joigus

Thanks a lot. Very useful. +1

I can't think of any reason why that would be impossible. My intuition, though, is that trying to study this process in dirty jets of QCD is perhaps not the best way. But the more accurately the QCD background is known, I suppose the easier it will become to subtract it from whatever's happening and detect cross sections of new physics. I would suggest to contact people who know about luminosities, etc. in the LHC. I'm not sure that people neglect it because they feel certain about it. Maybe it's just about difficulties in measuring it. In the last years, some colossal BHs have been argued to be just too big to have accreted from stellar matter. Perhaps they are more primeval objects than anybody had thought thus far. I don't think we have a complete picture of how all BHs arise. Collapse from neutron stars may just be one way for a stellar object to become a BH. For all I know, BHs could be violating baryon conservation like crazy. And then there's the possibility of primordial BHs... If you take a look at the SM Lagrangian, it just looks as if baryon number were the remains of an honest-to-goodness gauge theory, but some extreme process had stripped the baryons completely clean of their baryonic gauge "dressing". The space of possible ideas that are still reasonable is richer than we sometimes dare to think. I have just looked up "baryon number violation and black holes" and there seem to be lots of papers. And even one that proposes something very similar to what I was trying to suggest (that they have something to do in baryogenesis): https://cds.cern.ch/record/355696/files/9805455.pdf It's from 1998. Keep in mind that it's usually called "baryogenesis", but what people really mean is both baryogenesis and leptogenesis.

Those are quite plausible. I applaud them.

LOL. Pray you, insulate the walls!!!

You're right. What else can I say? +1 Perhaps this: I've been looking at Calabi-Yau manifolds for years and to me they look like things that, no matter where you're at in them, seem to try to twist spherically in one direction and hyperbollically in another. They're like (and I'm struggling for a rough picture here) trying to open holes in every point but never quite completely opening them, so what they "open" is just more and more saddle points. I don't know if it's clear what I'm trying to point at here. Irrespective of how sensible this picture is, you may be totally right that the topology may be totally crazy, and it's only the coarse-grained picture of it that gives the illusion of locality. But somehow I don't think any of that touches much on Bell's theorem territory, so to speak. I could be wrong, of course. ER=EPR is another issue I'm struggling to understand. It seems that experts themselves are trying to figure out what feature of BHs is really fundamental in the sense that other features like scrambling, or entropy, etc., are more naturally derived from the defining issue. I must look at ER=EPR in more detail. I've got some references but I never seem to get around to it.

Oh, oh. Much of the heat in the Earth's interior comes from furious radioactive decay. Full of heavy elements there. That's why Kelvin got the age of the Earth wrong by quite a long shot. If you assume air temperature to come from there you may be faced with no sensible hydrodynamic regime being able to account for it. I think that's why, even though I was sloppy, sheer substitution in hydrodynamic formulas with T at centre = Tcore gave me crazy numbers. And believe me, "crazy" is an understatement. It's true that I tend to do these calculations at 3 in the morning, so... I do believe you are deep in the regime of "hard balls" there. Ionization may play a part too, as MigL says. May I ask where this problem came from? Did somebody give it to you as an assignment or is it just for the fun of it? Yep. I think it's a plasma down there even if you impose isolating walls. But even so, the "stellar" approximation would be less off than assuming an ideal gas. Nothing ideal in that situation.

Good try. +1 But he's proved you wrong because... He's got a Latin name for those things. Who could argue with that? And at this point I leave.

Good point. I think betting might be involved too. I've thought of that myself.

Thank you, you're pretty funny yourself. I'm sorry about the coffee stains. Mind you, he's written "Nothing" with a capital.

He must have watched a couple of documentaries about intelligent design.

This really says it all about your "approach".

Selective breeding changes the rules of the game. Even at molecular / tissue formation level. Have you ever wondered why black and white spotted animals are very common in selectively-bred species and not at all in the wild? How does the fur of these animals know their immediate ancestors have bred selectively? I can give you references if you're interested. "Selective breeding gives wild variation" is a known pattern that's in the process of being understood. It's been witnessed. But the evolution clock is so slow that you have to look very hard. I can give you references if you're interested. You don't understand evolution, but now I understand that you don't understand evolution.

Looking forward to it. Don't feel any pressure. I think I can try and look it up. So, again, no rush. The observation is interesting enough so that I won't forget. You're probably right. I'd say I'm learning about this probably much more slowly than you are. I trust you far more than I trust myself, and I don't say that out of courtesy. I wouldn't dare to correct you at this point. I've been watching 3 ICTS lectures by one of the authors of the Kerr/CFT duality you told me about (Alejandra Castro) whom Lubos Motl (wrongly, probably) mentions as Alejandra Fidel Castro (LOL). Curiously enough, she avoids mentioning anything about future timelike and past timelike at some point. Those are AdS/CFT lectures. The sound is terrible in the 3rd lecture. Chern-Simons gravity is very nearly unfathomable to me. And all of it, I think, is in 1+2 gravity, so... Apparently you can formulate the equivalent of geodesic equations by prescribing a gauge choice in the SL(2) or SL(N) (higher spin) group. That's the most interesting idea I got from the lectures. Anyway, it was never my intention to suggest that there's a direct relationship between Stokes' theorem and AdS/CFT. It was somebody else's.

But couldn't we say that for anything to be inconsistent with reality, we must have a picture of that whole reality, which we... don't? I tend to see "reality" as a place holder for whatever we intuit the next level of description may be. Perhaps the next level of reality description implies dropping our naïveté about what it must look like. Complex numbers, non-trivial topologies... The works!! I've read a comment by @swansont far back in the past forums about "physical reality" that I don't remember exactly but I found very interesting, and it's similar to what I've just said. Maybe he can help me recover it. Or rephrase it.

I may have missed it. I did take a look at your suggestion: and it got me linking back to my previous observation of how far away from an ideal gas we probably are. Very close to electron degeneracy regime at the deep core. I think @MigL's suggestion of thinking in terms of Oppenheimer-Volkoff equations of state is not very far-fetched, to say the least. I know next to nothing about that though.

Sorry, just to correct myself. It is associated with a local conservation law, but not local DOF associated (gauge fields). I think you understood me. I sincerely doubt it. The LHC is being useful at the level of studying a lot of QCD background. But it's very difficult IMO to use it to detect such a small deviation from SM. If one in 1039 (or wherever the threshold is from Superkamiokande and such) protons decayed there, it would be very difficult to highlight it from the background, I surmise. Very interesting possibility. +1 There is actually an argument in favour of baryon number violation that has to do with BHs. There may be exotica to be explored in the spectrum of primordial or supermassive BHs.

I'm starting to think I didn't understand the point that the OP was trying to make.

Thank goodness you've asked "can baryon number be violated?" and not "will we ever see baryon number violation?" If you look at the relevant pieces of the standard model Lagrangian, it strongly suggests that baryon number can be violated. Otherwise, what's this continuous symmetry doing there not associated with a local conservation law, completely looking like a gauge symmetry but the local degrees of freedom being absent? It's very peculiar. Plus it's the best way so far to explain baryogenesis and matter/antimatter asymmetry. The directions I tend to look at when the lights go off and I think about this are mainly: GUT extensions to the SM are not written in stone. The role that the scalar field plays in Nature is kind of like a parametric all-purpose machinery, not something fundamentally understood.

That's exactly what I was thinking. There's a circularity here. g(r) is no problem. It's T(r) what's a pain in the neck. Last thing I've tried is to use the energy equation for a diatomic ideal gas, which is, \[U_{\textrm{int}}=\frac{5}{2}Nk_{B}T\] and then to relate the internal energy of the gas with the gravitational potential energy to eliminate the temperature, but no luck. The density comes back. Maybe I was too tired. You still have the T(r) problem. Even if you use a virial expansion, you still have the T(r) problem.

My apologies again. I made a mistake here (as usual): \[\int_{S}\textrm{curl}\boldsymbol{v}\cdot d\boldsymbol{S}=\oint_{\partial S}\boldsymbol{v}\cdot d\boldsymbol{l}\] The circuit must be the boundary of the surface. I didn't mention it, but it was always on my mind.

I personally don't take offence at the concept of science being wrong, even though I use my leisure time mostly to learn more about it and I've made of it my method to try and understand the world better, like most of us here I would say. I don't think science aims for absolute truth. It's not about being right or wrong beyond any doubt. It's about being more right and certain and less wrong and uncertain, and pushing the limits of doubt and ignorance. Science doesn't provide us with a magic wand to dictate ethics either. It evidences correlations, most of them of statistical nature. It sheds light on plausible causal connections, it refutes previous ill-conceived ideas. If we do that, we are in a better position to take better decisions, diagnose better, tackle evil before it happens. But this can only be achieved by adding to the structure more layers of rational thinking and open discussion. Our understanding is never complete. What kind of philosophy marginalizes individuals? Do you mean something like social Darwinism? It's not a universal trait of philosophy, AFAIK. I'm guessing you've voted that there are good and bad philosophical theories...

On a related note, but much more humbling for us: https://www.newscientist.com/article/dn11330-pubic-lice-leapt-from-gorillas-to-early-humans/#:~:text=A genetic analysis of pubic,about 3.3 million years ago.&text=But they claim it is,from having sex with gorillas. I don't want to draw any conclusions. Just saying... The most interesting thing is whether these hybrids of sturgeon and paddlefish can in turn reproduce. Most admixing results into sterile individuals.

Very good point, as always. +1 More modern criteria of speciation are slowly diluting into fuzzy categories. If plants, fungi, protists, bacteria etc, could talk, they would give us a memorable speech about interbreeding. Wouldn't they?

I didn't!! +1 Please elaborate or give me a reference, if you don't mind. I agree. ----------- I would like to think, and comment, and read more comments, about how all this Stokes' theorem story could have some bearing on the question of time, as integrating on the boundary of a set requires orientation, while integrating on a bulk that is not a boundary, doesn't. Same as time. I googled for the circle, as I wasn't sure. Here's what I found: My apologies, @studiot, because I've been talking all the time about exterior calculus without mentioning, explaining, or giving a proper reference: https://en.wikipedia.org/wiki/Exterior_derivative It's the technique to wrap it all up (Stokes, Green, Gauss, etc.) into one unified description. Thus, for example, Stokes' theorem (or is it Green's?) can be obtained by exterior differenciating a line element (1-form): \[d\left(v_{x}dx+v_{y}dy\right)=\] \[=v_{x,x}dx\wedge dx+v_{x,y}dy\wedge dx+v_{y,x}dx\wedge dy+v_{y,y}dy\wedge dy=\] \[=v_{x,y}dy\wedge dx+v_{y,x}dx\wedge dy=\] \[=\left(v_{y,x}-v_{x,y}\right)dx\wedge dy\] \[\int_{\partial\Gamma}\textrm{curl}\boldsymbol{v}\cdot d\boldsymbol{S}=\oint_{\Gamma}\boldsymbol{v}\cdot d\boldsymbol{l}\] It's powerful because you can do it for any dimensions, surface element, line elements, volume elements, and in general, n-surface and (n-1)-surface elements.

Exactly. It's a non-starter. I couldn't agree more. +1 Bad arguments give you a chance to highlight interesting issues, common misconceptions... Maybe we all discover here that Darwin missed a subtle point, or perhaps that some of us are missing a matter of subtle detail, some loophole, some interesting aside. If not the case, we all refresh the well-known facts, arguments, etc., and our understanding gets refreshed/reinforced, better understood.