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There's so much wrong with this comment.

> you are telling me there is something that makes up the majority of matter in the universe (27% dark matter vs 5% matter) and we still haven't observed a single iota of it, even after spending more than 3 decades and billions of dollars?

Of course we observed it. In how galaxies spin. We did not observe dark matter directly. So far existence of dark matter is not questioned because it is backed by multiple predictions and observations. Question is about its composition.

> well it fits all of our understanding of the universe and what we observe in a few things

Not sure what it means.

> It comes on top of things that cosmologists have been wrong for very very very long times on. Look how long they thought it was silly to consider the big bang. maybe it would be easier to accept if they were like 'well the big bang is a very interesting idea but it just doesn't fit evidence' instead of 'that's a stupid idea, my idea (static universe) is simpler so its right'.

This is gross oversimplification to the point where it loses all meaning. I can't even begin to answer because it.

> speaking of which, we really need to get off this 'simple idea is the right idea' dogma. The universe owes us no such obligation to be simple.

I guess General Relativity is complex enough that most still try to drag what they learned in high school to fit reality

> look how much relies off the idea that the universe is the same everywhere, which we now know as wrong, but cosmologists are only slightly admitting to that fact.

Did I missed a Nobel Prize for proving cosmological principle wrong? Because so far all I seen was an overwhelming evidence for its correctness.

>'simple idea is the right idea' dogma. The universe owes us no such obligation to be simple.

You aren't wrong, but the simple answer is a really good heuristic. Its just, when you're wrong, you're gonna be really wrong and it'll be almost definitionally interesting and noteworthy.

> for example, look how much relies off the idea that the universe is the same everywhere, which we now know as wrong

What is this in reference to?

perhaps the topology of spacetime and usual assumptions of some kind of constant (or no) curvature everywhere as apposed to something with more complex curvature?

The cosmological principle[1]. It's not an experimental result, it's just an assumption.

[1] http://curious.astro.cornell.edu/about-us/101-the-universe/c...

I thought it was the strong equivalence principle in general relatively, or the (nameless?) assumption that the same laws of physics hold true everywhere.

Regardless, my question was about the part of the quote which said: "which we now know as wrong."

What aspect of the cosmological principle, strong equivalence principle, or the universal application of physical law do we now know to be be wrong?

Its the idea if you take one slice of the universe, it should be the same as any other slice. in this case, not talking about different physics but different makeups.

then they noticed that the spin of galaxies is correlated. like one pie in the sky of galaxies tend to spin left, and the next one tends to spin right, and the next one after that left again. as far as I know, its unsolved as to why. some think it might be that the observed galaxies are spinning around something much bigger that we have yet observed, others think its an influence by the cosmic web.

the idea that the universe is the same as everywhere (although an assumption) is very much baked in lots of theories, including the arguments that support dark matter.

This is not my subfield so I may be talking out of my depth, but it feels like you are conflating two different concepts. There is a physics assumption that laws are universal, then there is a cosmological assumption that energy distribution after the Big Bang was (near-)uniform. Dark energy and dark matter follows mostly from the physics assumption not the cosmological one.

Do you have a cite for the galactic spin thing?

it seems to me you are conflating different concepts. I haven't said anything about physics laws.