A deepening crisis forces physicists to rethink the structure of nature’s laws

https://www.quantamagazine.org/crisis-in-particle-physics-forces-a-rethink-of-what-is-natural-20220301/

by theafh • 4 years ago

162 103 4 years ago

peter303• 4 years ago

The muon was the first WhatTheF particle discovered from cosmic rays. It and its associated quarks and leptons do not appear to participate in any physics necessary for the observable universe functioning.

And the muon vexes us again with an observed g2 moment the differs from its theoretical value greater than measurement error. This again suggests there is more unknown physics out there.

lumost• 4 years ago

I strongly suspect that new high energy physics advances will come from investigating astronomically generated phenomenon.

- Gravitational Waves for probing extremely large and small objects - Cosmic Rays for probing high energy particles. - Solar probes to detect particles made from stellar phenomena

leashless2• 4 years ago

I think these datasets also point the way to some new physics.

https://slate.com/technology/2021/07/shane-harris-interview-...

bigbillheck• 4 years ago

Depends on what you mean by 'observable'. Proton mass (for example) depends in part on all 3 generations of quarks.

iratewizard• 4 years ago

They could just be spandrels. Lots of things in nature exist with no real purpose.

antonvs4• 4 years ago

The idea that all particles should "participate in physics necessary for the observable universe functioning" is not a rational position, unless you assume a premise such as "the universe was created for a purpose."

Without such a premise, it is completely expected that not every aspect of the universe should have something to do with its functioning.

Even in pure mathematics, with no dependence on the physical universe, you have Gödelian unprovable propositions which, as Gregory Chaitin put it, are "true for no reason, they're true by accident." If the universe did not include a physical equivalent to this, it would be quite a surprise which would tell us that something very unusual was up.

robwwilliams2• 4 years ago

LOL, what a fun perspective. You just made Einstein groan.

russdill• 4 years ago

I sometimes wonder if the laws governing the universe are a bit like a Taylor series. An infinite set of terms each with a smaller effect on reality quickly approaching zero.

voxl• 4 years ago

I kind of see what you're getting at, but don't think you've described it well.

My attempt to restate your position: Suppose you write a program that just so happens to log information every leap day. No one uses the information, it doesn't effect the rest of the observable output. If you delete this logging from the program, no one else notices.

The complete observable properties of the universe (the program) include this logging, but the functioning of it is not really dependent on the logging. Thus, we probably should expect that there are some aspects of the universe that are independent, they don't really matter (or at least don't substantially matter) beyond their own observation.

misja111• 4 years ago

The point is that in empirical science, we take our observations of the universe as the starting point. And not any ideas or theories of how we think the universe should function. There was a time before empirical science took off, that the latter was still the modus operandi, a lot of beautiful theories were made but in the end science got hopelessly stuck.

It's funny that we're a bit in a similar situation now. Again we have a bunch of theories, e.g. in cosmology and quantum theory, that are based on not much more than an idea of how things should be. The Great Unification Theory springs to mind for instance. And again we seem to be stuck.

oraphalous• 4 years ago

I wish they didn't use the term "crisis" for this. It's nothing like the problems other disciplines are having with respect to replication failure - where maybe the term is appropriate.

Physics can still explain / predict a shit-load of phenomena. It's not a crisis - just more work to do.

brummm2• 4 years ago

I mean, replication failures are a result of bad science, bad analysis and a poor understanding of statistics in many cases. It's not so much a crisis in the state of human knowledge but the state of the education of the scientists in those other disciplines.

naasking• 4 years ago

It's a crisis because it's so widespread and the denial that it's a problem is strong.

pasadenasunset• 4 years ago

The phenomena are related, though. One could argue that the social sciences, with greater latitude in definitions of measurement and thresholds for statistical significance, had been building sand castles for decades. Eventually, the entire rotten edifice will collapse.

In contrast, the greater restrictions of theory and measurement in physical science didn’t easily allow researchers to do pointless hand-waving that looked good. In some sense, the “crisis” in physics is less embarassing, as it is simply theorists bumping into limits enforced by reality. They didn’t make it up as they went along.

I’m also doubtful the lauded “open science” movement will accomplish anything besides the mass transfer of intellectual property to centralized data platforms, to be mined by replication specialists.

I’m biased, admittedly, after watching an APA zoom conference on the advantages and wonders of open science, and why researchers should join in. The lead presenter’s #1 reason to join open science was “that I didn’t lose my data anymore, it was all nicely and neatly centralized on the OSF server.”

Speechless.

robwwilliams2• 4 years ago

In biology, neuroscience, and psychology replication failure is often the result of an impedance mismatch between reductive models and real systems complexity.

This is an acute problem in animal research where 90% of work gets away with using a single genotype in a single environment. And then the “wise” old heads at NIH wonder that there is a replication bias? Really?

ordu• 4 years ago

They refer to a crisis in a sense Thomas Kuhn used. The point where paradigm shift is needed. Physics has experience with it. General relativity theory was a paradigm shift following a crisis.

javajosh3• 4 years ago

Kuhn is a red herring. The issue is that physicists are too far removed from experimental checks. The scientific method requires experiment to confirm a hypothesis. The separation of theory from experiment has enabled a generation (or three) of physicists to ignore experiment entirely, spending happy careers playing with the implications of unfalsifiable theories like M-Brain theory or string theory. One gets the impression of a group of very smart people hiding behind their credentials, first unwilling to let their theories be tested, and next brazenly claiming that their theories cannot be tested, and that's okay. That's not okay, and they should lose their jobs.

colechristensen• 4 years ago

I wish people used the word crisis less and with a more narrow definition restricted to a short time which unexpectedly forces decisions or changes with long ranging consequences, and not a synonym for “shit is bad”.

brummm2• 4 years ago

There is a slight mistake in the article. The standard model does not describe the neutrinos. In the standard model neutrinos are massless particles, but in reality they are not.

pdonis3• 4 years ago

The standard model does not describe the neutrinos. In the standard model neutrinos are massless particles, but in reality they are not.

That's a bit strong. The SM still makes good predictions for many processes involving neutrinos. We just know, since the discovery of neutrino masses, that the SM, or at least the original version of it (there are proposed mechanisms that can handle neutrino masses without modifying anything else in the SM, although they still have some issues), can only be an approximation regarding neutrinos. But the SM is pretty much considered an approximation (or, as it is usually termed, an effective field theory) anyway.

KolenCh8• 4 years ago

I understand your point, but depending on who you ask, the (massive) neutrinos are well described in the Standard Model framework, just we we don't know exactly what that term looks like.

So depending on who you ask, they may not regard (massive) neutrinos as "beyond standard model".

ncmncm3• 4 years ago

I have been as derisive as anybody about string theory's entire lack of experimentally realizable predictions. But some things give me pause. The first is its interpretation of black holes as existing entirely at the event horizon surface, with no actual space-time inside; and the black hole entropy exactly matching the set of states of strings living in the 2D horizon layer. Eliminating that singularity is a big delivery.

This seems like another case where it can deliver something useful.

akvadrako• 4 years ago

How does that depend on string theory? Also, what do you mean by "string theory"? Do you mean M-theory?

ssivark2• 4 years ago

Per current understanding, “M-theory” is one of five consistent descriptions of string theory , all of which are supposed to be related by dualities i.e. each description makes certain aspects easily manifest, but they’re all equally “correct”.

KolenCh8• 4 years ago

I don't see your train of thought here, you first mention the lack of "experimentally realizable predictions", i.e. not falsifiable, and then gives one of the many examples that string theory solved without being able to experimentally verified.

Why would that give you a pause? How this single example is different from all other "predictions" from string theory?

Jerry2• 4 years ago

Prof. Sabine Hossenfelder has a great article on the lack of progress in fundamentals of physics: "The present phase of stagnation in the foundations of physics is not normal " [1]

Choice quotes:

We know this both because dark matter is merely a placeholder for something we don’t understand, and because the mathematical formulation of particle physics is incompatible with the math we use for gravity. Physicists knew about these two problems already in 1930s. And until the 1970s, they made great progress. But since then, theory development in the foundations of physics has stalled. If experiments find anything new now, that will be despite, not because of, some ten-thousands of wrong predictions.
Ten-thousands of wrong predictions sounds dramatic, but it’s actually an underestimate. I am merely summing up predictions that have been made for physics beyond the standard model which the Large Hadron Collider (LHC) was supposed to find: All the extra dimensions in their multiple shapes and configurations, all the pretty symmetry groups, all the new particles with the fancy names. You can estimate the total number of such predictions by counting the papers, or, alternatively, the people working in the fields and their average productivity.

According to her, and many other physicists, there hasn't been any major progress in phenomenology since 1970s when Higgs boson was postulated.

[1] https://backreaction.blogspot.com/2018/11/the-present-phase-...

ramraj07• 4 years ago

You don’t even need to be a physicist to see that they haven’t introduced anything new physics wise in the last 5 decades. Alcubierre drive maybe?

whatshisface2• 4 years ago

Off the top of my head, they've made progress in quark-gluon plasma, discovering the AdS/CFT correspondence, and practical techniques for quantum computing. There's been enormous progress in computational methods, too. There's also been something very interesting going on with twistors. Oh, and 50 years ago quantum field theory was not on a formally sound footing, but now it is (not completely but it's closer). There's also a lot of progress in renormalization (RG group flow).

Oh, and don't forget about fifty years of Moore's law. We have solid state to thank for that.

I'm sure I could think of more if I gave it more time. The truth is that there have been no earthshattierng paradigm shifts in the last fifty years, but that's OK because they tend to happen once every couple centuries.

Iwan-Zotow• 4 years ago

Alcubierre drive maybe?

this is old physics, just another solution of the GR

lyaa• 4 years ago

Topological materials are relatively new and increasingly promising for both technological and pure science reasons.

salty_biscuits• 4 years ago

Fractional quantum hall effect is a massive one. All the action is in condensed matter. Somehow less newsworthy despite being closer to practical applications than high energy physics.

throwawaylinux• 4 years ago

A lot of fields go through S-curve advancements, which is normal.

Physics is unfortunately looking very normal.

derbOac• 4 years ago

Might not be a coincidence that Higgs has said he wouldn't have an academic position today.

narrator2• 4 years ago

Could Einstein, being a patent clerk, have gotten his papers published these days? Is there room for non-professionals, or people outside the system to come in and disrupt it? It seems that there's a lot of disregard of wild alternative theories like quantum mechanics would have seemed in the early 20th century.

wrycoder• 4 years ago

Dr. Hossenfelder is a Research Fellow at FIAS. I don’t think she is a professor.

narrator2• 4 years ago

The last time we moved fundamental physics forward we got nuclear weapons. Thus, one could argue that there's good and bad parts to our current technological stagnation. Imagine having a spaceship that could travel at relativistic speeds. Can you imagine getting into a traffic accident with that thing?

scythe• 4 years ago

The theories that we were dealing with around the dawn of QM/GR were relatively tractable; we could make long-enough-term predictions about the behavior of many systems and we had a library of observations that clearly and reproducibly deviated from those predictions. We had even begun to draw vague correlations among the diverging data.

Today, we have experimental data that diverges from predictions... regarding... the number of neutrino collisions we can observe in certain giant tanks of highly pure liquids, and... the scale of variation in the cosmic microwave background and long-range mass density is too small, oh, and... galaxies rotate kinda weird... free neutron lifetime measurements disagree by about 1.1%.... there's not quite enough lithium in the Universe (no, really)... good luck tying all this together into a theory of everything!

KolenCh8• 4 years ago

"The Trouble with Physics" by Lee Smolin also talk about this, and the general "group-think" situation of theoretical physics.

anamax• 4 years ago

Wolfram might disagree about the "lack of progress" in the fundamentals of physics.

It's said that every cosmologist who dies gets to add a "law of nature" consistent with known observations. I wonder what Conway added.

antonvs4• 4 years ago

What progress would Wolfram point to? Please don't tell me the answer involves cellular automata. That's completely unsupported by any evidence.

stjohnswarts• 4 years ago

I hate when people call it a “crisis” . Science has brought us amazing insights and capabilities. It's not in a crisis. They will simply have to shift gears and work on other projects if they have dug as far as they can for now with today's technology and mathematics. There is still plenty to spend human brain power on and physicists have plenty of new places to go to.

joe__f• 4 years ago

I absolutely agree with this. There's also a quote in the article from one of the scientists saying they don't like calling it a crisis

KolenCh8• 4 years ago

You're quoting

“Some people call it a crisis. That has a pessimistic vibe associated to it and I don’t feel that way about it,” said Garcia Garcia. “It’s a time where I feel like we are on to something profound.”

They are using past experience of a crisis (say from late 19-century) to infer what comes next is a major paradigm shift. This might very well be true, but we didn't know that. We should be optimistic about our career and the future of physics, true. But we should not be in denial that this is a crisis. There's absolutely no information (but hints) we have right now that tells you a breakthrough is coming. The next paradigm shift may happen in arbitrary far future, or may not happened at all if it is out of the reach of humanity.

Also, people don't call it crisis just because we hit a wall. But we're hitting a half century wall now (since 1970s.)

pasquinelli• 4 years ago

i think you've defined the crisis.

They will simply have to shift gears and work on other projects if they have dug as far as they can for now with today's technology and mathematics.

if that's what they simply have to do, is it being done?

piva00• 4 years ago

I get the same reaction. Makes me think if it isn't the current zeitgeist mindset of continuous and constant growth seeping into scientific evaluation by laypeople.

Science doesn't need to constantly grow into all directions it has achieved at the same time, it's not a market competition. I feel that sometimes it gets evaluated as such by some media vehicles...

KolenCh8• 4 years ago

Well, it is a crisis to people who bet their career in this field. These people are here to stay (in the field) and since there are no experimental progress that shed lights on fundamental physics, the effort of all these people are stuck in coming up with theories in existing paradigm that is still compatible with the increasingly more stringent limit from experimental physics.

They didn't shift gears and work on other projects. The whole field bet in String Theory and are stuck. Like explained in the book "The Trouble with Physics", it is a career suicide for people not wanting to deal with String Theory and still be a theoretical physicists in high energy physics.

One may say a similar crisis has happened by the end of 19-th century. All but a few peculiarity in Physics were explained by the then modern physics. Some thought theory of physics were almost "complete", and only later to find out a major paradigm shift (actually 2, quantum theory and relativity) completely changed the way we viewed physics, and now becomes our cornerstone to understand physics.

AFAIK, physicists generally like this kind of crisis, some make a career chasing crisis, because this might be the hint of new physics and the next paradigm shift.

rossjudson• 4 years ago

First Europe is broken, then the global climate, and now physics. Reality has had a bad week.

sans-serif• 4 years ago

Those are all "crises" in different senses of the word.

wiz21c• 4 years ago

but none of them brings a happy face...

krazii• 4 years ago

Why does nature have to be lawlike?

dboreham2• 4 years ago

Otherwise there's no spec for the sim developers to follow.

tsimionescu4• 4 years ago

Nature doesn't have to be anything.

However, a universe that doesn't have any laws would be an amorphous mush. Forget about planets and stars, it could not even have atoms or molecules - you need an awful lot of stable structure (i.e. laws) to get something as complex as a water molecule out of random particle interactions.

ciphol6• 4 years ago

Our investigations ever since the scientific revolution have progressively shown it to be more and more lawlike. It would be a bit of a surprise if this stopped being true.

silent_cal2• 4 years ago

Science assumes that nature is lawlike. Otherwise it would be senseless to make predictions.

silent_cal2• 4 years ago

If it wasn't, we couldn't do any science.

pc2g4d• 4 years ago

I like that they draw the Higgs boson as a D20 :-D

yalogin• 4 years ago

Do we know what the pay discrepancy between physics research and computer science and finance jobs. I wonder if we are attracting the brightest minds in high paying jobs.

Havoc• 4 years ago

Crisis sounds so negative. Isn’t this desirable. Ie means there is more to be discovered . I would have thought people in the field would be stoked about the possibilities

mrich• 4 years ago

Just recently finished the Three Body trilogy and there are some interesting connections to the described dilemma in there (alien objects hindering scientific progress of mankind by messing with particle colliders, n dimensional space and weapons that destroy whole dimensionalities)

ohiovr• 4 years ago

They should have known how wrong they were when they saw the motion of galaxies right then and there.

KolenCh8• 4 years ago

Summary:

# Background material

- Fundamental (particle) Physics has no progress since the 1970s.

    - discovery of Higgs is confirmation of old Physics.

    - other predicted fundamental particles has never been discovered.

- Fine tuning problems

    - smallness of Higgs mass

    - smallness of the cosmological constants

- reductionism as Kenneth Wilson's concept of effective field theory (EFT)

    - separation of scales—UV (small scales)

        can be treated as a cut off of IR (large scales).

# Main message

The 2 fine tuning problems above are examples that are UV-sensitive, unlike other usual examples in EFT.

This is hint of physics that mixes UV and IR scale: example of black hole—higher energy -> larger event horizon.

"Gravity is anti-reductionist"

Then it went on to cites these papers pointing to relevant research about this idea:

* [\[0801.2562\] Naturally Speaking: The Naturalness Criterion and Physics at the LHC](https://arxiv.org/abs/0801.2562)

* [Phys. Rev. Lett. 82, 4971 (1999) - Effective Field Theory, Black Holes, and the Cosmological Constant](https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.82...)

* [\[2107.03530\] Densities of States and the CKN Bound](https://arxiv.org/abs/2107.03530)

* [\[2106.04622\] Calculating the Higgs Mass in String Theory](https://arxiv.org/abs/2106.04622)

* [\[hep-th/9912072\] Noncommutative Perturbative Dynamics](https://arxiv.org/abs/hep-th/9912072)

* [\[1909.01365\] IR Dynamics from UV Divergences: UV/IR Mixing, NCFT, and the Hierarchy Problem](https://arxiv.org/abs/1909.01365)

* [\[1904.08426\] The Weak Scale from Weak Gravity](https://arxiv.org/abs/1904.08426)

* [\[1305.6939\] Natural Tuning: Towards A Proof of Concept](https://arxiv.org/abs/1305.6939)

* [Phys. Rev. Lett. 127, 101101 (2021) - Hidden Symmetry of Vanishing Love Numbers](https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.12...)

A deepening crisis forces physicists to rethink the structure of nature’s laws

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