For over ten years, the dark side of the universe has been headline news. Detailed studies of the rotation of spiral galaxies, and 'mirages' created by clusters of galaxies bending the light from very remote objects, have convinced astronomers of the presence of large quantities of dark (unseen) matter in the cosmos. Moreover, in the 1990s, it was discovered that some four to five billion years ago the expansion of the universe entered a phase of acceleration. This implies the existence of dark energy. The nature of these 'dark; ingredients remains a mystery, but they seem to comprise about 95 percent of the matter/energy content of the universe. As for ordinary matter, although we are immersed in a sea of dark particles, including primordial neutrinos and photons from 'fossil' cosmological radiation, both we and our environment are made of ordinary, baryonic matter. Strangely, even if 15-20 percent of matter is baryonic matter, this represents only 4-5 percent of the total matter/energy content of the cosmos.

Foreword.- Author's preface.- Acknowledgments.- List of illustrations.- Chapter 1: Introduction.- Chapter 2: Matter concentrated.- Chapter 3: The realm of the nebulae.- Chapter 4: Getting warmer....- Chapter 5: Cosmic Cluedo: where, when, and how?.- Chapter 6: 300,000 years on: all present and correct.- Chapter 7: Cosmic canvas.- Chapter 8: Lifting the veil: simulations.- Chapter 9: A constant search.- Chapter 10: From telescopes to accelerators.- Appendices.