Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Muon G-2 Experiment at Fermilab Finds Hint of New Particles

quantamagazine.org

Post reply on HN
Print view View original

31–40 of 65 posts

Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#31

Post by idolaspecus »

whimsicalism wrote: post #18
DrBazza wrote: post #13

Regardless of whether this is a real result, I always had trouble "trusting" the "Standard Model" when I was at university. There are too many knobs to twiddle, and levers to pull in order to get the results. The mathematics is non-trivial. Just reading the article gives you an idea of how difficult it is to make predictions from the model. Compare it to this comment about General Relativity: "Widely acknowledged as…

It doesn't seem obvious that the fundamental models of reality would just happen to match up with the mathematical constructs that we humans have come up with.

On the flip side, it wouldn't be entirely surprising if mathematical constructs that we have thought of are in fact very good models of fundamental reality. We should remember that, after all, nothing exists outside of fundamental reality, and if certain basic patterns can be encoded such that the encoding is both high-fidelity and simple, that won't be shocking. It might be awe-inspiring, but not really surprising.

Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#32

Post by ISL »

mseepgood wrote: post #30
ISL wrote: post #10

Earlier quoted context omitted.

Physicist here: 1. One should be rather specific about what 'the complete foundation' might comprise. The depth of questions one can ask is infinite, but some questions are more important than others. The g-2 experiment is asking a specific question: "Does the anomalous magnetic moment of the muon open a door to discoveries that are inaccessible with modern colliders?" It is tempting to regard fundamental physics as…

> It is tempting to regard fundamental physics as a study of "Why are we here?", but it is really a study of "How are we here?" The difference is subtle but substantial. If "Why?" is what you're seeking, you are more likely to find that answer within, rather than within the study of physics. I don't want to know why, I just want to know the complete set of rules at the lowest level.

It is unlikely that we will ever grasp the complete set of rules at the lowest level. I don't say this to be defeatist, but rather as a statement of pragmatism.

To do so would be to have a convincing grasp of Planck-scale physics -- a detailed understanding of physics at and above energy-densities reached in the Big Bang. Some precision experiments and astrophysical measurements do constrain certain Planck-scale models, but a true test of whether or not we understand early-universe physics is likely to necessitate creating a few Big Bangs ourselves. Doing so, with known technology, seems impossible. If it were possible, doing so would seem fraught with actual risk.

(N.B. for the non-expert reader: there are cosmic rays that strike the Sun at least once every five minutes (and Earth, at least once a month) with energies 10,000,000 times greater than anything humans have ever achieved. Those collisions, over the last 4,500,000,000 years, have not yet resulted in the disruption of spacetime or the formation of a black hole. You are very, very, very safe from physicists breaking the universe as you know it. :).)

Edit to add: You, mseepgood, aren't alone in your desire for knowledge. One Stephen Hawking once stated, “My goal is simple. It is a complete understanding of the universe, why it is as it is and why it exists at all.”

Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#33

Post by refulgentis »

ISL wrote: post #32
mseepgood wrote: post #30

Earlier quoted context omitted.

> It is tempting to regard fundamental physics as a study of "Why are we here?", but it is really a study of "How are we here?" The difference is subtle but substantial. If "Why?" is what you're seeking, you are more likely to find that answer within, rather than within the study of physics. I don't want to know why, I just want to know the complete set of rules at the lowest level.

It is unlikely that we will ever grasp the complete set of rules at the lowest level. I don't say this to be defeatist, but rather as a statement of pragmatism. To do so would be to have a convincing grasp of Planck-scale physics -- a detailed understanding of physics at and above energy-densities reached in the Big Bang. Some precision experiments and astrophysical measurements do constrain certain Planck-scale mode…

dumb q I was never smart enough to ask when I was doing a physics degree: how do we know the big bang required enormous energy and thus is impossible? in the few peeks we got at grad school physics, I walked with away with the likely erroneous impression that the best guess was the big bang happened due to "quantum fluctuations in a vacuum" which sounded suspiciously close to "at random" - and I won't lie, since, I've just assumed that at any point there could be another big bang and we'd be blown away!

Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#34

Post by peteradio »

fasteddie31003 wrote: post #25

Question for physicists: Are the G-2 results more groundbreaking than discovering the Higgs particle to moving physics forward?

If physics is climbing a mountain.

G-2 result is seeing the next hand hold (hoping its not a mirage).

Higgs discovery and its subsequent precision measurement is resting your toe into a hold and flexing your calf upwards.

Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#35

Post by Diederich »

fasteddie31003 wrote: post #25

Question for physicists: Are the G-2 results more groundbreaking than discovering the Higgs particle to moving physics forward?

I'm not a physicist, I just pay some attention to these things.

The Higgs particle was expected, and so finding it within expected ranges was confirmation of the standard model.

The G-2 results are showing deviations from the expected ranges from the standard model.

In the former case, Higgs, the standard was further, strongly confirmed. In the latter case, G-2, there's a strong indication that the standard model is fundamentally missing something.

I think that's pretty exciting!

Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#36

Post by willis936 »

DrBazza wrote: post #13

Regardless of whether this is a real result, I always had trouble "trusting" the "Standard Model" when I was at university. There are too many knobs to twiddle, and levers to pull in order to get the results. The mathematics is non-trivial. Just reading the article gives you an idea of how difficult it is to make predictions from the model. Compare it to this comment about General Relativity: "Widely acknowledged as…

Nature doesn't care how complicated it is. A bias towards beauty is a trap that any serious scientist will not fall for.

https://www.youtube.com/watch?v=xFKgIOX8IRE

Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#37

Post by ISL »

refulgentis wrote: post #33
ISL wrote: post #32

Earlier quoted context omitted.

It is unlikely that we will ever grasp the complete set of rules at the lowest level. I don't say this to be defeatist, but rather as a statement of pragmatism. To do so would be to have a convincing grasp of Planck-scale physics -- a detailed understanding of physics at and above energy-densities reached in the Big Bang. Some precision experiments and astrophysical measurements do constrain certain Planck-scale mode…

dumb q I was never smart enough to ask when I was doing a physics degree: how do we know the big bang required enormous energy and thus is impossible? in the few peeks we got at grad school physics, I walked with away with the likely erroneous impression that the best guess was the big bang happened due to "quantum fluctuations in a vacuum" which sounded suspiciously close to "at random" - and I won't lie, since, I'v…

I think the safest answer regarding the Big Bang is that we don't really understand the mechanism. In particular, anything regarding inflation stands on truly dubious ground (It gets the necessary outcomes right, but we have no presently-testable theory regarding the mechanism. Any mechanism that does must defy the laws of physics as we know them).

I can't pretend to be an expert here, but the quantum-fluctuations in a vacuum that we all experience at all times do, over longer times ("long" here is generally unfathomably short), need to satisfy energy-conservation. To do otherwise requires paying an overwhelming probabilistic cost (a much bigger nigh-infinity than your garden-variety nigh-infinity). If you're worried about unexpected instantaneous death from the universe, I would argue that one should be far more concerned with, say, a gamma-ray burst nearby from within the galaxy (or, far more likely yet, a nuclear war) than being overrun by a Big-Bang-like event.

For that same reason (energy conservation), perhaps the central question one might ask of the Big Bang theory is, "How did it come to pass that all of that energy wound up in such a tiny volume?" There are plenty of theories out there, the best of which attempt to confront inflation at the same time, but I am unaware of a clear leader.

I don't mean to entirely disregard the importance of quantum fluctuations in cosmology. Indeed, the large-scale structure of the cosmic-microwave background is very consistent with pure quantum fluctuation, as if the fluctuations of a tiny volume of space had been magnified to cosmic scale. It is simply this experimentalist's opinion that there is probably substantially more to the story than the universe having won the lottery of all lotteries in order to exist at all.

Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#39

Post by quantum_mcts »

fasteddie31003 wrote: post #25

Question for physicists: Are the G-2 results more groundbreaking than discovering the Higgs particle to moving physics forward?

Physicist. Some people in the community are quite excited because it hints at something beyond SM. The problem is that the quoted theoretical prediction for g-2 is not a settled issue and is a subject of a long controversy between various groups of theorists. https://physics.stackexchange.com/a/627852/386

Re: Muon G-2 Experiment at Fermilab Finds Hint of New Particles

#40

Post by whimsicalism »

willis936 wrote: post #36
DrBazza wrote: post #13

Regardless of whether this is a real result, I always had trouble "trusting" the "Standard Model" when I was at university. There are too many knobs to twiddle, and levers to pull in order to get the results. The mathematics is non-trivial. Just reading the article gives you an idea of how difficult it is to make predictions from the model. Compare it to this comment about General Relativity: "Widely acknowledged as…

Nature doesn't care how complicated it is. A bias towards beauty is a trap that any serious scientist will not fall for. https://www.youtube.com/watch?v=xFKgIOX8IRE

A bias towards "beauty" or simplicity of some form is inevitable and part of good science.

For every theory, you can generate a more complicated theory with more moving parts that generates the exact same predictions. For instance, my theory of gravity is the same as general relativity, except that at 3 PM April 9th, 2021, all gravity will be reversed.

You have to appeal to some principle to sort out such theories from good descriptions of how the world works.

Post reply on HN