What is dark matter? Dark matter in simple terms

Dark matter is a type of matter that is believed to make up about 85% of the matter in the universe. It does not interact with light or other forms of electromagnetic radiation, which makes it invisible to telescopes, rendering it undetectable.

Dark matter is called "dark" because it does not emit, absorb, or scatter photons, which are the particles that make up light. The only way we can infer the existence of dark matter is through its gravitational effects on the stars and galaxies.

The first evidence of dark matter was discovered in the 1930s, by Swiss astrophysicist Fritz Zwicky, who observed that the mass of a cluster of galaxies was much higher than what could be accounted for by the visible matter in the cluster. Further studies and observations of other galaxy clusters have confirmed the presence of dark matter.

The most widely accepted theory of dark matter is that it is made up of a type of particle called a WIMP (Weakly Interacting Massive Particle). WIMPs are thought to interact with normal matter only through the weak nuclear force, and as a result, they do not emit radiation and are very difficult to detect.

Scientists are studying dark matter to try and understand its properties and how it affects the structure and evolution of the universe. They are conducting experiments to try to detect WIMPs directly or to produce them in particle accelerators.

Dark matter is crucial to our understanding of the cosmos because it helps explain why galaxies and galaxy clusters are structured the way they are. Without dark matter, gravitational forces would not be strong enough to hold galaxies and galaxy clusters together.

In conclusion, dark matter is a mysterious form of matter that cannot be seen, detected or interacted with by light or electromagnetic radiation. It makes up a significant proportion of the matter in the universe, and its existence is inferred through gravitational effects on visible matter. Although many questions remain about dark matter, its study is essential to understanding our universe's structure and evolution.