Disclaimer: I know enough about astronomy to know that I know pretty much nothing.
As dark energy was explained to me, it is a placeholder in the equation(s) for measuring the expansion of the universe. Rephrasing, we know the universe is expanding but we can’t account for some amount of the force involved.
I hope I am making sense and I am not too far out in the weeds.
To my question: all of the stars are blasting out not just photons but also substantial amounts of physical matter in various states (gas, plasma, solid) that also includes material from the various objects in the solar system (eg atoms of water from mars). Wouldn’t that mixture of massless photons and physical material have some significant influence on everything else?
Nope. Wrong.
BOTH are not “real” things, as far as you describe. They BOTH describe phenomenon we have no precise explanations for.
Dark matter: Many (NOT all) galaxies rotate or otherwise act like they have a LOT more mass around them than we can observe. Mostly visible by further out objects rotating faster than they should. If there were only as much mass as we can see, outer objects should mostly be waaaay slower.
Dark energy: The furthest distances in the universe are accelerating away from us. That acceleration requires energy from somewhere. It does NOT happen within galaxies, but of course we can see millions of galaxies with the ultra-sensitive telescopes we have today.
In BOTH cases, we do not have a detailed explanation for, but we DO have MANY observations that confirm the effects. They are BOTH real phenomenon, and neither have solid explanations, yet. Hence the “dark xxx” names.
Dark matter is not just a mathematical construct to explain velocity curves, even though historically that was the first step. Since then, we found compelling evidence of dark matter acting as gravitational lenses. It is a very real phenomenon, as we absolutely know that there is an excess of matter that is dark, i. e. not radiating or absorbing light. Some open questions still exist about dark matter, such as whether it is made up of particles and how they are generated. But the question of whether it is real is settled.
Dark energy is more of a placeholder name at the moment to explain the accelerating expansion of the universe. It is more contested in the scientific community and there is no direct evidence of this energy yet, some cosmologists deny the existence of dark energy at all and claim that is a mathematical flaw in general relativity (the equivalent explanation of dark matter as a flaw in current models called modified Newtonian dynamics or short MOND, is a very fringe theory by now). As such, the question of whether dark energy is real is not settled, it is currently a prediction to explain some observations but lacks further evidence.
The name “dark”, in reference to dark matter or dark energy, has nothing to do with light or photons; it refers to the fact that they can’t be detected. We haven’t been able to build any kind of device that can measure either or even determine whether they are or are not present within a certain area of space.
As far as we know, they either exist somewhere within our universe, or the equations we’ve “proven” to represent the fundamental reality of the universe as we know it are wrong in some way.
If you ask me, either prospect is equally exciting and interesting.
Rofl no… the ENTIRE POINT is that there IS DIRECT-BY-NECESSITY TO MATCH EVIDENCE of Dark Matter and Dark Energy as described in current models. How many galaxies do you think our current telescopes can see!? It’s FAR more than thousands!!
You cannot say either does not exist and claim to have a more accurate model of the universe, unless you have A LOT of observations to explain in EXTREME DETAIL to every astronomer.
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Nope, wrong. Dark matter is LITERALLY modeled as matter we cannot detect.
… how… do you think science works?? We get EVERY sign of matter, call it Dark Matter, yet have no basis for saying yes it’s actual mass out there?!
You are a fool if you think science does not say Dark Matter has mass…