Dark Matter as possible ground state for all matter

AI Thread Summary
The discussion explores theories suggesting that Dark Matter (DM) could serve as a precursor or ground state for Observable Matter (OM), particularly in a pre-Big Bang context. Participants question whether DM interactions could occur faster than light, given that DM only interacts gravitationally with OM, while emphasizing that gravitational effects are generally constrained by the speed of light. The conversation highlights that if DM's gravitational effects were not limited by this speed, it could lead to significant changes in cosmological theories, although the actual impact might be minimal. Theories proposing such changes face skepticism, as they must provide robust evidence to challenge established physical laws. Ultimately, the complexity of alternative theories complicates the discourse, with a focus on the need for empirical validation.
Bill Minerick
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Are there any theories based upon Dark Matter (DM) being a precursor or sublayer or ground state to Observable Matter (OM)? Pre-Big Bang? Galaxy distribution linked to DM tendril intersections is consistent with DM providing a pre-existing structure.

Any theories based upon DM interactions being able to occur faster than the speed of light since DM only interacts with OM gravitationally?

Are there experiments which indicate that gravitational effects are limited to the speed of light? If DM gravitational effects are not constrained by "c", wouldn't a lot of cosmology ideas be changed?

Do such theories provide alternative solutions to questions answered by Big Bang, Inflation Theory, Quantum Theory? Maybe DM scale is below Plank size limit.
 
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Bill Minerick said:
Are there any theories based upon Dark Matter (DM) being a precursor or sublayer or ground state to Observable Matter (OM)? Pre-Big Bang? Galaxy distribution linked to DM tendril intersections is consistent with DM providing a pre-existing structure.

Ground state? I don't see how. The ground state of a material still interacts through whatever forces it does when it's not in its ground state. The structure of dark matter is the result of gravitational collapse, not a pre-existing structure.

Any theories based upon DM interactions being able to occur faster than the speed of light since DM only interacts with OM gravitationally?

Gravitation is limited to c as well.

Do such theories provide alternative solutions to questions answered by Big Bang, Inflation Theory, Quantum Theory? Maybe DM scale is below Plank size limit.

If your theory breaks a fundamental law of physics, let alone multiple ones, you need to have amazingly good evidence to justify it. Otherwise it doesn't matter if the theory provides answers, as those answers are probably wrong.
 
Bill Minerick said:
Are there experiments which indicate that gravitational effects are limited to the speed of light?

There are a few GR experiments, but these is something hard to directly measure. There are lots of theoretical reasons to think that gravity moves at the speed of light.

If DM gravitational effects are not constrained by "c", wouldn't a lot of cosmology ideas be changed?

If DM gravitational effects weren't constrained by "c", there would be some changes, but surprisingly few ones. Most of the effects of dark matter end up being pressure effects, which means that if you set "c=infinity" there are relatively few changes. Everything is controlled by the speed of sound which is much lower than then speed of gravity.

One common approximation that people make in cosmology is to set "speed of light=infinity". It turns out that this approximation doesn't change very much, since the speed of gravity doesn't cause many observational differences.

This is the flip side to the first answer. If the speed of gravity makes a big difference, we can do an experiment. If it turns out that it's hard to do an experiment to measure the speed of gravity, that means that's it's not going to have much practical effect.

Do such theories provide alternative solutions to questions answered by Big Bang, Inflation Theory, Quantum Theory? Maybe DM scale is below Plank size limit.

The trouble we have are too many alternatives. The hard part is not assuming this new weird thing about DM, but showing it this is wrong.
 
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The formal paper is here. The Rutgers University news has published a story about an image being closely examined at their New Brunswick campus. Here is an excerpt: Computer modeling of the gravitational lens by Keeton and Eid showed that the four visible foreground galaxies causing the gravitational bending couldn’t explain the details of the five-image pattern. Only with the addition of a large, invisible mass, in this case, a dark matter halo, could the model match the observations...
Hi, I’m pretty new to cosmology and I’m trying to get my head around the Big Bang and the potential infinite extent of the universe as a whole. There’s lots of misleading info out there but this forum and a few others have helped me and I just wanted to check I have the right idea. The Big Bang was the creation of space and time. At this instant t=0 space was infinite in size but the scale factor was zero. I’m picturing it (hopefully correctly) like an excel spreadsheet with infinite...
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