Lectures for Leaving Cert students… and interested bystanders

Why are particles sometimes waves?

Professor Padraig Dunne looks at the boundaries between waves and particles. In the Leaving Cert Physics course, students study waves. They learn about interference of waves and the resulting peaks and troughs. They also study the mechanics of particles, for example golfballs, using Newton's laws of motion. But when observed on a very small scale, the distinction between waves and particles becomes blurred. Electrons, usually thought of as particles, undergo interference, and light, usually thought of as a wave, can act like a particle when it interacts with atoms. So maybe this is all a problem of language?

Tackling problems in physics, describing the physical world using mathematics, carrying out experiments and comparing results critically with predictions from theory are all part of the training of a physics student.

One of the first modules that students of Physics may take at UCD is called “Frontiers of Physics”. This module looks at Einstein's theory of Special Relativity and the basis for the theory of Quantum Mechanics, with applications in atomic, nuclear and particle physics. Topics include: wave particle duality, the photoelectric effect, X-radiation, lasers, qbits, radioactivity and the decay law, modes of decay including branching, anti-matter, radioisotopic dating, fission, fusion and the fundamental structure of matter.