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The Reason We Haven’t Directly Detected Dark Matter

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

#161

Post by mmusson »

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…

There is not scientific consensus on this issue. The article is written as if particle dark matter is the only viable option. I would recommend reading another expert on this issue for comparison. https://tritonstation.wordpress.com

Dark matter and Lambda-CDM have fundamental problems too.

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

#163

Post by mmusson »

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…

There is not scientific consensus on this issue. I would recommend reading another expert on this issue for comparison. https://tritonstation.wordpress.com

Dark matter and Lamda-CDM have some fundamental problems.

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

#164

Post by BurningFrog »

beefield wrote: post #27
analog31 wrote: post #19

Earlier quoted context omitted.

As I understand it, gravity is the interaction between things with mass, but it's a weak interaction, thus hard to detect on a particle by particle basis. You might be able to detect if there's an extra potato in a bag because a potato is a whole bunch of particles. But identifying that just a few of those particles are not the regular stuff -- protons, electrons, etc. -- by weighing the bag, would be difficult.

But you do not need to measure it particle by particle. Just because those have mass, there should be a bunch of dark matter particles hanging around with earth. And given that we have quite good idea what earth consists of, there should be a discrepancy in some of the measurements that use earth's mass against the mass we have from our understanding of earth's composition. Unless, of course, the extra mass of earth…

We don't have that good idea of what the earth consists of. I think much of those theories are based on counting backwards from knowing the mass, and if we have 5% dark mass orbiting Earth, it wouldn't make any material difference.

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

#165

Post by Avshalom »

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…

Dark Matter IS the scientific knowledge that came from challenging the consensus.

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

#166

Post by cygx »

TangoTrotFox wrote: post #159
cygx wrote: post #154

Earlier quoted context omitted.

This should, in and of itself, begin to cast down on the hypothesis even lacking a better alternative. Only if your search was exhaustive: Scooping up a spoonful of ocean is not enough to conclude fish do not exist...

That's really the problem here though. You cannot falsify dark matter, and you cannot prove a negative. Imagine I say there is a 5 headed green deer that weighs 2000 pounds and can speak Gaelic, but it's really good at avoiding being spotted - so good in fact that you can even look at right at it and might not see it. And you can even touch it and not even know you're touching it! What would you could consider an exh…

The idea of non-visible matter as a fix for stellar motion dates back to the 19th century, when our knowledge about the cosmos was far more limited (remember, we only learned about other galaxies in the 1920s - it post-dates general relativity!). That the hypothesis is still viable today with our more elaborate understanding of the universe does validate the idea to some degree: Our cosmological models cut have killed it off easily.

So unless a better model that works equally well comes along, I see no reason to discard the dark matter hypothesis just yet: The universe has no obligation to be filled with a type of matter detectable with the means of today...

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

#168

Post by dogma1138 »

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 think you misunderstand the threads.

Dark Matter isn’t a thing it’s a place holder it has many candidates some more probable than others it might be that there is only one class of dark matter it might be that there are multiple classes of dark matter.

It might be that all the dark matter will be new forms of matter it might be that some or all of it will end up being baryonic matter.

It also might be that we won’t find it at all in which case we might need to say that our understanding of gravity and the geometry of space time isn’t nearly as representative of reality as we thought maybe dark matter is gravity leaking in from other universes maybe it’s the affect of additional dimensions of space time maybe quantum gravity causes some wired emerging phenomenon that affects the geometry of space time that we attribute to missing mass.

There isn’t a consensus amongst scientists on anything related to dark matter other than based on observations we are missing a truckload of mass in the universe.

And currently people are trying to explain it by looking for new forms of matter, normal matter that is very cold and so we can’t see it, and even attempting at modifying the theories of gravity to account for the observations we see with new relativistic and classical modified gravity models.

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

#169

Post by michaelsbradley »

stephengillie wrote: post #153
burlesona wrote: post #130

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 problem is that gravity, like EM, follows an inverse-square rule. If gravity had a 4th dimensional component, we would expect to see an inverse-cube situation. The equation is: 1/(1-dimensions) Youtube video that explains this in depth: https://www.youtube.com/watch?v=3HYw6vPR9qU&t=726s

Re: EM, the Biot-Savart force law can result in long-range attractive forces proportional to d^-1 instead of d^-2. So if it’s operative at galactic and intergalactic scales (between plasma filaments) and we’re not fully taking it into account, then we may be discounting the most powerful long-range force in the universe.

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

#170

Post by Michael_Groom »

You might want to check out a very interesting non-linear spinor theory[1] which contains a chapter on dark matter and dark energy analytically explaining the formation and inner structure, as well as the ratio of dark matter and dark energy throughout the development phase of the universe. Page 29 lists all components of DM/DE and normal matter.

[1] http://norbert-winter.com/wp-content/uploads/2018/07/2018_02...

Full theory can be found here: http://norbert-winter.com/wp-content/uploads/2018/02/2017-03...

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