Los límites de la Cosmología

George f. R. Ellis

El enfoque epistemológico de la cosmología lleva a recordar algunas perogrulladas y a plantear verdaderas dificultades. El hecho de que no exista más que un único universo observable impide cualquier comparación de este objeto con otro, una condición que sin embargo es necesaria en cualquier procedimiento científico.

That is, cosmology is not one of positive sciences.

For fans of “landscapes” and all stuff, simply to say that Ellis considered the vague discourses about “multiple universes” like outside of physics.

Me too!!! Extremely good!

Congrats!

It was an instructive joke.

Many of these students now are at major US universities.”

So we are witnessing the final convergence between
String Theory and Post-Modernist Deconstructionist
Literature Theory.

My only question. Why did it take so long?

If quark and lepton numbers are conserved separately, the GUT mechanisms of proton decay are excluded. This is achieved in TGD framework since quarks and leptons correspond to different
conserved chiralities of M^4xCP_2 spinors induced
to space-time surface. The couplings of quarks and leptons to CP_2 Kahler gauge potential are n=1 and n=3 multiples which gives standard model quantum numbers correctly. Color is now not a spinlike quantum number but basically angular momentum like: this means a profound difference compared to QCD.

One can of course consider the possibility that quarks have lower mass states. TGD indeed suggest the existence of fractal hierarchy of QCD like theories for colored excitations of also leptons and there are some experimental findings giving some support for this conjecture. This picture is consistent with W and Z^0 decay rates if these QCD like theories are not asymptotically free and exist only in some finite energy and momentum transfer range. This framework allows to consider the transformation of ordinary baryons to baryons of scaled down hadron physics by a kind of tunneling mechanism.

Best,
Matti

The current lack of evidence for proton decay can be interpretted in one of several ways:
0.Protons indeed does not decay ever.
1.Protons decay in ways predicted by the standard model, but its life time is too long to be detectable.
2.Protons decay in ways we do not know, and our current detection technology would not have registered any signal.

I think the 3 is the most possible scenary. There are plenty of things that the standard model can not explain. The most notable ones would be super high energy particles detected in nautral occuring cosmic rays. The energy is many times higher than the energy/mass of most elememtary particles, like proton and neutron.

What kind of cosmic process would leads to that kind of energy? There has been no plausible answer so far. You can throw in a black hole or things like that, but at most you can get something with an energy level of the same order of magnitude as

The years when the proton refused to decay were very interesting. Everything indicated that it should. We had a beautiful, simple, elegant, minimal model, namely SU(5), that unified all three subnuclear interactions. It was proposed by our best and brightest. There was no hint of an inconsistency. It all looked great. However —- God refused to play along.

Perhaps God tried hard to tell us something very important but failed;-).

Matti Pitkanen

I trust Greene’s reasoning and articulate descriptions of SUSY, I understand the concepts better than I did before. But I can’t help but feel that I’m reading about a framework that is literally being reverse-engineered to fit models that have already demonstrated tangible results. It will be interesting to see which will be discovered first: The Calabi-Yau shape predicting all particle charges, forces and masses or direct proof of the Higgs particle in the LHC.

P.S. The search for the right Calabi-Yau shape seems contrived in the way that re-normalization seemed contrived. Feynman invented re-normalization but was openly hostile towards it. Are any SUSY theorists at least showing mild skepticism about this issue?