This is a philosophical topic. The professional title of the person who writes about “naturalness” does not change the fact that the topic is a philosophical topic. The topic is philosophical and it is independent of the professional title of the person who writes about this topic. If the person who writes about naturalness in particle physics is a physicist this does not make the topic physics but makes the physicist a philosopher.
Sabine Hossenfelder writes that “naturalness, [is] an idea that has become a prominent doctrine in particle physics. In brief, naturalness requires that a theory’s dimensionless parameters should be close to 1, unless there is an explanation why they are not. […] Assuming a probability distribution for the parameters at high energies, you can then quantify the likelihood of finding a theory with the parameters we do observe. If the likelihood is small, the theory is said to be “unnatural” or “finetuned”. The mass of the Higgs-boson is unnatural in this sense, so is the cosmological constant, and the theta-parameter.”
So physicists need to invent philosophical mumbo jumbo in order to call that old ad hoc term, the cosmological constant, “unnatural.” What can be more pathetic than physicists discussing this ad hoc term they dubbed “cosmological” and “constant” for over a century. Cosmological constant is neither cosmological nor a constant but an ad hoc parameter. These physicists, don’t they have anything more substantial to discuss?
The second, and newer, type of naturalness, is based on the idea that our universe is one of infinitely many that together make up a “multiverse.” In this case, if you assume a probability distribution over the universes, you can calculate the likelihood of finding the parameters we observe. Again, if that comes out to be unlikely, the theory is called “unnatural.” This approach has so far not been pursued much. Particle physicists therefore hope that the standard model may turn out to be natural in this new way.
Physicists discuss naturalness of theories they invent by assuming that “our universe is one of infinitely many that together make up a “multiverse.” Why? “In this case, if you assume a probability distribution over the universes, you can calculate the likelihood of finding the parameters we observe. Again, if that comes out to be unlikely, the theory is called ‘unnatural.'”
Not sure if this is a parody of philosophy or if it is a parody of physics. I guess this is what happens if people who spend their education –a very long education, about 25 years– to study how to solve differential equations and make calculations by using 18th century methods and spending years and years learning data analysis techniques and bad programming but study zero –yes, zero– hours of philosophy but when they grow up and start writing papers they write bad philosophy or physicophilosophical mumbo jumbo and call it physics! These physicists are real jokes. Their professional title is Doctor of Philosophy but their knowledge of philosophy is nada, zilch. For a physicist philosophy is any topic that falls outside of legal physics tropes he is familiar with. Their professional titles should really be “Doctors of Data Reduction and Calculation”. Because this is what they learn to do. Even their philosophy is about calculation. To find out if a theory they invented is natural they compute some probability in potential hypothetical universes that may exist only to make the theories they invented natural.
Well, I have to give credit to Sabine Hossenfelder. I was writing the above as I was reading her article paragraph by paragraph but then I saw that she ridicules and destroys these naturalness arguments so eloquently that I cannot hope to match even if clones of myself wrote about the topic in infinity of multiverses for infinity of time dimensions invented by Lisa Randalls of physics.
Ms. Hossenfelder writes: “The biggest problem, however, is the same for both types of naturalness: You don’t have the probability distribution and no way of obtaining it because it’s a distribution over an experimentally inaccessible space. To quantify naturalness, you therefore have to postulate a distribution, but that has the consequence that you merely get out what you put in. Naturalness arguments can therefore always be amended to give whatever result you want.”
Damn these phyisicists! They are not only sharlatans but they are crooks too:
“And that really is the gist of the current trend. The LHC data has shown that the naturalness arguments that particle physicists relied on did not work. But instead of changing their methods of theory-development, they adjust their criteria of naturalness to accommodate the data. This will not lead to better predictions.”
How did this happen? How did we allow these crooks corrupt the old science of physics into this state of corruption? Who is responsible? What can we do to cleanse academic physics from these useless and unnaturally bad philosophers who posture as physicists?
But this is not over. The charlatanism in physics hit the fan long time ago:
“You see what is happening here. Conjecturing a multiverse of any type (string landscape or eternal inflation or what have you) is useless. It doesn’t explain anything and you can’t calculate anything with it. But once you add a probability distribution on that multiverse, you can make calculations. Those calculations are math you can publish. And those publications you can later refer to in proposals read by people who can’t decipher the math. Mission accomplished.
“The reason this cycle of empty predictions continues is that everyone involved only stands to benefit. From the particle physicist who write the papers to those who review the papers to those who cite the papers, everyone wants more funding for particle physics, so everyone plays along.”
Academic physicists especially theoretical so called physicists are a bunch of corrupt academic opportunists, it looks like.
— These are the the referenced articles, by Sabine Hossenfelder, A philosopher’s take on “naturalness” in particle physics, The Multiworse Is Coming