Dao Academy

CoursesCourse 6

The quantum revolution

At the smallest scales, light comes in lumps, particles behave like waves, and measuring a thing changes it. This course explains how quantum mechanics overturned the clockwork universe, why it runs the technology around us, and what it teaches about the edges of knowledge.

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Lessons

  1. 1 Two small cloudsIn 1900 physics seemed to many almost finished. Two clouds that Kelvin named turned out, with hindsight, to hide two new physics. 12 minCompleted
  2. 2 Waves and particlesLight comes in packets, electrons spread out like waves, and any record of the path wipes out the bands: the double slit, the strangest experiment in physics. 16 minCompleted
  3. 3 The rules of the very smallConfined things have energy in steps, a particle can be in a superposition of states, position and speed can’t both be sharp, and particles can tunnel through walls. 12 minCompleted
  4. 4 The edge of perceptionWhy nobody has seen a half-dead cat, how physicists see what can’t be seen, and this course’s idea that new worldviews begin at the edge of what we can measure. 13 minCompleted

You’ll be able to

  • Explain the two “clouds” that troubled physics around 1900, and how, with hindsight, they pointed toward relativity and the quantum.
  • Describe wave–particle duality and the double-slit experiment, and what “measurement” means in quantum mechanics.
  • Explain quantization, superposition, the uncertainty principle, and tunneling, with a real technology built on each.
  • Use this course’s idea of the scale of perception to ask why intuition fails far from human sizes and speeds, and how new instruments widen what we can know, from the telescope to quantum computers.

About this course

This course covers 量子力学 (Quantum Mechanics), the fourth and final part of a sequence on how physicists think. It continues from Course 5, Energy, entropy, and order.

The argument and examples lead. Around them we add background for readers outside China, the views of other scientists where they differ, and hands-on activities. We say clearly which ideas are settled science and which are interpretation.