In some of the world’s rivers, an incoming high tide can arrive as a smooth jump decorated by undulations, or as a breaking wave. The river reverses direction and flows upstream.
Understanding tidal bores involves
· analogies with tsunamis, rainbows, horizons in relativity, and ideas
from quantum physics;
· the concept of a ‘minimal model’ in mathematical explanation;
· different ways in which different cultures describe the same thing;
· the first unification in fundamental physics.
Michael Berry is Emeritus Professor of Physics, H H Wills Physics Laboratory, University of Bristol