I If Dark Matter and Dark Energy exist, what produces them?

[pixelperfect]

My query is really to find out what everybody thinks about 'empty space'. Does dark matter/energy exist and if so, it fills all voids in the universe? Where does it come from? Is it produced by some force? Without DM/DE, does space even exist? Say the supernovas, the collision of neutron stars, and so on produces it. Then without those events we basically have no DM/E. There again, does anything exist?

Any thoughts?

 

[jbriggs444]

My query is really to find out what everybody thinks about 'empty space'. Does dark matter/energy exist and if so, it fills all voids in the universe? Where does it come from? Is it produced by some force? Without DM/DE, does space even exist? Say the supernovas, the collision of neutron stars, and so on produces it. Then without those events we basically have no DM/E. There again, does anything exist?

Any thoughts?

What have you learned so far in your own search for information on dark matter and dark energy?

 

[mathman]

Dark matter and dark energy are two completely different things. Their only connection is the word dark.

Dark matter is "stuff" which is detected by gravitational effects.

Dark energy is completely unknown. It appears from the equations of general relativity.

 

[WatchTheChaos]

Heya, an inexperienced teen here, chipping in his 2 cents about the matter.

Dark matter is estimated to account for about 28% of the known universe⁽¹⁾, and doesn't interact with electromagnetic force, as opposed to normal matter, that does. As mathman said, it's detected by its gravitational effects; namely keeping large amounts of mass, like galaxies that are rotating faster than their normal gravity's limits, together. That being said, it isn't proven. There's a chance there's a force we don't yet recognize, shaping stars together into galaxies.

And then there's dark energy.

Dark energy is often associated with the vacuum of space, is approximately 67% of the universe. It's distributed evenly throughout the universe, and it's effect remains unchanged even as the universe expands. It's this even distribution that leads us to believe that dark energy doesn't really care about gravity, which leads to a repulsive force, accelerating the expansion of the universe. Based on the Hubble law, it's rate of expansion and acceleration can be measured, confirming its existence and giving us the sweet 67% estimate.

Just by these two definitions, we're able to knock your first question out of the way. Yes, it exists. The second question is a bit iffy, since one might consider dark energy to be a void in itself. I'll say yes to it, nonetheless. And where it comes from? It's hard to say, after all, with one being an unproven theory and the other seemingly endless, there's no conclusive evidence as to what might create them. I believe that also covers your question about if it is made by some force.

Next, the matter about if they're created by supernovas and neutron stars colliding. Like I said earlier, I don't know, but this doesn't seem to be the most likely answer. After all, there's finite matter in the universe- it can't really be created nor destroyed. As of such, if dark energy and/or dark matter is really created by those means, there's only a finite amount of stretching the universe will take... eventually, there will be no more supernovas or neutron stars. Matter will eventually settle to entropy, billions of years in the future, and calculations today show that it's more than probable the universe will continue to expand, even as the universe goes still. Just a teen speculating, though, and it sounded better in my head.

Now, under the hypothetical conditions that A: There are no supernovas or colliding neutron stars, and B: Dark matter and/or Dark energy is created by those means, it would mean the universe would be exponentially smaller, and 100% 'light matter' (stuff like your laptop, yourself, the earth... matter, you see?). That would exist. But you wouldn't- imagine it, literally no space between every bit of matter in the universe. We would collapse into a black hole as large as this hypothetical universe, and slowly bleed off into nothingness as hawking radiation. So, to sum that up, a black hole would exist-- wouldn't count as 'nothing'-- so yes, something would exist.

I hope I answered your question. well I tried to cover all of your questions and gave reasonable responses. Remember, I don't know everything, go take my advice with a grain (heap) of salt.⁽¹⁾ https://home.cern/about/physics/dark-matter
(No direct quotes from here, but I used it as a reference) https://www.cfa.harvard.edu/seuforum/de_speedingup.htm

 

[Arman777]

Dark energy is often associated with the vacuum of space, is approximately 67% of the universe. It's distributed evenly throughout the universe, and it's effect remains unchanged even as the universe expands.

It means that the density of the dark matter doeant change. For example, If you have a box with some amount of matter and, after you increase the size of the box the matter density decreases ( the situation also goes for radiation). But in Dark energy even you increase the size of the box ( or reduce it) the density of the Dark energy remains constant.

Based on the Hubble law, it's rate of expansion and acceleration can be measured, confirming its existence and giving us the sweet 67% estimate.

It's actually not exactly found by that.
We know that

$Ω_b+Ω_k+Ω_Λ+Ω_c=1$

Scientists just put random values to these input and try to find what best fits the current observational data. Since we measure the baryonic matter density it can be ruled out of this process but still the main idea is we don't measure the dark energy. We just put values to these equation then run a simulation and see which simualtion give us a best fit to current cosmological observation.

Where does it come from? Is it produced by some force? Without DM/DE, does space even exist? Say the supernovas, the collision of neutron stars, and so on produces it. Then without those events we basically have no DM/E. There again, does anything exist?

We don't know where it's "exactly" come from. But we have some ideas for sure.

Yes without DM or DE space can exist and it my last article on PF insight I explained how type of universe would it be.

Supernovas or Neutron star colliosions don't produce anything. How's that possible even possible. Let's suppose for a moment "it creates DM and DE". So %4 of the baryonic matter creates the rest compound of the universe (which that's %96 of the total universe). I don't think that makes sense.

Again a universe without DM or DE is possible just the universe would be in a much different shape then ours.

Next, the matter about if they're created by supernovas and neutron stars colliding. Like I said earlier, I don't know, but this doesn't seem to be the most likely answer. After all, there's finite matter in the universe- it can't really be created nor destroyed. As of such, if dark energy and/or dark matter is really created by those means, there's only a finite amount of stretching the universe will take...

No its not creates by supernovas or collisions. I didnt understand how you got that conclusion. Universe is infinite there can't be a limit in streching. It just expands.

 

[phinds]

Does dark matter/energy exist?

This question exposes a fundamental misunderstanding about what those terms mean. They are used to describe evidence, so questioning whether they exist is inappropriate. SOMETHING exists in both cases and the evidence for each is overwhelming. The real question is not "is something causing what we see happening" which is what your question amounts to, but rather "WHAT is causing what we see happening?". In both cases, we don't know the answer, although there are various (unproven) theories of explanation.

 

[newjerseyrunner]

Dark energy appears to exist everywhere in space, but dark matter does not simply fill all voids, it seems to be physical stuff that moves around with gravity. In terms of what produces it, I believe the accepted theory is that it's always been and was produced directly in the aftermath of the big bang.

 

[jeremyfiennes]

One current estimate of the universe's composition is: visible matter 4%, dark matter 24%, dark energy 72%. But what about visible energy: light and gamma ray photons, etc?

 

[Bandersnatch]

One current estimate of the universe's composition is: visible matter 4%, dark matter 24%, dark energy 72%. But what about visible energy: light and gamma ray photons, etc?

Radiation density has been negligibly small for most of the history of the universe, because it dilutes the fastest as the scale factor of the universe grows.
If I'm getting this right, at the current epoch its fractional density is something like 0.008%.
You need to go back to around the surface of last scattering, to get noticeable densities, and it becomes dominant around 330 kyrs prior to that.

 

[jeremyfiennes]

Radiation density has been negligibly small for most of the history of the universe, because it dilutes the fastest as the scale factor of the universe grows.
If I'm getting this right, at the current epoch its fractional density is something like 0.008%.
You need to go back to around the surface of last scattering, to get noticeable densities, and it becomes dominant around 330 kyrs prior to that.

Ok. Thanks. Nice clear answer.