Understanding the “multiverse”

Book review: In Search of the Multiverse by John Gribbin

Price: NZ$55
Hardcover: 240 pages
Publisher: Allen Lane (August 27, 2009)
Language: English
ISBN-10: 1846141133
ISBN-13: 978-1846141133

These days when people talk about the “multiverse” they usually mean the idea that our “universe” is just part of a larger, perhaps unending, collection of “universes.” And that these different universes may have different characteristics, different values of physical constants, for example.

So, I was a little surprised to find John Gribbin beginning his book with the “many worlds’ idea of Hugh Everett. The idea that the different possibilities inherent in quantum-mechanical descriptions leads to formation of many words as events lead to multiple quantum-mechanical choices. A little disappointing as I wanted to learn about the origin of multiple universes in inflationary “big bang” theory. He discussed this only in the second half of the book.

Cosmological cranes – not skyhooks

In his book “Darwin’s Dangerous Idea“ Daniel Dennett draws out the philosophical significance of evolution by natural selection. Darwin himself hesitated to apply his ideas to humanity, let alone to wider philosophical issues.

Dennett describes how natural selection explains phenomena such as development and evolution, using “cranes”, rather than “skyhooks”. How development can arise internally rather than relying on an external “designer” or “manipulator.” He also describes natural selection as the “universal acid.” All this implies the concepts of natural selection can be applied more widely than just biology.

One application Dennett mentions is in cosmology and he briefly describes Lee Smolin’s idea of cosmological natural selection in his book. 2009 is the International Year of Astronomy. It is also the year we celebrate the 200^th anniversary of Darwin’s birth (February 12) and the 150^th anniversary of publication of his The Origin of Species. So it is fitting to link the two commemorations and cosmological natural selection does this.

Fine tuning argument

More and more I hear the apparent “fine-tuning” of the universe being given as an argument to “prove” existence of a god. This goes along the lines that there are a number of critical physical constants underlying the nature of our universe. If either of these had even slightly different values our universe would be very different. Stars and galaxies would not form. Carbon would not be manufactured in the stars and hence life would not occur.

Proponents of this “proof” argue that the chance of our universe having physical constants with these values is impossibly small. Therefore there must have been a divine intelligence to ensure our universe has physical constants with the measured values.