For today’s high-budget, big-hair episode of The Last Theory, I flew all the way to Oxford.
This beautiful stone building is where I studied physics, way back in the twentieth century:
Yes, I’m that old.
The twentieth century was a truly exciting time in physics.
From 1905 to 1973, we made extraordinary progress probing the mysteries of the universe: special relativity, general relativity, quantum mechanics, the structure of the atom, the structure of the nucleus, enumerating the elementary particles.
Then, in 1973, this extraordinary progress... stopped.
I mean, where are the fundamental discoveries in the last 50 years equal to general relativity or quantum mechanics?
As Eric Weinstein has claimed on BigThink and reiterated on The Joe Rogan Experience: “...elaborations on the standard model... ...all but stalled from the theory side since around 1973...”
The question is: why?
Why has there been no progress in physics since 1973?
I’ve come to Oxford to tell you why progress stopped, and why it’s set to start again: why progress in physics might be about to accelerate in the early twenty-first century in a way we haven’t seen since those heady days of the early twentieth century.
The professionalization of physics
How many professional physicists were there at the dawn of the twentieth century?
A few hundred?
A few thousand?
There just weren’t that many people who were paid by universities to make progress in physics.
And yet these few hundred or few thousand physicists did make progress.
Astonishing progress.
How many professional physicists are there today?
A few hundred thousand?
A few million?
There are several orders of magnitude more people paid by universities to make progress in physics today than there were at the dawn of the twentieth century.
And yet all these physicists aren’t making any progress.
Something paralyzing happens when a pursuit becomes a profession.
When Lord Kelvin, a man of independent means if ever there was one, pursued physics in the nineteenth century, he wasn’t aiming to secure tenure at some prestigious university, and he wasn’t worried about paying the mortgage on his many-turretted mansion.
There was no money in physics back then.
Whether we like it or not, Lord Kelvin’s wealth allowed him to follow whatever wide-ranging ideas in physics piqued his interest, regardless of whether or not some narrow-minded university don approved.
Now that physics is a profession, however, any physicist with an eye to a secure salary does have to worry whether a whole host of narrow-minded university dons approve.
Here’s where these academics lecture:
I don’t know what they’re like today, but when I was here, I found the lectures awful.
And here’s where these academics work:
I mean, seriously, have you ever seen such an uninspiring place to probe the mysteries of the universe?
This is an inspiring building.
This is an inspiring building.
This is an inspiring building.
This?
Honestly, it’s difficult to imagine the academics who work here approving a wildly contrarian PhD thesis.
Dead-end physics
What happens when the younger generation’s research has to be approved by the older generation?
Well... String Theory. String Theory is what happens.
The thing is, physics is hard. It takes serious mental work to wrap your mind around something as difficult as String Theory. You have to mould your mind to be fluent in the mathematical language in which such theories are framed.
Once you’ve moulded your mind, it’s difficult to unmould it.
Even if you’re able to remould your mind, you’re not much inclined to. You’ve made too much of an investment in an accepted way of thinking about the universe to want to start from scratch with an alternative way of thinking about the universe.
Imagine you’re a young physicist.
You have some wildly contrarian ideas. But when you take them to your thesis adviser, he gently guides you to safer ground.
If you’re not, like Lord Kelvin, a man of independent means – if you’re dependent on grants and fellowships and professorships and, ultimately, tenure – you follow your thesis adviser’s guidance. For now, you toe the line, learning the theories of the older generation, probing some peculiarity in the equations, working around the edges.
You imagine that once you’re more secure, you’ll go back to your wildly contrarian ideas.
But you’re never quite secure. You do have a mortgage to pay, not on a many-turretted mansion, but on a small house on the edge of an extremely expensive university town.
And if you do find secure tenure at a prestigious university, well, by then it’s too late. You’ve invested half a lifetime into the older generation’s theories. Your mind is moulded.
Now you’re the older generation.
You’re still interested in wildly contrarian ideas, but you know you’ll never be fluent in the fundamentally different languages in which such theories might be framed, and certainly not sufficiently fluent to advise on a PhD thesis framed in such a foreign language.
Whenever a young physicist comes to you with her own wildly contrarian ideas, you gently guide her to safer ground.
The outsiders
I don’t know exactly how many professional physicists there were at the dawn of the twentieth century, but I do know that Albert Einstein wasn’t one of them.
When, in 1905, he proposed that the passage of time is relative but the speed of light is absolute, and that energy and mass are the same thing, Einstein wasn’t being paid by any university to make progress in physics.
He wanted to be – he’d been lobbying academics to be considered for a lowly teaching position at whatever university might take him – but he wasn’t getting anywhere.
So he fell back on making a living as a patent clerk.
At the time he had his most revolutionary ideas, Einstein was an outsider.
I don’t think he needed to be an outsider.
I’m sure he would have had his most revolutionary ideas even if he’d been offered professorships at every university in Europe.
Similarly, I don’t know exactly how many professional physicists there are today, but I do know that Stephen Wolfram isn’t one of them.
When, in 2020, he laid out a path to a fundamental theory of physics based on the application of rules to hypergraphs, Wolfram wasn’t being paid by any university to make progress in physics.
He had been – in 1980, at Caltech, his PhD thesis in particle physics had been approved – but he then pivoted into computation, founded Wolfram Research and released Mathematica.
Wolfram remains an enterpreneur more than an academic.
At the time he launched the Wolfram Physics Project, he, too, was an outsider.
I’m not saying that Wolfram is Einstein.
Here’s one of the deep differences between them.
I don’t think Einstein needed to be an outsider to have his most revolutionary ideas.
I do think Wolfram needed to be an outsider to have his most revolutionary ideas in physics.
It’s no accident that when Wolfram studied physics in this beautiful stone building, he quit without getting a degree:
It’s no accident that Wolfram has said that when he was here in Oxford, he, too, found the lectures awful:
It’s no accident that Wolfram turned away from academia to become an entrepreneur.
Through his entrepreneurship, Stephen Wolfram has become, like Lord Kelvin, a man of independent means.
Whether we like it or not, Wolfram’s wealth has allowed him to follow whatever wide-ranging ideas in physics pique his interest, regardless of whether or not some narrow-minded university don approves.
He has not invested half a lifetime into String Theory, or any of the other theories that have gone nowhere in physics over the last 50 years.
His mind has been moulded instead by a lifetime of work in computation.
I suspect that without this complete freedom from the profession of physics, Stephen Wolfram would never have been able to lay out so completely different a path to a fundamental theory of physics, based on computation rather than mathematics.
Talking about a revolution
It may be an exaggeration to say that there been no progress in physics since 1973.
But I do think that physics has become paralyzed in the last 50 years.
And I do think that the reason lies among these beautiful stone buildings...
...and, yes, that ugly concrete one.
Some celebrated advances in physics have happened here since 1973, such as Roger Penrose’s work on black holes. But these advances have been based on the theories of older generations; Penrose’s work, for example, was based on Einstein’s general theory of relativity. I hesitate to say that a physicist as decorated as Roger Penrose was merely probing some peculiarity in the equations, working around the edges. Still, I can’t help but observe that the equations he was probing were written down by Einstein in 1915, way back in the early twentieth century.
When physics became a profession, a way to make a living, the incentives for physicists changed.
Professions are always vigourously defended by the professionals whose livelihoods depend on it.
In the case of physics, it’s not just the practice of physics that has been defended, but the theories of physics, too, as well as the language of physics.
Sure, the trend towards professionalization began long before 1973, but to me it’s no surprise that we’ve seen the effects compound over the last 50 years, as each generation of physicists has stymied the next with dead-end theories.
I believe that physics might be about to accelerate in the early twenty-first century in a way we haven’t seen since the heady days of the early twentieth century.
I believe that we’ll soon see new theories of physics based on a new language of physics: the language of computation rather than the language of mathematics.
And to me, it’s no surprise that this most promising development in physics I’ve seen in my lifetime has come from someone, Stephen Wolfram, who, rather than being a professional physicist, is an outsider.