Review: Once Before Time
by Jeff Foust
|Once Before Time is not a light, breezy introduction to the universe: the subject matter and the writing style can both be dense at times.|
Bojowald, a physics professor at Penn State’s Institute for Gravitation and the Cosmos, is one of the leading proponents of a model called loop quantum cosmology (LQC). It is based on a theory called loop quantum gravity, which attempts to combine quantum mechanics and general relativity into a model for spacetime (the name comes from the “extended, one-dimensional looplike” shape of spatial atoms in quantum gravity). Perhaps the key factor setting LQC apart from other cosmological models is that it does away with the Big Bang singularity: instead, there was something more like a “Big Bounce” where there universe collapsed to a finite, if microscopic, size, and then expanded again. That means there were universes before this one, raising the possibility of indirectly detecting the imprint of that previous universe on our own, such as through study of gravitational waves.
If all that leaves you scratching your head, you’re not alone. Once Before Time is not a light, breezy introduction to the universe: the subject matter and the writing style can both be dense at times. Bojowald attempts to liven up the book with some literature references and photos of abstract sculpture, but in the end that may say more about the author’s artistic preferences than enlightening the reader about the nature of spacetime. This is not a book for the casual reader curious about the origins of the universe. Instead, this is more appropriate for someone already familiar with many key tenets of modern cosmology who is interested in learning more about an alternative model.