All Questions
Tagged with cosmology dark-matter
265
questions
56
votes
4
answers
4k
views
Are modified theories of gravity credible?
I'm a statistician with a little training in physics and would just like to know the general consensus on a few things.
I'm reading a book by John Moffat which basically tries to state how GR makes ...
- 673
54
votes
4
answers
14k
views
How do we know Dark Matter isn't simply Neutrinos?
What evidence is there that dark matter isn't one of the known types of neutrinos?
If it were, how would this be measurable?
- 705
50
votes
8
answers
7k
views
Why isn't dark matter just ordinary matter?
There's more gravitational force in our galaxy (and others) than can be explained by counting stars made of ordinary matter. So why not lots of dark planetary systems (i.e., without stars) made of ...
- 603
29
votes
3
answers
10k
views
How do people calculate proportions of dark matter, dark energy and baryonic matter of the universe?
The Wikipedia page on dark matter mentions that the Planck mission had revealed that in our universe ordinary baryonic matter, dark matter and dark energy are present in the ratio: 4.9%, 26.8% and 68....
- 1,057
28
votes
4
answers
6k
views
How did the universe shift from "dark matter dominated" to "dark energy dominated"?
In order to get dark energy to dominate, wouldn't you first need another form of energy to push the expansion until dark energy could dominate? Otherwise I don't understand how the universe could ...
- 1,137
23
votes
1
answer
9k
views
How do we know Dark Matter is non-baryonic? [duplicate]
It seems widely stated, but not thoroughly explained, that Dark Matter is not normal matter as we understand it. Wikipedia states "Consistency with other observations indicates that the vast majority ...
- 3,241
22
votes
2
answers
3k
views
Why are neutrinos ruled out as a major (or even sole) component of dark matter?
A number of times I have encountered in text-books and articles that neutrinos might contribute only a small fraction to dark matter. The reason has to do with the fact that if all of the dark matter ...
- 547
20
votes
3
answers
1k
views
Why hasn't warm dark matter replaced cold dark matter as the standard model of cosmology?
The $\Lambda\rm CDM$ (cold dark matter with cosmological constant) is the current standard model of cosmology because the model comes with a long list of phenomena successfully explained by it. ...
- 18.5k
19
votes
5
answers
5k
views
Dark matter and dark energy references
I've been looking for questions about dark matter, and I've read some very interesting answers. However, I desire too look into it deeply.
This is not actually a question. I'm asking the community ...
17
votes
3
answers
4k
views
Is dark matter repulsive to dark matter? Why?
I think I saw in a video that if dark matter wasn't repulsive to dark matter, it would have formed dense massive objects or even black holes which we should have detected.
So, could dark matter be ...
- 1,077
16
votes
2
answers
4k
views
How long has dark matter been around?
I've read that dark matter's existence is theorized because galaxies spin/clump in a way that would require much more mass than there appears to be. Also that there is gravitational lensing in places ...
user202776
15
votes
6
answers
5k
views
15
votes
4
answers
3k
views
If dark matter can't lose kinetic energy, then why is it not traveling at relativistic speeds?
I have read this question:
The only way you can do this is to remove kinetic energy from the system.
With normal matter this is done through electromagnetic interactions, which turn the kinetic ...
- 29k
14
votes
3
answers
5k
views
How did we 'discover' dark matter? [closed]
I'm an astrophysics student and I've been researching this topic and there is one point that keeps eluding me.
How did the scientific community realize that there had to be dark matter in the ...
- 508
14
votes
3
answers
3k
views
Is Dark Matter in Motion?
What is known about the motion of dark matter, especially in galaxies?
It seems as though a particular distribution of dark matter might be required to cause the very flat galactic rotation curves ...
- 13.7k