Dark Matter!

 DARK MATTER 

April 4, 2021

Hello, my dear space lovers! So as our dear friend suggested for research on Dark matter and Dark energy, here I am with all the research on complete darkness😝😆

Well, in this post I will be talking only about Dark Matter. My next post will be all about Dark energy. So, stay tuned.

For now I can tell you that dark matter slows down the expansion of the universe, while dark energy speeds it up.                                                                                     Dark matter works like an attractive force — a kind of cosmic cement that holds our universe together. This is because dark matter does interact with gravity, but it doesn't reflect, absorb, or emit light.

Yes, friends we only call it dark matter because it does not interact with light, it doesn't reflect light, doesn't absorb light, doesn't interact with electromagnetic radiation, or LIGHT AT ALL. I know it is a very physics-y statement, and not quite SCI-FI. There are still so many mysteries surrounding dark matter. So, you may find some different content elsewhere, but I ensure you I have tried my best to combine different sources.  

We are going to talk about:

What is dark matter?

How do we know it's there?

What isn't dark matter? 

And why we might be wrong about all of this in the end.

Firstly we answer the composition of the universe-                                                         Dark energy makes up 69% of the energy density in the universe.                       And 26% is Dark Matter                                                                                             And about 5% is Baryonic Matter or ordinary matter. 

Yes, just 5% of this Baryonic matter includes me, you, our Earth, the solar system, all the stars, the milky way galaxy, all other galaxies, EVERYTHING WE CAN SEE it's all only 5% of the energy in the universe. 

I know you all must be wondering how do we know that Dark Matter comprises 26% of the rest of the stuff in the universe despite being invisible. Yeah, because it does not interact with light, how do we see it? Well, how do we know something's there when we can't see it?

  1.    So, let's take the example of wind. You can't see the air moving, but you can see its effects on other things. Such was the case with dark matter. All the way back in 1993 this dude, Fritz Zwicky was studying a cluster of galaxies called the Coma Cluster. When Galaxies orbit one another they are often playing this game (I don't know its name in English)(Similar game but only with 2 people opposite to each other.)

The faster they are going, the stronger they need to hold on to one another.  And the force holding the galaxies together is GRAVITY. The faster they go, the more gravitational attraction they need to hold them together. We know that more gravity only comes from adding more mass. Zwicky saw the galaxies moving faster than the gravity of the mass he could see could hold them together. 

              This was the first hint that there might be something out there he could not see. He called it DARK MATTER. 

2.    The next evidence for dark matter comes from a totally crazy phenomenon. It goes something like this- When you are looking at a star, the light from the star is usually coming straight at you. But when you place a giant object, like a galaxy or a cluster of galaxies, in between you, then the light coming towards you is bent. The gravity from giant objects bends light. It's almost as if there were a giant lens in between you and the star. This is weird but we call it Gravitational Lensing.

                     

       

Depending on how much the light is bending, we can estimate the size of the galaxy. Because more mass, more gravitational pull on the light. 

Now, there's even more evidence for dark matter. It has to do with how stars are moving around the galaxy. They are moving around the galaxy faster than they should be. 

What exactly is DARK MATTER? Dark Matter is a bunch of MACHOs. Come on, not nachos (MACHOs) Massive Compact Halo Objects. These are things like brown dwarfs, white dwarfs, even black holes, things that have very low luminosity. Some of the mass might be MACHOs.

The leading theory is that dark matter is likely a WIMP.

W- Weakly

I- Interacting

M- Massive

P- Particle 

These WIPMs couldn't interact with the electromagnetic force, or light.

Dark Matter is so new and unknown, we might yet prove ourselves wrong on all of these hypothesis. 

I want to Thank Yashvi for bringing us in light about the dark matter.😆😂

I hope you liked this, I tried as much as I could to write from different sources. I know, this still does not give a clear idea what dark matter is, but I am going to take some more time to research on Dark Energy and so my next post will be directly on Sunday.