"Centaurus A Contradicts Dark Matter Models"

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Discussion Overview

The discussion revolves around the implications of the satellite galaxies of Centaurus A rotating in a thin plane, as reported in a 2018 article, and its potential contradictions to dark matter models. Participants explore the nature of dark matter, its existence, and the characteristics attributed to it, while also addressing the appropriateness of questions regarding dark matter.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant notes that the satellite galaxies of Centaurus A are rotating in a thin plane, which may challenge the existence of a dark matter halo.
  • Another participant argues that the existence of dark matter is not the right question, suggesting that while its nature is unknown, its effects are well understood.
  • Concerns are raised about the tone of responses, with one participant feeling that their questions were dismissed as unreasonable.
  • Links to relevant articles and papers are provided to facilitate further understanding of dark matter and its implications.
  • A participant expresses a desire to better understand dark matter before asking further questions, indicating a willingness to engage with the topic more deeply.

Areas of Agreement / Disagreement

Participants express differing views on the nature and existence of dark matter, with some suggesting that its effects are understood while others question its existence based on new findings related to Centaurus A. The discussion remains unresolved regarding the implications of these findings on dark matter models.

Contextual Notes

Some participants indicate that further background knowledge on dark matter may lead to more focused questions, highlighting a potential limitation in the current understanding of the topic among some contributors.

megacal
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According to the article in Astronomy Magazine June 2018, the satellite galaxies of Centaurus A are rotating
in the same direction in a relatively thin plane, vs randomly distributed if there is a dark matter halo/sphere
surrounding large galaxies.

Any thoughts on this new finding? I've only had undergrad physics & math, but am very intrigued & curious about dark matter...or if it even exists, since there is only indirect evidence for it.
  1. Are we inside a cloud of it?
  2. If it has mass, doesn't it coalesce like barions into massive
    solid objects over time?
Thanks in advance for your insights.
 
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megacal said:
  1. Are we inside a cloud of it?
  2. If it has mass, doesn't it coalesce like barions into massive
    solid objects over time?
Have you done any research at all into what dark matter is? The most cursory reading regarding it will answer both questions immediately.

And by the way, the question of "does it exist?" is very much the wrong way to look at it. The point is that SOMETHING exists and we understand its characteristics pretty well, we just don't know what it is so we call it "dark matter" until we have a better understanding of what it IS to go along with our understanding of what it does.
 
Sorry, Phinds, but that's a very condescending reply to what I still believe are reasonable
questions. This is why I hesitate to ask any questions here.

Yes, I've read many articles about dark matter, and searched here first before asking my questions.

My bad, I should know better by now. Sorry to waste your time.
I'll look elsewhere for answers.
 
megacal said:
According to the article in Astronomy Magazine June 2018

Do you mean this article?

http://www.astronomy.com/news/2018/02/centaurus-as-satellites-rotate-together

It's helpful to provide a link when you give a reference, so it's clear exactly what you are referencing.

Also, the arxiv preprint of the actual paper is here:

https://arxiv.org/abs/1802.00081

That is probably a better basis for discussion.

megacal said:
that's a very condescending reply to what I still believe are reasonable
questions

The questions are reasonable. They are also answered easily by looking at the Wikipedia article on dark matter, which does a pretty good job of covering the subject and gives many good references. You will be able to ask more focused questions and get more useful information here if you have some basic background first.
 
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