What is Dark Matter? Dark Matter in a Nutshell

Dark Matter in a nutshell 

Introduction 

The matter in which the modern scientists are higly interested in is the Dark Matter.

So, what is Dark Matter? How it was formed? Who suggested the idea of Dark matter? How much amount of it is in the universe? Does it interact with other particles? What is Baryonic Matter? Can we detect dark matter or has anyone detected it till now?
Let find out.
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What is Dark Matter?

Dark matter is a type of matter. Dark matter is called Dark because it does not appear to interact with electromagnetic field, which means it doesn't absorbs, reflect or emit electromagnetic radiations, and is therefore difficult to detect.

Primary Evidences

The primary evidence comes from the calculations done after studying about different galaxies in the universe.It was observed that may of the galaxies would fly apart, not move as they move or even do not form until and unless they contain a large amount of unseen matter inside them.

There are also other evidences which includes observations in Gravitational lensing, Cosmic microwave background and also in fields like observations in formation and evolution of galaxies.

Discovery of Dark matter 

The first to suggest the existence of Dark Matter using stellar velocities was Dutch astronomer Jacobus Kapteyn in 1922. Fellow Dutchman and radio astronomy pioneer Jan Oort also hypothesized the existence of dark matter in 1932.

Originally known as the “missing mass,” dark matter’s existence was first inferred by Swiss American astronomer Fritz Zwicky, who in 1933 discovered that the mass of all the stars in the Coma cluster of galaxies provided only about 1 percent of the mass needed to keep the galaxies from escaping the cluster’s gravitational pull. 

Amount Present in Universe 

The total mass–energy of the universe contains 5% ordinary matter and energy, 27% dark matter and 68% of a form of energy known as dark energy.

Thus, dark matter constitutes 85% of total mass, while dark energy plus dark matter constitute 95% of total mass–energy content.

Detection of Dark Matter

If dark matter is made up of sub-atomic particles, then millions or even  billions, of such particles must pass through every square centimeter of the Earth in each second.

Based on these there are experiments performed in order to detect dark matter. These experiments can be classified into two types: 1) direct and 2) indirect.

Direct detection experiments aims to detect the dark matter particles directly with the help of an detector. Till now there is no well established claim of direct detection of dark matter.

Indirect detection experiments search for the products of the self-annihilation or decay of dark matter particles in outer space. For example, in regions of high dark matter density (e.g., the centre of our galaxy) two dark matter particles could annihilateto produce gamma rays or Standard Model particle–antiparticle pairs.

Conclusion and future

Since the dark matter is not been observed directly it is still a mystery. It it exists, then it must barley interact with the ordinary Baryonic matter and radiation. Most of the dark matter is thought to be non-baryonic.

There can be a new type of elementary particle which has not been discovered yet.

Although the concept of dark matter is widely accepted, but since it is not directly observed , the arguments exists.

Thanks for Reading!

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