Dark matter is one of the most intriguing and mysterious substances in the universe. It is called “dark” because it does not emit, absorb, or reflect light, making it invisible to telescopes and other instruments used to observe the universe. Despite its elusive nature, scientists believe that dark matter plays a crucial role in the universe as it holds galaxies together and helps to explain the observed gravitational forces.
The existence of dark matter was first proposed in the 1930s by Swiss astronomer Fritz Zwicky, who observed that the observed mass of galaxy clusters was not enough to account for the gravitational forces holding the clusters together. Since then, numerous studies and observations have provided further evidence for the existence of dark matter. For example, scientists have observed that the movements of stars in galaxies can only be explained if there is more mass present than what can be seen.
One of the biggest challenges in studying dark matter is that it cannot be directly observed. Scientists have to rely on its gravitational effects on visible matter, such as stars and galaxies, to infer its presence. However, they have been able to develop theories about its properties and behavior, such as the fact that it is thought to be composed of weakly interacting massive particles (WIMPs) that move slowly and do not interact with visible matter.
The search for dark matter has been a major focus of astronomical research for decades, and scientists have developed several experimental approaches to try to detect it. For example, large underground detectors, such as the Large Hadron Collider (LHC), are being used to search for signs of WIMPs by detecting the interactions between dark matter particles and normal matter. In addition, scientists are also using satellites, such as the Planck satellite, to map the distribution of dark matter in the universe by observing its gravitational effects on light from distant galaxies.