System Upgrade on Tue, May 28th, 2024 at 2am (EDT)
Existing users will be able to log into the site and access content. However, E-commerce and registration of new users may not be available for up to 12 hours.For online purchase, please visit us again. Contact us at customercare@wspc.com for any enquiries.
To the eyes of the average person and the trained scientist, the night sky is dark, even though the universe is populated by myriads of bright galaxies. Why this happens is a question commonly called Olbers' Paradox, and dates from at least 1823. How dark is the night sky is a question which preoccupies astrophysicists at the present. The answer to both questions tells us about the origin of the universe and the nature of its contents — luminous galaxies like the Milky Way, plus the dark matter between them and the mysterious dark energy which appears to be pushing everything apart. In this book, the fascinating history of Olbers' Paradox is reviewed, and the intricate physics of the light/dark universe is examined in detail. The fact that the night sky is dark (a basic astronomical observation that anybody can make) turns out to be connected with the finite age of the universe, thereby confirming some event like the Big Bang. But the space between the galaxies is not perfectly black, and data on its murkiness at various wavelengths can be used to constrain and identify its unseen constituents.
Sample Chapter(s)
Chapter 1: The Enigma of the Dark Night Sky (3,069 KB)
Contents:
- The Enigma of the Dark Night Sky
- The Intensity of Cosmic Background Light
- The Spectrum of Cosmic Background Light
- Dark Cosmology
- The Radio and Microwave Backgrounds
- The Infrared and Visible Backgrounds
- The Ultraviolet Background
- The X-Ray and Gamma-Ray Backgrounds
- The High-Energy Gamma-Ray Background
- The Universe Seen Darkly
Readership: Informed readers interested in astronomy.
