Yep. But in most scenarios corresponding to human experience the first is reasonably applicable and much easier to understand.

Thermodynamic temperature is defined as the rate at which the internal energy of a system changes as its entropy changes.

In contrast, temperature from kinetic theory is essentially a measure of the average translational kinetic energy of the particles in a system.

The two are sometimes, but not typically, equal. The temperature that you know and love is the second one, but thermodynamic temperature is also widely used in science.

Wait long enough and every system will tend toward its highest entropy and typically lowest energy state. But then we’re not really talking about the effect of the magnet’s magnetic field anymore so that’s a whole different conversation that depends on things like the stability of atoms and protons.

> Given enough time, in theory, the entire mass of the magnet would eventually be irradiated outward as light energy.

I don’t think this would happen. I think the spinning magnet would preferentially emit light with polarizations that would slow down the magnet’s rotation over time, until it’s no longer spinning. I think hardly any of the magnet’s mass would be converted into light in this process.

Rotating a magnetic does quite simply create EM waves, alongside other electromagnetic field changes. It just doesn’t only create EM waves. There is certainly nothing irresponsible or even really incorrect about their explanation. It’s a bit of a simplification, sure, but that’s appropriate in this context.

Superficially, kind of? There are many differences though. One is that the ether was proposed in order to provide a rest frame for light, whereas the fields upon which modern physics is based are fully relativistic. Another is that the ether was thought of as a physical thing thing with density, velocity, etc., and whereas fields can’t really be described in those terms, at least not as directly. It’s more that fields can give rise to them.

TL;DR an ether theory is similar to fields in that they permeate all of space, but they’re fundamentally different from each other in properties and mechanics.

> Yes and no. Classes are one of many ways to learn.

And yet I’ve never once met a person who has self-taught themselves in QM whose comprehension wasn’t riddled with misconceptions and glaring holes. Not all fields lend themselves to independent study, and I think QM is especially difficult to learn well without deliberate guidance and feedback. I suppose it is technically possible to get that outside of taking classes, but I think uncommonly enough to be safely neglected.

> Just spending at least 100-200 hours familiarizing with the materials of a field can be enough if time to find a genuine hole in scientific understanding.

That depends greatly on the field, though, and I think tends to become less and less true over time as scientific knowledge and understanding grows.

Nothing about the double slit experiment is paradoxical. It’s just unintuitive.

That’s actually a problem with astrological signs even without galaxies colliding! Our astrological signs are discernibly different than they were a couple thousand years ago and, due to Earth’s precession, no longer correspond to the same times of year as they did originally.

Your dad looks 14!

Well we know that when black holes meet they merge. We’ve observed black hole mergers and know that they release a huge amount of energy as gravitational waves, which are pretty harmless unless you’re right there.

Also, it’s believed that x-rays would be emitted, but that isn’t because of the event horizons touching, which is what you originally asked, but from the interactions of the black holes’ accretion disks and other nearby matter with each other and with the complex gravitation on the region around two merging black holes.

But yes even those x-ray bursts would be highly collimated and would only effect a small region directly in their path.

They merge into one black hole in a process that is very much non-destructive.

Yes, some stars are out in the tidal arms, some have or will even be ejected from the galaxies, but so what? If our solar system suddenly found itself alone in the universe, it would have no practical effect on our existence whatsoever. We’d be just fine.

> while close to the galactic cores the gasses are even hotter with a huge jet of superheated gas shooting “down” from them.

You’re reading way too much into the image. There’s no superheated gas, and certainly not jets of it. It’s all just stars and dust. It’s just that their regular orbits are disrupted.

Galaxies are mostly nothing. Their densities are tiny (on the order of 10^-29 g/cc), about 10^26 times less than earth’s atmosphere. Stars are so sparse that the chance of even one collision between stars is nearly zero. And collisions between galaxies occur over hundreds of millions of years. Such collisions are disruptive to the orbits of stars and such, but they aren’t destructive in any sense.

Why would we think that? Most individual star systems are completely unaffected during galaxy collisions and mergers. Compared to the vast space between them, stars and their planetary systems are minuscule.

And the black holes wouldn’t “wreak havoc” on anything but the very small fraction of stars on their immediate neighborhood.

> I guess is my point and SM has made almost no progress on these things in a while. Might be time to start looking at alternatives to SM.

Um, what? First of all the SM of cosmology has come a very long way even in just the past couple of decades. It is not stagnant.

Second of all, most of the specific problems you highlighted are shortcomings of the standard model of particle physics, rather than of Big Bang cosmology itself. And if you think physicists aren’t looking for alternatives and extensions of the standard mode of particle physics then you’re confused. That’s what most particle physicists are trying to do every day. The problem is that it’s hard, it requires huge, expensive, and complex particle accelerators and detectors and that makes progress slow.

TL;DR Most physicists aren’t looking for alternatives of the Standard Model of Cosmology, because it works extremely well and its shortcomings are mostly shortcomings of the Standard Model of Particle Physics. Correcting the Standard Model of Particle Physics to account for its shortcomings is literally what most particle physicists are trying to do. Cosmologists switching gears to focus on something like MOND stands zero chance of addressing most of the problems you mentioned, since those problems are particle physics problems, not cosmology ones. You are confused.

Neither model has had much evidence? Y’all are too hung up on “direct” detection of dark matter. It would be nice but it isn’t necessary. The ΛCDM model has been around for decades and has been making predictions that whole time, and its predictions keep being verified. How is that not evidence??

There is a ton of evidence for dark matter and the ΛCDM model as a whole. The fact that it correctly predicted the CMB power spectrum so accurately is extremely compelling on its own, even if that were the only prediction that it made.

>We always talk about how successful it is, but it's got some serious problems.

It is very successful, even in the face of its shortcomings. That's the nature of science: there are always unresolved problems to figure out. Our most successful scientific models will always be incomplete. And usually it's that: it's more common for our models to be incomplete than flat out wrong.

>Not a hint of dark matter to be found, so far. Just a gravity effect we can't account for.

The word "just" is doing a hell of a lot of lifting in that sentence. And it's not just an effect, but many. There is missing gravity in the velocity dispersions of galaxies. There is missing gravity in the rotation curves of galaxies (but not all galaxies!). There is missing gravity in galaxy clusters. There is missing gravity related to gravitational lensing (or perhaps a better way of putting it is that in some cases, seemingly empty space strongly distorts the trajectory of light). There is missing gravity associated with the power spectrum of the CMB. There is missing gravity in the formation of structures like galaxies. There is missing gravity compared to the observed curvature of the universe. There is missing gravity in the large scale acoustic oscillations of the universe. There is missing gravity associated with redshift distortions of galaxy clusters and voids.

No attempt to explain all of those things as simply a misunderstanding of gravity has been successful, despite many decades of trying. Some of those phenomena have never been explained by any models of modified gravity ever (like the Bullet Cluster lensing, anomalous rotation curves of galaxies, and the CMB power spectrum). No such model has ever even come close to explain all of them simultaneously. On the other hand, all of them are well-explained by the existence of a consistent amount of dark matter, organized in ways consistent with each other (e.g. the dark matter distributions needed to explain rotation curves are consistent with the distributions needed to explain lensing, etc.), without having to even try being creative. It basically just works out.

Finally, not having detected dark matter directly in a lab setting is not really a problem for the ΛCDM model. The whole point is that it's dark. It cannot interact electromagnetically, and by that very nature it would be very hard to detect. So far we've only ruled out the lowest hanging fruit. It would've been nice if we got lucky and found it quickly, but expecting that to happen if dark matter exists is naive. And on a related note, detection of something via its gravitational effects is still detection. When talking about particles that interact primarily through gravitation, obviously we would first notice them by their gravitational effects... In particle physics we "detect" particles through their effects on other fields (e.g. no one has ever seen a top quark, we've only ever see the particles that they decay to and note that they're consistent with the standard model). Why should gravity be ineligible when we use the other fields for this purpose all the time?

> A universe with accelerating expansion from dark energy that we also can't detect.

This is a huge question mark not but it's not a failure. The cosmological constant is a simple solution that, as far as we can tell, is consistent with all of our observations and comes with a straightforward interpretation (though of course it's also at the heart of the problem of reconciling quantum mechanics and gravity). In many ways, the accelerating expansion itself can be considered a tentative detection of dark energy. Though of course there are other competing justifications for the acceleration that we aren't yet able to rule out, too.

>Matter/antimatter asymmetry, neutrino mass, and the strong CP problem.

All big questions! But no one is claiming we've finished cosmology. Those are all some of the most active areas of research, there are dozens of hypotheses attempting to address each of them. And more importantly, no other cosmological models attempt to explain those issues, either.

This article is sensationalist garbage. The observed lopsidedness is interesting, but it isn’t even remotely solid evidence for MOND or against the ΛCDM model of cosmology.

I mostly agree with you. I am glad people are working on MOND, because you never know. But as it stands, anyone who swears by it is delusional.

I think supersymmetry gets less hate because it is not a replacement for an existing, extremely successful model, but rather a very simple extension to the standard model of particle physics, with the potential to fill in a lot of holes. Many MOND proponents argue that dark matter’s existence is a poorly motivated and unrealistic postulate, but frankly that notion is just ignorant. And I think that attitude also sours people toward MOND, by extension.

That’s true; GR is not conservative. Your estimate of time is by probably too small by tens, if not hundreds, of orders of magnitude, though. For example, the Earth’s orbit is decaying due to gravitational wave emissions, to the tune of about 200 Watts. Assuming everything else magically stayed the same, it would take about 10^23 years (100,000 quintillion years) for Earth to hit the sun. The rate at which gravitational waves would extract energy from a cloud of dark matter would be unimaginably smaller than that.

Also, if WIMPs actually do interact via the weak force, that would probably stop - or at least further delay - black hole formation as they become more densely packed.

No. Clumping together requires dissipative forces (like friction) — there needs to be some way of removing kinetic energy from a system for it to clump together. The leading theory explaining dark matter is that it is made of weakly interacting massive particles (WIMPs). They interact through gravity and the weak force, but nothing else. Gravity is a conservative force and cannot cause clumping on its own, and the weak force is too weak to cause it to any significant extent, either.

That also explains why dark matter forms roughly spherical halos around galaxies that extend farther out than the regular matter. It also explains observations like the mass distribution of the bullet cluster. Two galaxy clusters collided, and all the ordinary matter slowed down as all the gas and dust collided, but the dark matter just passed right through unimpeded, separating out the regular and dark matter of the clusters.

TLDR: gravity doesn’t cause clustering. It needs help from dissipative forces that dark matter doesn’t really experience.

I’ve seen the full image. I think you’re underestimating the precision that can be accomplished by a talented artisan, even by hand, without fancy tools.

It would be well within the means of a skilled craftsman to make a sufficiently precisely patterned stamp or press to accomplish what we see in that image, especially given how thin that gold is (the article even says such artifacts are rare to find, since they “tear like paper”). All you need to make a perfect circle is a stick and string, or even just two sticks tied together. Scoring and then smoothing/polishing precise concentric circles into a pattern made of wood or stone wouldn’t be hard for a craftsman with metal tools, and if the stamp is precise, it will stamp a precise pattern into something so easily malleable.

Making circles isn’t hard. In fact, circles are the easiest shape to make! Compasses (the drawing tool, not the navigation one) were common at least as far back as Ancient Rome, for example. Also, those circular patterns look stamped or pressed to me, and there are two distinct sizes of them. So they probably made the circular patterns on a wooden piece and then stamped it onto the gold, which is very malleable.

Using a lathe for this would be wildly overkill.

> Nah. It is an effort to explain to people who understand physics but little else why other peope, who don't understand physics, understand more than they do.

Except you can’t do that effectively if you don’t understand physics in the first place.

> You're mistaking what is conventional within physics for what is meaningful in real life. "System" is the wrong word for a single substance, even one so profoundly important to physicists as Bose-Einstein condensates.

What? No. A system is any portion of the universe chosen to be analyzed. Anything outside the system is considered an environment, and it is ignored except for its effects on the system. System is a perfectly valid word to mean what I intended to mean, and it absolutely can refer to a “single substance.” What even does that mean? If I want to know why a metal is lustrous I can’t treat it as a single thing. Its luster arises from quantum mechanical effects arising from its atomic scale structure and properties.

> It is used to model one very specific and particular (pun intended) kind of quantum system, which is really important because that specific "condensed matter" is a macroscopic substance, unlike most quantum systems, which are sub-atomic, so small that even using the contrast macro/microscopic is actually weird.

Condensed matter doesn’t apply only to one specific kind of system. It applies to a huge range of systems. It is in fact so broad that it’s the single largest sub field within physics, and has significant overlap with other disciplines. Things as mundane as metallic surfaces, salt crystals and as exotic as superconductivity, BECs, and liquid helium fall under the umbrella of condensed matter, as do most phase transitions.

And again, you’re missing the point. I gave it as an example. I also gave other examples, too. Over the years, quantum coherence has been observed in bigger and bigger systems, from large particles all the way to the 40 kg mirrors used in the LIGO experiment, each of which was placed near its quantum mechanical ground state.

> Nobody disputes that deterministic objects "demonstrate quantum mechanical properties"

Are you really that dense? Nobody except for the person I was talking to before you jumped into the conversation. I literally made my arguments to a person disputing what you’re saying no one disputes. It seems like you’re just being contrarian at this point.

> So the use of one example of a "macroscopic thing" demonstrating quantum properties (which, as far as I know, aren't observable as distinct from conventional properties in BEC without special equipment and in highly restricted circumstances) really doesn't have the weight you think it would, in this discussion.

That might be the case if it’s what I did. But it’s not. And you’d know that if you weren’t basing your responses to me based on brief skims of relevant Wikipedia articles about condensed matter, for example. Once again you’re outing yourself here. You not only don’t understand the physics, you don’t even know what entire fields within physics refer to. There’s a reason why I said “condensed matter” and not “BECs.” That’s like confusing “Newtonian mechanics” for “the mechanics governing how balls roll.”

> Not a strawman, just an example of what it would take to justify saying that QM effects "the macro world" of everyday objects.

No, very much a strawman. We haven’t proved that Newtonian mechanics works for every conceivable macroscopic system, either. Nor can we do ever prove such a thing: science relies on induction, and while we can’t prove the validity of inductive logic in science, if that’s the point you’re making then it applies to every iota of scientific understanding ever, not just to QM.

> AKA language. AKA discussion. AKA the real world.

And here you’re using language to deliberately misrepresenting my meaning. My point was, whether it’s about “how” or not is a matter of semantics, it just depends on what we each meant by “how,” which can be interpreted different ways. But it’s telling that instead of engaging with my lengthy argument after that word, you’ve latched onto this one word to make a pithy point with little bearing on the argument at hand, instead.

> A very important issue, in theory. Why is it that you have trouble excepting that proving something in principle to other scientists isn't the same as having an effect on the rest of the world?

How many times must we complete this circle? I show you that it’s been proven in principle, and you say “okay but prove that it has an effect on the world.” So I give you countless examples of ways that it has an effect on the world. And then you ignore all but one and say “but prove that it’s always true.” Do you truly think you’re being reasonable here?

> "Relevant". What a pleasantly useful dragging of the goalposts halfway down the field that is.

Please explain how that word shifted any goalposts.

> I never disputed that QM is relevant in those examples.

So wtf are you on about? The other person did and they’re who I was talking to. You jumped into a conversation between two people to have your own side argument with the wind?

> I just did a better job of it, and I thought I'd be helpful and explain what it is you were doing wrong in that regard.

Of course you think you’ve done a better job. You also think you’re more qualified to talk about quantum mechanics than Bohr and Einstein were, and that your personal philosophy makes you immune to falling for misconceptions. You have a very high opinion of yourself; of that much I’m sure we can agree.

> You have it backwards. The parts I don't engage are either trivial or accurate. The sections of your comments I directly address are mostly just the more illustrative mistak

No, you consistently ignore important points that derail your entire argument. If they’re accurate, you’d have gone away already. If you view them as trivial, then you clearly don’t understand them.

TL;DR Stick to arguing about things you understand. You don’t understand quantum mechanics.

Your entire post uses ignorance of physics as a bludgeon.

> The term "systems" seems a bit of over-reach, in line with your original premise.

No, it is precisely the right word. Which you’d know if you knew enough about physics to have this conversation.

> What is important, for the purposes of this discussion, is that condensed matter physics is a specific sub-domain of physics, rather than all of physics itself,

None of this makes sense. Condensed matter physics is an application of quantum mechanics used to model properties of macroscopic systems. I used it as an example of how macroscopic things absolutely do demonstrate quantum mechanical properties, and gave examples of macroscopic phenomena that we can only explain in terms of quantum mechanics. I never said that it is “all of physics,” but that’s a nice strawman.

> which exemplifies the fact that QM doesn't literally explain how or why classic physics ("Newtonian physics" was the iconic representative) arises from the principles of QM. In theory we "know" it must, but as it has not yet been convincingly demonstrated in general cases, insisting that conjecture is fact is problematic.

I even gave you a link to a general proof of the correspondence principle and described an approach for an alternative proof, and it’s telling that you didn’t even respond to that at all, and instead built a strawman to argue against instead. Neither of those are conjecture, they are proofs. Your ignorance of them doesn’t mean they don’t exist. You should stop arguing about things you don’t know. You may be the best philosopher in the universe, but you can’t do philosophy about topics you don’t understand, let alone those that you aren’t even aware of.

> I would dispute half of that. Scientific models are entirely about how, and necessarily unconcerned with why.

Semantics. Science is about constructing models that reflect reality insofar as we can measure it. A scientific model is good if it is consistent with existing data and accurately predicts the results of future experiments. For example, quantum mechanics doesn’t address how things happen, only what will happen. GR does the same, although in both cases we use words that ascribe some sense of “how,” but it’s more to help us talk about and understand the math, than intrinsic to the model. For example, we often say that mass curves spacetime, and that’s what gravity is, but it’s possible to reframe GR in terms that have nothing to do with spacetime curvature. e.g. it can equivalently be thought of as arising from torsion instead of curvature, or even as a field on a standard spacetime background; all of these are probably mathematically equivalent and no experiment can ever, even in principle, distinguish between them. This nearly identical to the issue of interpretations in QM, it just gets less attention for a variety of reasons.

> I would say that the notation arises from the distinction rather than the other way around.

I’m not talking about notation, I’m talking about the meaning behind the notation (which I suspect you probably don’t know). Either way, you’re missing the point. The point is that in circumstances when hbar is small compared to the relevant scale factors of a system, quantum mechanics turns into classical mechanics. In that sense, classical mechanics is embedded in quantum mechanics.

> But of course, and I may be mistaken about this and please enlighten me about your reasoning if I am, I presume you meant classic physics reduce to QM, rather than the other way around, which is what you actually typed. I think the idea that quantum behavior necessarily reduces to Newtonian mechanics is absurd, isn't it?

No, I meant what I said. In the macroscopic limit, quantum mechanics reduces to classical mechanics. Just like GR reduces to classical mechanics in the limit of low masses and small scales. This is an important aspect of the development of scientific models, it is what the word “reduce” means in this context. It means that quantum mechanics is a more encompassing model, and by taking the appropriate limit you can reduce it to recover classical mechanics.

> I don't mean to sound flippant, but that is an awfully convenient excuse. Which is to say that since you cannot demonstrate that you can perform such a feat, it remains conjecture rather than knowledge, faith rather than fact, a valid supposition but not a foregone conclusion, that it actually can be done.

It’s not an excuse. In a Newtonian world, Newtonian mechanics could be used to deterministically predict the precise time evolution of a gaseous system given accurate and precise initial conditions, regardless of the number of gas particles. It is wildly impractical to do that for anything above a small number of particles, but that doesn’t make it conjecture. And again, I’ve already proved your second sentence wrong. You just chose not to even acknowledge it.

> "Often", after all, does not mean 'always', and whether the instant case is such an example requires empirical demonstration or else it is simply not convincing, all the more so because of the specifically confounding results that differentiates QM from classic physics.

Again, I literally gave you the proof. You’re not even just using ignorance as a weapon here, you’re using willful ignorance. QM has been unambiguously and explicitly proven to reduce to classical mechanics in the macroscopic limit. Hard stop.

> And also as I pointed out, it remains an act of faith to suppose that means it is true in reality.

And again, it’s been proven true in reality. The model of QM reduces to the model CM in the macroscopic limit. You can argue all you want against that, but you’d be wrong. The only place “faith” shows up is in the assumption that QM accurately models reality, but I’m not arguing whether it’s correct or not (and also that is always the case for every scientific model that ever has and ever will be constructed, making it a pedantic argument in the first place). The fact that QM reduces to CM is mathematical fact, regardless of the applicability of either model to the real world.

> Then it, quite arguably, has nothing to do with the discussion, in a way very analogous (or perhaps entirely identical) to whether QM "has nothing to do with" actual reality, but only mathematically models particular systems in scientific laboratories.

No, the other person made false claims about the limits of applicability of quantum mechanical systems. They weren’t arguing that we can’t know whether QM is actually, truly correct. They were clearly under the wrong impression that QM, even if true, doesn’t apply at macroscopic scales. That is what I argued against. You are merely creating strawmen.

> But I still insist you are overstating the case of their applicability, since functional utility in restricted examples does not actually prove general accuracy in all instances, even with further theoretical bases to support the belief that QM fully explains why Newtonian physics arises from quantum interactions.

Except I’ve given explicit examples of ways that QM empirically is relevant in macroscopic systems. But as usual, you simply don’t engage with the parts of my arguments that you don’t know how to address and pretend they never happened.