[A Navy Vet]

"The reason they call it “dark energy” or “dark matter” isn’t that we can’t see it, but rather that we have no clue what it is. It’s “dark” in the same sense as any mystery. And it’s not outside the possibility that it might not even exist, but we just don’t understand enough about physics itself to explain it."

Exactly. Dark matter and dark energy are only theories that even the best physics people have yet to explain what they currently don't know for fact. So how did that "string" theory work out? Last I knew, they still can't explain gravity, but they have some theories.......

[only1percent]

Dark energy and dark matter are literally dark in that they emit and reflect no radiation, although in another sense they are transparent. They do affect radiation though - dark matter’s gravity bends light and other radiation and dark energy’s acceleration darkens light through the Doppler effect.

[Telepathic Intruder]

"they still can't explain gravity"

Gravity is a space-time curvature created by the presence of mass (or energy). How does mass create space-time curvature? No one has a freaking clue.