[bmacho]

They have some equations that never ever match the observed data.

They like their equations, so they call the difference dark matter (which varies in space and time, as we expect). It is quite ridiculous if you think about it, and also is the fact, that they can get away with it.

I am waiting eagerly how will this turn out. (Well only the "dark matter exist", or the "Einstein equations are so useful that they create a meaningful dark matter concept with properties, even that they are incorrect" cases are interesting, if say MOND wins, that would be less amusing.)

[Ma8ee]

No, they have some equations that match the observed data extremely well, up to interplanetary scale, and are the basis for a lot of technology that we use daily.

Now there are some discrepancies between what we expect and what we measure at galactic scale. A very popular hypothesis is that these discrepancies are due to some dark material that we haven’t been able to observe otherwise.

[Karellen]

On the contrary, they match huge amounts of observed data.

If Einstein's equations didn't match any more observed data than, say, Newton's equations, no-one would have bothered adopting them. But there were lots of observed data at the end of the 1800s that didn't quite fit the models we had. Quite a lot were to do with light, but others were slightly weirder, like the precession of Mercury.

Then Einstein's equations came along and fixed all of them. They even made predictions about observations yet to be made, like the behaviour of clocks on satellites and spaceships, which are moving fast enough for special relativistic effects to be detectable, but also moving in a different-enough gravitational field for general relativistic effects to be detectable.

(Note, GPS relies on knowing and mitigating these effects in order to work accurately. But also, the designers of the first GPS system still weren't 100% sure it was the case, so they made it possible to change whether none, either, or both mitigations were active. It did turn out that both were needed - another win for Einstein.)

I suspect that if the "Einstein's equations not quite correct at intergalactic scale" case ended up being right, we would end up with something that's as different from Einstein as Einstein is from Newton. That is, a new set of equations that is functionally incredibly similar to the old ones, but with an extra term which is very nearly constant under most circumstances, but measurably diverges according to some yet-to-be-discovered criteria.

With Einstein's equations, this is the Lorentz factor γ, where 1/γ = √(1 - v²/c²). When v is only a small fraction of c, this term approaches 1, and Einstein's equations approach Newton's.

Note that in the case of v being small (compared to c), Newton's equations are still useful, and it's perfectly reasonable to use them to calculate motion and energy without including relativistic effects. And similarly, if we were to "replace" relativity with something else, there would be a lot of circumstances where the additional complexity of the replacement wasn't needed, and relativity would still be useful in the scale between Newton and it.

[occamrazor]

BTW, to strengthen your point: all space missions use Newtonian dynamics, not relativistic.

[WastingMyTime89]

Would be more correct to say that everyone knows the model doesn’t work at a very large scale (nor does it do at very small one by the way) and everyone wants to find a solution because that would be a major breakthrough.

No one is opposed to a better model by the way. MOND is not universally embraced as such because it doesn’t actually get ride of dark matter so there is little point in switching.

Amusingly I think a large part of why some people are so upset about dark matter is that they don’t really understand what a model is and believe that experimental science seeks to convey the truth which is an interesting faith but has little philosophical basis. I generally blame the fact that these points are poorly explained during most people education and most scientists are reluctant to talk about that to no lose the tenuous support of the general population.

[adastra22]

Well MOND gets rid of a lot of the dark matter, and is more consistent with observations. I think most physicists disregard it for now because it is not as fully developed a theory outside of cosmology.

[jhanschoo]

I have my equations, that tell me that I look straight from where I'm standing, I should see the sun rise in the morning, that never ever matches the observed data.

I like my equations, so I call the difference the wall in front of my face.

[bmacho]

You probably shouldn't call it 'wall', it is easy to mistake it for wall[0] (I did it first too).

[0] : https://en.wikipedia.org/wiki/Wall

[simonh]

What do you think they are “getting away with”. Is that something you think they should not be allowed to do? Who would stop them and how?

[teawrecks]

I'm too dumb on this subject to know the difference between your statement and the one directly challenged by the article. It just sounds like you're making the same "dark expenses" argument that it suggests is a mistake.