The article

Physicists Uncover Geometric ‘Theory Space’ in Quanta magazine isn't quite clear to me. Partly it's because I don't understand anti-DeSitter spaces, and partly because it isn't clear that the writer knows either.

And little things slipped by the editor, like "By 2016, Poland and Simmons-Duffin had calculated the two main critical exponents of the theory out to their millionth decimal places." That seemed completely crazy--and yep, the linked paper showed 1 part in a million, not a million decimal places. SMBC gets that right.

*You may want to take some advice from Peanuts: WRT The Brothers Karamazov--Charlie Brown says, "But don't you get confused by all those long Russian names?" Linus says, "Oh, when I come to one I can't pronounce, I just bleep over it."*

Researchers are pushing in all directions. Some are applying the bootstrap to get a handle on an especially symmetric “superconformal” field theory known as the (2,0) theory, which plays a role in string theory and is conjectured to exist in six dimensions. But Simmons-Duffin explained that the effort to explore CFTs will take physicists beyond these special theories. More general quantum field theories like quantum chromodynamics can be derived by starting with a CFT and “flowing” its properties using a mathematical procedure called the renormalization group. “CFTs are kind of like signposts in the landscape of quantum field theories, and renormalization-group flows are like the roads,” Simmons-Duffin said. “So you’ve got to first understand the signposts, and then you can try to describe the roads between them, and in that way you can kind of make a map of the space of theories.”

That's a bit of jargon to go wading through, but can you see what's wrong here? Take this: "the (2,0) theory, which plays a role in string theory and is conjectured to exist in six dimensions" This sounds like a theory in search of an application. (I've tried my hand at that myself--it wound up looking more complicated that what it was supposed to explain.)

String theory, for all its attractive foundation, hasn't produced anything substantial yet, and you know you're *really* at sea when a theory is just "conjectured" to exist in six dimensions. That doesn't mean this *(2,0)* research isn't interesting--it probably is--just that the connection to the physical world is likely to be tenuous. At best.

The renormalization theories were developed to handle equations that gave infinities (what is ∞ - ∞ ?). When your equations behave like that it seems like a clear sign that this isn't the optimal way of expressing the problem. Maybe this bootstrapping paradigm can be a way of re-expressing problems--though Simmons-Duffin seems to think renormalization is still going to be there.

One particular physics problem looked as though it lay on a "corner" of the boundary of the space of possible configurations of one kind of bootstrap transformations. That's certainly odd, and worth exploring. But when the amplituhedron gets pulled in as a possible connection, it doesn't exactly increase my enthusiasm for the project. That beast is a highly speculative model that hasn't shown any solid connection to real "electron hits pion" physics. Like another theory mentioned above.

UPDATE: FWIW, Motls likes the ideas. He's a string theorist, and has a little different idea about how well string theory has been doing.