“Dark matter” is a number of observed phenomena that independently hint at presence of matter not visible by other means, and when estimate can be inferred from observations give roughly the same estimate for the mass of that matter. There is no conventionally accepted explanation of dark matter, but great thing about scientific method is that it aims to capture facts and observations without interpretation.

So I stand behind “dark matter is obviously correct”. Although I’m pretty sure that WIMPs are BS.

"Phlogiston"/"ether"/take-your-pick-of-fictitious-forces was a number of observed phenomena that independently hint at presence of an active force not visible by other means, and when estimates can be inferred from observations give roughly the same estimate for the existence of that force.

Except none of these things are properly said to exist.

Dark matter is and always has been "fitting gaps in our current model to observed data". It's retroactive by construction and almost the definition of begging the question. Explanations for material origins as "dark matter" have nothing to do with reality and everything to do with a lack of imagination and humility.

I could explain fire by positing and observing phlogiston by fitting the residuals of incomplete models to data and I would have just as much "evidence" to stand on as dark matter zealots.

It is extremely anti-scientific, indeed an offense to the process of science itself, to 1) ignore the basic facts above (namely, that models of dark matter are nothing more than fitting residuals with flexible computational models) to inform the assertion of such baseless claims and 2) to assert those claims so strongly.

If several independent observation gave a similar estimation for the mass of “phlogiston” or density of “ether” that would be a very significant phenomena worth studying.

Phlogiston was a result of multiple independent observations: combustion, rusting, any number of exothermic reactions... it was still wrong.

As a bit of an aside, I've noticed a strong correlation with misuse of the singular and plural forms of the word "phenomenon" with non-physicists who want to sound like they know what they're talking about. By your standards, I have a pretty good theory that you're not a physicist. Are you comfortable applying your flavor of analysis and rigor to this observation, too...?

I have MS in Physics but didn’t pursue a PhD and went for job in programming for money. Not sure if it counts or not. English is not my native language and most of my papers were in my native language (except one in Physical Review Letters), so my ‘physics English’ is pretty bad.

I find this attitude against dark matter frankly baffling...without positing what it is your argument reads somewhat like "well night technically has all these things in it so dark nights don't exist".

Screams of tortured tautology, sure there are some "residuals", but unless you are shooting down a particular incorrect assertion there's nothing wrong with lumping a set of observations under some banner. I'm sure we won't call it dark matter at some point, just as we no longer think of atoms as being atomic...nevertheless dark matter serves a purpose in our current state of ignorance, being mad or upset at that to me makes no sense.

You know that meme about deep learning engineers saying "JuSt AdD lAyErS"? This feels like the "matter" version of that.

We don't call "ether" a precursor to modern theories, we call it a wrong theory, because there is no substance "ether" which exists. We don't say try to justify their use of the word "ether" because of some tenuous you-know-what-they-meant wink-and-nod, it was just wrong.

At least with the atoms example it's a useful abstraction (see: atomic physics, chemistry) but there's no use to positing matter exists if the mechanism is really completely different from invisible matter. We could just as easily call it "the galactic explanatory gap" and maybe name it after someone who did a lot of work on it, maybe "the Zwicky tension" or something without asserting the nature of the issue so strongly.

Ok, I sort of get your objection, but "if the mechanism is really completely different from invisible matter", that doesn't seem to be true?

I'm not a physicist, but the explanation I'd heard was that something appears to have mass (due to patterns of gravitational objects seen through telescopes), but we can't see it.

So to be completely fair, we don't see any matter, we do see unexplained gravitational phenomena, which is optically invisible, but we do see something. Possibly, our model of gravitation is just completely wrong, and actually there are different forces which modulate the force of gravity.

Of the two, it seems dark matter is less controversial (matter that doesn't seem to reflect light) than positing new fundamental forces, as one involves a known set of theories (maybe its something like antimatter, or an alternative configuration of particles to the standard atomic ones at a quantum or particle physics level). I don't think ignoring it as a rounding error is a reasonable approach, unless you have some strong sources arguing that the physicists equipment is just bad (source, please), at least that's my impression.

Again, I can make anything "appear" to have invisible mass if I ignore the appropriate theories and fit mass in where it "ought to be" to recover the observed dynamics.

Theories besides dark matter don't posit new fundamental forces, they posit that our understanding of gravity is incomplete and only applies in the limit of high-mass-density spacetime regions. This kind of elaboration of our physical theories has significant precedent: Newtonian mechanics is recovered when considering general relativity in the limit of distance scales much smaller than light-seconds and time scales much longer than infinitesimal time. It could be as well that our current models are only applicable in the limit of regions of dense mass. When things thin out (say, near the edges of galaxies) the transition to a modified dynamics appears to have significant explanatory power (since the limit no longer applies) with the added benefit that there's actually a model that can be validated or falsified.

I'm not an armchair physicist, I'm actively working on my PhD in Physics.

Dark matter is the prevailing theory because it best explains our current observations. I'm aware that doesn't mean its right, and we don't have conclusive proof that it is.

There's definitely a problem with our current model looking at the Hubble tension, but the reason for that is still unknown.

So I love when armchair physicists come in and say dark matter is obviously wrong.

"Best explains our current observations" is tautological because you can imagine invisible mass for any system to explain arbitrary observations provided you are only modeling the system instantaneously (note galactic vs human timescales). Dark matter fanatics want to assert the supremacy of a system that is literally derived by fitting residuals using computational models, but anything can be explained that way using results of a simulation if you wanted.

I could elaborate a complicated system of invisible mass to explain geocentrism if I wanted. Doesn't make it a good model.

You will note I didn't actually say "dark matter is wrong" but rather "there is nothing to the very foundations of the model itself". I'm not arguing against dark matter so much as for a theory of substance.

> actively working on my PhD

Not paid enough to afford an armchair, you mean? :)

> it best explains our current observations

I always figured dark matter to be nonsense because nobody ever listed any said observations, but only ever parroted that line. Even xkcd is guilty of it https://xkcd.com/1758

So better start giving out examples or you won't ever convince anyone. I'll start. The one that convinced me is the Bullet Cluster collision where it seems that regular matter collided and slowed down but something else which contributes most to the overall mass passed right through without interacting at all: https://en.wikipedia.org/wiki/Bullet_Cluster#Significance_to...