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A bestiary of exotic hadrons

(cerncourier.com)
152 points rbanffy | 5 comments | 20 Dec 24 15:29 UTC | HN request time: 0s | source
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FabHK ◴[20 Dec 24 16:36 UTC] No.42472523[source]▶
Do we have anomalies accumulating here that indicate the early phase of a scientific revolution in Thomas Kuhn's terminology, that is, a replacement of the standard model/QCD? Or is it still "so far, so good"?
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drpossum ◴[20 Dec 24 16:54 UTC] No.42472672[source]▶
Do you feel like those two options would cover all possible scenarios for "the state of the field"?
replies(1): >>42473208 #
anyfoo ◴[20 Dec 24 17:56 UTC] No.42473208[source]▶
Well, either the standard model is right, or it isn't, isn't it? They asked for indication of an "early phase", not that we're ready to throw the standard model out (which, boringly, held up extremely well so far).
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whatshisface ◴[20 Dec 24 18:13 UTC] No.42473343[source]▶
The standard model Lagrangian is a sum of many terms, and changing one of them, adding a new one or even a radical revolution in our understanding of the results of integrals taken over it would not count as a Kuhnian revolution. Physics has not had one of those since Newton.
replies(1): >>42474043 #
Keysh ◴[20 Dec 24 19:22 UTC] No.42474043{3}[source]▶
Physics has obviously had Kuhnian revolutions since Newton, the emergence of relativity and quantum mechanics being two obvious examples.
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whatshisface ◴[20 Dec 24 20:28 UTC] No.42474705{4}[source]▶
Physics advances like geography: there's a New World in the Americas, but Libson is still there. Newtonian mechanics remains as the consequence of relativity and quantum mechanics where we "live," and the existence of other things under different conditions doesn't change that. Kuhnian revolutions involve the old models being discarded.
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shwouchk ◴[20 Dec 24 21:01 UTC] No.42474978{5}[source]▶
We did "discard" newtonian gravity and mechanics in favor of sr,gr and qm as fundamental theories. They still give good approximations over a wide range of conditions so we keep using them for calculations.
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1. whatshisface ◴[20 Dec 24 21:12 UTC] No.42475085{6}[source]▶
I wouldn't call it discarded if it's still used for everything it used to be used for, while also being a logical implication of the new theories
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2. shwouchk ◴[21 Dec 24 00:26 UTC] No.42476489[source]▶
it’s a necessarily a logical implication that this theory would be a good approximation at certain scales just by the sheer fact that it used to be a theory that fit observations at some point. That is also true of “completely incorrect” theories like heliocentricity.

In the case of NM we happened to have something that is often also computationally simple and efficient so we keep using it, but it is by no means a “correct theory”. just a useful model that is still useful.

i daresay it will continue to be useful for some things even if we eg discover that we are living in a simulation and manage to escape! As long as some part of us will continue to experience this reality it will be useful - the math is simple and gives good approximations in many cases.

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3. shwouchk ◴[21 Dec 24 00:32 UTC] No.42476514[source]▶
maybe a clearer case - the “planetary” model of electrons floating around the nucleus is useful in chemistry and is still taught in grade school, but i would definitely call it “discarded” in that no one doing research in the field would use that - it’s just a useful model for “engineering” practitioners
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4. XorNot ◴[21 Dec 24 05:14 UTC] No.42477688{3}[source]▶
I wouldn't say it's useful in chemistry. Chemistry at any basic level is deeply concerned with the shape of the probability fields of electrons around a nucleus since it's the dominant contribute to the shape of molecules and strength of bonding.

EDIT: Like ironically I would say the planetary model has 1 unique utility, which is that for hydrogen-NMR it's useful to just assume that 1 electron is producing a little magnetic field like a Bohr model atom.

replies(1): >>42480442 #
5. shwouchk ◴[21 Dec 24 16:12 UTC] No.42480442{4}[source]▶
im less interested in having a pedantic argument online regarding exact meaning of useful and exactly for what. the bottom line with this example is that its a useful model for some things and therefore still is taught in science classes today as a “correct” description just like NM, both of which which are not, fundamentally.

Take it or leave it :-)