The Journey of Light across the Universe

Sougata Dutta
25 August, 2022
2 mins ago

All the light we can see; and the rest – ‘tis not the darkness out there – just all the light we cannot.

Believe it or not, the entire universe is filled with light. Radiant beaming light. No matter where you are in the universe or at least in the observable universe as we know it, you will always find light. Or rather it should be said that light will find its way to you. Light always does. Light allows the miracle of sight. But that miracle is a short one. A what we see and observe with our naked eyes is a thinly lit world. We see so many colours around us and yet, those billion colours are only an extremely narrow spectrum of all that which exists as light.

Nature of light: A peek into what is

This that you see now is what is known as the visible spectrum. It is an extremely thin range of frequencies or energies. The other term you might associate with these is wavelength. Image, the distance between two consecutive quantum oscillations of a photon which at the same time is also a wave, emitted via the release of energy. And this visible spectrum is all the light you can see. A range from about 4000 – 7000 Angstrom.

Believe me seems a lot, but it isn’t. Because on either side of this range you have other ranges too. The Ultraviolet, X-ray and Gamma rays beyond the violet’s 4000 angstrom and the infrared, microwave and radio waves beyond the red’s 7000 angstrom.

How they get made: And there is now light

Light in this universe has a multitude of sources. It can come from an incandescent light bulb or a candle’s fire in the night’s darkness providing a sensual illumination to the GenZ. The light you observe across the universe cannot however be directly seen by us. But the light of the stars begins its journey within the star’s core and takes some million years to travel to the edge of the star. And then it sets on a journey across the 93 billion lightyear long universe.

The Cosmic Noise: The CMB Radiation and picture of universe

There is a constant radio noise which the scientists found at the epoch of research in radio astronomy. And from that noise we got to click the universe’s picture. And that picture has allowed us to see the universe in its entirety with light from all across the universe, the kind we cannot see.