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152 points rbanffy | 13 comments | | HN request time: 0.001s | source | bottom
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FabHK ◴[] 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"?
replies(3): >>42472672 #>>42473315 #>>42473325 #
drpossum ◴[] 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 ◴[] 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).
replies(1): >>42473343 #
1. whatshisface ◴[] 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 #
2. Keysh ◴[] No.42474043[source]
Physics has obviously had Kuhnian revolutions since Newton, the emergence of relativity and quantum mechanics being two obvious examples.
replies(1): >>42474705 #
3. whatshisface ◴[] No.42474705[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.
replies(3): >>42474978 #>>42476053 #>>42476398 #
4. shwouchk ◴[] No.42474978{3}[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.
replies(1): >>42475085 #
5. whatshisface ◴[] No.42475085{4}[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
replies(1): >>42476489 #
6. libraryofbabel ◴[] No.42476053{3}[source]
If you read Kuhn's book, you'll see he uses quantum mechanics as one of his examples of a scientific revolution. I mean, you might think he's wrong, but that's stretching the definition of "Kuhnian Revolution" a bit. And sure, Newtonian mechanics might come out in the classical limit, but the probabilistic aspect of QM alone represents a completely different way of viewing the universe than the Newtonian model.
replies(1): >>42476091 #
7. whatshisface ◴[] No.42476091{4}[source]
I do think Khun is wrong under his own definitions. Quantum amplitudes are over mechanical possibilities, and they no more overturn them than icing overturns cake. :-)
replies(1): >>42477531 #
8. Keysh ◴[] No.42476398{3}[source]
From Chapter VII of Thomas Kuhn, The Structure of Scientific Revolutions (https://www.lri.fr/~mbl/Stanford/CS477/papers/Kuhn-SSR-2ndEd...):

"If awareness of anomaly plays a role in the emergence of new sorts of phenomena, it should surprise no one that a similar but more profound awareness is prerequisite to all acceptable changes of theory. On this point historical evidence is, I think, entirely unequivocal. The state of Ptolemaic astronomy was a scandal before Copernicus’ announcement. Galileo’s contributions to the study of motion depended closely upon difficulties discovered in Aristotle’s theory by scholastic critics. Newton’s new theory of light and color originated in the discovery that none of the existing pre-paradigm theories would account for the length of the spectrum, and the wave theory that replaced Newton’s was announced in the midst of growing concern about anomalies in the relation of diffraction and polarization effects to Newton’s theory. Thermodynamics was born from the collision of two existing nineteenth-century physical theories, and quantum mechanics from a variety of difficulties surrounding black-body radiation, specific heats, and the photoelectric effect.4 Furthermore, in all these cases except that of Newton the awareness of anomaly had lasted so long and penetrated so deep that one can appropriately describe the fields affected by it as in a state of growing crisis."

Later in the same chapter, he gives three examples of crises that led to paradigmatic revolutions: "a particularly famous case of paradigm change, the emergence of Copernican astronomy."; "the crisis that preceded the emergence of Lavoisier’s oxygen theory of combustion"; and "the late nineteenth century crisis in physics that prepared the way for the emergence of relativity theory."

Kuhn absolutely considered relativity and quantum mechanics to be examples of paradigmatic revolutions, just like Newtonian mechanics in the 17th Century and the earlier Copernican revolution.

If you want to argue that Kuhn was wrong about history, then you can do that (and I would at least partly agree); but if you want to claim Kuhn didn't say what he actually said, that's a different matter.

9. shwouchk ◴[] No.42476489{5}[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.

replies(1): >>42476514 #
10. shwouchk ◴[] No.42476514{6}[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
replies(1): >>42477688 #
11. ordu ◴[] No.42477531{5}[source]
I think you make a mistake when you look at physics with your modern eyes. Knowledge should make you see more, but this is the case when it makes it hard to see the history. Try to look at it with eyes of 19 centuries physicist.

Physics was all deterministic and objective. And then comes QM saying that there is no determinism and about the role of an observer, and comes GR saying there is no objective observer, because different observers can't agree about time and length.

I heard that physics professors in 19 century told their students that they had chosen the wrong career because physics was almost done. There were slight difficulties with electromagnetism, but they surely is going to be resolved in coming years. And then all that shiny and almost complete physics was blown up because very foundations of it were destroyed.

It was a paradigm shift. If it wasn't then what is? Copernicus? But the Ptolemaic astronomy did work and it works today. With its limitations of course, but it works. You can calculate positions of heavenly bodies with epicycles. Galilean laws of motions? But the laws of Aristotle works no worse then when Aristotle invented them.

12. XorNot ◴[] No.42477688{7}[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 #
13. shwouchk ◴[] No.42480442{8}[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 :-)