The universe seems to be full of mysteries. One side of the spectrum, everywhere we look, we find galaxies, stars, planets and clusters of gases that leave an amazing spectacle that we as humans have been admiring for generations. However, on the other side and the most frightening and interesting part of our universe is what we cannot see. This brings in the mystery behind Dark Energy and Dark Matter.
Dark Energy is an energy source believed to act in opposition to gravity and causes what scientists consider to be making our universe expansion rate to be increasing. I say believe as observing Dark energy is very, very tricky due to it not reacting with any light of the electromagnetic spectrum, therefore it is invisible. Roughly 68% of the entire universe is made up of Dark Energy and to put that in perspective, all baryonic matter (or normal matter that we know of e.g atoms) makes up only 5%. Makes you feel small huh?
Dark Matter on the other hand is non-luminous material that again doesn’t interact, emit or absorb light. So you may ask “how do you actually know it exists? If you can’t see it, and it doesn’t interact with anything?” Well, we know it exists due to it exerting significant gravitational forces on things in the universe, such as galaxies. And we measure this due to a scientific technique known as gravitational lensing. This refers to a distribution of matter (such as a cluster of galaxies) between a distance source and an observer, that is capable of bending the light from the source as it travels towards the observer. So if an astronomer sees a ring form around a galaxy like in the picture in this blog, they can identify that something is bending the light, which is basically dark matter.
These two mysterious phenomena are very important as they may hold the clues to the fundamental question’s as too ‘why do we exist’ and so on… which I think every single human being has asked themselves at least once in their lifetime. The important thing is identifying what it actually is, because at the moment we know more about what dark matter and energy aren’t, than what they actually are.
It’s fascinating, but we still are on the lookout for deciphering this mysteries code of Dark Energy and Dark Matter. And I can’t wait to find out.
Here’s to the future (clink)