What is matter? Matter is the stuff from which we and all the things in the world are made. Everything around us, from desks, to books, to our own bodies are made of atoms, which are small enough that a million of them can fit across the breadth of a human hair. Inside every atom is a tiny nucleus and orbiting the nucleus is a cloud of electrons. The nucleus is made out of protons and neutrons, and by zooming in further you would find that inside each there are even smaller particles, quarks. Together with electrons, the quarks are the smallest particles that have been seen, and are the indivisible fundamental particles of nature that have existed since the Big Bang, almost 14 billion years ago. The 92 different chemical elements that all normal matter is made from were forged billions of years ago in the Big Bang, inside stars, and in violent stellar explosions. This Very Short Introduction takes us on a journey from the human scale of matter in the familiar everyday forms of solids, liquids, and gases to plasmas, exotic forms of quantum matter, and antimatter. On the largest scales matter is sculpted by gravity into planets, stars, galaxies, and vast clusters of galaxies. All the matter that that we normally encounter however constitutes only 5% of the matter that exists. The remaining 95% comes in two mysterious forms: dark matter, and dark energy. Dark matter is necessary to stop the galaxies from flying apart, and dark energy is needed to explain the observed acceleration of the expansion of the universe. Geoff Cottrell explores the latest research into matter, and shows that there is still a lot we don't know about the stuff our universe is made of. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subject quickly. Our expert authors combine facts, analysis, perspective, new ideas, and enthusiasm to make interesting and challenging topics highly readable.

Geoff Cottrell obtained his PhD in Radio Astronomy at the Cavendish Laboratory, Cambridge University. After researching contact electrification of solidified rare gases near the absolute zero of temperature at UMIST in Manchester, he joined the UKAEA Culham Laboratory, working on the Joint European Torus (JET) experiment, where he became Session Leader. He observed a new form of super-thermal radio emission (Ion Cyclotron Emission) from energetic fusion alpha particles in the plasma. From 1999, he worked on a central issue for the development of fusion energy - fusion materials, in particular calculating the effect that energetic fusion neutrons would have on the wall of a power reactor. He was Director of the Culham International Summer School for Plasma Physics from 2006-2011. He is a fellow of the Royal Astronomical Society, and visiting scientist at the Oxford University Astrophysics department and at the Rutherford Appleton Laboratory.