Gerard 't Hooft received the Nobel Prize for his work on the weak interaction. And he is a gentle person. Since many years, he is trying to work towards unification. Here is is latest paper. Read it. The title is good: "A class of elementary particle models without any adjustable real parameters".
Unfortunately, many ideas for which Hooft became known are missing. He does not talk a lot about smallest distances on black hole horizons, even though he was one of its main proponents. It is nice to see that he mentions strings and supersymmetry only only in passing. But he asks questions about black hole evaporation and about conformal invariance; why is he still worried about these issues?
And unfortunately, the whole discussion leads nowhere. There is no tangible proposal, no tangible idea, no hint about where to go to. The only interesting statement in the whole paper is the title. What a pity! After all, any theory of everything should belong in the class of models "without any adjustable real parameters"! But the paper does not present such a model. Not even a glimpse about one.
Why is this so disappointing? Hooft stills believes that space and time exist "beyond the Planck scale". If you believe that, you never get anywhere. Hooft thinks about conformal invariance, its breaking and the dilaton. All these problems only appear if you believe that space and time exist "beyond the Planck scale". Yes, Hooft shows us: if you believe that space exists beyond the Planck scale (which is not true in this universe), then you are forced to think about many problems that do not exist in this universe.
Ex falso quod libet.