Naturalness: dimensionless ratios

[seazal]

Something of this nature, but then perhaps laced with anti-matter?

There is high probability naturalness still works. Is it not string theory is really naturalness all the way.

But any idea how string theory can proceed without any supersymmetry (null at all levels)? Are you a string theorist, an LQGist, or a Hossenfendist?

We may be dealing with very very complex problem. I wonder if the Chinese are clever enough to figure it out or it will be out of reach for a few thousand years.

If they would only detect the Higgs and nothing more than it with 100 TeV. Would they ever learn the secret of dark matter or cosmological constant by mastering the knowledge and knowing all properties of the Higgs? Maybe they really want to know if the vacuum was fine tuned to metastability or unstable. If they succeed building the 100 TeV collider, 99.5% of the physicists working there including Dr. Yang would still be influenced by western thoughts and concepts. Is it not.

 

[jim mcnamara]

Moving the thread to to General Discussion, as it has become speculative. This means the source requirement is not as stringent.

 

[Auto-Didact]

To get back on topic: I agree with Hossenfelder that an unnatural theory need not be a problem and that we shouldn't spend too much time focussing on it; there is a term for this: numerology. However I believe she makes an error when she then says that having naturalness as a criterium is unscientific and therefore wrong.

I will explain why: basically, what Hossenfelder has done is conduct an observational study among physicists using qualitative research methodology - a way of doing science I'm not sure she is that well acquainted with - and then offered her conclusion; given her lack of experience in doing this kind of research, it is still somewhat impressive.

First, she identified a problem: the stagnation of success in the practice of theoretical physics, i.e. no new successful theories since the SM. Over a period of many years, she identified a certain recurring behaviour among physicists ("looking for explanations for numerical parameters for questionable reasons"); observationally, she identified that this behaviour was often accompanied by the term "naturalness".

She then empirically, through questioning, interviews, discussions and literature review, identified what the term means in this context and identified this as a particular view, an aesthetic even ("the view that theories should have no large numerical discrepancies between parameters") occurring within the physics community.

All of the above is nice scientific work, probably worthy of a graduate level social science thesis. Incidentally, this is also the point where most social scientists - being of course empirically minded, not theoretically minded - would stop and just couch their tentative conclusions in a very traditional non-provocative discussion; Sabine however is not your typical social scientist but in fact a theoretical physicist, so naturally, she takes things much further.

She goes on to operationalize the aesthetic that she identified as a term: "naturalness". Based on this operationalization, she then extrapolates that most or all contemporary uses of the term in the context of physics refer to the same aesthetic; this is where things get murky, because this premise is questionable. Moreover, it even seems to be an error, however the error is anything but obvious - it certainly wouldn't be to a scientist without any serious experience in doing qualitative research, i.e. probably >90% of physicists.

To me however - a specialist in social science as well by necessity - it seems obvious that most uses of the term 'natural(ness)' does not necessarily refer to her specific operationalization of the identified aesthetic occurring among physicists; the phraseology of something 'being natural' is a widely used vague common language phrase, of which the meaning is nevertheless often either clear from context or can be clarified by further questioning.

Mathematicians as well as practitioners of mathematics, across all different historical and professional subdivisions, love to use the phrase: 'being natural' to them usually means something quite different from Sabine's very specific operationalization; I can only summarize (or roughly operationalize) the typical meaning as the following: "any procedure or action or property of some thing which can clearly or intuitively be recognized by seasoned experts to belong to some particular mathematical (sub)domain".

Put more bluntly, the term 'natural' being a generally used term literally has multiple meanings which cannot all be assumed to always refer to the aesthetic that Sabine identified without further inspection; even as a technical definition it is not unique because practitioners of mathematics at almost all levels also tend to use the term to refer to blatantly different things without any reservation; it goes without saying that this includes many physicists as well.

One would have to clarify in each case what is meant by the term 'natural' when it is used, before blindly labelling the user as being driven by the identified aesthetic. If it turns out that the typical usage of the term among physicists significantly disagrees with the aesthetic operationalization, then the rest of her argument i.e. her conclusion that adherence to naturalness is a problem for science somewhat falls apart, because then interpreting the term natural to refer to adherence to the aesthetic would simply be an unfounded extrapolation from a subsample of physicists to physicists in general.

 

[Auto-Didact]

Peter Woit has a new blogpost where he evaluates the situation of a new collider over at CERN. He thinks the situation is bleak, stating among other things:

Faced with a difficult choice like this, there’s a temptation to want to avoid it, to believe that surely new technology will provide some more attractive alternative. In this case though, one is running up against basic physical limits. For circular electron-positron machines, synchrotron radiation losses go as the fourth power of the energy, whereas for linear machines one has to put a lot of power in since one is accelerating then dumping the beam, not storing it. For proton-proton machines, CM energy is limited by the strength of the dipole magnets one can build at a reasonable cost and operate reliably in a challenging environment. Sure, someday we may have appropriate cheap 60T magnets and a 100 TeV pp collider could be built at reasonable cost in the LHC tunnel. We might also have plasma wakefield technology that could accelerate beams of electrons and positrons to multi-TeV energies over a reasonable distance, with a reasonable luminosity. At this point though, I’m willing to bet that in both cases we’re talking about 22nd century technology unlikely to happen to fall into the 21st century. Similar comments apply to prospects for a muon collider.

...

Where I think Hossenfelder is right is that too many particle physicists of all kinds went along with the hype campaign for bad theory in order to get people excited about the LHC. Going on about extra dimensions and black holes at the LHC was damaging to the understanding of what this science is really about, and completely unnecessary since there was plenty of real science to generate excitement. The discussion of post-LHC experimental projects should avoid the temptation to enter again into hype-driven nonsense. On the other hand, the discussion of what to defund because of the LHC results should stick to defunding bad theory, not the experiments that refute it.

The discussion in the comments is quite lively, with points from both sides, quite well worth a read through.