Dark energy: the 68% of our universe

In the last post, we talked about dark matter. In this post, I want to discuss dark energy. 

Just like dark matter, we don't know much about dark energy. However, it makes up about 68 per cent of our universe.

Now there are a few things we know about dark energy. I will break them down for you.

As I talked about in my last post dark matter is present in the form of clusters around galaxies. On the other hand, dark energy is uniformly distributed throughout the universe. 

Another thing is that dark energy is a repulsive energy. This means it's like anti-gravity. Gravity makes two objects attract, dark energy makes them repel. 

Dark energy is the reason why our universe is expanding every second. 

Dark energy is both an amazing and an unsettling topic, isn't it?

Dark Matter: One of the biggest unsolved mysteries of the universe

I am sure you have definitely heard of normal matter but have you ever stumbled across the word dark matter.

If you have, then you must have wondered what it is.

Let me simplify this for you.

Dark Matter is a hypothetical form of matter. Dark Matter does not interact with light and hence, it is invisible. 

It is present in the form of clumps around galaxies. 

We don't know what it is or what is it made of because we cannot see it. However, dark matter forms a significant 28.8% of our universe.

All we know is that dark matter is not made of protons, neutrons and electrons like the matter we know about us. 

We also don't know if it interacts with normal matter or not, but if it does, the interaction is really weak.

Decoding light years

A light-year is a unit of length, similar to a meter or a foot. Meters and feet are commonly used to measure small distances, such as the distance between two cities or the height of a person. In contrast, light-years are used to measure vast distances in space, such as the distance between stars and planets. 

Now this is where it gets tricky. 

Light-year is the distance travelled by light in a Julian year (365.25 days). 

So how is it not a unit of time but a unit of length? We multiply the number of seconds in a Julian year by the speed of light (the distance travelled by light in a second). Which is-

31,557,600 seconds (no. of seconds in a Julian year) * 299,792,458 meters per second (speed of light)

Then we get the value of a light year in meters. Which means that if the distance between two bodies is a light year, then the distance between them is- 

9.461 × 10^15 meters (9.461 quadrillion meters); or

 9.461 trillion kilometres(5.879 trillion miles)

If you travel from location A to location B at a certain speed and in a certain period of time. This distance is the distance you have travelled, which also makes it the distance between locations A and B. 

The same way this is the distance light travels in a year. 

I hope this helps. If you need any help or have a problem understanding any of these things let me know in the comments.

Your personal invitation to the Cosmic ball: Let’s dance our way to knowledge about this universe

Ever since I was a kid, I have been fascinated by space. I fondly remember the countless nights I spent stargazing with my mother, captivated by the beauty of the cosmos and the mysteries hidden behind those twinkling stars. I know I am not alone in this fascination; many others share my curiosity about the universe.

However, let's be honest: astronomy can be quite complex and difficult to understand. There have been many times when I found myself feeling lost. That's why I created this blog—to help others who, like me, are passionate about space but may lack the resources or knowledge to explore it further.

Just to clarify, I am not a space expert, nor do I know everything. My goal with this blog is to learn more about astronomy while helping others learn as well. So, anyone with even the slightest interest in space and astronomy is welcome to join us at The Cosmic Ball.