The Novice Writer: What is A Universe?

What is a Universe?

What do you mean by the observable universe?

Let’s answer all these questions and inculcate ourselves with new science that surrounds us these days.

Universe informally means “EVERYTHING”: mountains, oceans, the moon, and the hot nuclear ball of hydrogen (SUN) and lot more.

If the universe is everything does that mean it contains the things that we know, or it contains the things that we believe exist but is not aware if they do? For example: would we consider “THE FUTURE” as the part of the universe??

We hence, divide the universe into two broad categories:

1- Observable universe.

2- Whole universe.

The observable universe is the one which we have seen with our telescopes and thus confirmed the existence of that matter and have to manage to explain it completely or would possibly observe if we pointed are the telescope on it.

The whole universe is everything that had been existing in the past and will be existing in the future. It consists of things which surround, things that we know, things that we might know or the things that we might never lay our hands on.

Why haven’t we able to observe a part of the universe?

We might not have been able to observe a part of the universe for two reasons:-

1- Either it is in future.

2- Or it is so far away that light hasn’t had time to reach us for it to be visible yet.

To get started with the concepts of the universe we have come to a conclusion that universe had a beginning and is 13.8 billion years old.

Light takes the time to travel in space so, anything far away from us might not have reached us yet. Just like a thunder from a distant lightning strike isn’t audible until you wait long enough for the sound to reach you. But if you were blind then Thunder would have been the first sign of the existence of the storm only once the sound of it had reached you. So you can infer it as to how long ago storm must have existed.

What do we know about the universe?

We pretty much know just three things:

1- Space and time.

2- Particles and waves

3- Physical laws that describe: how particles and waves behave in space with respect to time giving rise to factors getting affected by it like gravity, matter, forces, and Higgs.

How big is the universe??

Does it have a center??

Does it have an edge??

Is it getting bigger and if so then why??

As we know the observable universe is a universe that we observe from the surface of the Earth. Hence, as the universe is just 13.8 billion years old and light takes the time to travel through space (approximately 299792459 meters per second), then regardless of what direction we look at, we can say that the light has been traveling for 13.8 billion years. So, it is logical to think that observable universe is twice as large as 13.8 light years which is 27.6 light years in all directions.

But this is not the case!!

If we consider the fact that universe is expanding at a constant speed. The source of the light that we receive has above away. Today, those objects which have emitted light 13.8 billion years ago are approximately 46 billion light years away from us. Hence, the diameter of our observable universe is actually 96 billion light years huge.

To give you the sense of the universe we can compare the Earth in the observable universe as the size of the smallest virus in our solar system.

This comparison is not quite useful and precise as we are neither aware of the accurate length of the virus nor are we inculcated with the size of our solar system which itself is a part of an ever-expanding universe.

The universe as a whole is a lot bigger than our observable universe and is assumed to be infinite in length and is ever expanding in size.

Hence, we can’t find the edge to the universe.

What about the center of the universe??

Centre of the observable universe is finite and completely defined. Earth is the center of our observable universe. As the observable universe is just the region of space visible from the Earth. But it isn’t right to say that we are the center of the entire universe. For example, assume yourself standing on a tall tower and see around. The sphere that you form is your observable area and you are at the center of it but that does not mean you are at the center of the complete Earth as a whole. There are areas out of your field of view. Similarly, is our observable universe we are the center of it but we might not be the center of the entire universe as such. Hence, the limit of the horizon as of now is a sphere of radius 46 billion light years long that was formed by the objects that emitted light 13.8 billion years ago. As universe keeps expanding our horizon keeps on increasing. Thus, to explore the complete universe we just need to wait and watch. We will be able to do so as and when light from more distant places will get time to reach us.

“Understanding that our understanding might be wrong is essential, and trying to figure out the ways we can help us find our way to the truth.”

Question	Observable Universe	Whole Universe
How big is it?	93 billion light year	Infinite
Does it have the center?	Yes	No
Does it have the edge?	Yes	No
Does it get bigger?	Yes	Yes