The advent of sensitive high-resolution observations of the cosmic microwave background radiation and their successful interpretation in terms of the standard cosmological model has led to great confidence in this model's reality. The prevailing attitude is that we now understand the Universe and need only work out the details. In this book, Sanders traces the development and successes of Lambda-CDM, and argues that this triumphalism may be premature. The model's two major components, dark energy and dark matter, have the character of the pre-twentieth-century luminiferous aether. While there is astronomical evidence for these hypothetical fluids, their enigmatic properties call into question our assumptions of the universality of locally determined physical law. Sanders explains how modified Newtonian dynamics (MOND) is a significant challenge for cold dark matter. Overall, the message is hopeful: the field of cosmology has not become frozen, and there is much fundamental work ahead for tomorrow's cosmologists.

'This tightly written, sophisticated (though essentially non-mathematical) review of the status of the concordance model - a flat universe with all of the observations internally consistent - and its modest gaps form the core of the discussion. … The discussions are clear, rich, and thought provoking. This book is well written and belongs in all college libraries.'

K. L. Schick Source: CHOICE

'… I recommend this book. It is a good intorduction to an important topic in modern astrophysics and cosmology, accessible to the 'interested layman' but also valuable for those with more-advanced knowledge of astrophysics but with less knowledge of MOND.'

Phillip Helbig Source: The Observatory

'… a light but advanced reading addressing the discrepancies in the standard Lambda cold dark matter (ΛCDM) cosmological paradigm that supports dark matter (duh, obviously) and compares it to an alternative outlook … Thus, although it is of general interest, it gears towards those with some background in cosmology and astrophysics.'

B. Ishak Source: Contemporary Physics