Particle Physicists Continue to Make Empty Promises
backreaction.blogspot.com
backreaction.blogspot.com
I have yet to see anyone contradict her basic premise with factual information. I wish she were wrong, as I would love to see a breakthrough towards an experimentally verified Grand Unified Theory, including an explanation for what we currently identify as dark matter (similarly for dark energy). From what I read, physicists that criticize her take their own wishes for reality, and prefer to attack the messenger rather than confront the reality of the message.
I'm also not really convinced of what she categorizes as failure. She enumerates quite a few incorrect predictions, but is that sufficient to show that the experiments were a failure? There are literally thousands of papers published because of the LHC and CERN claims hundreds of results. Maybe you can show that they are mostly worthless (which is not the same as boring or not spectecular), but she doesn't really seem to even try to do that.
You make a good point - without the expensive accelerator data, we’d have no idea that these omg ridiculous stupid waaaa predictions are true or false!!!
No, even with the accelerator data we probably still won't be able to conclusively rule out many approaches. We'll only be able to rule out overly specific variants of those predictions. Which, given the infinitude of available theories, doesn't do much to narrow things down.
Think of it this way: At one point, geocentric theories of planetary motion based on nested crystal spheres were requiring ever more elaborate arrangements with more spheres. More observations with greater precision only required adding more spheres.
We're somewhat in the same situation WRT high-energy physics today, in that larger and more powerful accelerators will only rule out particular theory variants, just as more powerful telescopes would only have ruled out particular arrangements of crystal spheres. Just as geocentrism as a category of theories isn't falsifiable by greater precision, many of the current approaches toward HEP aren't falsifiable by ever more powerful accelerators. You can always add another dimension or mathematical elaboration to explain the observations.
Which simply means that right now, another large particle accelerator probably isn't the most useful experimental approach to figuring out how to reconcile the two well-supported theories we do have.
That's happened to many people (Hossenfelder included?) but it's now happening to the community and no one likes it. But given that is how science as an institution operates they shouldn't be surprised.
Here's a thought experiment. Would there be a bid for a new 100Tev machine if super symmetry had been confirmed at LHC? My bet is :for sure. And the key argument would be "we told you that we were good last time, so you have to back us this time"
Something had to happen at that scale, the Higgs wasn't guaranteed. Sabine gets experimental physics backwards because no one planned the LHC to confirm the Higgs, but to know whether the Higgs existed and if it didn't what did instead. My money was mostly on it not showing up; many physicists were convinced it wouldn't, then it was there but we couldn't know beforehand.
There's a scientific case for making precision measurements of it, as was done with the electroweak bosons for very good reasons that she dismisses without showing any kind of understanding about the research she wants to shut off.
Regardless, the point stands: we knew that something is missing from the Standard model, and we knew that it must exist in a very precise range of energy. If it didn't exist there, it could have called into question the whole SM.
In contrast, we don't know that there must be some kind of dark matter at the 100TeV scale. We know that one particular type that we have thought about could exist, but we have other candidates as well, and there are ways that the 100TeV prediction could also be moved to higher energy levels.
Meanwhile, we don't even know if dark matter is a kind of matter or a modification of the force of gravity or a problem with approximations of Einstein's equations used in practice etc.
I'm not sure we're done with composite models. There are more exotic alternatives and then the fact remains that neutrino masses aren't in the SM.
I consider pretty hopeless to keep thinking that you can modify GR like plasticine in all the instances in which putting amounts of matter that doesn't radiate works (maybe it works because it's there and its effects on other stuff is how you "see" it). It has the appeal of making some people feel like they can call a whole profession or several a bunch of crooks, and that's pretty much what it has going for it outside of the scientists working in earnest on it.
The scientific method has usually worked by either coming up with theories and testing them; or by measuring things we thought we knew and finding new explanations when those turn out to be false.
What has not really worked too often has been coming up with mathematical models out of thin air, fitting them to all of the current data, extrapolating them to things we haven't been able to observe yet, and then building those things to check if they also worked.
That is why research into astronomical objects to ever greater precision is a promising candidate: we know what we expect to find if our current theories are correct, we know of real problems with our theories, and we can come up with new theories that predict such and such structures that should be visible in precisely such and such conditions.
This is the exact same model of how physics advanced from Tycho Brahe to Newton - people had models of the motions of the stars, they collected data to confirm those models, and found problems that they couldn't explain. Then Newton came along and found a mathematical model that, for the first time, explained those observations, and even reconciled them with other observations on the ground. We then spent a lot of time testing Newton's theories and didn't find any holes for a few hundred years.
Along came electromagnetism, the study of its dynamics, and the discovery of the speed of light problem, which couldn't be explained - requiring a new model that could actually explain everything we knew + the new data, and so on.
But this is the story of early to mid 20th century physics! General relativity, the initial quantum mechanical theories, Dirac’s equation and anti-particles, neutrinos were all the product of this process of adding mathematical conveniences and extrapolating to things that turned out to be real. You can argue that more recent efforts in this direction have been much less successful than those were, but I think you have to turn a completely blind eye to the history of modern physics to claim that method “has not really worked too often”.
I'm less well versed about the other subjects you mention, but there were several unsolved problems in physics at that time that absolutely required new theories (the photoelectric effect VS the wave behavior of light, black body radiation, the need to reconcile quantum mechanics with special relativity). In all of these cases, we had unexplained data or inconsistencies between theories.
By contrast, most of the theories that could be tested with a new collider are not solving anything - they are just theories about things that might exist, but could very well not exist at all. There is no hope of gaining insights into the measurement problem or quantum gravity at the next collider.
Even the theories of dark matter that could be tested are still too early to be worth a 20b bet. There are too many equally plausible theories of dark matter to say any one of them is promising enough to be worth that amount of money. And even ruling one of them out will not have a major effect on the field. It's not like it would rule out string theory, for example.
There are two criticisms she articulates very clearly:
1. SUSY is not a testable theory, as it can always "retreat" to higher energy levels, without any real limit.
2. There is no scientific reason to believe SUSY should be true - it doesn't solve any real problem with any of the known theories of the universe. There are infinitely many ways that the universe could be different wherever we haven't looked yet - we can't possibly test all of those theories.
The combination of both arguments leads to the following "law": until we have a theory that solves unsolved problems in physics AND that makes concrete predictions with bounded parameters (so that a failure will explicitly rule out this theory, instead of pushing it endlessly to "maybe at higher energy levels"), we shouldn't be paying huge amounts of money to test things blindly.
This is the fundamental difference between, say, the Higgs prediction and SUSY - we were looking for a concrete thing that it was necessary to exist for the rest of the Standard Model to make sense; and we knew a clear range of energies where the Higgs must exist; if we found it like we did, we know the theory was correct. If LHC didn't find the Higgs, then it would have definitively ruled it out, leading to an explicit need for a new SM.
By contrast, SUSY has not been confirmed, but it is also impossible to rule out entirely, and none of our models NEED SUSY to be right - so in the end, experiments for SUSY don't achieve anything. We might as well be launching space missions to look for Russel's teapot.
But apparently the only point worth making is progress in particle physics has been slow. Well, to be fair the point Hossenfelder tries to make is that there's been no progress, and since that's not actually true convincing people of it regardless takes more work.
I would also mention that things like the Voyager missions are still providing novel data ~50 years after their launch. Will the same be true of the LHC, or any other particle collider?
The HEP problems aren't going anywhere. Lets deal with more pressing concerns now and come back to HEP problems later.
This is e.g. why the current rocket companies had to do a lot of reinvention and research instead of just switching the Saturn V production line back on.
For sure, but we know we can do it because we've already done it.
Also, there are other avenues for particle physics that don't require 20 billion dollars to start with. The 20 billion isn't going to retaining particle physicists, it's mostly going to hardware, engineering construction etc. efforts.
- many interesting falsifiable theories emerge that are resolvable at the accessible energy scale.
- technology catches up to make the engineering of such a thing cheaper.
It's not a terrible idea to wait. An important part of why the LHC was more effective than the hole in texas is that chemists using NMRs and doctors using MRIs drove technical and production improvements that brought down the cost of superconducting magnets.
There is this narrative that theoretical physics drives investments in technical innovation that improves other scientists, but I'm not sure that narrative is entirely true. It's often the other way.
I think we've done enough of that. At this point I'm really only interested in positive proposals, what new stuff can we do? If we have a wave of new successes any old failures will fade out on their own.
I have no idea of they are something particle scientists do or if they belong to another branch of physics.
Everything's disappointing, I am (ironically given my tone here) only interested in hearing from those leading with solutions.
In summary, the reason for quantum gravity experiments is that investigating contradictions in our theory has always been the best source of progress in science, and experiment has to lead theory. We know that QM and GR contradict each other, and therefore we should research that.
She gives a variety of experiments that can research that. The equipment for which is of use in a variety of other sciences. (Particularly astronomy.)
There are plenty of other areas of real research that are still nominally 'particle' physics that are actually able to put to paper real goals for what they expect to achieve.
There are also facilities like NSLS II that are heavily subscribed and doing research that is both very real world and pie in the sky.
Keep this in mind too - the Tevatron at FNAL would have had the Higgs discovery if they could have run another 3-5 years - they already had data order 3 sigma IIRC. Likewise, they would have had a lot more data on the top, something LHC has been gathering since the confirmation of the Higgs. This would have come at a fraction of the cost of the Higgs. Beyond that, has Higgs done anything more than add to the already known to be narrow avenues left for SUSY?
She is absolutely correct that the particle physics community needs their feet held to the fire to justify such an enormous single outlay and being a jobs program for a few thousand physicists is not one of them.
Collider projects were much more interesting to a public who had remembered the sea change of reactors and the bomb. While I love the LHC, from a productivity standpoint there are other projects which have been bearing more fruit for ~50 billion.
Time to spend some money else well.
This Wikipedia entry is 1) generically about the type of unproven theoretical model without experimental support that is used in an attempt to justify investment in the next big collider; 2) more specifically, about a theoretical model that has been shown to be wrong in terms of describing what we observe.
I agree that we could probably spend billions of dollars better than on another enormous collider, even within high-energy physics, but it probably wouldn't be best spent on E8 Theory. Figuring out how it would be best spent, however, would be contentious to say the least.
Tremendous value has been created by their work and an institution like CERN is hard to replicate because it is hard to get brilliant people to a agree what to do for the next 30 years of their lives. I’ve been taught by professors that did precisely that. Whatever theorists predict is not the only reason for them to do it, higher energies are a technical challenge, a data processing challenge, something to focus your attention and creativity on. There is no question we should try to build better telescopes, a 100 TeV collider is a better microscope for High Energy Physics.
This is personal to me, some of my friends work at CERN. I can’t help but feel it is personal to her. I actually met her once, she seemed nice enough, I just don’t understand why she focuses her time on work that is adversarial as opposed to constructive.
What an awful reply to legitimate criticism. I infer that some of your friends at CERN talk about her (quite successful) book this way?
Lee Smolin, who did "cut it" and who worked in several first rate institutions, wrote about the same thing in his 2006 book The Trouble With Physics. So Sabine Hossenfelder is not alone with these opinions.
We've all been there. Props for recognizing it, admitting it, and dealing with it.
Generally speaking, in Central and Western Europe it doesn't matter which institution a researcher is from. They're all good and those at top-tier institutions are only marginally better at best.
In the book God Particle, the author describes how the funding for colliders in USA stopped after the cold war and it was extremely demoralizing even as a reader.
More structural funding for open source software would also be welcome. Software that deals with communication (browsers, protocols, email, filesystems, codecs, etc.) should be fully open and developed by universities and government institutions, imho.
An academic committee to decide what software was worth funding, in the 80s, would probably have come up with a very different list to yours. And would have hired people from safer, more academic, backgrounds than Sir Tim.
The NSA called to say that they like your thinking there!
That is very clear. You didn't engage her argument at all.
Is is really too much to ask for scientific mega project to generate all that value, while at the same time same pursuing a central object that is scientifically viable?
Really - I thought that we were debating an article by a scientist, who along with many other scientists disagrees with that position.
>>This is supported by technical arguments which are hard to communicate to the general public.
And yet the general public is being asked to pay for it. Perhaps sorting out that gap and explaining how understanding dark matter will be as important as (for example) curing cancer or alzheimers disease, or more prosaically cystic fibrosis or malaria would be a good thing? Or even understanding ecologies and the global climate? Will the new accelerator be carbon neutral? Will understanding dark matter prevent the collapse of our planet and the deaths of our children?
If I were a politician funding this project I would want some pretty cold, hard information on these things.
If a physicist criticises recommendations by epidemiologist without reference to the theory of how diseases spread, should you count that as disagreement from the consensus of how to fight infectious diseases?
It's difficult to know. General relativity is useful for GPS. Superconductivity is useful for NMR that actually sometimes saves children from cancer. Neither of the applications were clear at the discovery time.
(My favorite was Magnetoresistance. You start to explain it as a weird quantum boring effect of the spin of electrons in magnetic conductors, and when the other person is convinced that it totally unuseful you explain that it is used in hard disks. SSD are killing the fun.)
Superconductivity -> NMR ~60 years?
Do we have that long?
These projects are a way to train high skilled STEM people (competition to stay at CERN is brutal, but most go on to industry) in a structured way that then work on a lot of other societally relevant problems.
I think it's more correct that you will be generating observations in largely the same way as in the past, but with higher resolution and fidelity.
> You already know we haven’t found anything yet—otherwise you’d have heard of it. But even null results are valuable guides for theory development. They teach us that some ideas—for example, that spacetime might be a regular lattice—are simply incompatible with observations.[1]
So this is really mostly about a "you had your chance with the toy, now it's time to let others play" argument, though she's very adamant that it's not. This is really the large problem with her criticisms: the case that exists is for particle physics getting less priority, but her argument is that it should stop completely, the collaborations disbanded, and everyone goes to find a new job because they can't be trusted to think clearly.
[1]: http://nautil.us/issue/45/power/what-quantum-gravity-needs-i...
Huh? Where is she saying this? Everything I've read from her suggests that she's against building bigger accelerators, not stop investigating particle physics.
E.g. from http://backreaction.blogspot.com/2019/03/nonsense-arguments-...:
> Science is exploratory and to make progress we should study what has not been studied before, true. But any new experiment in the foundations of physics does that. You can probe new regimes not only be reaching higher energies, but also by reaching higher resolution, better precision, bigger systems, lower temperatures, less noise, more data, and so on.
> No one is saying we should stop explorative research in the foundations of physics. But since resources are limited, we should invest in experiments that bring the biggest benefit for the projected cost. This means the higher the expenses for an experiment, the better the reasons for building it should be. And since a bigger particle collider is presently the most expensive proposal on the table, particle physicists should have the best reasons.
In fact in the very post you link to she dismisses the idea of high precision measurements: "Yeah, except that I am the one saying we could do better things with $20 billion than measuring the next digits of some constants"
In point 18 of this article: http://backreaction.blogspot.com/2019/03/nonsense-arguments-..., her first suggestion for an alternative avenue of research is
> (a) Astrophysical and cosmological observations attributed to dark matter. These are discrepancies between theory and data which should be studied closer, until we have pinned down the theory. Some people have mistakenly claimed I am advocating more direct detection experiments for certain types of dark matter particles. This is not so. I am saying we need better observations of the already known discrepancies. Better sky coverage, better resolution, better stats. If we have a good idea what dark matter is, we can think of building a collider to test it, if that turns out to be useful
Anyway, I'd like to link Dorigo's post where this anti-science stirrup might have shown up first:
https://www.science20.com/tommaso_dorigo/what_it_means_to_be...
I don't find it surprising tbh.
Compared to open source in general the CERN stacks are horrible, typical sloppy academic software of no use to the general public. Tons of stuff like the cling C++ interpreter that look interesting but are never polished to be generally useful.
Truth is, I did get your point. Perfect refinement is not necessary in every context. Your comment, like CERN's interpreter, though sloppy was fit for purpose.
The web browser enabled my whole very comfortable career so I'm willing to overlook a sloppy C++ interpreter here and there.
[1]: https://www.youtube.com/watch?v=0Zpeh9wuzMs&feature=youtu.be...
Theory of Relativity was invented at the Swiss Patent Office.
The criticism is that the ROI = (the potential advance) / (invested money) is too small. As you pointed out it can be argued that the real goal is elsewhere: in the engineering / technology or science of complex systems. Creating a big machine that verifiably works brings many unexpected advances in many fields. And what is more important it is a symbol of human advancement which unites people and inspires them to pursue science. Since humans need a clear goal to invest much resources in a constructive endeavor. It may not be that important though that the ROI in fundamental physics is small, as long as people work hard together. But it can be argued that the whole process begins to resemble religion more than a scientific method; which can be problematic as religions have a bad reputation among scientific community.
The people working at CERN directly and their collaborators truly belief in the goal of understanding the fundamental forces of nature. And they had tremendous success doing so. They are the gold standard for a well managed long running big science project. Just recently they found the Higgs boson. Hossfelder worked for years on extremely speculative ideas in quantum gravity, they weren’t super well received, most people liked string theory better. Bottom up and top down reasoning in particle physics phenomenology suggests there are more discoveries to be made at the energy frontier. I like to see a future where eventually we build a solar system sized particle accelerator not stop at a radius of ~100 km
That's unknown in advance. To take example from maths, the conic sections, braid theory, number theory—they all used to be very abstract and un-applicable parts maths, until one day.
CERN found Higgs - which was proposed decades before CERN was built. There is nothing like the Higgs proposal around today.
That's the real problem. Spend $20bn on some new models, and then you can spend $20bn chasing the most interesting prospects.
That's far more likely to get you somewhere exciting than the experimental equivalent of throwing more spaghetti at the wall and hoping some of it does something unexpected.
This is a very incorrect description of the problem. The situation in basic particle physics is that models are super plentiful; Six months in 2016 saw 500 different papers written to explain a novel signal that ended up not being real, so it's not models that are missing.
* CERN: founded 1954, as a lab for nuclear physics
* PRL electroweak symmetry breaking papers: 1964If our way of generating new theories has given bad predictions for 50 years, at what time should we stop and try out other ways of extending the confirmed theories?
It is unknown in advance if putting your hand through a fire will hurt you this time as well, but after 50 years of doing so, perhaps it's time to stop.
And the problem has never been making new theories, the problem is always that we have a very good model, and no principled way for choosing between all the possible theories that gives rise to almost precisely that model.
So people tried to invent reasons and so far nobody has had any luck. And Hossenfelder is correct that in hindsight naturalness wasn't a very good rule.
But by the same hindsight, no theory that could be detected in previous experiments would have worked either. In this view, making the experiments at all was a complete waste, we should just have drawn the winning theory from a hat and stopped all further work.
If we have a theory that could solve the measurement problem (or detect quantum gravity etc.), and a plausible experiment for that theory, we should perform this experiment - it may well yield valuable data whatever result we get.
Conversely, if we have a theory that predicts that more particles may exist at higher levels of energy and nothing else, then there is no good reason to perform this experiment. Especially if the precise level of energy is a free parameter of the theory, so the theory won't change if the experiment fails.
> And Hossenfelder is correct that in hindsight naturalness wasn't a very good rule.
I believe that she is correct that naturalness wasn't a very good rule at all, not just in hindsight. It's as good a rule as it would have been to expect all numbers to be multiples of Pi.
The measurement problem isn't a physics thing, just like naturalness that's more of a life-style choice. In fact, the only reason to have problems with wave-function collapse is precisely a naturalness reasoning, technically it makes very accurate predictions just fine.
A GUT is specifically the part of a TOE that has nothing to do with gravity... A TOE is a GUT + a theory of quantum gravity.
If we had the Standard Model + a theory of quantum gravity, this could be a complete theory of the universe (pending explanations for dark matter, dark energy etc.). These could very well be completely separate phenomena, there is no reason to believe they reduce to a single phenomenon - that there exists a TOE.
> The measurement problem isn't a physics thing, just like naturalness that's more of a life-style choice. In fact, the only reason to have problems with wave-function collapse is precisely a naturalness reasoning, technically it makes very accurate predictions just fine.
This isn't entirely accurate. There is a very clear quantitative question behind the measurement problem: what kind of system constitutes a measurement device, in the sense of invoking the need for the Born rule? There must be some precise size/kind of system that, when a particle interacts with it, you can no longer use Schrodinger's equation to predict its movement after that interaction - you must apply the Born rule. We know that this doesn't happen after a particle collision, but that it does happen after a collision with a "detector".
This is a clear empirical question (you don't need to call it a problem), well within the realm of physics. It may be extremely difficult to answer, but I see no reason to imagine it is a priori impossible to resolve.
- Large-scale climate engineering
- Digitizing human consciousness
- Strong AI
- True life extension
- A replacement for the ISS
If you limit your characteristics to "involves high energy particle physics" it's pretty easy to put blinders on and pretend there aren't large challenges facing humanity that could potentially be solved by hard science progress and a lot of funding.
It would be great if people managed to organized around any of the goals you mentioned, so far it hasn’t happened at a comparative scale for various reasons.
I agree with her. These are nonsense arguments.
> Science shouldn’t be a zero sum game.
(2. The “No Zero Sum” argument)
> new accelerator leads to excellent technical advances at all levels of the stack
5. It is not a waste of money
11. It may lead to spin-offs.
12. A big particle collider would benefit many tech industries and scientific networks.
Any argument that sidesteps that is nonsense. If goal of investing in fundamental physics is not R&D it's just a side effect as I assume.
If I read your argument correctly it's "We can't give argument that this is the best way spend money if you want to solve these problems, but it will generate other side benefits that may help indirectly". It's honest argument if put that way.
As for the argument that cosmology or astronomy are more promising ways of yielding new insights, that's not something she ever bothers to discuss in detail. There's no articles about how the extremely noisy and uncertain constrains from astronomy are more worth to gamble on that than the much cleaner direct detections from accelerators.
And there's certainly no arguments about how we should stop giving so much money to the exoplanet researchers and their instruments instead of making satellites to measure the cosmic radio background. (There's not even a little post about how SpaceX will hamper radio astronomy by making sure there's no radio quiet place left on earth).
They have not given a good answer why particle accelerators they are asking for would give any answers at 100 TeV.
It's just biggest they can hope to get.
I don't understand this argument. We should prefer a particular experiment not because it is more likely to answer a research question but because it, itself, is more challenging?
As another example take the EU quantum initiative, they managed to get ~1 Billion and have promised to get ~5000 people working on it for ~10 years. That works out to ~20000 per person / per year. This only works because a lot of these people are so passionate about this project, that they are willing to self exploit themselves for years.
(And, BTW, the fact that some investment has a good ROI doesn't mean you should pick it over another with a higher ROI)
Poor people "shouldn’t" die from simple diseases. Is this the game, we are wishing away things we don't like?
Science 100% is zero sum. Especially talking the figures we are here.
How about we start with creating free science text books (that are not garbage) for the world then we'll let you blow multi-billions on your religion?
It's true for accelerators and a huge number of other things too. If this isn't unique to accelerators, it's not really a case for accelerators specifically.
> Isn’t it nice that a fraction of the smartest people on the world are not working on getting you to click Ads and are using machine learning to advance our understanding of the fundamental forces of nature?
This isn't a good faith argument. What if we got our smartest people working in hospitals or schools or orphanages instead of getting you to click ads? Maybe that's where the money should go. Think of the children.
> Generally speaking developing a new accelerator leads to excellent technical advances at all levels of the stack. Web browsers and HTML were invented at CERN.
The exact same argument can be made for military spending. The internet was invented at...
It is always such a dishonest argument to talk about spin-off benefits.
The empty promises she is talking about are the equivalent of the promises by politicians during a campaign: they are for the larger public, for the people who (rightfully!) don't want to get more informed than that.
In the background, both in science and in politics, technical folks know what they mean and, especially, where the money is actually going.
In the case of politics, it happens unfortunately that big chunks of the money involved go into private pockets.
Based on my experience, in the case of particle physics, that money invariably goes to wide technological improvement.
Very few sane people really cared whether the Higgs boson existed, but the world is a better place because we got our efforts together in order to find an answer.
- Superconducting magnets and power distribution
- Radiation hard ASICs and detectors
- CAD software like KICAD
- ROOT
- Grid computing infrastructure
- Analog circuit design (1024 channel low power ADCs, pixel sensors)
- FPGA design for data aggregation and communication
Would I trade a European-controlled alternative to Android and iOS for yet another particle collider in Geneva? Yes, absolutely.
Of course, the more fundamental point is that industry seems perfectly happy to try (and fail) at making Google competitors, while nobody in industry is going to do fundamental physics research.
PS: it sounds like there is some sort of EU plan for this:
https://fsfe.org/news/2020/news-20201023-01.en.html
They probably also need to fund an alternative to TSMC.
I find it a bit rich that Hossenfelder can criticise particle physics for only ruling out some dark matter with words such as "a type nobody has seen". There are no direct detection of dark matter at all, so why does she insist that the models particle physics speak of are any worse than the others?
At the core of the controversy around Hossenfelder is that from the fact there's not been any really _unexpected_ experimental results for four decades concludes that there's no point in doing particle physics. There is not really much more to the argument than that, the rest is just quoting the optimistic physicists over the pessimistic ones and pretend they don't agree on the need for more experiments.
JET has proved it is possible: https://ccfe.ukaea.uk/research/joint-european-torus/
ITER is taking JET's work to the next level https://www.iter.org/
Maybe it can't ever be made cheap or practical but worst case scenario it produces interesting results and spin offs like CERN does now.
I remember times when LHC was powered on. It was exiting and many things were speculated that this door would open.
And well... it all fizzled out quite quickly.
Building bigger collider feels like doubling down on a huge sunken cost fallacy.
It seems to me that particle physics post-LHC is just the same as it was pre-LHC. We verified the existence of the Higgs, which is great, but that meant no revisions to the Standard Model were needed as it already assumed the Higgs. And no exotic or unexpected new particles have turned up.
You can definitely argue that the technology spin-offs from the LHC have been great; but is that really an argument for another collider specifically, or just Big Science in general?
To put it another way, what’s the argument for a collider that goes beyond “provide employment for hundreds of high-energy physicists, and throw some unprecedented engineering and logistical challenges at then”? Is there a pitch that’s based on the science rather than the technology?
The LHC hasn't really shown us where to look, the hope is that a larger collider can give a more clear indication.
That said, I have this feeling that we're approaching the limits of "going big". There was a very interesting talk[2] over at Perimeter Institute recently about larger colliders and their feasibility.
[1]: https://www.physicsforums.com/threads/what-are-the-most-impo...
As a related tangent: we have verified the existence of the Higgs, but only partially.
What was so far measured was the interaction strength between Higgs and W bosons, Z bosons, and the top quarks: these are the main channels of Higgs production at the LHC, and they fit the theory prediction within 20%. Yes, 20%. Not precise at all. What about interaction between Higgs and the other 5 kinds of quarks? Electrons? Muons? Tau? Itself? The data ranges from +-100% to none at all.
In particular the measurement of Higgs-Higgs interaction is an important one: the assumption Standard Model makes about the strength of this interaction is not unique, and others are possible. We don't know yet: not enough data. Moreover models with multiple Higgs particles are possible. Again, we don't know yet, not enough data.
This is why some cautious researchers claim that we have discovered "a scalar particle", "believed to be Higgs", but further measurement is needed to determine all of its properties.
This is one of the main activities at LHC and among the theoreticians at the moment: measuring Higgs interactions with other particles. There is still way to improve precision with more data from LHC, but ultimately there is only so much it can do without increasing the energy.
In other words, we can all disagree. As it happens I do, but she's also not a lunatic whose ideas can just be dismissed as obviously uninformed.
Couldn't a more thorough understanding of particle physics be relevant to things like nano-materials or better understanding superconductivity or possibly additional ways to contain plasma for fusion?
Obviously we cannot indefinitely build larger accelerators, and if it turns out that there is no support to go at least one size bigger, then perhaps our best hope is to find more effective ways to use the existing ones we have.
As a random example to illustrate what I mean: https://www.google.nl/amp/s/phys.org/news/2018-07-plasma-siz...
Maybe stopping here will force more thinking along these lines? I hope so, anyway.
Basically if one idea out of a hundred major ones really takes off, that's considered a success for a researcher. We're talking one, maybe two real hits throughout the entire scientific career. Researchers are well aware that much of what they do and publish is of little consequence. And they have to make "empty promises" from time to time to continue getting funding from the easily distracted politicians and upper management. They also almost have to have lofty, aspirational goals to keep the motivation.
Basically 99% percent of work of a good, hard working researcher consists of going down the alleys to see if they are blind, which they nearly always are. But the remaining 1% often makes the whole thing worthwhile to all parties involved. The question is, can you pull off that 1% hail Mary or not.
The potential discoveries we're talking about in this case could upend industries, reshape the world economy, and bring about the post-scarcity future, at least when it comes to energy. If we're willing to strain credulity a little, they might even enable interstellar travel. Is that worth a few days of the Pentagon budget? To me, it is, as long as we maximize the chance of the aforementioned Hail Mary.
In contrast, an engineer that doesn't succeed with her ideas at least 50% of the time would quickly find herself out of a job, so by definition the amount of risk engineers take on is as little as possible.
This is a fair debate to have, even if my personal preferred answer is “do both”.
A typical experiment is to accelerate a lot protons and a lot of antiprotons (or other particle), make them collide, and see the "debris".
The "debris" can be a lot of things. So you must filter some of them. For example pick only the one that produce exactly two photons and two "jets" of mixed particles that are difficult to identify. Now you calculate the energy of the photons and make a nice graph, of number of collisions versus energy of the photons. Using the standard theory you expect a smooth curve, but if there is a new particle you will see a peak somewhere.
If you see something, you only see the peak. So good luck imagining what the particle can be and how it interact with the other particles.
Another team peek another filter, like the experiment that produce two photons and electron and a positron. They make a nice graphic and hope to see an unexpected peak.
Another team ...
If the current theory predicts a peak somewhere you should find it, but if you find an unexpected peak yuo may have founded a new particle.
The theoretical frameworks are useful to guess which filters may be interesting and give a chance to find a new particle. The problem is that there are just too many possible filters and you can't try all of them.
It just pisses me off that we spend trillions on bombing random people in the desert, yet a few billion for e.g. fusion research is an insurmountable obstacle.
As an aside, I think this is a great example of a role which fundamental science plays in society: It can facilitate step changes in technological progress.
Edit: are you downvoting because you don't think my comment contributes to the discussion, or because you don't agree?
This misrepresents what she says about weasel words.
Also she specifically addresses the "Discovery or serious exclusion"
I didn't downvote but I would guess you've only skimmed the written article, try watching the video.
It is both curious and sad to see the outsize attention given to bitter polemicists (and not just in physics).
Please read https://www.nature.com/articles/s41567-020-01054-6 .
Edit: downvotes? let me rephrase: if you care about particle physics then there was no reason to ignore the original proposal. if you care about outrage, on the other hand...
And in that tradition I guess I should have expected a dismissive reply using 'generic press release' to describe the Comment that introduces an entire section of Nature Physics.
It's a rare sight, and the contrarian view is necessary, we need red teams so that things don't become too one-sided and people can overcome their biases. I think the inherent structure in academia and in institutions like CERN make it difficult for dissenting voices to be heard, so I'm glad that the view that's going against the grain is getting more attention. In this era of censorship and punishing of whistleblowers I'm surprised she's freely critiquing their core arguments. Although I do see a lot of ad hominem attacks.
In a better forum the original proposal by the particle physics community would have reached the front page and then a version of this blog post could have been a valid comment.
Now it is the other way around and I think that is unfortunate. Why does it happen?
But-
I still think we should keep doing particle physics, for a while longer. We have built up a huge global community of physicists and engineers who do particle physics, and without a way for them to conduct experiments there won’t be any jobs for those people to do, and in 2 generations all that expertise will be gone. The praxis will be gone. After all, that’s what technology really is; it isn’t a set of books on a shelf, it’s networks of people, with skills and connections to each other, who can get things done. Let’s make sure we don’t pull the plug early.
i.e. exactly what happened for the top quark, without proof of which we wouldn't have a working standard model. Why wasn't that the example?
The last time a huge, costly, dedicated collider was built, it was in service of the Higgs prediction, and that worked out quite nicely.
For the LHC specifically, it was widely expected that it would find evidence of supersymmetry, and that pinning down the details would help identify which extensions to the Standard Model are worth pursuing. But in fact a) no evidence of supersymmetry has been found, and b) no new lines of inquiry have been suggested. Most theorists have simply adjusted their existing models, moving the goalposts to account for the lack of experimental support.
This is exactly what Hossenfelder is complaining about. Why double and triple down on the same strategy that hasn’t worked yet? Why not at least spread your bets across some different strategies?
More to the point, what is the alternative strategy that’s more likely to produce useful data? “Don’t do experiments to validate or invalidate theory” doesn’t obviously seem like it’s going to produce better results.
I'm no physicist either, so take my hot take with the appropriate pinch of salt. :) My understanding is that some variants and parameters should have been excluded, if you hold theorists to their ~2005 predictions, but in practice most theorists are essentially burying their heads in the sand, or ignoring their past predictions and just making new ones. Both Hossenfelder and Peter Woit (of the "Not Even Wrong" book and blog) have documented many such cases. Many theorists are still assuming supersymmetry as a basis for their work and essentially ignoring the fact that it didn't show up where expected.
More to the point, what is the alternative strategy that’s more likely to produce useful data?
I think it's "remove the focus from high-energy physics and particle colliders, bring more attention to less fashionable areas that might benefit more from huge big-budget experiments." I don't know of any specific proposals to do something completely different with the budget that might otherwise go to e.g. CERN's Future Circular Collider proposal. Hossenfelder has pointed to other big science projects that could produce more scientific bang-for-the-buck than the LHC, such as LIGO and the James Webb space telescope.
Someone will figure out how to make 1000 Tesla electromagnets at some point, and it's off to the races again. Without the need for more construction.
[Edit]Wrong! Turns out protons do emit energy as well... up to 6.7 KeV per turn. Source: https://en.wikipedia.org/wiki/Synchrotron_radiation
For this reason I've seen suggestions to do round electron-type accelerators but using the much heavier muons to get around the radiation problem.