Wonder - A Scientific Oratorio
Edwin Hubble at work on Mount Palomar, USA.
Credit: Mount Wilson Archive, Carnegie Institution for Science
Theme 1 - The Big Bang
The Universe is expanding. Clusters of galaxies are flying apart at ever-increasing speeds. This expansion began almost 14 billion years ago in the Big Bang.
In the 1920's Edwin Hubble (after whom the Hubble Space Telescope was named) noticed that all the distant galaxies were moving away from us. He realised this did not mean that the Sun and Earth were in a special place, at the centre of all things, but that space itself was expanding.
[Imagine drawing galaxies as dots on a balloon and then inflating the balloon - the galaxies all move away from each other, space is represented by the stretching fabric of the balloon.]
If we imagine winding the clock back, looking into the past, the galaxies would have been much closer together. The logical conclusion is that almost 14 billion years ago the distances between them were zero. From this initial singular point of extreme densities and temperatures that we call the Big Bang, space expanded into the Universe we see today.
The traditional picture sees the Big Bang as the beginning of the Universe, the beginning of time. However astrophysicists are also thinking about what might have come before the Big Bang and whether our Universe and our Big Bang is simply the most recent in an endless cycle.
