MASTERING-BITCOIN · Unit 1 · Video 1 · Interactive Practice

No Banks Required: The Four Innovations That Power Bitcoin

IKey Formulas

Formula	Name	Description
$R_n = \frac{50}{2^n}$	Block Reward	BTC reward per block after $n$ halvings
$\text{Halving every } 210{,}000 \text{ blocks}$	Halving Interval	Reward halves approximately every 4 years
$\displaystyle\sum_{n=0}^{\infty} 210{,}000 \times \frac{50}{2^n} \approx 21{,}000{,}000$	Hard Cap	Maximum bitcoin that will ever exist
$\text{Difficulty adjusts every } 2{,}016 \text{ blocks}$	Difficulty Adjustment	Maintains target block time of ~10 minutes

IIVisualization 1: Bitcoin Supply Curve

Bitcoin's total supply follows a predictable, diminishing issuance curve. Unlike fiat currencies where central banks can expand the money supply indefinitely, Bitcoin is capped at approximately 21 million coins.

Explore: Move the year slider to see how much bitcoin exists at any point in time, the current block reward, and what percentage of the total supply has been issued.

💡 Notice how the curve flattens: The supply rises steeply from 2009–2016 (the first two eras produce ~75% of all bitcoin), then dramatically slows. By ~2035, over 99% is already issued. What does this mean for miners' long-term revenue? (Hint: transaction fees become essential!)

IIIVisualization 2: Block Reward Halving Explorer

Every 210,000 blocks (~4 years), the mining reward is cut in half. This built-in monetary policy means no committee or central bank decides when to reduce issuance — the code enforces it automatically.

Explore: Adjust the slider to see how many halving eras to display. Watch how each era contributes progressively fewer coins to the total supply.

💡 Key insight: Era 0 alone produced 10.5 million bitcoin — exactly 50% of the total supply. Each subsequent era produces half as many coins. By the end of Era 4 (started 2024), over 96% of all bitcoin has been mined. The formula $R_n = 50/2^n$ creates a geometric series that converges to exactly 21 million.

IVVisualization 3: Difficulty Adjustment Simulator

Bitcoin adjusts its mining puzzle difficulty every 2,016 blocks (~2 weeks) to maintain a target block time of 10 minutes. This means more miners equals more security — NOT faster coin creation.

Explore: Change the network hashrate to simulate miners joining or leaving. Watch how the difficulty adjustment brings block times back to the 10-minute target after just one adjustment period.

💡 Key insight: Only the first adjustment period after a hashrate change shows off-target block times. After the difficulty adjusts, blocks return to ~10 minutes — whether the hashrate doubled or halved. This is why more computing power means more security, NOT faster coin creation. If half the miners quit tomorrow, puzzles get easier and blocks still arrive every 10 minutes.

VQuiz Questions

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