Dark Matter: A Brief Introduction

                                                      Dark Matter

           Most part of our Universe is dark i.e. there is no way we can see the "dark" part as it doesn't interact with light. The visible matter comprises only 4% of the total mass of the Universe. The rest of the pie is taken by mysterious  Dark Matter. Dark Matter doesn't doesn't interact at all with the light. It doesn't emit any radiations. It is just there. So, how do we know that it exists? Well, the Scientists inferred its existence from the motion of stars in the Galaxies. As per the conventional laws of physics, the stars farther away from the center of the Galaxy should move at lower speed than the stars towards the center. However, this is not what exactly happened.All the stars were found to move at same speed regardless of their position. This led to the conclusion that there is something in the vast empty space of the galaxy that itself is invisible but has a profound effect on the visible matter through gravitation. It is supposed that this very things is responsible for keeping the farthest stars intact in a Galaxy that would otherwise fly off. This gave rise to the idea of Dark Matter.