Counting myself among “every physicist”—and an old one at that—who has been awestruck with the complexity and power of string theory but not having dabbled actively in field theory for some time, I had high hopes that the amazing Ed Witten would help me understand it better. Instead, I came away with a moderately stiff neck from straining to hear the “rhymes” of the theory. And I must confess that the references to “diffeomorphisms” reminded me of “sexual dimorphism,” something comparable to mathematical gender equality, if that’s possible.
More seriously, I was disappointed that Witten did not discuss what a lot of us would really like to know: Is string theory—can it ever be—falsifiable? What, if any, are its applications in the physical world? Who is working on these aspects of the problem? Is it really “not even wrong,” as Peter Woit’s book by that title (Basic Books, 2006) notes?
