The “dark” in dark matter refers less to the fact that we can’t see it, and more to the fact that we don’t know what it is. Same with dark energy. We see the observed effects, and try to fit it into what we know: that the universe contains one or another form of matter or energy. But as stated, it could just mean a general misunderstanding of the full nature of gravity. Or it could mean a completely different, undiscovered force altogether.
The need for dark matter comes from the speculation that galaxies don’t have enough mass in them to keep the galaxy together.
How much mass does a tornado have ? How is it able to pick up immense objects ?
Space is full of small dark particles of dust that cannot be detected. We don’t know how much of it there is. Is that some of the missing ‘matter’ ?
I have a strong dislike for any theory of all matter that requires that “85% of all matter cannot be detected nor created except by exotic theories that only we can decipher, but we know it must be there because our exotic theory says it has to be there, so it has to be there.”
There is more evidence for heaven than “dark matter” and “dark energy” ....