I bought theoretical physicist Michio Kaku's latest book, The God Equation: The Quest for a Theory of Everything, after seeing him interviewed by Stephen Colbert.
I enjoyed the book, though I agree with some Amazon reviewers that it doesn't really break new ground. But since my understanding of the old ground is shaky, I enjoyed Kaku's take on familiar topics.
Particle physics. Relativity theory. Quantum mechanics. Big bang. The search for common ground between how relativity and quantum theories view reality. String theory.
Spoiler alert: physicists haven't yet come up with a viable Theory of Everything. String theory is the leading candidate, but string theory suffers from not-so-minor drawbacks such as an almost complete lack of ability to test its validity.
To a theoretician, all these criticisms are troublesome but not fatal. But what does cause problems for a theoretician is that the [string theory] model seems to predict a multiverse of parallel universes, many of which are crazier than those in the imagination of a Hollywood scriptwriter.
...Some might argue that these alternate universes are only mathematical possibilities and are not real. But the problem is that the theory lacks predictive power, since it cannot tell you which of these alternate universes is the real one.
Still, there's a lot to like about string theory.
It could resolve the conflict between relativity theory (space-time is smooth) and quantum theory (the subatomic realm is lumpy) by positing that extremely tiny strings are the fundamental constituents of reality.
Mystics would resonate with that notion, a point I made in my first book, God's Whisper, Creation's Thunder. Here's how Kaku puts it.
As a result of the torrent of equations, a new picture was beginning to emerge. Why were there so many particles?
Like Pythagoras more than two thousand years ago, the theory said that each musical note -- each vibration of a string -- represented a particle. Electrons, quarks, and Yang-Mills particles were nothing but different notes on the same vibrating string.
What is so powerful and interesting about the theory is that gravity is necessarily included. Without any extra assumptions, the graviton emerges as one of the lowest vibrations of the string.
...As physicist Edward Witten once said, "String theory is extremely attractive because gravity is forced upon us. All known consistent string theories include gravity, so while gravity is impossible in quantum field theory as we have known it, it's obligatory in string theory."
So while a huge amount of work remains to be done on string theory, there's a possibility it could live up to the title of Kaku's book, The God Equation.
However, this wouldn't be the God most people worship, but Einstein's God.
In this and other letters, Einstein despaired of answering questions concerning the meaning of life, but he was clear about his thinking concerning God.
One problem, he wrote, is that there are really two kinds of Gods, and we often confuse the two.
First, there is the personal God, the God that you pray to, the God of the Bible who smites the Philistines and rewards the believers. He did not believe in that God. He did not believe that the God who created the universe interfered in the affairs of mere mortals.
However, he believed in the God of Spinoza -- that is, the God of order in a universe that is beautiful, simple, and elegant. The universe could have been ugly, random, chaotic, but instead it has a hidden order that is mysterious yet profound.
In his final chapter, Kaku speaks about meaning in a familiar fashion that resonates with me.
In the end, I believe that we create our own meaning in the universe.
It is too simple and easy to have some guru come down from the mountaintop, bearing the meaning of the universe. The meaning of life is something that we have to struggle to understand and appreciate.
Having it given to us defeats the whole purpose of meaning.
If the meaning of life were available for free, then it would lose its meaning. Everything that has meaning is the result of struggle and sacrifice, and is worth fighting for.