The Bottom Line
The cyclic model that they offer as an alternative seems to resolve many outstanding questions of the current theory, though remains untested at present. Time will tell if further findings bear out the cyclic model's appropriateness.
- Provides a comprehensive look at what is known about universal history.
- Presents a cyclic model, eliminating the need for an inflationary period of history.
- Describes the process of how cosmology is practiced in exquisite detail.
- New theory appears to be fully consistent with experimental evidence.
- Theory presented is based on string theory concepts, which are themselves questionable.
- Provides no conclusive evidence of the theoretical assertions.
- 284 pages, hardback, Doubleday 2007
- 11 chapters + glossary, further reading, & index
- Written by two respected physicists with a distinguished history of work in the fields of cosmology and theoretical physics.
Guide Review - Endless Universe: Beyond the Big Bang
Even with these modifications, the theory is far from flawless. One problem is called the flatness problem, which indicates (according to WMAP imaging) that the universe contains very little curvature of space. The Big Bang theory does not currently explain why the universe did not have initial imbalances. The homogenity problem and (ironically) inhomogenity problem both question why the distribution of matter and energy in the earliest moments came out as they did. Many choose to ignore these problems through applying some variant of the Anthropic Principle, but some cosmologists become quite fascinated with the implications of these problems.
In their book, physicists Paul J. Steinhardt & Neil Turok explain their cyclic model of universal evolution, which matches the majority of evidence and would also provide explanations for these existing problems. In this theory, the "Big Bang" is actually created by membranes (elements predicted by string theory) which collide with each other in multi-dimensional space. In this model, there is not necessarily just one Big Bang, but rather a series of them that happen over and over again, back and forth across potentially infinite time.
Though Steinhardt & Turok make a clear and compelling case for the need of revision to the current theory and for their own interpretation, this is hardly a slam dunk. Among other issues, their cyclic model is heavily dependent upon string theory, which has yet to be proven in its own right.
One of the best reasons for this book is its realistic description of the how cosmologists work. For anyone interested in a physics career, this would be a fascinating read, especially since Steinhardt is one of the key figures in the early development of Inflation Theory.