Sabine Hossenfelder on strong CP, hierarchy

[Vanadium 50]

Sleuth, you've said some harsh things. Forgive me if I am direct in replying.

You accused scientists of arrogance, twice, and then proceeded to misstate the situation. I find this...ironic.

Second, your statement that you weren't talking about anyone here when you said that is cowardly. You called the community arrogant - several times. You have members of that community here. Show some courage and either retract your statement, or stand by it - but saying that the community is arrogant, except for the handful of people who happen to post here is a cowardly way out.

Third, you have it exactly backwards on cutoffs. Setting a cutoff to zero doesn't make it valid everywhere, it makes it valid nowhere. You need to set it to infinity to make it valid everywhere.

Fourth, whether or not the solution to the hierarchy problem will be uncovered by the LHC has no bearing at all on whether there is a hierarchy problem. It's possible that the hierarchy problem has an entirely different solution. I don't think it will turn out that way, but it could. In any event, the hierarchy problem would be there even had we never built the LHC, and it was known before we built it that a Higgs boson light enough to cause EWSB of the sort we see is problematic because of quantum corrections.

Fifth, you write:

, don't YOU see it, you fools ?".

in quotes. I challenge you to find that anywhere in the scientific literature. I think you just made that up. Sticking words in the mouths of your opponents is a shabby, shabby means of debate.

Finally, you write:

maybe we should cut down our egos a bit

Fair enough. You first.

 

[Sleuth]

Vanadium, ok, I think the discussion is going completely in the wrong direction.

I was not referring to people on the forum, whether you believe it or not, instead to an attitude of a part of the community during talks, conferences etc, but I don't feel like repeating this again. I don't see any reasons to talk about cowards and everything else you said.

Probably I expressed my point of view with too much emphasis, my bad. I apologize if I offended anyone, it was not my intention to be arrogant.
I think the message is clear so I don't need to repeat it again. My ego is already way too small to cut it down even more, you don't know me.

Have fun

 

[MathematicalPhysicist]

I understand you will not like the example, but to me this is so similar to Ptolemaic cosmology and epicycles. People had a framework that seemed to work, namely a system made of things rotating on circular orbits around the earth, and in their mind there was no other possible system. Therefore, of course, they tried to bend it and adapt it adding always a new piece, a new circle, to try to reproduce observation. It was "clear and obvious" to everyone, that if the system did not work, it meant that there HAD to be another epicycle, what else could it be?

Fortunately, at some point someone came about and changed the perspective, and then everything was simple and beautiful again and none of those crazy (according to the Ptolemaic system "inevitable") epicycles was actually needed.

I know you all understand this story better than me, so I ask myself, how is it possible that our minds are so powerful that we can imagine Gauge theories, symmetry breaking, bending of space-time under the action of gravity, and we still we cannot learn a bit of humbleness from stories that repeated over and over again in our past? So in conclusion I say, fine if we want to do models and present ideas using the framework that we have trying to look for a hint of a solution, it is the best we can do now and it is completely legitimate; On my side, I know I am not the new Einstein and I probably will not be the one changing perspective, so all fine. But at least, let's give it the benefit of the doubt, ok?

Cheers

Well, as you yourself say history repeats itself; any theory or models that will come will replace our current understanding and the same new theories will be replaced again and again; everything repeats itself endlessly.

Every physical theory is in the end result, false according to classical logic which is the basic building block of every thought; take it as you like.

 

[Sleuth]

I completely agree with you!

 

[ohwilleke]

(This is mostly in response to post #36, which might not be obvious as a couple of other posts were made to the thread in the meantime while I was writing this post.)

A Question Of Terminology - Trying to Defuse The Emotional Side Of The Discussion

Different Senses Of Words And The Emotional Baggage That Comes With Them

When one talks of scientist displaying "arrogance" in regard to the strong CP problem and hierarchy problem, one is using the word in an abstract and somewhat non-common sense way as opposed to the usual sense of describing the personal internal emotions and attitude of a person towards other people (much as the word "natural" as used in regard to the hierarchy problem is being used in a technically defined sense and isn't being used in its common sense meaning of "the way things actually are in nature").

There are some false friends in physics terminology like "color" for QCD charge which aren't troublesome or contentious because everyone is absolutely clear that the sense of the word being used is totally different from the common meaning of the word. But, in the case of words like "arrogance" and "natural" in the context of the strong CP problem, hierarchy problem and related discussions, its easier to inflame emotions in discussions using these words because the technical meanings are closer to the common meaning and because this choice of words is intended to some extent to evoke some of the same heuristic reactions as the common meaning.

Still the sense in which one uses the word "arrogance" in this kind of discussion is not quite the same as the one in which you use it to describe your coworker to a friend at a cocktail party. Someone who is "arrogant" in this sense, may be a very polite, civil person who reeks humility and usually displays deferential conduct in this scientist's interactions with other people.

In the sense used in the strong CP problem/hierarchy problem, unlike its common sense usage, "arrogance" is a close synonym to "hubris" rather than to "impolite jerk".

"Arrogant" Is Intended To Characterize "Naturalness" Analysis As A Type Of Unscientific Category Error

What one means when saying that a scientist is "arrogant" in reference to strong CP problem/hierarchy problem type questions in physics is that someone is making suppositions about what the laws of nature and its physical constants ought to look like, in the form of a Bayesian distribution of priors about what those laws of nature/physical constants should be, without having any empirically supported or scientifically valid basis for choosing those Bayesian priors. In the eyes of critics of seeing these issues a true "problems" in physics, attributing any scientific meaning to these Bayesian priors is a form of category error.

Critics see it as a category error because the set of all possible laws of nature and physical constants in the abstract (as opposed to in relation to different hypotheses formulates independently based upon empirical observation such as trying to decide if GR or F(R) theory better describes reality), is not a scientifically valid matter upon which to generate Bayesian priors because "possible laws of nature and physical constant values" are not things which have any reality in any space-time and hence can't be assigned a weight in any way that is meaningful or adds information to what we know from other means.

Buried Religious Subtexts

Both "arrogance" and "natural" in this scientific context is also dicey and emotional because both words carry with them a subtext of residual religious belief that has carried over linguistically even though anyone who is engaging in this debate has implicitly abandoned the religious worldview and metaphysical context in which this religious imprints into our language and usage arose.

In the case of the term "arrogance" or the synonym "presumptuous" or "hubris" the unacknowledged religious subtext is that it is not the place of a mere mortal to second guess the mind and motivations of a creator god. The terminology is actually somewhat self-undermining because the whole point of the critics is that framing these issues as choices to be made by a creator god or some abstracted amoral generic equivalent of a creator god, is not a scientifically value way of looking at the world, even thought these words derived from religious and interpersonal contexts perilously adopts the very frame of reference that critics are seeking to reject. George Lakoff would take the critics to the woodshed for this poor rhetorical choice that is self-undermining in a very subtle, unconscious way.

In the case of the term "natural" the unacknowledged religious or metaphysical subtext is that the laws of nature and its physical constants were established by an anthropic intelligent designer creator god who has certain known aesthetic preferences which are known to his devotees and that the way that the laws of the universe and its physical constants should be can be inferred in a meta fashion from the presumed stylistic preferences of a presumed creator god as computer programmer or game designer with a certain set of choices available much as someone playing a "create your own universe" game on a computer. Needless to say, we have no reliable scientific reason to think that our laws of the universe or the values of our physical constants really came into being in a context like that one.

But, the tendency of both sides of the debate to resort to language with religious baggage isn't entirely surprising because at its heart this debate is one about the metaphysical assumptions of fundamental physics as a discipline, even if the question is rarely posed that way and even though scientists who pursue an analysis of whether laws of physics and physical constants are "natural" rarely frame their analysis as a metaphysical one even though the very heart of this analysis is implicitly a metaphysical one that assumes that it is scientifically valid to think about a set of all possible laws of nature and all possible values of fundamental physical constants.

Using Greek Philosophy Terminology

To go really old school, the strong CP problem/hierarchy problem and related issues use a very philosophically Platonic mode of reasoning, and in modern science we have in most other contexts rejected Platonic modes of reasoning in lieu of modes of reasoning rooted in Aristotelean world views that posit that there is not a "real" world of "ideals" that exists separate and apart from the observationally observable world. In one definition of modern Platonism (from the link earlier in this paragraph):

Platonism is the view that there exist such things as abstract objects — where an abstract object is an object that does not exist in space or time and which is therefore entirely non-physical and non-mental.

Critics would see this Platonic mode of reasoning as inconsistent with the scientific method.

Thus, in sum, what critics are trying to convey with the shorthand term "arrogance" is that the circumstances in which the proponents of these questions as genuine "problems" in physics is that the act of generating any Bayesian prior in this situation, regardless of its exact details, is not scientifically or logically justified.

Modern mathematicians do engage in Platonic modes of reasoning, but tend to be more clear about expressly and formally stating when they are relying upon axioms that rely upon no factual or empirically observed basis for their existence and instead are only conjectures from the mathematician. And, modern mathematicians are usually more upfront and clear than physicists exploring these kinds of Platonic problems that they are making no assertions about the physical validity of matters which they assume as axiomatic.

Are There Better Alternative Words?

The trouble is, that it is hard to come up with alternatives to the word "arrogant" in this context that don't have comparable emotional baggage.

For example, another strong synonym to the word "arrogant" in this physics context is "presumptuous", but "presumptuous" certainly has emotional baggage as well, although perhaps it is slightly less inflammatory because while "arrogant" is a term that usually goes to one's conduct interpersonal relationships in its common meaning, "presumptuous" does not have the same kind of social and interpersonal connotation.

If anyone could come up with a word that is synonym for "arrogant" as used in the technical sense that it is being used by critics of this approach with less baggage, perhaps it could help make the discussion less heated. I'm simply at a loss to come up with one at the moment.

An Aside

I'm laughing a bit at myself when the automatic censorship feature of PF was invoked when I posted this, but honestly, the censored version conveys the intended meaning just as well in this context.

Practical Consequences

The trouble is that whether formulating a Bayesian prior in this situation is "arrogant" or is scientifically justified in this situation is really the core question at the root of the entire debate. And, it turns out, there are a lot of practical, real world consequences to whether it is proper to formulate a Bayesian prior in this kind of situation or not.

Many hundreds of millions of dollars, maybe billions of dollars of scientific funding decisions, and many thousand of big picture career choices about how very smart people with PhDs in physics decide what they will devote their research agendas and write dozens of academic papers about and think about, hinge on this very fundamental, yes or no, question which superficially seems very abstruse.

Resolution of this issue influences how project managers at major HEP experiments devote scarce resources to do particular kinds of data analysis of collider experiments, and about which questions will receive the highest priority to be answered. The invisible victim, when the critics lose and the naturalness proponents win, are all of the scientific hypotheses and scientists advocating them who generate their research agenda without reference to concepts like naturalness and have fewer resources allocated to them as a result of pursuits of naturalness oriented research agendas which would have been much less of a priority relative to alternative research agendas if the "arrogance"/"naturalness" question were resolved the other way.

If "naturalness" is a dead end as a fruitful way of generating hypotheses and prioritizing new scientific investigation, then this bad idea may have delayed breakthroughs with different views about the scientific method that could prove in the end to be more fruitful approaches to discovering new scientific knowledge by decades. Critics are increasingly vocal now precisely because the "naturalness" assumption has in hindsight proven to have not generated much useful guidance about which projects and hypotheses to pursue and indeed in hindsight appears to have been counterproductive over the time frame of the last forty years or so.

Of course, even a broken clock is right twice a day. Naturalness, whether or not it is a valid means of generating a scientific hypothesis to test and whether or not it is a valid means of prioritizing different research agendas, may sometimes led to a useful result, even if not using this frame as a criterion for generating scientific hypotheses and prioritizing research agendas would have produced better results (something we won't know until we try the alternatives).

And, of course, the whole existence of the debate at all points out some blind spots in the common formulations of the "scientific method" itself, which is very clear and prescriptive about how to test and how to compare hypotheses that have been generated once they exist to test, but is very vague and provides little guidance about how to generate hypotheses and how to prioritize research possibilities in an optimal manner before we spend the time and money necessary to get in the business of hypothesis testing once we have a list of questions to test that is longer than the available resources to test or explore or generate them.

It is really most unfortunate that such high stakes depend upon a quite esoteric and subtle disagreement within the high energy physics community over whether this one very basic type of methodology is, or is not, a scientifically valid methodological tool.

My view

To put my cards on the table, I'll disclose my views on the merits.

As I've stated in other similar threads at PF, I think Sabine is spot on correct. I don't agree that the strong CP problem or the hierarchy problem or some kindred lines of inquiry are genuine, valid scientific "problems" and instead consider them to be on a par with numerology. This kind of analysis can be interesting, but it doesn't provide much insight (indeed, sometimes numerology is more informative than naturalness analysis which is really just a particular subspecies of numerology anyway).

In the same vein, I think that much of the work done based on the anthropic principle and the "multiverse" as a way of determining why the laws of the universe or the values of physical constants are way they are, is pseudo-science.

I think, as she does, that the scientific community has experienced a generation or two of group think that has led it astray, and that being right or wrong on this question has nothing to do with whether you are in the majority or not. It is not an issue that can be resolved democratically.

But, the main purpose of this particular post is not to get to the bottom of the correct answer, but to at least frame it in a way that adds light to the dispute, to let some of the unnecessary emotional air out of the bag, to try to prevent misunderstandings, and to focus on the core issue at stake since in my humble opinion this is really a disagreement over fundamentals and not primarily a question dependent upon technical details to any great degree.

 

[king vitamin]

I am one of those people who is impressed by the asymptotic safety prediction of the Higgs mass. That seems to require a "desert" (no new physics) above the electroweak scale, and something unexpected at the quantum gravity scale.

mitchell porter, if it's not too much of a digression from the main topic at hand here, could you elaborate on this statement? Does the Higgs mass play nicely into theories of asymptotically safe gravity (which I assume is the "agravity" mentioned later in your post)?

 

[mitchell porter]

could you elaborate on this statement? Does the Higgs mass play nicely into theories of asymptotically safe gravity (which I assume is the "agravity" mentioned later in your post)?

The special feature of the Higgs and top masses is that they place the standard model at the edge of metastability. One interpretation of this (see section 5.1 here) is that the Higgs quartic and its beta function both go to zero at the Planck scale. A 2009 paper showed how to obtain this under the assumption of asymptotic safety of gravity.

Agravity is short for adimensional gravity, gravity with only dimensionless couplings. It resembles conformal gravity. See "Agravity" and "Agravity up to infinite energy". The idea seems to be, embed the standard model in a nongravitational field theory in which all couplings are asymptotically safe (Francisco Sannino's group works on this), then couple that field theory to dimensionless gravity so as to preserve those special Planck-scale boundary conditions without finetuning (see figure 1, page 15 of the second agravity paper).