(former PhD in Particle Physics in QCD here, far from an expert)
> While the theory is incredibly powerful in its domain, we have been unable to unify it with gravity and other theories of matter. This is a problem because it's supposed to be a theory summarizing the fundamental building blocks of the universe and it should therefore describe _everything_.
I think this is a misunderstanding of what the Standard Model is and the scientific process that went into it. It is a model for describing the interactions of electroweak and strong force interactions, and that's it. This is based of years of experimental data and coming up with a consistent theory that fits the data. No one went out to come up with a "theory of everything", missed and ended up with the standard model.
The Standard Model is clearly a low energy effective theory of something more, almost by definition. The problem is we have absolutely no data to drive predictions of higher order theories (which could also turn out to be low energy effective theories themselves). Without data, there is a very real chance that the standard model is the best model we're going to have for particle physics.
> the theory is ugly. It's a mess with many parameters and weird interpretations all shoved together. Physicists don't like this. Not just for aesthetic reasons, but also out of experience. It reminds people of pre-relativity electrodynamics for example. Lorentz had what was essentially a working theory of relativity but it was a mess. People fear the standard model is the new lorentzian relativity, essentially correct but missing some key insight that is needed to fix it.
Ugly is a subjective term. A lot of people talk about stuff like 'naturalness' problems with the standard model, but is that really a problem? Who are we to say what numbers are the natural order of things. Gravity is orders upon orders of magnitude weaker than all the other forces, is that 'natural'?
I think comparing it to Lorentzian aether is a little harsh. If you compare special relativity to Lorentzian relatively, special relativity is just a simpler model (it doesn't need aether). I think it's extremely unlikely at this stage that given only the data we have right now, someone would be able come up with a theory that would be fully consistent with the Standard Model but is simpler and doesn't predict new stuff. It's not impossible, but it is very unlikely.
Actually I think the biggest problem with the Standard Model is how to go from the theory to real predictions. Formulating the lagriangian of QCD is the easy bit, converting that to real predictions (either on the lattice QCD end at large alpha_s or perturbative QCD at small alpha_s) is extremely difficult. It's almost laughably absurd where it is not unheard of for calculations of single processes to take a decade or more.
I think a lot of commentary on this thread is losing sight of what the world "model" really amounts to in a scientific context.
It's an abstraction. A bunch of math that just-so-happens to result in accurate predictions. That's all it really is. How the universe really works (putting Tegmark aside) is a separate, ultimately philosophical question.
Much of particle physics is simply exploring the parameter space in which various models might be applicable. In the most exciting case, the model crumples in some new, unexplored region.
The value of bigger accelerators comes down whether the higher energies, in which we have not yet explored, are worth exploring, relative to the cost of doing so. That is certainly debatable.
But it's not a "desert." Nobody knows what higher energies will reveal.
> It's an abstraction. A bunch of math that just-so-happens to result in accurate predictions. That's all it really is. How the universe really works (putting Tegmark aside) is a separate, ultimately philosophical question.
But philosophy is not knowledge, and it is in fact math that is the only form our knowledge can have in this area, whether we like it or not.
Physics is based on metaphor not math. We take common experiences like space, distance, speed, temperature, "energy", quantify them with other stable experiences we can use as reference units, then select the operations on them which happen to have predictive value. The operations have become more abstract over time, but they're still more complex variations on the same underlying concepts - for example generalising 3D Euclidean space to the abstract ideal of a set of relationships in a mathematical space defined by some metric.
There's nothing absolute about either the math or the metaphor. Both get good answers in relatively limited domains.
One obvious problem is that reality may use a completely different set of mechanisms. Physics is really pattern recognition of our interpretation of our experience of those mechanisms. It's not a description of reality at all. It can't be.
And if our system of metaphors is incomplete - quite likely, because our experiences are limited physically and intellectually - we won't be able to progress past those limits in our imagination.
We'll experience exactly what we're experiencing now - gaps between different areas of knowledge where the metaphors are contradictory and fail to connect.
This is all wrong, unfortunately, and that’s because it is based on a wrong premise. Experience and knowledge are two different things, and whether we are capable of experiencing certain aspects of reality or not, math is how we know things. In the areas we cannot experience directly the ability to form mathematical images and ideas can even be thought of, if you will, as an extension of our ability to “see.”
>Physics is based on metaphor not math. We take common experiences like space, distance, speed, temperature, "energy", quantify them with other stable experiences we can use as reference units, then select the operations on them which happen to have predictive value.
If you experience pushing this object that feels to weigh 1kg with a force that feels like 1 N, you are going to experience seeing it accelerate at 1m/s^2.
I think we probably agree on the core issue, I just kept things a bit too brief.
There are people who feel like I described, and there are people who disagree to varying degrees (physicists, amitrite?). But I do think we all kind-of agree that we'd prefer to find experimental results that break the standard model vs proving it right now, but it seems unlikely we're going to find that smoking gun anytime soon. The model is an attempt at fitting data and like you said it works in the regime it was designed for, but it can't be _the_ theory of everything. It would be great if it broke somehow so we could investigate _why_ and drive new avenues of research based on that which might be more promising in resolving gravity and the other forces (or the anti-matter mystery, or shed some light on what dark-matter is)*
As the OP said, it's still good science if we prove that the current theory holds up, but no one is really happy with it at this point because everyone knows it's not going to be the final unified theory that we all want to see
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* personaly I have a gut feeling those three are going to be resolved in rapid succesion if they're ever solved
> While the theory is incredibly powerful in its domain, we have been unable to unify it with gravity and other theories of matter. This is a problem because it's supposed to be a theory summarizing the fundamental building blocks of the universe and it should therefore describe _everything_.
I think this is a misunderstanding of what the Standard Model is and the scientific process that went into it. It is a model for describing the interactions of electroweak and strong force interactions, and that's it. This is based of years of experimental data and coming up with a consistent theory that fits the data. No one went out to come up with a "theory of everything", missed and ended up with the standard model.
The Standard Model is clearly a low energy effective theory of something more, almost by definition. The problem is we have absolutely no data to drive predictions of higher order theories (which could also turn out to be low energy effective theories themselves). Without data, there is a very real chance that the standard model is the best model we're going to have for particle physics.
> the theory is ugly. It's a mess with many parameters and weird interpretations all shoved together. Physicists don't like this. Not just for aesthetic reasons, but also out of experience. It reminds people of pre-relativity electrodynamics for example. Lorentz had what was essentially a working theory of relativity but it was a mess. People fear the standard model is the new lorentzian relativity, essentially correct but missing some key insight that is needed to fix it.
Ugly is a subjective term. A lot of people talk about stuff like 'naturalness' problems with the standard model, but is that really a problem? Who are we to say what numbers are the natural order of things. Gravity is orders upon orders of magnitude weaker than all the other forces, is that 'natural'?
I think comparing it to Lorentzian aether is a little harsh. If you compare special relativity to Lorentzian relatively, special relativity is just a simpler model (it doesn't need aether). I think it's extremely unlikely at this stage that given only the data we have right now, someone would be able come up with a theory that would be fully consistent with the Standard Model but is simpler and doesn't predict new stuff. It's not impossible, but it is very unlikely.
Actually I think the biggest problem with the Standard Model is how to go from the theory to real predictions. Formulating the lagriangian of QCD is the easy bit, converting that to real predictions (either on the lattice QCD end at large alpha_s or perturbative QCD at small alpha_s) is extremely difficult. It's almost laughably absurd where it is not unheard of for calculations of single processes to take a decade or more.