Disclaimer: I am not a physicist.<p>Maybe gravity will turn out to be just a computational artefact. The more energy and states in a volume, the "slower" progression of the [local] system. An effect like this could appear as curved space at energy concentrations. Perhaps GR could be derived from something like this?
PBS Spacetime has some really nice videos about Gravity (Newtonian vs GR)
<a href="https://www.youtube.com/watch?v=NblR01hHK6U" rel="nofollow">https://www.youtube.com/watch?v=NblR01hHK6U</a>
Warning: speculation follows.<p>If we understand correctly, the universe is about 13.7 billion years old. I recall reading once that there is enough mass (matter plus dark matter) that the Swarzchild Radius of that much mass is approximately 13.7 billion light-years.<p>What if we're <i>inside</i> a black hole? How would that affect how we interpret what we see at large distances? (For example, does that explain the Hubble redshift? Does it explain dark energy?)<p>And, if it's true, then what is a black hole? Can you have a black hole inside the Swarzchild radius of another black hole?
Honest question. If the concept of dark matter flows from our current understanding of gravity, and gravity is so admittedly poorly understood, how confident are we that dark matter is "a thing"? I know an intuitive sensibility is not the best foundation for an understanding of The Universe, but every time I read about dark matter, I get a very "Aether"-ish vibe. I just imagine comments section in the 2070 version of HN getting a good natured laugh about dark matter.