The night sky is the most universal part of our environment. Throughout history, people have gazed up at the same ‘vault of heaven’, though each culture has interpreted it in its own way. Ever since the Babylonians, patterns have been recorded in planetary motions. The need for a precise calendar, and for navigation across the oceans, has motivated advances in timekeeping, optics and mathematics. Indeed, astronomy has always been a driver for technology. And, thanks to huge telescopes, probes and advanced computers, modern astronomers have discovered the amazing cosmic panorama described in this book.
Theorists like myself lag far behind in trying to make sense of it all. But we have made progress. We can trace cosmic history back to a mysterious beginning nearly 14 billion years ago, when everything was squeezed hotter and denser than anything that can be created in a laboratory; we understand in outline how the first atoms, stars and galaxies emerged. We realize that our Sun is a typical star among the billions in our Galaxy; and that our Galaxy is just one of many billions visible through a large telescope. Moreover, some theorists speculate that a further ‘Copernican demotion’ may lie ahead: physical reality is almost certainly more extensive than the domain we can observe; indeed ‘our’ Big Bang could be just one of many.
But recent advances haven’t just extended our cosmic horizons: they have revealed richer detail. Probes to other planets of our solar system (and their moons) have beamed back images of varied and distinctive worlds. More important still, we’ve inferred, by detecting very slight changes in the motions and brightness of stars, that most of them are orbited by retinues of planets, just as the Earth and other familiar planets orbit the Sun. In coming years, we will be swamped by fascinating new data – perhaps even evidence of life around other stars.
Astronomy now attracts wider interest than ever before – its discoveries are part of modern culture. Moreover, the joy of discovery isn’t now limited to professionals — indeed they are swamped by the sheer quantity of data. So there is scope for ‘citizen scientists’, who can access and download data from surveys made with the world’s best telescopes, and perhaps discover a new galaxy or a new planet. And serious amateurs, using small telescopes with the latest instrumentation, can match what professionals with much larger telescopes could do 50 years ago.
Our brightest neighbour
Planet Venus is very visible, partly because sunlight is easily reflected by the sulphurous clouds that blanket its atmosphere. Venus is the closest planet to our Earth, within reach of questing space probes, although its hot, deadly atmosphere prohibits any human exploration of its surface.
The technical details of all modern science are arcane. However, I believe that the essence of any discovery can be conveyed in accessible language. To condense a concept into 30 seconds is a bigger challenge, but one that has been triumphantly met by the authors here.
This book deserves wide readership among those fascinated by the extraordinary ‘zoo’ of objects in the cosmos – a cosmos governed by physical laws that allowed creatures to evolve (on Earth and perhaps on alien worlds too) with minds able to ponder its wonder and its mystery.