Much Ado

I have been trying to find an analogy to help me understand the expansion of the universe. It’s been almost s year. Track an air bubble from below the surface of the sea. As it rises it expands and accelerates. For known reasons. So as a large helium weather type balloon. No added energy required.

Is it possible that photons can not be created inside a black hole, rather than the extreme gravity preventing light from escaping?

Great, thanks again. Your links were good. Do you know of any terminology that refers to existence, other than matter or energy, I am thinking that the effective condition is neither matter nor energy.

Very helpful thank you. To clarify my thoughts, why is the effective condition referred to as dark "matter". The definition of matter is clear enough, or is it? Must it be matter.

Thank you, please then, why is "Dark Matter" inferred in galaxies relative to mass - gravity deficiencies ?

Is mass the only "creator" of gravity? Assumptions = Limitations

Klaynos, universe

If our universe is in orbit around something, what would the evidence look like ? If the orbit were irregular ? If it was spinning/rotating ?