I read a 2002 book on the Standard Model in 2021…after all these years what changed? Not much if we except Fermilab’s g-2 experiment. The experimental results are being widely quoted as 4.2 sigma, against the 'consensus' Standard Model theory - with the higher loop order correction from the strong nuclear force estimated from the R ratio in electron/positron collisions. Using lattice QCD, the latest results are much closer to the observed experimental values. I'm still trying to find a quoted sigma.... if I were cynical, I'd point out that yelling 'new Physics' gets a lot more funding than 'let's buy some more supercomputer runtime for quantum lattice simulations'. Check out the error bars in a Forbes and Nature articles.

The odds it is just a `fluke` result at 4.2 sigma.

I found this:

"The findings have reached the threshold of 4.2 sigma uncertainty, close to the "gold standard" level of certainty in scientific evidence of 5 sigmas, but not quite there yet. It still means that there's a 3-in-100,000 chance that this is a fluke."

Now we have string theory, useless but not discarded. Or M-theory, even more useless. Other completely useless theories like loop quantum gravity are still in competition, but the race for the Grand Useless Theory of total uselessness is still being run. A lot of theories are being discarded because they are being shown to have some usefulness, even if only in ten-dimensional conical manifolds with three time dimensions. But even in such a nonsensical case, if you make any prediction you get disqualified. The hope is to come up with an overarching theory that can explain everything imaginable and thus reach maximum uselessness. There's some noise coming from MIT that they may have finally achieved 'uselessness supremacy', as it's called.

The Standard Model is a map, not the territory. There are large areas still marked "Here be dragons..." But for the bits of it that make sense it will always be useful. Particle physicists know that the Standard Model as we have it is not the "final" theory. Ask any of them. They're always excited when something doesn't fit. The new g-2 data, and the B physics results some months ago, seem to suggest something new. That's cool!

Of course, recent (and in some cases not so recent) developments in M-Theory make this book rather dated to say the least. ( )