If You’ve Always Wondered What M-Theory is All About (and I know you haven’t)

The Elegant Universe, Brian Greene

Reading this book has inspired me to consider writing a science blog. In particular, my vision is to write about physics, where each entry is a basic conceptual building block that eventually leads to a full-blown, lay-person’s guide to quantum mechanics. (Blog entry #1 will explain how if person A is on a train moving west and person B is on a train standing still, it can be equally valid to say that person A’s train is standing still while person B’s train is moving east.) This is, for the most part, a selfish goal, because it will force me to articulate what I learn and help with my retention. Essentially, while reading science books, I feel like I really “get” it, but as soon as I start to try to explain any of it to someone else I get a bit lost.

Brain Greene makes excellent use of analogies to bring home extremely complicated concepts in physics, particularly (for me) when he starts in on string theory, which evolves into M-theory with the realization that string theory requires 10- or 11-dimensional space. This is not as crazy as it sounds. For our large-scale purposes, the additional dimensions beyond the 4 we know and love are on a scale so small we are essentially unaffected by them.

M-theory attempts to bridge the irreconcilable differences between general relativity and the force of gravity and quantum mechanics and the strong, weak and electromagnetic forces – the holy grail of physics, a “grand unified theory” of everything. At the time the book was written, 1999, M-theory looked like a promising grand unified theory. It’s weakness appeared to be that it’s scale made it impossible to find testable predictions, the way new theories gain acceptance in the scientific community. However, given that the book was released 18 years ago (whaa??!!) it’s probably worth my time to seek out some updates on the science. 🙂

My favourite paragraph from the book was this one (emphasis mine):

“I think I understand. Although the detailed description you and I might give for strings may differ — whether they are wound around the circular dimension, or the particulars of their vibrational behaviour — the complete list of physical characteristics they can attain is the same. Therefore, since the physical properties of the universe depend up on these properties of the basic constituents, there is no distinction, no way to differentiate, between radii that are inversely related to one another.” Exactly.

I love it because it’s so cryptic, and yet Greene proudly proclaims it as “exactly” making his point. It just happens to remind me of a similar paragraph in Bill Bryson’s A Short History of Nearly Everything, although in Bryon’s case, his concluding proclamation is more relate-able:

Here is a sentence from the New York Times, explaining this as simply as possible to a general audience: “The ekpyrotic process begins far in the indefinite past with a pair of flat empty branes sitting parallel to each other in a warped five-dimensional space. . . . The two branes, which form the walls of the fifth dimension, could have popped out of nothingness as a quantum fluctuation in the even more distant past and then drifted apart.” No arguing with that. No understanding it either.

Beautiful.

Rating: If you are a collector of nerdy science books, then buy it!

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1 Response to If You’ve Always Wondered What M-Theory is All About (and I know you haven’t)

  1. Chrystal says:

    Electron orbitals!
    🙂

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