All the matter and light we can see in the universe makes up a trivial 5 per cent of everything. The rest is hidden. This could be the biggest puzzle that science has ever faced. Since the 1970s, astronomers have been aware that galaxies have far too little matter in them to account for the way they spin around: they should fly apart, but something concealed holds them together. That ’something' is dark matter – invisible material in five times the quantity of the familiar stuff of stars and planets. By the 1990s we also knew that the expansion of the universe was accelerating. Something, named dark energy, is pushing it to expand faster and faster. Across the universe, this requires enough energy that the equivalent mass would be nearly fourteen times greater than all the visible material in existence. Brian Clegg explains this major conundrum in modern science and looks at how scientists are beginning to find solutions to it.
Author
Brian's latest books, Ten Billion Tomorrows and How Many Moons does the Earth Have are now available to pre-order. He has written a range of other science titles, including the bestselling Inflight Science, The God Effect, Before the Big Bang, A Brief History of Infinity, Build Your Own Time Machine and Dice World. Along with appearances at the Royal Institution in London he has spoken at venues from Oxford and Cambridge Universities to Cheltenham Festival of Science, has contributed to radio and TV programmes, and is a popular speaker at schools. Brian is also editor of the successful www.popularscience.co.uk book review site and is a Fellow of the Royal Society of Arts. Brian has Masters degrees from Cambridge University in Natural Sciences and from Lancaster University in Operational Research, a discipline originally developed during the Second World War to apply the power of mathematics to warfare. It has since been widely applied to problem solving and decision making in business. Brian has also written regular columns, features and reviews for numerous publications, including Nature, The Guardian, PC Week, Computer Weekly, Personal Computer World, The Observer, Innovative Leader, Professional Manager, BBC History, Good Housekeeping and House Beautiful. His books have been translated into many languages, including German, Spanish, Portuguese, Chinese, Japanese, Polish, Turkish, Norwegian, Thai and even Indonesian.
