Dr. Gaurav Jhaa Blogs

  Dark matter is a hypothetical form of matter that is thought to make up about 85% of the universe's total mass. It is called "dark" because it does not emit, absorb, or reflect any electromagnetic radiation, making it invisible to telescopes. Despite its invisibility, the existence of dark matter is inferred from its gravitational effects on visible matter, radiation, and the large-scale structure of the universe. The first indications of the existence of dark matter came from observations of galaxy rotation curves. In the 1930s, Swiss astrophysicist Fritz Zwicky noticed that the outer stars in galaxy clusters were rotating much faster than expected based on the visible matter alone. This implied the presence of an unseen mass, which he called "dunkle Materie" or "dark matter." Since then, many other pieces of evidence have been collected supporting the existence of dark matter. For example, the cosmic microwave background radiation, the large-sc