High energy theoretical physicists haven't had anything to do for the last 50 years

31 Jul 2025

Modern fundamental physics rests on two great pillars: General relativity, which describes gravity, and the Standard Model of particle physics, which accounts for the other three known ‘forces’ of nature—electromagnetism, the weak nuclear force, and the strong nuclear force. These are, as far as we currently know, all that exists.

The theory of General Relativity (GR), published by Einstein in 1915, begins as an attempt to revoke the special status given to inertial frames of reference in Newtonian mechanics. In Newton’s framework (and even in Special Relativity), inertial frames (roughly speaking, coordinate systems that are not ‘accelerating’) play a privileged role. Einstein’s great achievement (or at least one of them) was the observation that being in an accelerating frame of reference is indistinguishable from being in a gravitational field. Einstein had previously shown that acceleration causes time to slow down and lengths to contract. This leads to a remarkable conclusion: that gravity, too, must affect time and space. And in fact, gravity is equivalent to the curvature of space and time.

GR has been complete, in a theoretical sense, since the day it was published. No fundamental additions or revisions have been needed to its core in over a century.

The Standard Model, on the other hand, is a quantum field theory of the other three fundamental ‘forces’. The theory was essentially finalised in the early to mid 1970s, when three major pieces fell into place:

1. Quantum Chromodynamics, the theory of the strong interaction between quarks and gluons.

2. Electroweak unification, which showed that the electromagnetic and weak nuclear forces merge at high energies

3. The Higgs mechanism, which explains how particles acquire mass through spontaneous symmetry breaking.

So in terms of theory develpment, the situation is roughly speaking that GR has been done since 1915, and the Standard Model has been done since the 1970s. Which leads to a natural question:

What exactly have high energy theoretical physicists been doing for the last 50 years?

Great question, me

I think the best answer I can give to that is as follows. High energy theoretical physicists have been the semi-unwitting participants in a natural sociological experiment that seeks to answer the question of what happens to science when there’s no science left to do.

And the result has been pretty darn fascinating.

Ok but if you want a more concrete answer, the main thing they have been doing is string theory.

String theory is an entirely speculative framework that aims to unify the Standard Model with General Relativity. That sounds like it ought to be a pressing problem. But it turns out there’s no real conflict between the Standard Model and General Relativity in any experimentally accessible regime. Both theories work astonishingly well in their domains. The Standard Model explains practically everything we’ve observed in particle colliders with an astonishing degree of accuracy, and GR continues to pass every test thrown at it.

So what drove the creation of string theory? Mostly the aesthetic sensibilities of physicists. Perhaps a touch of ennui thrown in for good measure.

Since there is no conflict between established theory and experimental evidence that needs to be resolved, they just came up with something they think is fun and pretty. In fact, this is what they have been doing for many decades now, with little to no regard for any connection with reality.

Not only is almost all theoretical work that has been done in the last 50 years fundamentally disconnected from reality, but it is unlikely to ever be experimentally testable. The kinds of energies needed to directly probe quantum gravity are utterly out of reach. If you wanted to test Planck-scale physics—the regime where quantum gravity becomes important— and you assume naive scaling based on the large hadron collider, you’d need a particle collider at least the size of the solar system. I’m not holding my breath.

Is that really science?

Another great question from me.

Allow me to indulge in a metaphor. Let’s say I start out with some people playing a football match in a stadium. However, I progressively start to remove elements from the picture. First I remove the crowd. Then the referee. Followed by the grass, and the goal posts and the ball. Continuing until there is nothing really left that has anything to do with football as we understand it.

Tell me: At what point during this process do we say that whatever is happening, it’s no longer a football match?

In high energy theoretical physics, we have taken away so much of what is normally understood to be science, that I don’t think it can be called science anymore. If you’re not doing experiments, developing falsifiable theories, putting them to the test and connecting with empirical results, then it’s not science.

Why do we fund this? Well because most people aren’t really aware of what’s going on. Physics is a high prestige activity, and the taxpayer is seemingly happy to give a small chunk of their income to paying for it in return for the occassional scientific media hype job/physics porn.

What's the alternative

Now there are a lot of people who have lamented the state of high energy theoretical physics before me. None of what I’m saying here is new. However, they usually have some wild ideas of their own that they’re very attached to, that they’re very convinced would have been a way better direction to go down rather than the self-masturbatory string theory route. It’s not uncommon to hear, for example, people of the loop quantum gravity persuasion saying their field should have got more attention and resources. Or the foundations of quantum mechanics people saying there should be more research into what a measurement really is, etc.

They might have a point. A small point.

But you may have guessed that I don’t really believe them. I’m pretty sure that if the field had moved in the direction they wanted, there would have just been mental masturbation over there rather than over here.

The end of science

See the real problem is that practically speaking, there’s nothing left to discover.

I’m not saying we have reached the end of human knowledge of physics. I’m saying that until our experimental capabilities advance significantly, which doesn’t look like it’s happening any time soon, everything else is just masturbation.

And it turns out that actually I have a lot of sympathy for string theory. When there’s nothing left to do, why not choose the biggest, prettiest, most fun toy in the playground to amuse yourself with?

This gets at a very important broader point though. What if what has happened in high energy theoretical physics happens elsewhere?

I would say actually in many ways it already has. There are large sectors of the academy that really do not have anyhting useful to do. The humanities for one, which are incredibly corrupt. But also the social sciences, though the situation has not degenerated quite as much.

I experienced this first hand in economics. The issue there is that the systems that one is attempting to understand are so complex that we really don’t have a chance, and aren’t going to have a chance anytime soon. The modern academic discipline of economics has produced remarkably little knowledge since its inception, notwithstanding the enthusiastic commentary of people whose paycheck relies on them being enthusiastic.

The broader trend that I’m pointing to is that there is diminishing returns to science. The more you know, the harder it is to know more. This is a problem that’s becoming increasingly relevant, and making the academy more and more redundant. And I don’t know what to do about it.