[metacritic12]

Doesn't this "explanation" just shift the question to what is stiffness? Like it refactored the question but didn't actually explain it.

Previously, we had statement "the weak force is short range". In order to explain it, we had to invent a new concept "stiffness" that is treated as a primitive and not explained in terms of other easy primitives, and then we get to "accurately" say that the weak force is short due to stiffness.

I grant the OP that stiffness might be hard to explain, but then why not just say "the weak force is short range -- and just take that as an axiom for now".

[ajkjk]

I think it's a big improvement. Stiffness is something you can picture directly, so the data -> conclusions inference "stiffness" -> "mass and short range" follows directly from the facts you know and your model of what they mean. Whereas "particles have mass" -> "short range" requires someone also telling you how the inference step (the ->) works, and you just memorize this as a fact: "somebody told me that mass implies short range". You can't do anything with that (without unpacking it into the math), and it's much harder to pattern-match to other situations, especially non-physical ones.

It seems to me like the right criteria for a good model is:

* there are as few non-intuitable inferences as possible, so most conclusions can be derived from a small amount of knowledge

* and of course, inferences you make with your intuition should not be wrong

(I suppose any time you approximate a model with a simpler one---such as the underlying math with a series of atomic notions, as in this case---you have done some simplification and now you might make wrong inferences. But a lot of the wrongness can be "controlled" with just a few more atoms. For instance "you can divide two numbers, unless the denominator is zero" is such a control: division is intuitive, but there's one special case, so you memorize the general rule plus the case, and that's still a good foundation for doing inference with)

[BrandoElFollito]

Intuition does not work in quantum mechanics. Intuition is based on observations at your scale, and this breaks dramatically at quantum levels. So this is not a good criterium.

[ajkjk]

That's false. Intuition does work in quantum mechanics, if you do the work to build up a good intuition for quantum mechanics. Which means exactly what I'm talking about: building your intuition on models that give true results in the situation, and which allow you to combine and remix atomic ideas in useful ways.

Unfortunately the version of QM that is taught in textbooks is not especially useful for figuring out what the intuition is. I have my own model that I've concocted that does a much better job, but there are still plenty of things I don't understand well (having not done, like, a graduate degree in it).

[BrandoElFollito]

I have a PhD in physics, which does not say much apart from the fact that I had to think about this a lot. My PhD was in particle physics.

What I learned over the years is that, unfortunately, at some point you rely on maths. You solve equations, make predictions, and compare this to measurements. Uf they match your model (conveyed through equations) is "good for now"

The problem is that a lot of what you mathematically witness, then measure at macro scales (you do not get to measure quantum effects at their scale, only their effects on the apparatus) does not make sense at our scale.

A particle appearing for a shirt moment from nothing, interacting with another particle and vanishing, WTF?

A particle with energy X hitting a "wall" with energy Y > X and going through? WTF?

Single particles interacting with each other? Another WTF

QM is full of surprises that sound cool when presented with enthusiasm and simple words, or used in MARVEL movies but they are as intuitive for typical people as cosmic travel for Neanderthals . Sure you can handwave your way through them but how does that work with a cave and wall paintings - which is what they would witness on an everyday basis.

[ajkjk]

Well, I don't agree. Maybe you are talking about how people's intuition initially breaks on the double-split experiment, or spinors, or whatever else? But I'm not talking about broken macroscopic intuition failing on quantum systems. Of course that doesn't work. There is a separate "quantum" intuition that you get over time which lets you make true inferences. Surely you have a bunch of it if you've got a PhD in this stuff.

Things like: if you think of particles as blobs of mass and charge, you get the wrong answers; if you think of them as interfering waves then you start to get right answers. If you think of them as interfering light waves, you get the right answer for a while until you hit a situation where spin=1 gives the wrong answer, or m≠0 means the transverse component is nonzero, so you fix your intuition on that and get better answers. If you think of particle-waves as discrete atomic objects you can't intuit how different particles can be created in scattering; if you think of them as a label given to a particular vector which can be decomposed as a sum of other vectors which interact differently with different fields then you can see how particle creation/annihilation works.

Etc. There certainly are models you can construct in your mind that make this stuff start to make sense. I don't have them all, but I'm working on it. Mindlessly doing math might work for homework problems but it's not enough for actually explaining anything; you need some mental picture of what's going on as well. But the math is always there to make your intuitions concrete and keep them grounded in reality.

[BrandoElFollito]

Look, physics is about discoveries and explanations. If your model explains everything we have measured then great -- publish it and you will get proper recognition.

I do not know your theory so I cannot comment on it, but when I was in academia I received quite a lot of these theories and they were breaking down rather quickly.

Physicists are always interested in new things but what you present must make sense and - most importantly - explain things and agree with measurements. If suddenly you end up with incorrect values it means the model is wrong. It may be completely wrong or maybe it needs adjustments.

The best way to send your message to the world is to publish.

[lilyball]

Besides the fact that stiffness shows up as a term in the equations, stiffness is a concept that can be demonstrated via analogy with a rubber sheet, and so lends itself to a somewhat more intuitive understanding.

Also, the math section demonstrated how stiffness produces both the short-range effect and the massive particles, so instead of just handwaving "massive particles is somehow related to the short range" the stiffness provides a clear answer as to why that's the case.

[drdec]

If you read far enough into the math-y explanations, stiffness is a quantity in the equations. That makes it more than a hand waving explanation in my book.

[exmadscientist]

In addition to what the sibling comments have said, the "axiom" is actually the term in the equations. That is, fundamentally, where this all comes from. "Stiffness" is just a word coined to help describe the behavior that arises from a term like this. Everything flows from having that piece in the math, so if you start there and with nothing else, you can reinvent everything else in the article. (Though it will take you a while.)

You might also ask where that term comes from. It really is "axiomatic": there is no a priori explanation for why anything like that should be in the equations. They just work out if you do that. Finding a good explanation for why things have to be this way and not that way is nothing more and nothing less than the search for the infamous Theory of Everything.

[_yb2s]

This is often I think a really unsatisfying thing about physics. Usually the qualitative descriptions don't quite make sense if you think very hard about them- and if you dig deeper it's often just "we found some math that fits our experimental data" - and ultimately that is as much as we know, and most attempts at explaining it conceptually are conjecture at best.

When I was a physics undergrad, most of my professors were fans of the "shut up and calculate" interpretation of quantum mechanics.

Ultimately, this is probably just a symptom of still not having yet discovered some really important stuff.

[devnullbrain]

As a rule, I think physics should be expected to make less sense the further it gets from the human scale. It's not because it's inherently more complex, it's because we benefit from millions of years of brains evolving to understand what we can see and touch.

[openrisk]

The universe does not owe us explainability in terms of everyday intuition.

You don't just "find some math that fits the data" the way you would mechanically tune the parameters of a given mathematical model to fit empirical data.

Indeed finding a mathematical formulation that seems to describe a corner of reality with any fidelity is such an extraordinary thing that physicists have always puzzled about why it is even possible!

Now it turns out that these mathematical inventions "work" even when our intuition (built on experiences around human scale) cannot quite grasp them. This is the case both in the realms of the very small (quantum) and very big (relativity).

This doesnt mean that at some point we might not find deeper mathematical abstractions that "work better" (e.g., this was the string theory ambition) but the practical result would still be every bit "shut up and calculate".

[l33tman]

This is far from the truth in particle physics. The symmetries we've found there (together with the Lorentz symmetry from special relativity) guides and constrains the math very strongly, to the degree that it allows you to predict the photon and the other force-carrying particles, and it even allowed predicting the existence and mass of the weak force carriers (discussed in the article) along with the Higgs mechanism that gives masses to them and most of the other particles. This is certainly a triumph of the Standard Model.

There are limits to how much you can do though, I mean at some point it's going to be "just math that fits reality". If you try to enumerate the number of mechanisms and realities that could give a decent enough diversity of composition that life can arise in some form, there's going to be more than our universe possible.

[bsder]

> When I was a physics undergrad, most of my professors were fans of the "shut up and calculate" interpretation of quantum mechanics.

Well, you build "intuition" via "experience"--generally lots of experience to get small amounts of intuition.

> Usually the qualitative descriptions don't quite make sense if you think very hard about them- and if you dig deeper it's often just "we found some math that fits our experimental data"

Well, the math needs to fit the data and have predictive power. That "predictive" side is really important and is what sets "science" apart from everything else.

> Ultimately, this is probably just a symptom of still not having yet discovered some really important stuff.

Sure. But wouldn't the world be incredibly boring if we had it all figured out?

[cellular]

In my gravity simulations, on my YouTube, i found the short weak force distance was the same needed to avoid opposite charges from gaining so much speed that the next iteration's position wouldn't slow the electron down after passing the proton!

Imagine my surprise!!

We might live in a simulation!

[pas]

care to link to your YT videos?

[monadINtop]

I think its more than "we just found some math that fits the data" in the sense that its not just a case of adding some terms to match an observed curve - for example like with Rayleigh-Jeans' law vs Wein's Approximation of blackbody radiation and eventually Max Planck's solution by quantizing energy to the curve match experiment, without actually having anything else to say about it.

Spiritually it feels more like what happened later, when people took the idea of quantized energy seriously and began finding ways to make it a theoretically consistent theory which also required a radical new approach of disregarding old intuitive assumptions about the way the most fundamental things worked solely to obey a new abstract, esoteric, purely theoretical framework (an approach which was sometimes controversial especially with experimentalists).

But of course this new theory of quantum mechanics turned out to be immensely successful in totally unprecedented ways, in a manner similar to Relativity and it's "theory first" origin with trying to ensure mathematical consistency of Maxwell's equations and disregarding anything else in the way (and eventually with Einstein's decade long quest to find a totally covariant general theory that folded gravity into the mix).

With physics the more I dug into "why" it was rarely the case that it was "just because", the justification was nearly always some abstract piece of math that I wasn't equipped to understand at the time but was richly rewarded later on when I spent the time studying in order to finally appreciate it.

The first time I solved Schrodinger Equation for a hydrogen atom, I couldn't see why anyone could've bothered to try discovering how to untangle such a mess of a differential equation with a thousand stubborn terms and strange substitutions (ylm??) and spherical coordinate transformations - all for a solution I had zero intuition or interest in. After I had a better grasp of the duality between those square integrable complex functions and abstract vector spaces I found classical QM elegant in an way I wasn't able to see before. When basic Lie theory and representations was drilled into my head and I had answered a hundred questions about different matrix representations of the SU(n) and S0(3) groups and their algebras and how they were related, it finally clicked how naturally those ylm angular momentum things I saw before actually arose. It was spooky how group theory had manifested in something as ubiquitous and tangible as the structure of the periodic table. After drudging through the derivation of QFT for the first time, when I finally understood what was meant by "all particles and fields that exist are nothing more than representations of the Poincare-Spacetime Algebra", I felt like Neo when everything turned into strings of code. And there's no point describing what it was like when Einstein's field equations clicked, before then I never really got what people meant by the beauty of mathematics or physics.

I guess its not really the answer "why" things are, but the way our current theories basically constrain nearly everything we see (at least from the bottom up) from a handful of axioms and cherry-picked coupling constants, the rest warped into shape and set in stone only by the self-consistency of mathematics, I feel like that's more of a "why" than I would've ever assumed answerable, and maybe more of one than I deserve.

[_yb2s]

I only got as far as "solved Schrodinger equation for a hydrogen atom" and never got to the next stage you describe with physics.

In a sense, I think your explanation is consistent with mine, but with the deeper context of math being a language itself, and the math itself being a more satisfactory explanation to someone with a greater intuition for what the equations actually mean. I can pump through all of the major equations in physics and explain almost anything I want with them, but it always just feels like rote application of algebra rules to completely arbitrary seeming formulas- nothing like what you describe. Frankly, I think I was more interested in girls than studying when I was a physics student decades ago, and I could probably get a lot more out of it revisiting this stuff now.

However, I do still think there is a real chance that we are missing something big that would fit all of these pieces together with qualitative explanations. Personally, I think Julian Barbour is likely on the right path with his timeless physics, but if so it will need a lot more research and development.

[scotty79]

'Stiffness' is a better concept because it can be used to explain behavior of all forces of finite and infinite range and why force mediators can have mass or not.

If you need to assume some axiomatic concept it's better to assume one that can used to derive a lot of what is observed.

[cellular]

I don't think electric force is necessarily shorter distance than gravity.

But electric charges cancel out each other over big regions, while gravity never cancels.

[seanhunter]

Not a physicist, but in classical mechanics stiffness is just the proportionality of some restorative force (ie the extent to which something tries to bounce back when you push it). It definitely would be overkill to make it an axiom.

So say you have a spring if you compress it, it pushes because it wants to go back to its natural length and likewise if you stretch it there is a restorative force in the opposite direction. The constant of proportionality of that force (in N/m) is the stiffness of the spring, and the force from the spring[1] is something like F=-k x with x being the position measured from the natural length of the spring and k being the stiffness. So not knowing anything about electromagnetism I read this and thought about fields having a similar property like when you have two magnets and you push like poles towards each other, the magnetic field creates a restorative force pushing them apart and the constant is presumably the stiffness of the field.

But obviously I’m missing a piece somewhere because as you can see the force of a spring is proportional to distance whereas here we’re talking about something which is short-range compared to gravity and gravity falls off with the square of distance so it has to decay more rapidly than that.

Edit to add: in TFA, the author defines stiffness as follows:

   For a field, what I mean by “stiffness” is crudely this: if a field is stiff, then making its value non-zero requires more energy than if the field is not stiff.

So this coincides with the idea of restorative force of something like a spring and is presumably why he's using this word.

[1] Hooke’s law says the force is actually H = k (x-l)ŝ where k is stiffness, l is the natural length of the spring and ŝ is a unit vector that points from the end you’re talking about back towards the centre of the spring.

[neutronicus]

A simple, classical case where "stiff" fields arise is electrostatic plasma physics.

Electrons are tiny and nuclei are huge, so you have a bunch of mobile charge carriers which cost energy to displace to an equilibrium position away from their immobile "homes". A collection of test charges moving "slowly" through the plasma (not inducing B field, electrons have time to reach equilibrium positions) will produce exponentially decaying potentials like in the article. If you want to read more, this concept is called "Debye Screening"

Anyway, this might be a more helpful approach than trying to imagine a spring - a "stiff" field equation is an equation for a field in a medium that polarizes to oppose it, and you can think of space as polarizing to oppose the existence of a Z Boson in a way that it doesn't polarize to oppose the existence of a photon.

[pishpash]

Because you may get something else out of stiffness besides this explanation? Usually that's how a level deeper explanation works.