Abstract

Is anything ever stationary? How accurately does the doctor measure your pulse rate? What is inside an atom, or a molecule? What happens when an atomic magnet bounces? Do molecules behave like light – just a bit? Why do light beams always spread out? Energy is normally conserved but could we take out an energy overdraft? Can molecules turn inside out? Could we stop a pendulum – or an atom? Is there really nothing in a vacuum, and how long is a photon? And does it matter?

The Uncertainty Principle of Heisenberg illuminates these questions and many more. Initially a tentative idea in Quantum Mechanics, its role is now centre stage.