B Sabine Hossenfelder on the search for new particles

[ohwilleke]

The way I look at things has baryon asymmetry not even remotely a question of initial conditions.

Baryon asymmetry is an issue only if one assumes an initial condition based upon conditions that do not flow from any empirically tested physical theory.

 

[ohwilleke]

If the initial number of baryons is zero, and they come to being from some other field, any SM production process will produce only a tiny asymmetry. If you believe a model of this type (as most cosmologists do) then it is simply wrong to treat this as a question of initial conditions.

Why should the initial number of baryons be zero? Nothing we have observed compels or even directs us to that conclusion. The fact that lots of scientists think it is pretty that way isn't a scientific answer.

 

[PAllen]

Why should the initial number of baryons be zero? Nothing we have observed compels or even directs us to that conclusion. The fact that lots of scientists think it is pretty that way isn't a scientific answer.

Because you have an era when quarks don’t exist yet. You may not like such a model, but for those who do, you cannot even pose baryon asymmetry as an initial conditions question. Instead you must have a creation process that favors quarks over anti quarks. I believe most cosmologists favor such models. Sabine first rejects such models without stating or explaining it, before she can even pose the question of initial conditions.

 

[PAllen]

Baryon asymmetry is an issue only if one assumes an initial condition based upon conditions that do not flow from any empirically tested physical theory.

No early cosmology theory can ever be tested under early conditions. We do the best we can.

 

[strangerep]

Can we see those attacks or do we have to take her word for it?

Hmm -- as if personal attacks were something that one should spread.

I'm out.

 

[Hornbein]

Returning to the original topic:

Jerry Pournelle's Iron Law of Bureaucracy is that the main goal of any institution will eventually change. Solutions for the problem it was created to solve will be pushed aside. The true purpose will become to preserve and increase the income of this organization. I don't see that physics is any worse in this regard than anything else. Do to its small size it is certainly relatively harmless. As to Sabine's efforts, I can't say it any better than did the Bobby Fuller Four.

 

[malawi_glenn]

Hmm -- as if personal attacks were something that one should spread.

I'm out.

Then we are back to "me too" movement, no proofs required.

Why it has that value instead of another one in a counterfactual version of reality is not a "problem". Maybe it's natural philosophy, but it isn't science.

So you have no interest in all to know why the photon mass is zero? After all, it might just be a paramter that is exactly zero. Or why electric conductivity for some materials become 0 below a certain temperature? As I wrote earlier, physics is also about finding patterns. Would just be stamp collection otherwise. I bet we would not have special or general relativity with this mindset

If I had to guess, I'd put it about about 20%-30% of hep-ph (and maybe 10-15% of hep-ex).

I was referring to "2sigma" anomalies papers. Not the other cathegories mentioned.

 

[PAllen]

Then we are back to "me too" movement, no proofs required.

During the "string wars" she did post a long series of horrific posts by supposedly serious physicists on her blog, that she deleted from the main blog, but posted separately for documentation. I have no doubt she has received vile posts due to her current critiques. As noted above, I disagree substantially with much of her current critique, but more so with anyone who responds inappropriately.

 

[vanhees71]

The "measurement problem" at its most tepid is how to determine what constitutes a "measurement" in a less subjective and more rigorously defined way.

There is nothing subjective in what our experimental colleagues do when investigating quantum phenomena but a well-defined setup of preparation and measurement devices, which can be objectively verified and reproduced (at least in principle).

 

[Roza]

For example, why do we need Dark Energy? The recession of galaxies can be explained by known physical phenomena. And gravity, using also known quantum phenomena and some more.

 

[pinball1970]

For example, why do we need Dark Energy? The recession of galaxies can be explained by known physical phenomena. And gravity, using also known quantum phenomena and some more.

https://en.wikipedia.org/wiki/Accelerating_expansion_of_the_universe

 

[ohwilleke]

There is nothing subjective in what our experimental colleagues do when investigating quantum phenomena but a well-defined setup of preparation and measurement devices, which can be objectively verified and reproduced (at least in principle).

"Our experimental colleagues" work well away from the gray areas.

For the same reason, the well known theoretical inconsistencies between the Standard Model and General Relativity which are widely accepted to exist in the scientific community don't impede much work with either theory because most experimental and observational work happens in domains where one or the other is the dominant effect, even though there are circumstances (e.g. at the event horizons of Black Holes) where the way that these theoretical inconsistencies are resolved has observable consequences.

But there are circumstances in which a rigorous definition matters that are not well explored with experimental or observational evidence (and it doesn't take $100M+ USD experiments and a cast of hundreds or more to investigate those issues experimentally).

For some of the relevant work see, e.g.: Matteo Carlesso, Angelo Bassi, "Current tests of collapse models: How far can we push the limits of quantum mechanics?" arXiv (January 27, 2020) published in Quantum Information and Measurement (QIM) V: Quantum Technologies; OSA Technical Digest (Optical Society of America, 2019), paper S1C.3 DOI: 10.1364/QIM.2019.S1C.3 and related scientific work discussed in Bob Henderson, "The Rebel Physicist on the Hunt for a Better Story Than Quantum Mechanics" New York Times (June 25, 2020) (also citing to https://arxiv.org/abs/1909.11301 by overlapping authors which has since been published at 53 J. Phys. A: Math. Theor. 215302 (2020)).

 

[ohwilleke]

No early cosmology theory can ever be tested under early conditions. We do the best we can.

If we can't test it, it isn't science. It is speculation, perhaps informed speculation, perhaps natural philosophy. But nothing more. Some questions are unanswerable, at least with available technology and knowledge.

The discipline might be better served by more humility about what we know or can know, and less guesswork.

 

[ohwilleke]

Returning to the original topic:

Jerry Pournelle's Iron Law of Bureaucracy is that the main goal of any institution will eventually change. Solutions for the problem it was created to solve will be pushed aside. The true purpose will become to preserve and increase the income of this organization. I don't see that physics is any worse in this regard than anything else.

Pretty much true, but not an argument against trying to improve the status quo. Bureaucracies are subject to external constraints including the economic resources available to the scientific enterprise. So, there are always going to be outside pressures to be less wasteful. Whether the outside pressures are sufficiently strong to overcome the problems partially depends on the priorities of the leaders in the community of physicists.

 

[Maarten Havinga]

The discipline might be better served by more humility about what we know or can know, and less guesswork

So true! It's good to remain open to new ideas on cosmology and critical of your own preferred view.

 

[OscarCP]

In "Gödel, Escher, Bach: An Eternal Golden Braid" published in as long ago as 1979, Douglas Hofstadter wrote, in the Introduction, I seem to remember, that he had left working on quantum physics after he got fed up with the very problem described in the "Guardian" article cited at the start of this thread: he mentioned that the straw that broke the camel's back of his love of the subject was a paper by someone who proposed "not just one new particle, nor two, but twenty of them" all at once.

To this I would add my favorite peeve with modern physics, astrophysics in this case: dark matter.

Why? Because:

(a) It is something that spending millions and millions and millions of dollars, euros, yuan, yen, rupees, etc. in funding have failed to produce conclusive results after looking for it for years and years and years.
Not that there is no need for some new theory of how things work, because, obviously the case has been abundantly made that there is. Just that the current leading explanation, at least in publications count, is not really that great.

(b) It is entirely ad hoc: it "saves the phenomena" the way using deferents and epicycles to make the incorrect geocentric theory of the universe work was, in the middle Ages, developed by European astronomers (Indian and Arab ones had better ideas.)

(c) It is one way to explain things without revising, among other things, General Relativity, that in every way it has been tested has worked extremely well, in spite the ever greater precision of the tests, so it has never been falsified. At least yet.
I would vote for revising GR with a new new theory that, at the same time it makes dark matter unnecessary, does not fail any of its successful tests. But that probably will take years to do it successfully to some supremely gifted individual that, given how science is funded these days, shall probably starve to death in a garret without heating, in winter, before making the big breakthrough.

Or, now in a more satirical way, I think on how in Phillip Pullman's "His Dark Materials" trilogy its mentioned that a mysterious, magical and pervasive substance called "dust" may be, in fact, what "dark matter" is. That, in a series of novels where humans' spirits live in companion animals, there are witches, angels and assorted fantastic creatures - and bears can talk.

All of which, at least to me, seems quite appropriate.

 

[cjl]

For example, why do we need Dark Energy? The recession of galaxies can be explained by known physical phenomena. And gravity, using also known quantum phenomena and some more.

We need dark energy precisely because the details of the recession of galaxies does not fit with known physical phenomena.

 

[OscarCP]

Dark energy my be also ad hoc, but is a different kind of ad hoc than dark matter, when it comes to why is it assumed to exist in order to explain observable gravitational phenomena without having to really change General Relativity.
Besides that, and as I understand it and, please, correct me if I am wrong, it involves fiddling with only one number in GR, in principle maybe once and for all, or in practice, until further observations strongly suggest that a further tweak may be needed. This number is the value of the Cosmological Constant that is, by design, practically asking to be tweaked, and not some huge distribution of invisible matter across the Universe, everywhere assuming the different shapes and densities needed to fit the data.

That does not mean, beyond any reasonably doubt, that something material and, so far unseen, is not out there, called it "dark matter" or "Newcastle United", if you like, providing extra mass as required to keep using GR as is, but even so, it need not be a new and it would seem undiscoverable bunch of BSM new particles, or even of old and well-known particles.

Chi lo sa?

 

[OscarCP]

as well as "quantum gravity", but I rather don't comment on colleagues working in the neighbor building...

What I can say for studying quantum gravity is that the lack of fit between General Relativity and Quantum Physics is not some little obscure anomaly that might or might not be due to just a measurement fluke, that only people keen on padding their CVs with too many otherwise forgettable publications think and write about.
Some of the last and current centuries' physics' luminaries have worked on this and, or pursued it as a topic along their careers.

 

[vanhees71]

You misunderstood what I said. Finding a quantum description of the gravitational interaction is the only open problem concerning quantum theory. The socalled "foundational problems" are pseudo-problems of a metaphysical/philosophical nature. If you find one day consistent quantum theory of gravitation, you can start to interpret it in all kinds of philosophical manners, but it's pretty sure that trying to solve some vaguely defined philosophical pseudo-problem about the "foundations of quantum mechanics" won't help to find such a theory.

 

[Roza]

We need dark energy precisely because the details of the recession of galaxies does not fit with known physical phenomena.

I'm sure you can explain.

 

[pinball1970]

I'm sure you can explain.

If you type "accelerating Universe" in the search bar there are threads discussing your question.

Like this

Thread 'Acceleration of the Universe' https://www.physicsforums.com/threads/acceleration-of-the-universe.694573/

 

[Roza]

Thank you, but I do not believe in the expansion of the universe, there may be other explanations.

 

[martinbn]

Thank you, but I do not believe in the expansion of the universe, there may be other explanations.

It is not a matter of belief. What are those other explanaitions? Баба Яга?

 

[Roza]

It is not a matter of belief. What are those other explanaitions? Баба Яга?

If we imagine that there is a center of the Universe, then the recession of galaxies can be explained by Dark Energy, which is illogical for nature

 

[fresh_42]

If we imagine that there is a center of the Universe, then the recession of galaxies can be explained by Dark Energy, which is illogical for nature

If we assume something false, everything will be true, which is illogical by nature. Therefore we are not allowed to assume false.

The subject of the cosmological expansion is off-topic. Please return to the actual topic of this thread.

 

[OscarCP]

You misunderstood what I said. Finding a quantum description of the gravitational interaction is the only open problem concerning quantum theory. The socalled "foundational problems" are pseudo-problems of a metaphysical/philosophical nature. If you find one day consistent quantum theory of gravitation, you can start to interpret it in all kinds of philosophical manners, but it's pretty sure that trying to solve some vaguely defined philosophical pseudo-problem about the "foundations of quantum mechanics" won't help to find such a theory.

Glad to realize that we agree. As to those who discuss the foundational problems, or rather those mysterious things that show the huge difference between our familiar world of dogs and airplanes and grease stains when we accidentally drop food on our clothes, on the one hand, and that totally unfamiliar one of particles and quantum fields, etc. on the other?
Well, that is a natural thing to do, even when, as you pointedly mention, you think that doing what they do may be futile because there is still left open a big theoretical hole in the very subject they are discussing.
You definitely seem to have a point there. So let's consider it:

Those people, myself and you and everyone who ever cracked open a book on the subject, or read about it in Scientific American or wherever, we are all simply trying to wrap our heads about, for example, things that exist but don't exist, because they only exist in their interaction with other things and if they are not doing that, they pretty much don't exist in any way that can make sense to us. And don't get me started on the two-slit experiment.
Of course, many people don't ponder as much as others, many (yours truly included) are happy to use Quantum Physics' equations occasionally, cook-book style, to get a job done.
Others are happy to understand the equations and how they relate to each other and what are they for, and so they are comfortably familiar with these, with the formal aspects of the underlying theory, and feel it is a waste of time and talent to look into this with puzzled eyes and ask "yes, but how can this be?"
And some others make their lives pursuit to come up with a way of thinking that makes all this less annoying. Because the questions are there and they are not going away as long as the itch to understand what this or that "really means" remains.
And that is to say, in my opinion, for as long as human beings that have even a passing familiarity with the subject are still around.

Filling a hole in the existing theory does not necessarily remove from it all of it's current "weirdness", so some philosophical pondering might be on things that remain as they were before the hole was filled. Because who can tell now what will then be and not be so?
Choosing seriously the "what" to work on is always a gamble in any scholarly field, philosophy of science included, as is most of everything that counts in life.

And there is more about waiting or not until a gravity/quantum connection is finally agreed upon: Physics has proven itself to be, perhaps more than other sciences, a matryoshka doll of open questions: one is opened, finally, to the light of day and another one is found right inside it also waiting to be opened.

So, unfortunately perhaps, those people in the building next to yours are not going away any time soon, and when and if they do, they are probably going to be replaced in no time.

 

[weirdoguy]

It's good to remain open to new ideas on cosmology and critical of your own preferred view.

Still, being open to new ideas does not mean being open to ideas thrown by people who has no technical background in cosmology and physics in general. That would be called "time wasting".

 

[Maarten Havinga]

What do you know about whose and which new ideas I meant? I meant Milgrom's ideas, Vavrycuk's ideas, and perhaps more (Verlinde comes to mind)

 

[OscarCP]

In a general way that applies as much to "ambulance chasing" small anomalies hoping to find enough to justify yet another BSM-themed paper, as it does to keeping an open mind on new ideas in Cosmology (or on anything else, for that matter, even when it may be necessary to consider it first and not to reject it out of hand) I recall something that Douglas Hofstadter, again, wrote either in the "Mathematical Games" section of "Scientific American" when he had first joined Martin Gardner there, or after Gardner retired and he had taken it over and renamed with the anagram "Metamagical Themas."

He wrote more or less as follows:

"Yes, one should keep an open mind, just not so open than one's brain falls out."