I am looking for collaborators on exploring whether geometric principles might provide a foundation for understanding how aspects of the Standard Model could emerge from simpler underlying structures. This is obviously an incredibly challenging area that many brilliant physicists have worked on, so approaching it as a learning exercise - happy to share details if anyone's interested in diving into theoretical physics rabbit holes. bufferoverflow (at) gmail.com
jiggawatts · 4h ago
The reason this is big news is that modern physics theories such as quantum electrodynamics and the Standard Model can be used to calculate certain measurements such as the anomalous magnetic moment of the electron to absurdly high precision, with prediction and experiment differing in only about one part per ten billion.
Run the same calculations for the Muon, and... err... not so good, previously differing by 3.5 standard deviations.
Either the theory is wrong, or the experiments are wrong. The former is very interesting, because Muons are easy to experiment on, and if we can find "new physics" in something so ordinary, then it's an "accessible" regime for conditions that can be reproduced in a lab (albeit a big one).
This paper is saying that the discrepancy has been solved by using a more fancy set of computations and newer experiments at Fermilab.
In other words: No new exciting physics.
Still though, this is interesting because a mystery was solved, even if the answer is in some sense boring.
JumpCrisscross · 2h ago
The promise of new science from a muon collider [1] is compelling.
The idea of a medically relevant neutrino dose is absolutely wild
JumpCrisscross · 1h ago
Emphasis on "kinda." These are mitigatable concerns, not roadblocks.
jxjnskkzxxhx · 2h ago
Thank you for going against the anti-intelectualism that is so prevalent on HN.
kayo_20211030 · 3h ago
Interesting. Quick, what's the correct response to the statement: "the standard model is wrong"? Generally, it's "it's not". Maybe it will be some day wrong, but glad to know it still holds.
staunton · 3h ago
At this point, "the standard model" basically means "state of the art particle physics without highly speculative stuff". People tell me that neutrino masses are part of the standard model now...
So if the standard model is wrong, long live the right standard model. At least, perhaps until it takes a completely new paradigm to go further.
JumpCrisscross · 2h ago
> People tell me that neutrino masses are part of the standard model now
People say stupid things. It’s a bit silly to blame that on the model.
staunton · 2h ago
Ok, how many free parameters are in the standard model?
Ask five random physics professors, insist on an answer while declining to answer questions for clarification. I guarantee you get at least two answers, maybe three (that's assuming you manage to get an answer from each...). See also people giving various possible answers on physics stack exchange...
JumpCrisscross · 2h ago
You’re acting like the SM is an unfalsifiable string theory that just revises all of its parameter every time the last batch is disproven. It’s not.
SM is not fully developed. And we know where it is wrong or painfully silent, e.g. neutrinos and gravity. But it’s a rigorous theory, possibly the most rigorous our species has ever developed, with central tenets that have held to ridiculous levels of precision. Of course there are conflicting hypotheses at its frontier. That’s sort of what defines the frontier. But at its core, the SM is robust. So robust that we mostly don’t talk about it, obsessing—as science should—with the parts where it doesn’t fit together as perfectly.
staunton · 2h ago
I'm saying that the standard model is evolving and there's no authority or institution that gets to definine what "the standard model" means. All of this is completely reasonable.
Maybe it can evolve forever to accommodate new results (e.g. by adding new fields), likely it can't (it's hard to imagine a reasonable modification for breaking CPT symmetry, not that this is the best example). If at any point noone can figure out how to evolve it before a radically different theory emerges to explain current discrepancies, we'll have what Kuhn might call a "paradigm shift", say "the standard model is falsified", and invent a different name for the new theory. I even included this possibility in my original comment, so I'm not sure what gave you offense...
That's completely unrelated to any given instance of this evolution being falsifiable. Each of them is, they stick around for a while and there aren't that many. All very proper, Popper is happy.
Meanwhile, string theory hasn't produced a single prediction that was later observed experimentally and one can even argue whether it has produced any predictions at all...
JumpCrisscross · 1h ago
> the standard model is evolving and there's no authority or institution that gets to definine what "the standard model" means
The standard model per se is not materially evolving. We're bolting extensions onto it. And there is disagreement over what those extensions mean, whether they're true, and what free parameters they may add.
> Maybe it can evolve forever to accommodate new results (e.g. by adding new fields)
The Higgs field was the last field to have been "added" to the model. Its existence wasn't prompted by experimentation, but vice versa.
avpix · 2h ago
19, each corresponding to a physical quantity that can be measured.
Could you help me with which variable we should focus on?
AnimalMuppet · 1h ago
If you decline to answer questions for clarification, it seems fair that they should decline to answer your question.
tmiku · 2h ago
I agree that it's not wrong, but I would certainly call it incomplete too. It's your choice which of those two points you want to emphasize, but calling the Standard Model "not wrong" with no mention of its incompatibility with General Relativity would feel disingenuous to me.
EA-3167 · 2h ago
"All models are wrong, but some are useful."
or
Granted, but good luck trying to find a new model that matches the tested predictions QM/SM makes, AND reveals new physics you can hope to test.
Run the same calculations for the Muon, and... err... not so good, previously differing by 3.5 standard deviations.
Either the theory is wrong, or the experiments are wrong. The former is very interesting, because Muons are easy to experiment on, and if we can find "new physics" in something so ordinary, then it's an "accessible" regime for conditions that can be reproduced in a lab (albeit a big one).
This paper is saying that the discrepancy has been solved by using a more fancy set of computations and newer experiments at Fermilab.
In other words: No new exciting physics.
Still though, this is interesting because a mystery was solved, even if the answer is in some sense boring.
[1] https://arxiv.org/abs/2303.08533
So if the standard model is wrong, long live the right standard model. At least, perhaps until it takes a completely new paradigm to go further.
People say stupid things. It’s a bit silly to blame that on the model.
Ask five random physics professors, insist on an answer while declining to answer questions for clarification. I guarantee you get at least two answers, maybe three (that's assuming you manage to get an answer from each...). See also people giving various possible answers on physics stack exchange...
SM is not fully developed. And we know where it is wrong or painfully silent, e.g. neutrinos and gravity. But it’s a rigorous theory, possibly the most rigorous our species has ever developed, with central tenets that have held to ridiculous levels of precision. Of course there are conflicting hypotheses at its frontier. That’s sort of what defines the frontier. But at its core, the SM is robust. So robust that we mostly don’t talk about it, obsessing—as science should—with the parts where it doesn’t fit together as perfectly.
Maybe it can evolve forever to accommodate new results (e.g. by adding new fields), likely it can't (it's hard to imagine a reasonable modification for breaking CPT symmetry, not that this is the best example). If at any point noone can figure out how to evolve it before a radically different theory emerges to explain current discrepancies, we'll have what Kuhn might call a "paradigm shift", say "the standard model is falsified", and invent a different name for the new theory. I even included this possibility in my original comment, so I'm not sure what gave you offense...
That's completely unrelated to any given instance of this evolution being falsifiable. Each of them is, they stick around for a while and there aren't that many. All very proper, Popper is happy.
Meanwhile, string theory hasn't produced a single prediction that was later observed experimentally and one can even argue whether it has produced any predictions at all...
The standard model per se is not materially evolving. We're bolting extensions onto it. And there is disagreement over what those extensions mean, whether they're true, and what free parameters they may add.
> Maybe it can evolve forever to accommodate new results (e.g. by adding new fields)
The Higgs field was the last field to have been "added" to the model. Its existence wasn't prompted by experimentation, but vice versa.
https://en.wikipedia.org/wiki/Mathematical_formulation_of_th...
or
Granted, but good luck trying to find a new model that matches the tested predictions QM/SM makes, AND reveals new physics you can hope to test.