Q: What does The Urantia Book say about the effects of Supermassive Black Holes and Dark Matter on galaxies and The Milky Way?

A: The Urantia Book does not really talk about “black holes, ” as such; instead, they talk about the “dark islands of space, ” as in this quote:

The Dark Islands of Space. These are the dead suns and other large aggregations of matter devoid of light and heat. The dark islands are sometimes enormous in mass and exert a powerful influence in universe equilibrium and energy manipulation. The density of some of these large masses is well-nigh unbelievable. And this great concentration of mass enables these dark islands to function as powerful balance wheels, holding large neighboring systems in effective leash. They hold the gravity balance of power in many constellations; many physical systems which would otherwise speedily dive to destruction in near-by suns are held securely in the gravity grasp of these guardian dark islands. It is because of this function that we can locate them accurately. We have measured the gravity pull of the luminous bodies, and we can therefore calculate the exact size and location of the dark islands of space which so effectively function to hold a given system steady in its course. (15:6.11)

As you can see, these dark islands “exert a powerful influence in universe equilibrium and energy manipulation.” They function as “powerful balance wheels” as well. They hold whole systems in place.

And, about these “dark islands” and the Milky Way:

Practically all of the starry realms visible to the naked eye on Urantia belong to the seventh section of the grand universe, the superuniverse of Orvonton. The vast Milky Way starry system represents the central nucleus of Orvonton, being largely beyond the borders of your local universe. This great aggregation of suns, dark islands of space, double stars, globular clusters, star clouds, spiral and other nebulae, together with myriads of individual planets, forms a watchlike, elongated-circular grouping of about one seventh of the inhabited evolutionary universes. 15:3.1

I am not sure if all Urantia Book students accept that black holes and the dark islands of space are one and the same, but it seems to me that they likely are. When they were first discovered, it seemed to science that they were exclusively destructive, but as more research has been done, many scientists now believe that they can not only destroy, but that they are also energy generators and regulators. I guess you’ll have to make up your own mind about that…

As for “dark matter…” I don’t find that word phrase in the book at all, but when I think about dark matter, I think about all of those worlds that we cannot see—such as architectural worlds, and the planets that do not emit reflective light from a nearby sun. Paradise is surrounded by one billion of these architectural worlds, and this is one reason that Paradise will always remain invisible to our earthly eyes, no matter how advanced we may become in peering into the universes. I think I read somewhere that a tremendous portion of the universe is actually dark matter—meaning matter that we cannot see with our telescopes, or except by indirect means.

HERE is a reference that I found from Google about dark matter…interesting reading.

I hope this answer has been helpful to you. Thanks for writing, and I hope that you got pointed in the right direction with the links I have given you…