Dark Matter: Let's learn more about it

 What is Dark Matter?

Roughly 80% of the mass of the universe is made up of material that scientists cannot directly observe. Known as dark matter, this bizarre ingredient does not emit light or energy. So why do scientists think it dominates? Matter makes up almost 32% of the total universe. Out of this, dark matter takes up 27% of the credit while normal/ordinary matter takes up 5%. Observations show that there is far too little visible matter in the universe to make up the 27% required by the observations, hence the term ‘dark matter'. As the name suggests, it is dark, not in the form of stars and planets we see. It is also not in the form of dark clouds of normal matter. 

As of now, dark matter is a hypothetical concept. But, if it really exists, it cannot be seen or detected. Dark matter does not interact with electromagnetic forces. Meaning, it does not absorb, reflect, or emit any kind of light or radiation. This makes it extremely hard to spot! There are many experiments conducted over the course of years to confirm the existence of dark matter.

Dark matter is not antimatter. There is a theory that new particles of matter and antimatter are constantly forming in the Universe. However, they annihilate each other and thereby maintain equilibrium. When matter annihilates with antimatter, unique gamma rays are produced. These gamma rays cannot be detected when dark matter is there. 

Dark matter is said to be of two types: Baryonic and Non-baryonic. Baryonic matter consists of protons, electrons, and neutrons, primarily called ‘baryons’. We can detect baryonic clouds when they absorb the radiation that passes through them. Most scientists think that dark matter is composed of non-baryonic matter. The lead candidate, WIMPs (weakly interacting massive particles), have ten to a hundred times the mass of a proton, but their weak interactions with normal matter make them difficult to detect. Neutralinos, massive hypothetical particles heavier and slower than neutrinos, are the foremost candidate, though they have yet to be spotted.