I'm studying physics at MIT right now. My two favorite professors are David Pritchard and Alan Guth. They're 84 and 76 years old, respectively.
At one of the dinners I attended with a big-shot Harvard Professor he shared his scientific journey to particle physics.
He started doing physics research in undergrad, then went to the Institute for Advanced Study for PhD in physics. He spent 10 years doing physics. Then he came to Berkeley, met some experimentalists and realized that he wasn't doing physics, he was just doing math. 10 years.
He told us that he was coming up with fun extensions of string theory that had "interesting correspondence with the standard model" and now thinks it was all "bullshit".
What I conclude is:
Most seminars I go to contain no physics content.[c][d] They're engineering, data fitting, endless complicated extensions of existing models, things somehow inspired by physical phenomena that devolve into just doing math, and so on.
As far as I can tell, nobody finds this problematic. Moreover most of the physicists at Harvard and MIT don't even realize that what they're doing is not physics at all, not even science, really.
How come?
People naturally gravitate towards the most fun research, which is math, not physics[e]. Real research is punishing, usually doesn't work, and makes it much more difficult to get tenure. Research will be about fun math and not about science, unless it must. Glass Bead Game [f][g]was about that.
The current generation of theoretical physicists never made a real physical discovery and neither did their mentors. They're working on external data, never talk to experimentalists, or just do math.
The Center for Theoretical Physics Department at MIT literally has its own building, removing them from even accidentally interacting with experimentalists.
When I go to experimentalist seminars, there are no theoretical physicists there. When I go to theoretical seminars, there are no experimentalists there.
Experimentalists don't usually think about science -- they do engineering and without theoretical guidance produce no progress (market competition with more technologically advanced competitor could help them, but this is academia).
Unless something changes, theoretical physics might forever remain extensions to the Standard Model (they very misleadingly call this "Beyond Standard Model" research -- it's not) and fun math.
Bottom line is: if you never had the experience of discovering new knowledge about the world OR had a mentor who had it, you literally won't know what science is or how to do it. After 2-3 generations, this experience simply gets lost, and people doing "science" don't know what science is. Again, this has already happened at IAS and is happening very quickly at Harvard and MIT.
So what happens if we run out of frontier on Earth and either get no major scientific discoveries for 2-3 generations or get majorly disruptive, as happened to civilization multiple times over the last 5,000 years?
I think we might very well not recover the idea of progress for a very long time (I wrote 1,000 years in my notes but who knows). We've already seen this happen with space 1970-2000, until Musk came along – technology was literally declining.
I only would have appreciated more how Rajeev and I hadn’t come any closer to The Grail. This was yet another surprise: that not every part of the frontier is equally earthshaking and that some are sort of trivial. Despite how knotty our project seemed to me, our conclusions were of extraordinarily limited scope.
“Quantum Gravity on a Circle …”
The paper we wrote did indeed flesh out a consistent theory of quantum gravity, one in which the concept of distance is defined by the phase of a quantum mechanical wavefunction. It even predicted black holes. But—and this is a very big but—the theory could only be true in a hypothetical one-dimensional universe that’s shaped like a ring, in other words a world nothing at all like the three-dimensional one in which you and I live, pay taxes, and die.
What we’d created is called a “toy model”: an exact solution to an approximate version of an actual problem. This, I learned, is what becomes of a colossal conundrum like quantum gravity after 70-plus years of failed attempts to solve it. All the frontal attacks and obvious ideas have been tried. Every imaginable path has hit a dead end. Therefore researchers retreat, set up camp, and start building tools to help them attempt more indirect routes. Toy models are such tools. Rajeev’s river almost certainly didn’t run to The Grail. The hope was that some side stream of one of its many tributaries (Virasoro, Yamabe …) would.
Actually that was my hope, not Rajeev’s. Rajeev, I believe, just liked doing the math. The thing was a puzzle he could solve, so he solved it. For him that was enough.
[a](as far as I can tell, the work of the Professor described above is a fad and has no real physical content either, although he's now working with data somehow)
[b]many such cases. such is life in the academic industrial complex as of late. 'publish or perish', 'demo or die', not 'think free or die'
[c]how does this extend to frontier labs, neolabs and the labs that are in the bottom 80%
[d]it gets very dark very fast when you venture away from the highest ivory towers tbh
[e]hey some ppl rlly love physics and experimental/applied physics.
my friend harish ramachandran made a name for himself designing an incredibly odd but effective experiment for measuring some time symmetry-charge parity violation constant in in the standard model.
on a table top.
in an atomic/molecular/optimal physics laboratory in the basement of utoronto.
perhaps this claim is more a statement as to *your* particular inclination towards mathematics rather than their intrinsic "fun-ness".
note also that different fields go thru 'golden ages' at different times (periods of rapid progress). that guy who talks about periods of 'revolutionary science' (kuhn i think) points to this. That said, never trust a philosopher of science who does not love the history of science at least as much as philosophizing!
[f]Great book
[g]now reading glass bead game
[h]it is rare to understand physics in most places.
caltech kinda goated in terms of physics understander density.
[i]engsci forces all the kids to do at least some quantum/modern/relativistic physics in addition to like maxwell and newton and lagrange and the classic gang.
and the engsci physics ppl get to hang out a lot in applied physics labs and in pretty wide range of upper level+grad math/physics
courses for a few years.
but yes. most graduate students seem to not understand a ton of physics.