Sorry. That guy does not know strings any more than anybody does.

It's an hypothesis without any testable experiments. No matter what M. Cuckoo says.

String theory has had decades of the brightest theoreticians on the planet pouring over it, including people like Ed Witten, probably one the smartest mathematical physicists on the planet.

String theory has advanced theoretical mathematics a whole bunch, physics, not so much. In fact, it has taken away the efforts from quantum field theory, which has every single physics Nobel prize since the early 60's. Not one for strings. OOOPSIE!

It was an interesting diversion, and something may yet come of it. But it does not look promising at this stage. In fact it looks more like mathematical legerdemain than anything else. No problem there. The mathematicians can probably use it.

Let them have it.

So far, physics has not seen much from it, no matter what M Kaku says.

there are important reasons to take the effort seriously, they're just mostly not the ones Kaku mentions. I think the main issue is the fundamental incompatibility between general relativity and quantum field theory, an issue that string theory has immense promise to resolve.

The big trouble with string theory, in my view, is that it ain't a theory of physics as people like you and me understand it - it's more of a template for a theory. It's a set of prescriptions for what a theory of real physics could look like. There is not "a" string theory but thousands, and none of them studied in any detail, so far, produces anything very close to a description of the universe we actually live in. Anything string theory predicts is either completely inaccessible experimentally or is not a unique prediction of string theory (e.g. supersymmetry could be true with or without string theory).

It's mostly a very clever idea with a massive PR department.

Which can be used within physics, or maybe even other disciplines.

But I think strings generally has not panned out in the way it had been envisioned. I hope something good comes out of the significant efforts that have been mounted, and are still being mounted. But it might very well be that strings are dead end. Meanwhile quantum field theory moves forward. But merging that with gravitation is a real problem.

We'll have to see what happens.

Special Relativity: 3 person-years

General Relativity: 15-20 person-years

Quantum Mechanics: 60-100 person-years (counting Bohr, Heisenberg, Schrodinger, Born, Dirac, & Pauli as fully engaged on the problem for 10-12 years)

(Bear in mind that all of the above produced a slew of testable predictions, and the developers were showered in Nobel
prizes.)

Then we come to String Theory. It began as a topic with Veneziano around 1970, took off in the mid-80s, and now
basically dominates theoretical physics in American academia.

Conservatively, two to three thousand person-years of research have gone into String Theory. Nobody has managed
to extract a testable prediction from it after all that effort. Future historians will wonder at how much time and money
got thrown at what (so far) has been a total dead end.

J.

Has read Edwin Abbott's Flatland?

Incidentally, one reason that Einstein failed was his refusal to accept the Heisenberg Uncertainty Principle, which offended him for purely philosophical reasons.