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grrrrreat t1_iwwp5nw wrote

I still get the sense it's all about a failed model and nothing specifically special other than incomplete theorems.

Kinda like the saying "any sufficiently advanced technology is indistinguishable from magic"


Dante2005 t1_iwwqhjf wrote

"Dark" was always the word for "unknown" or "unproven" so you are not wrong entirely.

If you can see that something affects another thing, but you cant see how exactly or it dark and wait for more data.

Science can only work with the data it has.

It is not trying to be obscure, there are just something's that there are no answers too quite yet.

But data can be extrapolated, like how oddly the universe is speeding up in its expansion.

We will get there.

EDIT: I just saw the sub reddit that I am on. if you need me to delete this comment I fully understand.


TheRidgeAndTheLadder t1_iwx1skv wrote

Is it controversial to say dark matter is an unknown for science?


stouset t1_iwy2go0 wrote

Sort of.

We have a lot of data that requires something like dark matter to exist. There’s a bunch of matter, and it moves in a way that requires way more matter than what we can see. We can detect gravitational effects pretty much everywhere that greatly exceed what we’d expect from the matter we detect. We can detect this so well that we have intergalactic maps of where this extra matter must be.

We just… don’t know what it is. We’ve basically ruled out all the stuff that we know about. And problematically, everything at small scales like what we deal with in the solar system seems within what we’d expect with normal matter. But when we look farther out, stuff acts like there’s way more gravity than there otherwise should be.


makingthegreatest t1_iwx7q6y wrote

Everything is unknown to an extent. Dark matter however has been known to humans for decades (nearly century) but there are unknowns to it (:


TheRidgeAndTheLadder t1_iwx9ysp wrote

Sure, but there are alternate theories that are compatible with experiments into the modern day.

We don't know for sure that dark matter is a thing because we don't know for sure our model is relevant in that area.


mouse1093 t1_iwxtr68 wrote

No, not controversial at all. Dark matter is one prevailing theory that explains a number of odd phenomenon and observations that standard cosmology gets wrong. Things like the spin rate of galaxies is an example. There may be other explanations that fix this problem (say perhaps super gravity) but none have been any more confirmed that the others.

Dark matter is also unknown in the sense that other than prescription of what it should be, we don't what it actually is. None of our current particles fit the bill and the theoretical particles we've thought could work haven't shown themselves in any tests to make them.


SouthEasternGuy t1_iwyko07 wrote

Dark matter is basically the name specifically for the stuff that is having gravitational effects on things but that they can’t attribute to a proper source. It happens A LOT so they just call it dark matter.

It’s not controversial by any means, it’s specifically an unknown


echoAwooo t1_iwyegq5 wrote

Nope. We aren't even sure it's there, we're just pretty sure.


Bakkster t1_iwx941i wrote

>"Dark" was always the word for "unknown" or "unproven" so you are not wrong entirely.

I thought it was more specifically dark as in didn't absorb reflect or emit light or other reflective radiation, unlike cosmic dust and stars. We just see the gravitational lensing as if it were a dense cloud of dust, but no dust.


Dante2005 t1_iwx9qbj wrote

I hear you, but dark in that form that you mentioned was about black holes, and in this you were 100% correct.


williemctell t1_ix083bh wrote

No, u/Bakkster is absolutely correct and this has ~nothing to do with black holes. Dark matter is “dark” because it doesn’t interact electromagnetically.


N8CCRG t1_iwyymll wrote

If you're arguing for a modified theory of gravity, lots of people have tried that, and lots of various measurements have set forth extremely good evidence that modified theories of gravity can't fix the problems. Meanwhile dark matter can.


typicalspecial t1_iwz89py wrote

I wouldn't discount modified gravity entirely. Of course dark matter can fix it, because dark matter is defined as whatever will fix it.


N8CCRG t1_iwzb3yk wrote

Not true. Dark matter is just defined as matter that we can't see but otherwise behaves like matter, and that fixes all of the various measurements. Meanwhile, modified gravity doesn't. You can make a modification that tries to explain one measurement, but then it fails to fix a separate measurement, and often make problems worse, like the proverbial floorboard that gets hammered down on one end and the other end pops back up.

And that's not my opinion, that's what the actual publications routinely find.


typicalspecial t1_ix0lyt7 wrote

It behaves like matter in that it influences gravity, and that's about it. Proposed particles get ruled out just as modifications do. Ruling out a modification doesn't invalidate all possible models; ruling out proposed dark matter particles doesn't invalidate dark matter being a particle. We can't definitively say it's matter until we can verify its interaction with anything.


N8CCRG t1_ix0oxql wrote

That's what defines matter: it interacts via gravity. Other interactions are different for every other type of particle we know about. Some particles interact through some mechanisms and others don't, but they all interact through gravity.

Meanwhile, modifcations have been blanket ruled out, not individually. Dark matter has been measured in so many different ways, we have been able to say that no modified theory of gravity could explain all of those measurements.


Nick0013 t1_iwy510p wrote

Given all of our observations on gravity and relativity, this (to me) feels even less plausible than the idea that there’s mass in the universe that we don’t yet have detection methods for.


blade944 t1_iwwqvki wrote

Very true. They found that galaxies didn't behave as they should based on current understanding of physics. So instead of looking at a possible broken model they imagined dark matter and energy to explain it all. So they've been desperately looking for any evidence whatsoever to support the idea but have found none. Yet they still cling to their models and ostricize any and all that question general and special relativity.


rydan t1_iwwteio wrote

I was told in college not to mention MOND or tell anyone that our professor mentioned it.


WrongAspects t1_iwx2yqv wrote

MOND was created to explain the spin rate of galaxies. It fails to explain all other observed effects of dark matter and has been by and large put in a shelf as an incomplete and possibly foolish theory.


gibfeetplease t1_ix0rib9 wrote

Hahaha what? MOND (which is what you’re describing) was heavily looked into, it’s just that it doesn’t seem to work well.

Physicists aren’t some dark cabal trying to cling to theories of the past, everyone wants to find something new. Taking a human view of things, if MOND was a good approach people wouldn’t jump on it, the chance of blowing apart GR and writing your name in history?