APRIL 2
Blocks
How Bitcoin Packs New Transactions Into the Next Page of Its Ledger
The Signal
Bitcoin gathers new transactions into blocks and adds them to its ledger.
The Reading
Bitcoin’s public ledger records how bitcoin moves between owners. Instead of one endless list, new transactions are grouped into bundles called blocks.
Imagine a shopkeeper recording sales. Rather than leaving loose receipts on the counter, the shopkeeper gathers them onto one numbered page. Bitcoin works similarly: a miner collects waiting transactions into a proposed block.
The block is not automatically accepted. Nodes check its transactions against Bitcoin’s rules. If it breaks a rule, they reject it; if it passes, they accept it as the newest part of the ledger.
A new block is found roughly every ten minutes on average, though the timing is unpredictable. Some arrive sooner, others later.
A block is one page of the blockchain, not the whole book. It is a bundle of transactions added to Bitcoin’s record.
First Principles
A block is a digital bundle of transaction records.
Miners propose blocks, and nodes validate them independently.
New blocks arrive at unpredictable times, averaging ten minutes apart.
Today’s Challenge
Write three transactions on paper:
Anna pays Ben $2.
Ben pays Charlie $1.
Charlie pays David $3.
Set a one-minute timer to represent Bitcoin’s ten-minute average. When it rings, draw a box around the transactions and label it BLOCK 1. Add another transaction outside the box to represent one waiting for a later block.
You have turned a loose list of payments into a block.
Tomorrow’s Signal
The Chain