Dark Matter is not so Dark By Katherine Lightwood

Dark Matter is not so Dark

By Katherine Lightwood

The Dark Matter... Sounds pretty dramatic haa...!!
Like some sinister squishy thing under the control of Darth Vader...!!

Although that's not the case... because it is only called Dark Matter because it doesn't interact with light. It doesn't reflect light, doesn't absorb light, doesn't interact with electromagnetic radiation or any light at all. That's what we call it dark... Yeah, it's that boring...!! I know, it's a pretty Physics statement and not quite a sci-fi. But I promise you there's is so many mysteries surrounding dark matter.

So, dark energy makes up 69% of the energy density in the universe. 26%of them is dark matter, 5% of them is the baryonic matter or our ordinary matter. And that 5% (the baryonic matter) that includes me, you, our earth, our solar system and rest of the so-called "visible universe". So, how do we know that?
All the way back in 1933, a dude named Fritz Zwicky was studying a cluster of galaxies called the Coma Cluster. When galaxies orbit one another they rotate in a strange way like faster they are going stronger they need to hold on to each other.

And if you ask me what's the force holding them together? It's gravity...!!

The faster they go the more gravitational attraction they need to hold them together. And we know more gravity only comes when more mass is added. So, that guy looked at how fast the galaxies are orbiting and he calculated how much mass is needed for the gravitational force to hold them together. But you know what...the guy found that there is a 'MISSING MASS'. Zwicky saw the galaxies moving faster than the gravity of the mass that he could see could hold them together. And that was the first hint that there might be something out there that we can't see. And that's why he called it the DARK MATTER.

The second evidence of dark matter comes with another phenomenon but totally different from the first. Let me explain to you what happened. When you are looking at the star the light from the star is usually coming straight at you.

But when you place a giant object like a galaxy and a cluster of the galaxy, in between you then the light going to its usual way is bent around. Yeah, the gravity from the giant object can bent light. And this phenomenon is called Gravitational Lensing. So, depending on how much light is bending, we can estimate the size of the galaxy. Because again, more mass more gravitational pull on the light.

But now, in the time of calculation when scientists calculate the mass... it just doesn't add up. There's MISSING MASS again...!!

Many scientists have speculated that Dark Energies are a bunch of MACHOs or Massive Compact Halo Object. And these are things like Brown Dwarfs, White Dwarfs, and even black holes. Things that have low luminosity but are small and dense. But the cosmological models of the early universe shows that we shouldn't see more than the 5% of the Baryonic Matter. So, there you go again...The Truth always lies in Restricted Areas, and we might never know. Who knows there is a bunch of dark matter sitting just behind my backyard. We'll see that... 

So, that was my thought of the day. To see more posts like this make sure to visit our main page. And Do not forget to visit our institute's page to know more about graphic design, 3D, animation courses and other awesome stuff. Till then good day to you.

Katherine Lightwood