There are different possible explanations of the CKM and PMNS matrices, but in the current most standard version of the Standard Model they involve the Higgs:

]]>This is what everyone with a big new idea hopes. About 99.9% of these people are wrong, but luckily not 100%.

]]>There are ‘small’ fundamental problems that, when realized and resolved, will usher in the theory of everything and a drastically more complete understanding of our universe. But looking in other areas of physics will not be helpful because they suffer from the same lack of realization. To wit, it is our understanding of mathematics and how we apply it that is skewed at the foundational level. The unskew will cascade rapidly through all of the sciences and ultimately result in a great simplification and unification of previously thought disparate phenomena.

]]>if one could imagine an atomic effect, in which both electromagnetism and gravity play a strong role, and thereby find something like Planck’s formula bringing some light about their connection on a deeper level?

I agree with your overall point, and I agree with this example: if such an effect were known it would be a very interesting way to learn more about how electromagnetism and gravity are related. Unfortunately nobody knows such an effect. The main problem is that gravity seems to have a negligible effect in atoms: for atoms, the electromagnetic force between proton and electron is about 10^{40} times bigger than the gravitational force, and indeed nobody has even been able to measure the gravitational force here!

It’s hard to do experiments measuring the gravitational force on short distance scales, and this has led to a flourishing of surprisingly-hard-to-disprove theories in which gravity does weird things on sub-millimeter scales due to extra dimensions of space curled up in shapes that have about this size. This size is incredibly *large* compared to those we normally study in particle physics, so it opens the prospect that quantum gravity effects kick in at incredibly *low* energies. Try:

• C.D. Hoyle, D.J. Kapner, B.R. Heckel, E.G. Adelberger, J.H. Gundlach, U. Schmidt and H.E. Swanson, Sub-millimeter tests of the gravitational inverse-square law, 2004.

• Nima Arkani-Hamed, Savas Dimopoulos and Gia Dvali, Phenomenology, astrophysics and cosmology of theories with sub-millimeter dimensions and TeV scale quantum gravity, 1998.

The first paper is experimental and shows how hard experimentalists work! The second paper is theoretical and shows how good theorists are at coming up with far-out ideas. I’m not a fan of these particular ideas.

I think the avenue I mentioned in my talk—continuing to study the strange anomalies associated to neutrinos—is a bit more promising. A lot of people are working on this! Try this for starters:

• Adam Falkowski (aka “Jester”), Other neutrino anomalies, *Résonaances, 2012.*

I wonder if today the problem of fundamental physics could be, rather ironically, (i) ‘too much’ knowledge, meaning that one has to find a theory that fits to many more known facts simultaneously, than in previous times, and (ii) a bias in actively pursuing the search for the universal theory, instead of solving seemingly unrelated problems, which still could make the difference?

With the latter I mean, thinking of Planck, that he was not primarily occupied with the goal to find quantum theory (how could he, of course). He ‘just’ wanted to solve the riddle of black body radiation. A quite restricted problem. Quantum theory more or less ‘happened’ to him.

I wonder, again, if there could be ‘small’ fundamental problems in very different fields of physics, say solid state physics, which could give a clue on a (more) universal theory, in a way as it happened in Planck’s case? For instance, if one could imagine an atomic effect, in which both electromagnetism and gravity play a strong role, and thereby find something like Planck’s formula bringing some light about their connection on a deeper level? Or think of Bekenstein’s approach to black hole entropy, coupling, with a quite simple formula, and for a quite restricted problem, very different fields of physics to each other, facilitating a new view or point of attack for the quest for a universal theory?

]]>Thanks! The closer you get to the cutting edge, the more blood and guts you see. But the view from high up is not so messy.

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