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Old July 12th 18, 09:01 PM posted to sci.astro.research
Nicolaas Vroom
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Posts: 212
Default Missing matter found in the cosmic web

The article "Missing matter found in the cosmic web" in Nature of 21
June 2018 (See https://www.nature.com/articles/d41586-018-05432-2)
Starts with the following sentence: "We live in a dark Universe: just 5%
of it consists of ordinary matter such as that found in atoms, whereas
the rest is `dark' matter and energy that cannot currently be detected
directly" The word dark is written within '' indicating doubt.

Accordingly to https://en.wikipedia.org/wiki/Dark_matter: "In the
standard Lambda-CDM model of cosmology, the total mass-energy of the
universe contains 4.9% ordinary matter and energy, 26.8% dark matter and
68.3% of an unknown form of energy known as dark energy. Thus, dark
matter constitutes 84.5% of total mass, while dark energy plus dark
matter constitute 95.1% of total mass-energy content."

Next we read in the nature article: "However, observations of the nearby
Universe suggest that up to 40% of this ordinary matter---which is made
up primarily of particles known as baryons---is missing" This is a
strange twist. What we observe/measure are 1) galaxy rotation curves and
2) an expanding universe. What we also observe is 3) stars and baryonic
matter throughout the universe. However the amount found as #3 is not
enough to explain #1 and #2. To solve this issue we introduced the
concepts of dark (missing) matter and dark energy. And this missing
matter is supposed to be nonbaryonic.

However accoringly to Wikipedia there is also a Missing baryon problem.
See: https://en.wikipedia.org/wiki/Missing_baryon_problem. That means
there are two problems: 1) A dark matter problem and 2) a Missing baryon
problem. (In reality there are more issues: CMBR and BB
nucleosynthesis)

What this article indicates is that there is much more baryonic matter
in the cosmic web (Universe) as original thought. To me this seems
logical because more and more ordinary matter becomes visible because
technology improves.

My question is why is newly found matter 'clasified' as a solution for
problem #2 (and not #1) Different question: Why are there two problems
in the first place?

Maybe Fig 4 at page 408 shows the answer. They mention the word Local
Universe which makes everything much more complex.

Nicolaas Vroom
http://users.pandora.be/nicvroom/

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