Something to do with everything in the universe interacting with everything else, which I always thought was a given...

https://en.wikipedia.org/wiki/Modified_Newtonian_dynamics#The_external_field_effect

I do like the idea that spacetime might have more complex curvature than Newton's inverse square law would describe. What if gravity acts like normal out to a certain distance from an object, but then starts to oscillate like a wave, or an Airy Disk, getting alternately stronger, then weaker, then stronger, etc. the further away from an object. Newton's Law of Gravity would be based on the "central spot" (0-ring) in which we live, and would not predict the effects of "fringes" further out, i.e. 1-ring, 2-ring... n-ring.





But more likely that's just my overactive imagination, and has nothing to do with MOND or anything else. Let's call it a metaphor.