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Learning path · Intermediate

How everyday technology works

Electricity, batteries, computers, the internet, GPS and encryption, explained from the ground up. 7 guides, about 55 minutes of reading.

  1. Electricity and circuits

    Charge, current, voltage and resistance, with the analogies that help and the ones that mislead.

    Step 1 · Physics · 8 min read
  2. Electricity and the power grid

    How electricity is generated, sent across countries and delivered to a wall socket, and why the grid must balance every second.

    Step 2 · Technology · 8 min read
  3. Batteries and energy storage

    How chemical reactions store electricity, why lithium-ion took over, and what limits the batteries in phones and cars.

    Step 3 · Technology · 7 min read
  4. How computers work

    From transistors and binary to processors, memory and software, the layers inside every computer.

    Step 4 · Technology · 9 min read
  5. How the internet works

    Packets, addresses, routers and protocols: what actually happens between typing an address and seeing a page.

    Step 5 · Technology · 9 min read
  6. Encryption and online security

    How secret codes evolved from Caesar's shifts to public-key cryptography that protects every online payment.

    Step 6 · Technology · 8 min read
  7. How GPS works

    How a phone works out where you are from timing signals sent by satellites 20,000 kilometres overhead, with a little help from Einstein.

    Step 7 · Technology · 7 min read