Assertion: dark matter's gravity | /r/HasProperty | explained by the existence of dark matter
Facets:
Source sentences:
text: Observations of the rotational speed of spiral galaxies, the confinement of hot gas in galaxies and clusters of galaxies, the random motions of galaxies in clusters, the gravitational lensing of background objects, and the observed fluctuations in the cosmic microwave background radiation require the presence of additional gravity, which can be explained by the existence of dark matter.