Infinity
Math · Advanced · Lesson 6 of 7

The Cantor Set

Dust with no length, and uncountably many points

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

  • Removing middle thirds forever leaves the Cantor set: total length zero.
  • Its points are base-3 expansions with only 0s and 2s, and they are uncountable.
  • Its fractal dimension is ln⁡2/ln⁡3≈0.63\ln 2/\ln 3 \approx 0.63.

Steps

  1. Remove the middle thirds
  2. Vanishing length
  3. Which points survive?
  4. How many points?
  5. Is ½ in the Cantor set?
  6. A fractional dimension