I find the proton as a gluon dandelion cloud enthralling
When we blast it with higher and higher energies, we're asking new questions: "What are the momenta of your quarks? What's your color field arrangement?" There are many possible answers to those questions and we're now starting to see the landscape of them.
So having different answers based on how you look is really answering different questions, just like asking an electron: What's your momentum? What's your location?
This has a specific meaning and is not a word I would use here. For something to be "decoherent" the particle phases would need to be "uncorrelated" or "random", but given the internal wavelengths, masses, and strength of the interaction of the particles involved against the spatial dimension of the proton this is not the case under quantum field theory.
In some ways the problem of this being "complicated" is because it's intractably coherent with a fluctuating large number of particles interacting via three "colors" of self-interacting charge (very different from electric charge and not just "three" independent charges) to consider. I'd put money on any decoherence would likely simplify the problem.
> Normally, the universe only asks protons the question: "are you a proton?" and it's like "Yep I'm a proton." (What's your baryon number? What's your charge? etc)
Protons have internal structure (the quarks and gluons) and size. Those are relevant to its interactions. To consider a proton "by itself" and just reduced to quantum numbers is not "normal" if by "normal" you mean "protons at a scale in nature you deal with every day". Those protons are bound in nuclei and are modified by the fact they are bound. These effects have been explicitly measured and documented, the EMC effect being one of them. The "new questions" you are referring to are in fact relevant questions at low energies and are not "new". They are a large active area of research typically referred to as "medium energy" (despite the fact it extends into "low" energy traditional nuclear physics and high energy QCD physics).
Even in a hydrogen atom, the internal structure of the proton modifies the chemistry by small changes in the electronic shell energies, in particular contributions to the lamb shift which has been used to measure the radius of the proton.
Maybe most directly, if what you described were the case you wouldn't have so many decimals in atomic mass numbers of nuclei.
> So having different answers based on how you look is really answering different questions, just like asking an electron: What's your momentum? What's your location?
The problems of looking at quarks and gluons at different energy scales are also endemic to other forces (e.g. electromagnetic) and all particles (for example, look up the running of coupling constants and renormalization theory). Saying they are "different" questions is more akin to comparing questions of skyscraper engineering and concrete dust mechanics. They are not orthogonal as I would consider momentum and location. They're questions of scale and things like emergent effects at different scales.
There are orthogonal questions of internal structure to be considered, though. Deep inelastic scattering processes at high energies tend to ask the "what are the momentum" questions. Elastic nucleon form factors ask more the "location". They both exist in a unified framework of "generalized parton distributions".
And like the proton, this statement is somehow heavier than the entire article. What an absolutely bizarre, arrogant choice of words.
Recently, GPT informed me that the strong force is really a tiny after-effect of the "QCD force" (in the same way that the Van der Waals forces are after-effect of EM). Also, more and more questions about "dark matter" seem to be building up, suggesting that the standard Newton-Einstein story of gravity is far from the complete picture.
25 years ago it seemed like physics was mostly complete, and the only remaining work was exploring the corner cases and polishing out all the imperfections. It doesn't feel that way anymore! The confusing part is that modern physics is so unbelievably successful and useful for technology - if the underlying theory was way off, how could the tech work?
Physicists thought the same thing c. 1900, but then one of the "corner cases" turned into the ultraviolet catastrophe[1]. The consequences of the solution to that problem kept the whole field busy for a good part of the 20th century.
I'm highly skeptical of the idea that physics is anywhere near complete. The relative success of our technology gives us the illusory impression that we're almost done, but it's not obvious that physics even has a single, complete description that we can describe. We assume it does for convenience, in the same way that we assume the laws are constant everywhere in spacetime. I view this as both exciting and terrifying, but mostly exciting.
Around 125 years ago, many thought the same about physics, that physics is mostly complete and it just explaining and finishing some edge cases and polishing all our measurements. There was just two things that were a little bit puzzling, the "looming clouds" over physics (per Kelvin description) will later lead to both Quantum Theory and Theory of relativity (Black body radiation and Michelson–Morley experiment) and the fundamental change of our understanding for physics after that.
So I would not take this position. Does this mean we are in a similar moment? maybe, who knows?
Maybe you should not take everything GPT tells you at face value? I have no idea what this QCD force is supposed to be. The strong force is _the_ force of QCD. The Standard Model still considers the electromagnetic, weak and strong force. The description of the weak and EM force can be unified into the electroweak force and there are theories that try to also unify it with the strong force and even gravity, but there are issues on the theory side and no clear evidence on the experimental side as to which direction is the correct one.
The Standard Model and General Relativity are still our most successful theories. It is clear that they don't tell the whole picture, but (annoyingly?) it is not clear at all where this is going.
Just for dark matter there are probably a dozen proposed hypothetical particles, but so far we have found none. But maybe it's something completely different...
Who says "way" off? It's not complete to explain everything, but it explains a lot correctly enough to use it for calculations, predictions and practical effects. Same way Newton was and remains useful, and how people have been using maths and technology to solve problems for a long time since before Newton was born.
This is kind of just semantics. QCD describes both the force binding quarks inside protons and neutrons, and the residual force binding protons and neutrons. This is all part of the Standard Model, which has been essentially unchanged for the last 50 years. The big theoretical challenge is to incorporate gravity into this picture, but this is an almost impossible thing to explore experimentally because gravity is very weak compared to the other 3 forces. That's why the Standard Model is so successful, even though it doesn't incorporated gravity.
You might enjoy https://en.wikipedia.org/wiki/List_of_unsolved_problems_in_p...
There are several hierarchical levels at which the strong interaction and the electromagnetic interaction bind the components of matter.
The electromagnetic interaction attempts to neutralize the electric charge. To a first approximation this is achieved in atoms. The residual forces caused by imperfect neutralization bind atoms in molecules. Even between molecules there remain some even weaker residual attraction forces, which are the Van der Waals forces, which are thus at the third hierarchical level.
For the strong interaction, there are only 2 hierarchical levels, approximate charge neutralization is achieved in nucleons, which are bound by residual attractive forces into nuclei.
So the forces between the nucleons of a nucleus correspond to the inter-atomic forces from inside a molecule, not to the Van der Waals forces between molecules.
Doing away with theory and just keep the guessing. But seriously very interesting, though I barely understand anything.
The study of these things, on the other hand, is genuinely complex and difficult. But that's epistemology, not ontology.
Quantum chromodynamics is actually pretty similar to Maxwell's equations of electromagnetism. The big difference is that unlike photos, gluons interact with each other. This means goodbye to linear equations and simple planewave solutions. One can't even solve the equations in empty space, and only recently have supercomputers become powerful enough to make good, quantitative predictions about things like the proton mass.
How could something so remarkably stable and functionally indistinguishable among its peers also be so complex?
To your question, I think there is an elegant answer actually; most composite particles in QCD are unstable. They're either made out of equal parts matter and antimatter (like pions) or they're heavier than the proton, in which case they can decay into one (or more) protons (or antiprotons). If any of the internal complexities of the proton made it distinguishable from other protons, they wouldn't both be protons, and one could decay into the other. Quantum mechanics also helps to keep things simple by forcing the various properties of bound states to be quantized; there isn't a version of a proton where e.g. one of the quarks has a little more energy, similar to how the energies atomic orbitals are quantized.
One of the implications is that there are many interactions where most possible Feynman diagrams contribute non-negligibly. The advances in theory arguably have much more to do with improvements in techniques and the applied math used, such as in lattice QCD and Dean Lee's group for instance.
Neutrons and protons differ in their composition, a neutron being made of 2 d quarks + 1 u quark, while a proton is made of 1 d quark + 2 u quarks, much in the same way as a nucleus of tritium differs from a nucleus of helium 3, the former being made of 2 neutrons + 1 proton, while the latter is made of 1 neutron + 2 protons.
For the strong interactions, nucleons (i.e. protons and neutrons) and nuclei are analogous to what atoms and molecules are for the electromagnetic interaction.
The strong interaction attempts to neutralize the hadronic charge (a.k.a. color charge), while the electromagnetic interaction attempts to neutralize the electric charge.
To a first approximation, the hadronic charge is neutralized in nucleons and the electric charge is neutralized in atoms.
However, because of the movement of the quarks inside of a nucleon and of the electrons inside an atom, the neutralization of the charge is imperfect and there remain some residual forces of attraction, respectively strong and electromagnetic, which bind the nucleons into nuclei and the atoms into molecules. Because they are just residual forces, the binding forces between nucleons in a nucleus are much weaker than those between quarks in a nucleon, similarly to how the binding forces between atoms in a molecule are much weaker than those that bind most of the electrons to the nucleus in an atom.
While the leptons may be considered as truly elementary, at least in the current state of knowledge, the hadrons are composed of quarks, and the quarks have non-null color charge.
At present there is no hope of being able to produce any particle where quarks are separated, i.e. any particle with non-null total color charge, because when the distance between quarks increases the attraction force between them also increases (like they would have been bound by an elastic spring), until the force becomes high enough so that a pair quark-antiquark is generated, so the original hadron may split into 2 hadrons, both of which have null color charge and no free quarks can be produced (e.g. the quark initially being pulled apart is split away, but it takes with it the antiquark newly generated, forming a meson particle instead of a free quark).
Attempting to separate the quarks of a hadron has a result somewhat analogous to the attempt of separating the north and south poles of a magnet, when breaking the magnet produces a new pair of north and south poles, so you get 2 new magnets, each with a north and a south pole, instead of getting a north pole separated from the south pole.
Therefore, because neither free quarks nor combinations of quarks where the color charge is non-null can be produced, no "quarkish" elements can exist.
Nevertheless, while the normal chemical elements have nuclei composed of nucleons, i.e. protons and neutrons, it is possible to have nuclei composed of other hadrons, i.e. nuclei where besides protons or neutrons there are one or more of the so-called hyperons, which have a similar structure to nucleons, but which contain some heavier quarks than the u and d quarks that compose nucleons (there are also extremely short-lived heavier hadrons that contain more than 3 quarks, as long as the total color charge is null).
However, all hyperons have an extremely short half-life, much shorter than a second, so if such an exotic element containing hyperons in its nucleus were formed due to a very unlikely sequence of collisions between particles with very high energy, it would decay extremely quickly.
At the huge scale of the Universe, even extremely unlikely events may happen somewhere, so perhaps a few atoms of such hyperonic chemical elements have a transient existence somewhere (during a small fraction of a second), but their quantity must be truly negligible.
While a few atoms of such elements can be produced artificially or naturally, there is no chance to ever produce a quantity great enough to make a piece of material that you could see with your eyes, much less take in your hand (ignoring the extreme radioactivity of such an element, which would destroy anything close to it).
The only possible exception might be in extremely high gravitational fields, i.e. inside neutron stars and black holes, where there may be a chance that such hyperons could become stable due to the extreme pressure, but we do not really know the possible structure of matter in such conditions and in any case at such pressures there would be no chemical elements in the normal sense, as there would be no free electrons.
"Definitely complicated enough for us all to keep getting paid for a long time."
read hhgttg
Protons are WASM modules: Portable, sandboxed, rich internals, stable interface.
Neutrons are headless WASM: Same runtime, no external API, harder to drive or inspect.
Nuclei are Kubernetes: Orchestration, emergent behavior, scheduling, binding energy as overhead.
QCD is the runtime: One spec, wildly different behavior depending on scale.
Experiments are profilers: You never see the code, only traces, distributions, hotspots.
HN comments are undefined behavior and non-renormalizable noise: Unconstrained interactions, long-range correlations, destroyed predictability.
zahlman•1mo ago
I find that rather surprising.
tsimionescu•1mo ago
ephimetheus•1mo ago
TheOtherHobbes•1mo ago
Analysing hand-me-down neutron events from indirect collisions isn't quite as useful.
antonvs•1mo ago
Of course more experimental data is a good thing, but in this case it doesn’t seem obvious that it would lead to anything really new.
terminalbraid•1mo ago
tzs•1mo ago
When that happens is less understood, hence the discrepancies you mentioned.
antonvs•1mo ago
The comment I replied to talked about "new physics". That's a term that's used in physics to describe physics beyond the Standard Model. Better experimental data about neutron internals could certainly help constrain the neutron lifetime, but that would be likely to be experimental constraints on existing physics, not new physics in the sense that the term is normally used.
ephimetheus•1mo ago
There’s an ultra cold neutron source at Paul Scherrer that is used to measure if the neutron has an electric dipole moment. This is complementary to high energy experiments.
librasteve•1mo ago
Spallation generation: High-energy protons (~800 MeV) hit a heavy target, releasing a wide spectrum of fast neutrons up to hundreds of MeV. These are then moderated down to useful energies for experiments.
It’s not the LHC, sure. But I don’t see any reason (apart from “why bother”) why they can’t do spallation in Geneva. OK maybe there’s a cooling problem…
raverbashing•1mo ago
But neutrons can't go around a tube being guided by magnetic fields
librasteve•1mo ago
gozzoo•1mo ago
anamexis•1mo ago
ephimetheus•1mo ago
somat•1mo ago
Oh, your going to love this theory.
https://fondationlouisdebroglie.org/AFLB-222/MARK.TEX2.pdf
In summary, There is a way to model electrons as a twisted self enclosed em field.
A decent digest summary of the paper is this video
https://www.youtube.com/watch?v=hYyrgDEJLOA (Huygens Optics: Are Electrons made of Light? )
mcherm•1mo ago
creddit•1mo ago
dpark•1mo ago
creddit•1mo ago
dpark•1mo ago
I like to imagine that people this ridiculous get into fist fights on the street constantly.
Normal person: “My wife is the absolute best.”
Pedant: “Don’t you dare insult my wife!” fists fly
zahlman•1mo ago
petre•1mo ago