The Reason We Haven’t Directly Detected Dark Matter • Hacker News Board

Re: The Reason We Haven’t Directly Detected Dark Matter

#121

Post by fermienrico » Sat, Oct 13, 2018, 3:57 PM UTC

dTal wrote: post #62

krapp wrote: post #56

I like how we have an article explaining the rationale behind dark matter and the scientific principles that lead to the conclusion that it exists, but most of the threads here are simple declarations that no, they must all simply be wrong or not considering some simple alternative. Can people maybe, just maybe not assume that scientists are idiots or, as once dead commenter puts it, charlatans? If you disagree with…

I was about to post something similar. Before you act on the urge to go pontificating about how the scientists have clearly got it wrong for this reason or that reason, ask yourself - do you really think they haven't thought of that? Don't you think that, if there is mileage in your idea, there would certainly be scientists pushing it? Addendum: Science (and more generally, specialization) requires that we trust that…

Contrary to your argument, there is also the Gell-Mann Amnesia effect: https://en.wikipedia.org/wiki/Gell-Mann_amnesia_effect

Note that I am not saying it is the case here, but simply pointing out that the "experts" authority can also be challenged.

Furthermore, this happens rarely, but notably that someone with no serious "expert" qualifications, they produce revolutionary work (Ramanujan, etc.)

Re: The Reason We Haven’t Directly Detected Dark Matter

#122

Post by djsumdog » Sat, Oct 13, 2018, 4:00 PM UTC

std_throwawayay wrote: post #39

If we can't detect it or disprove it, it doesn't even belong to science. It belongs to the same realm as witches and demons - until some smart physicist devises a way to actually detect it.

The Higgs field was in the realm of theory for a long time. The maths matched up, but it wasn't until the LHC that scientists had the instrumentation to even look for it. Two other collides at the time through they were getting close, but it turns out the Higgs Boson wasn't anywhere near where they thought it'd be.

It took a long time and a lot of work, but the experiments are reproducible (and they were reproduced several times to ensure they had found the Higgs and to learn more properties about it).

Re: The Reason We Haven’t Directly Detected Dark Matter

#123

Post by nabla9 » Sat, Oct 13, 2018, 4:01 PM UTC

everdev wrote: post #71

krapp wrote: post #56

I like how we have an article explaining the rationale behind dark matter and the scientific principles that lead to the conclusion that it exists, but most of the threads here are simple declarations that no, they must all simply be wrong or not considering some simple alternative. Can people maybe, just maybe not assume that scientists are idiots or, as once dead commenter puts it, charlatans? If you disagree with…

Almost all of our current scientific knowledge has come from challenging the consensus of the times. Scientific skepticism is always healthy and should be welcomed. Even if the original theory is correct, that doubt will simply help science better explain and prove the current understanding. I'd actually be more worried if everyone agreed about something. Even gravity we thought was fully solved until Einstein doubte…

>Scientific skepticism is always healthy and should be welcomed.

I strongly disagree.

Principled scientific skepticism from practicing scientist and expert is welcome and can contribute.

Layman scientific skepticism in hard sciences like physics is worthless and even harmful. No matter how skeptical a layman who reads popular science magazines is, they don't contribute. Only thing we can do is to learn. Our judgment and opinion is worthless.

People want to understand, contribute and discuss, but even if we have the education to understand the issues, we don't have the time or interest really think it trough. Everything valuable flows top down from experts to the layman.

Generic examples taken from the history like "Even gravity we thought was fully solved until Einstein doubted that we understood it fully" are just using different words to express tautologies. They don't provide information to the issues at hand.

Re: The Reason We Haven’t Directly Detected Dark Matter

#124

Post by dwaltrip » Sat, Oct 13, 2018, 4:03 PM UTC

bordercases wrote: post #118

CydeWeys wrote: post #93

Earlier quoted context omitted.

Gravity behaving like that would be a lot weirder than there simply being some types of mass we aren't able to detect yet. Physics has had a long history of predicting particles that hadn't been detected yet, and then actually going out and finding them. See neutrinos, the Higgs boson, etc. General relativity being wrong would be waaaay weirder.

> General relativity being wrong would be waaaay weirder. It only got empirical confirmation recently, it should still be open to disconfirmation.

General relativity is incredibly well tested. Showing that general relativity is wrong would be the physics discovery of the century.

https://en.m.wikipedia.org/wiki/Tests_of_general_relativity

Re: The Reason We Haven’t Directly Detected Dark Matter

#125

Post by cygx » Sat, Oct 13, 2018, 4:04 PM UTC

furgooswft13 wrote: post #69

roenxi wrote: post #37

Earlier quoted context omitted.

Our understanding of gravity might be completely wrong. If 85% of the gravity is unexplainable that seems like a pretty safe bet. Maybe it just behaves very differently at galactic scale. Much like the aether, it seemed most likely that light traveled through a medium until it turned out that it probably doesn't.

The aether stuff confuses me. We replaced light traveling through some medium, the aether, with light traveling through a photon field which permeates all of space, among many other fields. That sounds like an aether by another name. Yet now we say aether theories of the turn of the 20th century types are debunked and everyone then was wrong. Yes the medium of a field is very different in nature than any classical on…

A medium can have independent dynamics (consider waves in a bathtub: you can pull the plug, or move the whole thing around; you can't do that with a fundamental field).

It is true that from a slightly different perspective, modern physics has arguably resurrected a kind of aether (think condensates in quantum chromodynamics) - it's just that said aether is Lorentz-invariant...

Re: The Reason We Haven’t Directly Detected Dark Matter

#126

Post by jccalhoun » Sat, Oct 13, 2018, 4:04 PM UTC

gmjoe wrote: post #63

krapp wrote: post #56

I like how we have an article explaining the rationale behind dark matter and the scientific principles that lead to the conclusion that it exists, but most of the threads here are simple declarations that no, they must all simply be wrong or not considering some simple alternative. Can people maybe, just maybe not assume that scientists are idiots or, as once dead commenter puts it, charlatans? If you disagree with…

Agreed 100%. Indeed, this is one of the best articles I've come across which covers several of the reasons we believe dark matter exists, as opposed to us just needing to modify the theory of gravity. For whatever reason, dark matter seems to repeatedly rub people the wrong way today, more so than any other scientific concept I can think of. I actually wonder if it's something psychological -- if the universe is only…

>For whatever reason, dark matter seems to repeatedly rub people the wrong way today, more so than any other scientific concept I can think of.

I think that it is because it is so hard to understand. You can't see it or touch it but it is supposed to make up the majority of mater in the universe. So what is it then? For a lot of people that's a hard thing to get and it would be easier if the answer was something we understood like the scientists being wrong.

In that way it isn't any different than creationists or flat-earthers. Of course dark matter "deniers" don't have the same religious convictions of creationists.

Re: The Reason We Haven’t Directly Detected Dark Matter

#127

Post by zoomablemind » Sat, Oct 13, 2018, 4:11 PM UTC

Excuse a layman's observation here.

The dark matter problem rings as yet another mass-related anomaly we stumbled upon previously but on a nuclear scale.

"Mass defect" [1], as appropriately named, is observed on a nuclear scale (whole nucleus mass is less than mass of nucleons that the nucleus is composed of). It is explained with binding energy required to keep the individual nucleons of a nucleus together.

That is an 'invisible' mass that gets subtracted from the 'free' mass of nuclear particles as measured.

Any possibility to project such analogy onto a galactic scale?

[1]: https://en.m.wikipedia.org/wiki/Mass_defect

Re: The Reason We Haven’t Directly Detected Dark Matter

#128

Post by draw_down » Sat, Oct 13, 2018, 4:12 PM UTC

krapp wrote: post #56

I like how we have an article explaining the rationale behind dark matter and the scientific principles that lead to the conclusion that it exists, but most of the threads here are simple declarations that no, they must all simply be wrong or not considering some simple alternative. Can people maybe, just maybe not assume that scientists are idiots or, as once dead commenter puts it, charlatans? If you disagree with…

You don’t need to be an idiot or charlatan to be wrong or to be missing something important. All the people who didn’t know about germ theory, or who thought the earth was flat before we could prove otherwise, were they all idiots? No.

But, human ignorance is not to be underestimated, and the amount of knowledge we have about the universe is not to be overestimated.

Re: The Reason We Haven’t Directly Detected Dark Matter

#129

Post by dwaltrip » Sat, Oct 13, 2018, 4:14 PM UTC

kamaal wrote: post #111

CydeWeys wrote: post #93

Earlier quoted context omitted.

Gravity behaving like that would be a lot weirder than there simply being some types of mass we aren't able to detect yet. Physics has had a long history of predicting particles that hadn't been detected yet, and then actually going out and finding them. See neutrinos, the Higgs boson, etc. General relativity being wrong would be waaaay weirder.

>>General relativity being wrong would be waaaay weirder. If I'm not wrong, Newton's laws can still be held to be true in some cases even inside GR? Some where in the past, some one could come up with a new model which could show us new truths, and yet could contain GR to be true in some cases. In GEB, Hofstadter show us part of the ways so see intelligence emerging from noise and garbage, is to understand when you d…

Yes, you are correct. This is actually expected to happen at some point, as GR and quantun field theory are incredibly well tested and yet haven't successfully been combined into one theory.

However, when this happens, it will be one of the greatest physics breakthroughs of all time.

Because of this, any scientist needs very strong, compelling reasons for trying understand their results in a way that holds GR as somehow broken. The vast majority of of experiments don't have good justification for not treating GR as a given truth.

Re: The Reason We Haven’t Directly Detected Dark Matter

#130

Post by burlesona » Sat, Oct 13, 2018, 4:15 PM UTC

This strikes me a lot like “flatland”, ie. there’s something there but we’re not equipped to perceive it. Our experiments are mostly like extreme extensions of our own senses - seeing and touching things. But could something exist entirely within a dimensional space that we can’t touch or see? And if so how would we ever figure out how to detect it ... and even more meta, what if it was impossible for us to perceive the detection?

It’s all really fascinating.