Dark Matter Did Not Dominate Early Galaxies

[Claire.]

Dark Matter Did Not Dominate Early Galaxies

A new study finds the mysterious substance was at most a minor constituent of large galaxies in the early universe

Although the invisible substance known as dark matter dominates galaxies nowadays, it was apparently only a minor ingredient of galaxies in the early universe, a new study finds. This new finding sheds light on how galaxies and their mysterious "haloes" of dark matter have changed over time, researchers said.

Read more: Scientific American

[Claire.]

 

[fred_mc]

Interesting. I guess that Erik Verlinde's theory on emergent gravity, which I have found interesting, is wrong then because there would be no reason for dark matter to increase with time with that theory as far as I understand.

Dark matter is one of the most fascinating things I know of since it is so ghostlike, invisible and doesn't interact with ordinary matter.

Edited March 18, 2017 by fred_mc

[kartikg]

can it be that dark matter came from a 

different big bang? 

[fred_mc]

8 hours ago, kartikg said:

can it be that dark matter came from a 

different big bang? 

Interesting idea. I think if the extra gravitation we attribute to dark matter would be coming from a parallel universe (perhaps from real matter in a parallel universe), the big bang for that parallel universe would be a separate big bang. I've seen in science documentaries that gravitons can according to string theory possibly pass through the membranes between parallel universes. However, when I google, I can see that scientists have already thought about the idea that the extra gravitation could come from a parallel universe rather than from dark matter in our universe, and discarded that idea. I don't know enough physics to understand the motivation behind it but it seemed well thought through anyway.

[kartikg]

7 hours ago, fred_mc said:

Interesting idea. I think if the extra grav, itation.  we attribute to dark matter would be coming from a parallel universe (perhaps from real matter in a parallel universe), the big bang for that parallel universe would be a separate big bang. I've seen in science documentaries that gravitons can according to string theory possibly pass through the membranes between parallel universes. However, when I google, I can see that scientists have already thought about the idea that the extra gravitation could come from a parallel universe rather than from dark matter in our universe, and discarded that idea. I don't know enough physics to understand the motivation behind it but it seemed well thought through anyway.

I am not aware of the gravitational effects diet to parallel universes, my thinking was like big bang within our own universe spewing out dark matter

[fred_mc]

19 minutes ago, kartikg said:

I am not aware of the gravitational effects diet to parallel universes, my thinking was like big bang within our own universe spewing out dark matter

Hmmm, I don't think it works like that. Big bang gave rise to space-time, which has been expanding since then. I don't think there can be another big bang inside of our universe since space-time is already here, another big bang would in that case give rise to another space-time, which would be another universe, I think. I think you're thinking about an explosion inside of our space-time/universe giving rise to dark matter but big bang is not an explosion inside of space-time but something giving rise to space-time itself, and its expansion.

Edited March 19, 2017 by fred_mc

[kartikg]

Just now, fred_mc said:

Hmmm, I don't think it works like that..  Big bang gave rise to space-time, which has been expanding since then. I don't think there can be another big bang inside of our universe since space-time is already here, another big bang would in that case give rise to another space-time, which would be another universe, I think. I think you're thinking about an explosion inside of our space-time/universe giving rise to dark matter but big bang is not an explosion inside of space-time but something giving rise to space-time itself, and its expansion.

Yes I was thinking just like that explosion within an explosion. 

[aquatus1]

Is dark matter even a thing?  I was under the impression it was more or less a placeholder for a force we couldn't figure out.

[Calibeliever]

On 3/18/2017 at 2:26 PM, fred_mc said:

Interesting. I guess that Erik Verlinde's theory on emergent gravity, which I have found interesting, is wrong then because there would be no reason for dark matter to increase with time with that theory as far as I understand.

Dark matter is one of the most fascinating things I know of since it is so ghostlike, invisible and doesn't interact with ordinary matter.

Or, was it just as prevalent but not as condensed around galaxies yet?

[Calibeliever]

On 3/21/2017 at 11:08 AM, aquatus1 said:

Is dark matter even a thing?  I was under the impression it was more or less a placeholder for a force we couldn't figure out.

It has always felt a bit like Newton's Aether to me.