Previously, astronomers calculated galaxy mass as if they were perfect spheres. But a galaxy is a flat pancake. The new 'Lost and Found' model takes the actual shape into account: it sums up the gravitational pull from all parts of the disk, not just the central bulge. The result is stunning: many galaxies need a third less invisible dark matter than previously thought.
The secret is that in a pancake, gravity falls off more slowly — even distant chunks contribute, and stars on the outskirts zip along fast without extra hidden mass. Estimates show that only two-thirds of the old amount of mysterious substance is needed. The discovery by Vera Rubin and Fritz Zwicky isn't canceled: it's refined: the shape of galaxies changes everything.
In a flat galaxy, gravity at the outskirts doesn't weaken as sharply as in a sphere, the remote parts of the disk still pull.
If there's a third less dark matter, then even in the reality described by Blake Crouch in 'Dark Matter,' there's a little less magic.