Dark Matter

Dark matter is a hypothetical form of matter that does not interact with light or other electromagnetic radiation, and its existence is implied by gravitational effects that cannot be explained by general relativity. According to the standard Lambda-CDM model of cosmology, dark matter constitutes 26.8% of the total mass-energy content of the universe, and its composition is thought to be either weakly interacting massive particles (WIMPs) or axions. Despite the existence of dark matter being widely accepted, a minority of astrophysicists argue for modifications to the standard laws of general relativity, but none of these theories can describe every piece of observational evidence at the same time.learn more on wikipedia