What concept do modified gravity theories like MOND struggle to explain simultaneously with the Bullet Cluster observation?

Answer

The spatial separation of gravitational mass and visible matter (gas).

Modified gravity theories struggle to explain the clear spatial separation seen in the Bullet Cluster, as they generally predict that the gravitational mass should remain clustered with the visible matter component (the gas).

What concept do modified gravity theories like MOND struggle to explain simultaneously with the Bullet Cluster observation?

#Videos

How Do We Know Dark Matter Exists? - YouTube

physicsexistencecosmologydark matterevidence