Standard Model reference diagram

[NOTE – this is re-post from the original incarnation of this blog.]

Don’t know your baryons from your bosons? Mixing-up your mesons with your muons?

Even those who know the most common particles and split them between the two main categories of fermions and bosons can still get somewhat confused when more exotic beasts are mentioned. And when you try to get your head around the less familiar categories, things can get a little confusing.

Here’s one of the classic representations of the Standard Model that you might see on the web:

Click image for source

It’s great, but only includes elementary particles, ignoring those made of bound quarks; the hadrons referenced in the H of the LHC.

Anyway, I was digging about looking for something unrelated in my documents folder when I came across a spreadsheet I’d created when trying to learn the particles and their categories.

So for anyone just wanting to get their head around the various categories you might read about (or hear about on Star Trek!), here’s my attempt:

Standard Model


And if that doesn’t help visually, here’s a better representation that illustrates the crossover between categories better:


Click image for source

Metaphysical Foundations (Pt1)

In this post and the next I’m going to lay down some of the few metaphysical beliefs, suspicions and desires that I have, for the sake of clarity in my statements elsewhere, my own introspection, and an attempt to explain why so many of my other views are ever-shifting and non-committal.

Click for source

It should be noted that not a single one of my beliefs, either presented here or elsewhere, are non-contingent, or true articles of faith. I don’t even believe one hundred percent that either the objective universe or my subjective experience is real, so from here on in, any non-qualified statement about belief translates to some extremely high, but non-certain probability.

I’m not going to get this done in one sitting, so I’ll begin with some of the basics before moving to the more interesting stuff next time. These are the foundations on which any metaphysical positioning on my part needs to be based.

First off, I think it’s fair to say that I take a weakly positivist view. In other words, I think that most phenomena (certainly consciousness and free will if they exist) in the Universe (and I use the term here in the largest sense, inclusive of multiple universes, extra dimensions etc.) are in principle, and almost certainly in practice, functionally explicable by science. This includes phenomenal consciousness and (if they exist) qualia, non-epiphenomenal consciousness and incompatibilist free will. This is not to say that science is the only relevant sense in which phenomena can be understood, but it should at least be one way.

(As I have explained elsewhere, I take anything that is posited to exist outside of the universe (like the god of Abrahamic religions) to be beyond the scope of scientific investigation. I consider any speculation regarding such things to be futile, and any claimed knowledge of them, either objective via divine books (lol) or subjective through personal divine experience, to be misguided. On ideas where god is the Universe, or nature in some sense, I remain skeptical but open.)

Second is a belief that’s flipped over the years, as my own take on what it means has changed, but I think it’s fair to say in at least a weak sense that I’m a reductionist.

It’s not that I believe every property of every system at every scale of the universe is explicable by referring to the workings of the lowest level alone. So for instance, I have no problem with ideas of top-down causation. Rather I believe that ultimately, the foundations of the ‘reality’ we perceive and measure should inform us how and why the properties of that ‘reality’ emerge at all.

Thirdly, I believe that our scientific understanding of the world is incomplete. This is, of course, an uncontroversial statement, but the key element is that our foundational understanding is incomplete. We have no proper understanding of the underpinnings of the rest of our theories, because we have no proper understanding of how the universe works, or of what it consists, at  scales smaller than the Planck length.

In other words, in all likelihood, our current best theories – quantum mechanics and general relativity – are wrong. Not wrong in the logical sense that two plus two doesn’t equal five, but wrong in the sense of being only approximations of at least one deeper theory, in the same way that classical Newtonian gravity is only an approximation of Einstein’s General Relativity.

This fact strongly colours the other beliefs and ideas that follow, because we know that quantum mechanics and its unintuitive effects arise from energy fields that are grounded at a scale below the Planck length.

When combined with even quite weak reductionism, it should be obvious that we cannot sensibly commit to any metaphysical position with anything even approaching certainty. In fact, I’d argue that any weighting at all amounts to little beyond personal preference. All metaphysical positions remain highly speculative, including the dominant one, physicalism.

So, given the above, how should we approach forming metaphysical opinions that aren’t simply biased reflections of our personal preferences and wider views?

Again I’d suggest it should be obvious that we start at the places of closest approximation to the target. Here the target is currently physics at the Planckian and sub-Planckian scales, so our closest approximations are quantum mechanics and general relativity, and to have an informed metaphysical opinion, one needs to think hard about what the observed phenomena associated with these theories might suggest.

With that in mind I’ll now move from my “beliefs” to mainstream foundational scientific theories and ideas that I strongly suspect are true.

When we talk of a theory of quantum gravity that will succeed both quantum mechanics and general relativity, what we are effectively talking about are the laws that govern, and the ontology that consists in, the universe at the scale of the Planck length and below.

One thing considered a requirement of a fully-fledged theory of quantum gravity is that it be  background independent. This is because general relativity will need to be derived from it, and general relativity (unlike quantum mechanics) is itself background independent. All this means is that like general relativity with its spacetime manifold, the equations of quantum gravity need to completely capture the evolution of the systems they describe without reference to a coordinate system of an ontological unit outside of the theory.

With Loop Quantum Gravity, background independence naturally falls out of the theory, but it is also achievable with string theory via the holographic principle in the form of AdS/CFT correspondence.

The upshot of this is that space and time are almost certainly emergent phenomena. At scales smaller than the Planck scale, they are expected to dissolve. Therefore we can say that at its foundations, the universe is both non-local and non-temporal, and of course, this is borne out in effects at larger scales above where we see both special and temporal separation being no barrier in the strong correlation of entangled particles in quantum mechanics.

This opens up interesting and counterintuitive possibilities for the notion of causation in the world when we consider again (and we should never forget!) that we are talking about fundamental truths at the bottom of reality. For instance, Loop Quantum Gravity is based on spin foam (itself based on the topological causation intrinsic in Penrose‘s spin networks), and alternative notions of causation have been posited by the likes of Gregg Rosenberg in his Theory of Natural Individuals as an essential base for understanding how consciousness may fit into the natural world.

Considering a non-temporal source for the temporally-ordered macroscopic phenomena that emerge from that base also holds the possibility of accommodating multiverse predictions that come from the likes of the Many Worlds Interpretation of quantum mechanics, or the vast number of possible Calabi-Yau manifolds in String Theory. This is because without time, one can think of the sub-Planckian realm as an Eternalist block universe, with all possible pasts and futures present simultaneously.

As Rosenberg has indicated, once one conceives of this, the most basic question we can ask of the Universe – why is there something rather than nothing – morphs into “why is there something rather than everything”

Click for source

So, to summarize, I believe in the following:

– a weak form of positivism in regards to consciousness and free will
– a weak form of reductionism
– foundational scientific incompleteness

And I strongly suspect the following are true:

– a background independent theory of quantum gravity will replace QM and GR
– space and time are emergent phenomena
– the Universe is a non-spaciotemporal all-possibilities-present block universe

Ultimately, in examining our closest approximations to foundational truths,  one is rendered powerless to deny that all we think we ‘know’ is challenged. This applies not only to our current physical ontology, but also the notion of causation itself. With that in mind, I find it quite flabbergasting when otherwise rational and articulate thinkers declare that the basics of our theories are in some sense complete. In fact, the basics are the very thing we are missing.

That’s all for now folks, but next time out I’m going to get more speculative, as armed with the foundational beliefs and suspicions above, I approach the seeming conundrum of consciousness.

For Part 2 click here.

[last updated 14 September 2013)