Hello everyone, my first post here, and I'm not sure if it is in the right forum, or whether it should go in 'fun'n'games' or 'against mainstream'. Hopefully, I trust a moderator will decide and move it to the appropriate place if this isn't it.

This is unconventional, because I'm starting out with no preconcieved theory to offer, just some observations on knowledge and the universe, and throwing it open as a collective thought experiment to see where it goes.

Just to say a little about myself first. I am a graduate of the history and philosophy of science, who has a general interest in cosmology, metaphysics and sciences which are relevant to the issues of today such as climatology. My username is a partial anagram of my real name.

Two historical approaches to science are:

1) To take the current theory of the observed universe and reformulate it to better explain the phenomena, reusing and redefining existing concepts and terminology to work out the internal consequences of the universal assumption to see if theory matches empirical observation. - The mainstream scientific endeavour. It has a 'Holy Grail': 'The Grand Unification Theory'.

2) to assume nothing, start from basic principles and work outwards. - The Cartesian project. Descartes starts from "I think, therefore I am" and heads on to develop cartesian space and everthing else which exists in it. This also aims at discovering a theory of everything which accords with reality, but from a priori reasoning.

In this thread, I'd like to have it both ways, and end up somewhere in the middle. I haven't worked out much of it beforehand, so I'm just going to dive in:

Starting from Descartes principle axiom, the "Cogito".
I think, therefore I am.
Therefore the universe cannot be nothing, because I'm here to think about it.
Let 'U' be the universe.
U=something.
Since the Universe by definition contains everything knowable and perhaps unknowable:
U=Everything QED

So here we have a 'Grand unification theory' which is the ultimate answer. Problem is, as Douglas Adams showed, in order to make use of the answer, we need to define the question. To get a better handle on that we need to differentiate the universe in order to understand the interactions of stuff and then establish the relationships between them. 'Solve et Coagula', as the alchemists were fond of saying. Differentiation and integration, as Leibnitz and Newton discovered, are powerful tools in the box.

Our chosen tools then are Logic and Mathematics, with a bit of handwaving and prosaic description to help the non-numerical to keep up. Cantor and Goedel and Turing grappled with the unprovability of the axioms on which they rest, but they're the best we currently have, so no point beefing about it. We acknowledge the insecurity of the foundations and move upwards to build the next deck on our 'Tower of Babel'.

We differentiate the universe into a few basic elements:

Time, space, energy, mass. These accord with the 'naieve realism' of our perception of the universe which surrounds us. Why should we use these categories in preference to any others? Well. it's obvious innit?

So, Using cartesian space and metronomic time, and an insight he gets after drinking a couple of glasses of cider and taking a bang on the head from some falling fruit, Newton comes up with a damn fine theory which successfully explains and quantifies the interaction of matter and force (energy) with respect to time.

F=MA

Throwing in his newly discovered gravity, he can explain the course of the planets, the bending of light (nearly), and just about everything else with some simple geometry and a couple of constants.

By the time Einstein comes along, the utility of Newton's universe ("I frame no hypotheses") has proved so fruitful, everyone accepts gravity to be a 'real force' and something which has to be accounted for as a discrete quality of mass in any new theory.

Einstein overturns that and makes gravity a function of the curvature of space-time around mass, putting it into the void as an effect of mass, and thus removing gravity from mass as an inherent property. He integrates mass, space and time using gravity as the glue to bind them together.

E=MC^2

Vaildated by Eddington with the mercury Perihelion experiment, and now by the gravity probe, it's the undisputed best current model which gives quantifiable results. In addition, the geodetic 'gravimagneto' effect of relativity is seen to be analogous to electromagnetism, they use the same basic equations, which throws open the possibility of explaining various phenomena in other ways too. EU, plasma cosmology etc.

In trying to integrate it all back to our GUT equation U=sigma though, we run into a couple of snags. M and C are assumed to be constants. E is poorly understood as quantised states of indeterminate magnitude and location. The big bang theory rests on an increasing number of exceptional assumptions about 'dark matter' and 'dark energy' which don't fit in the general scheme very well, and the hubble 'constant' is forever being changed. Observed regularities in the distibution of red shifts, apparently adjacent situation of objects with very different redshifts. The circularity of defining distance and velocity with redshifts...

Many ideas exist as to how we can overcome these problems and get the constants to 'drop out of the equation'

I hope others might join in and elucidate a few of those problems and propose possible solutions or outline new characterisations of the problems, because my head is hurting.

Personally, I think the main problem with GUT thinking is that it is over-blown-- despite the lofty label, the idea is simply to unify gravity with the other unified forces, that's all. It isn't really an equation like U=sigma, that's too unified, as you correctly point out. I think there's a lot of misunderstanding about what "unification" means-- if you look at this post with a view to "unify" it, what you want to do is see all the black marks as part of the words, and all the light blue areas as part of the background. Then you have unified what needs to be unified, and you can read its meaning. But the idea of "grand" unification sounds like an effort to unify everything, the black bits and the light blue bits, but doing that to this post would render it meaningless, it would just become POST and nothing more, completely unified. So "grand" unification does not mean "complete" unification, though that confusion often arises. Unification is simplification, so always has a cost and a benefit. The benefit is that we have less to fit in our heads, the cost is that we distinguish fewer details, and the former only outweighs the latter when the purpose is to show more clearly the distinctions you maintain rather than the details you eliminate.

If a flood of water is coming toward us, then we benefit by unifying all that is water, whether that includes parts that are muddy and parts that are clear and parts that are flowing fast and parts that are swirling in eddies, but we also benefit by noticing that yonder high hill differs in an important way from yonder approaching water. If we unify everything, and just say "I'm surrounded by water/hill/air", then we drown.

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Lurking behind every good answer is an even better question.