VIT, Vellore, 23.10.2018.
Electromagnetic spectrum starts from very short gamma rays to x-rays, ultraviolet rays, visible light waves, and even longer infrared waves, microwaves to radio waves which can measure longer than a mountain range and travel through the vacuum of space at the constant speed of light. Everything around emits, reflects, and absorbs EM radiation differently based on its composition and the graph showing this interaction is called as a spectral signature which allows astronomers to identify the presence of water and organic molecules in faraway galaxies and to study the sunspots. Microwaves carry thousands of phone channels to our telephone calls and are the backbone of communication and our earth sensing systems. We are surrounded by microwave background radiation which is one of the important evidence for the big bang theory that speaks about the origin of our universe.