Or the ripples from a pebble someone tosses...

In 1915 Albert Einstein blew the scientific world apart by publishing his general theory of relativity. The Newtonian view of the universe that had been accepted for 200 years had to be revisited and revised, based on a new theoretical understanding of the fundamental laws of physics. Einstein's theories made various predictions about the behaviour of matter that, at the time, science was incapable of verifying. Famously, one of them - the gravity would bend light - was confirmed only a few years later, when the happy accident of a 1919 solar eclipse enabled an astro-physicist called Eddington to show that light from the stars was bent as it passed the sun

A much more profound implication of Einstein's work was that the three dimensions of space and the property of time are not different things, but are in fact four dimensions of the same 'stuff', that he called space-time. I do not pretend to truly undestand this myself - I think you have to master advanced maths to begin to grasp it. Gravity, Einstein said, was caused by something akin to ripples in the surface of space-time. Moreover, his equations suggested that cosmic events involving massive objects, with sufficient gravity, would create 'waves' in space-time that could, in principle, be detected

It has taken a century to do that - and again I'm struggling at the edge of my understanding. The advent of supercomputers with many thousands of processors has enabled physicists to run simulations of cosmic events - usually involving black holes - that take many hours to calculate. The 'answers' produced by the calculations can then be used to create visual displays, so that the results can be understood and communicated. Repeated iterations of the simulation, with slight variations, build up enough results for experimental astro-physicists to understand what to look for when analysing real emissions from actual events involving black holes

This picture is one such simulation - a model of two black holes orbiting each other. The red and blue lines represent the trajectorirs of the black holes; the diaphanous blue and orange swirls depict the gravitational waves created by the gigantic merry-go-round. The line at the bottom is just an image of a single gravitational wave

This is just a single mind-bending snippet from a wide ranging display of scientific achievement with some connection to Birmingham at the city's University