Book Review: The Hidden Reality

The Hidden Reality, by Brian Greene

I finished this book after about six years of on-and-off reading. Its difficult subject matter and the level of concentration required meant I could take it in only small doses. And that, of course, meant I often had to look back at previous explanations to understand the additional subject matter.

Oh yes, when I use the word "understand," I use it in the widest definition possible. Let's just say I have a nodding acquaintance with the topics. 

But Greene is an excellent writer and teacher. He uses strong yet simple metaphors to explain difficult concepts. He has helped me understand string theory -- to the point that I think I know what it is and how it works, although not enough to explain it to anyone else.

In this book, Greene reaches into whether multiple universes exist. Which, of course, gives lie to the term universe, but allows for some mind-boggling thoughts, ideas, and suppositions.

He dedicates chapters to how and why other universes might exist, sometimes right alongside ours, but in another dimension. There's the inflationary universe, which posits an eternity of Big Bangs --universes coming into being via a massive explosion of a tiny particle, expanding, then some of it shrinking back into another single particle before the entire exercise recurs.

He explains several others, deftly noting how some would prove string theory or black holes, or how some would mimic our universe, with only slight changes. He discusses whether  such universes would follow the same mathematical and physical rules as ours, and even goes so far to debate whether computers could form universes that would then create sentient beings. (Maybe ours is one?)

Greene says it is possible that quantum theory could explain multiple universes -- perhaps in the notion that every possible outcome has occurred somewhere in the infinite number of universes.   

These are universes we may never see because they are in different dimensions, or in a different fabric of time. It's unlikely we could ever prove their existence. This is a dilemma Greene acknowledges. 

"By invoking realms that may be forever beyond our ability to examine -- either with any degree of precision, or, in some cases , even at all -- multiverses seemingly erect substantial barriers to scientific knowledge. ... More distressing is that by invoking a multiverse, we enter the domain of theories that can't be tested."

With this, sometimes the theories in the book seem to swing away from science and more into theology and speculation. Sometimes, the ideas become so complicated that only a select few could  understand -- after all, few of us are Einstein.

But Greene says the answer is to follow the math. Take it as far as it can go, then keep going. He said past scientists who doubted their math -- even Einstein -- committed errors because of it. Those who trusted their math -- again, Einstein and others -- reached great heights because of it.

Believe in math's properties, and believe where it takes you, Greene says, even if those places are remote and temporarily inaccessible. Then let it take you beyond that realm, with the underlying goal to expand the knowledge of who we are and where we live.