers' median clock is more than ten minutes off; 70 minutes applied in 27.x. A peer offset beyond 70 minutes was ignored, not capped, and before July 2010 there was no limit. The median never moves backwards at all; one miner cannot hold it back or push it forward. The entry also notes that templates respect BIP-54's last-block rule since 32.1.
What was wrong