Dark matter was proposed initially because at galaxy scales the gravity force doesn’t seem to match the one created by the visible matter in that galaxy, while others tried to propose modified laws of gravity at that scale. He is probably defending the later via compactified dimensions, so at some scales gravity stops transmitting at one over the distance squared, as those extra dimensions start to make an effect somehow.
In case someone thinks I’m saying something crazy imagine a universe that is an infinite straw. When you zoom a lot in the surface you see two flat dimensions, so gravity would propagate at one over the distance. When you zoom out you stop seeing the dimension that loops over itself and only see one, so gravity gets constant at that scale.
You could get the same with a lot more complex manifolds, that look like 3+1 dimensions at some scales.
![References: [1] out of his ass](https://mander.xyz/pictrs/image/7d954d56-4739-4230-b641-f7a2ed05fa5c.jpeg){kind=link}
What he’s probably saying is not that far out.
Dark matter was proposed initially because at galaxy scales the gravity force doesn’t seem to match the one created by the visible matter in that galaxy, while others tried to propose modified laws of gravity at that scale. He is probably defending the later via compactified dimensions, so at some scales gravity stops transmitting at one over the distance squared, as those extra dimensions start to make an effect somehow.
In case someone thinks I’m saying something crazy imagine a universe that is an infinite straw. When you zoom a lot in the surface you see two flat dimensions, so gravity would propagate at one over the distance. When you zoom out you stop seeing the dimension that loops over itself and only see one, so gravity gets constant at that scale.
You could get the same with a lot more complex manifolds, that look like 3+1 dimensions at some scales.