Dark matter is a form of unknown matter that is thought to account for approximately 25 percent of the universe. Its presence is implied in a variety of astrophysical observations, including gravitational effects that cannot be explained by accepted theories of gravity unless more matter is present than can be seen. Scientists believe that dark matter acts like a spider’s web, holding fast-moving galaxies together, but what exactly it is remains open to speculation.
January 1, 2019
June 3, 2019