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I think the video's thesis is overstated; in this video Hossenfelder makes it sound like there are no (real) problems with the Standard Model and therefore no n

I think the video's thesis is overstated; in this video Hossenfelder makes it sound like there are no (real) problems with the Standard Model and therefore no necessary reason to postulate any new particles. While I agree completely with Hossenfelder about "pseudo-problems" such as the hierarchy problem not being real problems in need of a solution, my understanding is that there is at least one real problem and the solution may require new particles. Specifically, neutrino oscillation is experimentally confirmed, but my understanding is that you can't just bolt it on to the Standard Model without getting inconsistencies unless you make one of the following two changes: Either make neutrinos their own antiparticles, or introduce sterile neutrinos. That seems like a pretty good reason to look for sterile neutrinos! Also, I have to disagree with what she says about dark matter (or modified gravity, the distinction is irrelevant here -- both presumably introduce new particles); to say "All we need to know is the distribution of it so we can make predictions, who cares what it actually consists of?"... to my mind the point of fundamental physics should be to build a complete model of the laws of physics, and that sort of instrumentalism is just giving up. (We can also generalize from this to other cases where problems from cosmology or other areas of physics would seem to require explanations from particle physics, e.g., baryogenesis, since the Standard Model doesn't seem to produce enough CP-violation to explain that. I don't think it makes sense to exclude such indirect evidence from other fields when we speak of tests of the standard model.) None of this is to disagree that there's a lot of work on what Hossenfelder calls "pseudo-problems", which I agree seems to have produce a lot of failed predictions for little reason.

davrosthedalek 4y ago
Well, as you indicate, you think that some of the problems she labels as pseudo are not pseudo. But who is to decide which are pseudo problems, and which are not? And you are absolutely right about the "who cares" stance. If our estimates of DM and dark energy are right, only 5% or so of total energy in the universe is in SM physics (visible matter). How can we be satisfied with that?
- Sniffnoy 4y ago
  The distinction is easy to make because she draws a pretty bright line, one I agree with. The video doesn't mistakenly class the problem I mentioned as a pseudo-problem; rather, it fails to discuss it at all. Hossenfelder is pretty clear that internal inconsistencies are real problems. The problems she dismisses as pseudo-problems are attempts to explain the values of free parameters or otherwise try to explain the "origin" of the laws of physics. This doesn't fall under that.
  - consilient 4y ago
    > The problems she dismisses as pseudo-problems are attempts to explain the values of free parameters This is begging the question. Of course explaining the values of free parameters is a hopeless endeavor (it's in the name), but we don't actually know which parameters are free. We know which parameters are free in the standard model - but the standard model is just an effective theory. Radical instrumentalists like Hossenfelder might be satisfied with that, but a scientific realist shouldn't be.
    - Sniffnoy 4y ago
      Yeah, the whole thing with the Standard Model being only an effective theory is a definite issue, that's a good point. Actually Hossenfelder seems to more or less agree with this in the blog post she links? http://backreaction.blogspot.com/2019/01/good-problems-in-foundations-of-physics.html http://backreaction.blogspot.com/2019/01/good-problems-in-fo... (I'm looking at the section titled "Quantum Field Theory" and taking the problem it expresses as being essentially the same.) But, I'm not sure this really addresses the point? Like, as I see it, the basic question here is, which problems sufficiently require resolution that looking for that resolution is likely to bear fruit? And it's hard to see how "certain particle masses (or other seemingly-free parameters) seem small/large" qualifies. Small or large by what standard? It's a lot smaller/larger than 1? OK, but what's "a lot"? Who's setting the scale here? Ultimately the universe's scale is the only one that matters here, and if we find its numbers unusually "small" or "large" that's just a matter of incorrect expectations on our part! Like, if you want to say we should be looking for axions or magnetic monopoles on the grounds that a literal zero is suspicious, then, sure, I guess zero is fairly special and suggestive. But I don't see that there's any sense in trying to find explanations for numbers being "unusually small" or "unusually large" when there's nothing but our own expectations to mark these magnitudes as "unusual".

davrosthedalek 4y ago

Well, as you indicate, you think that some of the problems she labels as pseudo are not pseudo. But who is to decide which are pseudo problems, and which are not? And you are absolutely right about the "who cares" stance. If our estimates of DM and dark energy are right, only 5% or so of total energy in the universe is in SM physics (visible matter). How can we be satisfied with that?

Sniffnoy 4y ago
The distinction is easy to make because she draws a pretty bright line, one I agree with. The video doesn't mistakenly class the problem I mentioned as a pseudo-problem; rather, it fails to discuss it at all. Hossenfelder is pretty clear that internal inconsistencies are real problems. The problems she dismisses as pseudo-problems are attempts to explain the values of free parameters or otherwise try to explain the "origin" of the laws of physics. This doesn't fall under that.
- consilient 4y ago
  > The problems she dismisses as pseudo-problems are attempts to explain the values of free parameters This is begging the question. Of course explaining the values of free parameters is a hopeless endeavor (it's in the name), but we don't actually know which parameters are free. We know which parameters are free in the standard model - but the standard model is just an effective theory. Radical instrumentalists like Hossenfelder might be satisfied with that, but a scientific realist shouldn't be.
  - Sniffnoy 4y ago
    Yeah, the whole thing with the Standard Model being only an effective theory is a definite issue, that's a good point. Actually Hossenfelder seems to more or less agree with this in the blog post she links? http://backreaction.blogspot.com/2019/01/good-problems-in-foundations-of-physics.html http://backreaction.blogspot.com/2019/01/good-problems-in-fo... (I'm looking at the section titled "Quantum Field Theory" and taking the problem it expresses as being essentially the same.) But, I'm not sure this really addresses the point? Like, as I see it, the basic question here is, which problems sufficiently require resolution that looking for that resolution is likely to bear fruit? And it's hard to see how "certain particle masses (or other seemingly-free parameters) seem small/large" qualifies. Small or large by what standard? It's a lot smaller/larger than 1? OK, but what's "a lot"? Who's setting the scale here? Ultimately the universe's scale is the only one that matters here, and if we find its numbers unusually "small" or "large" that's just a matter of incorrect expectations on our part! Like, if you want to say we should be looking for axions or magnetic monopoles on the grounds that a literal zero is suspicious, then, sure, I guess zero is fairly special and suggestive. But I don't see that there's any sense in trying to find explanations for numbers being "unusually small" or "unusually large" when there's nothing but our own expectations to mark these magnitudes as "unusual".