The universe. What is it? Where did it begin? How did it begin? Did it even begin at all? These are some of mankind's most persistent questions. Because they haven't been answered. But we've come close. To understand who the universe is, we must trace the path that it arose from. Time.

We don’t what time is. Entirely. It is a dimension, one of the four that constitute reality for us. To explain this, there is a simple analogy. When you tell your friend to come over for dinner, you give him or her the length, Richard Street, the width, house 21 and the height, 2^nd floor. But you don’t end there. You also tell them the time to come, for without that, the coordinates are vastly incomplete.

Time may have existed forever, perhaps even before the big bang, because without that, the fundamental law of nature that the cause always precedes the effect on a timescale, would have no meaning. Stephen Hawking suggested that time originated with space, after the big bang. Let’s stick with that for now.

Space. Not the space as in outside the earth, but the 3 dimensional space that we and all matter seems to exist in. Before the big bang, all of the matter I the universe was just a volume-less point of infinite mass and density. It was hot and had a huge amount of energy, causing it to expand violently and explode. What was outside that point, or better where did the point exist? When this point exploded, it caused space to expand at least 8 times the speed of light. This point can be explained with a simple thought experiment. Our observable universe is 93.8 billion light-years in radius and the universe is just 13.8 billion years old. And since space expanded outwards from a point, light from any matter beyond 13.8 light-years form the origin, would not have even reached the origin. How then, can we observe matter 94 billion light-years away? More on that later.

Before the big bang, the universe was a point of infinite density and infinite amount of heat So after the big bang, photons, a species of elementary bosons responsible for the existence of the fundamental electromagnetic force were created. Equal levels of matter and antimatter were made, as photons, a species of fundamental bosons, split, reunited and split again. For every 1 billion antimatter particles 1 billion and 1 matter particles were made, along with 1 billion photons. The matter and antimatter particles cancel each other out, leaving a single matter particle for every billion photons. These particles eventually performed fission and fusion, formed the particles described in the standard model, 6 quarks, 6 leptons and 4 bosons, alongside many more. The first atoms were born, which formed 10s of new elements, mostly hydrogen, being the simplest atom.

 There were galaxies, planets, and other celestial bodies being made getting attracted by the gravity of other bodies, and getting destroyed. And a new page as formed in the history of the universe. Mankind has endeavoured to understand the workings of the universe for a very long time. As I have mentioned in earlier posts, our understanding of the universe can be divided into two parts. Cosmology and quantum physics. Cosmology deals with how the world works at super massive scales, and the current accepted model that most physicists follow is that of Einstein’s general relativity. Quantum physics helps us understand how things work at super small scales. The elementary particles, the nature of waves and particles, and much, much more. The current accepted model that most physicists follow is the standard model. These two models don’t always agree with each other. So, physicists are looking for a unifying theory, a super equation that will explain the universe wholly.

We know that the universe is expanding. Stars and galaxies are moving away from one another in an almost indescribable fashion, where they are moving away from any reference point that can be possibly taken. How do we know this? The Doppler Effect. The Doppler Effect shows that if the origin of a wave is moving away from a reference point, the frequency of the wave decreases, and increases when the source is moving towards a reference point. Light coming from stars is largely white, and if there is movement of stars, common sense suggests that there will be equal number of red stars (low frequency) as the number of blue stars (high frequency). But evidence is otherwise, as most stars are red, i.e. are moving away from us!

But if space is expanding, what’s beyond the edge of expansion? Well we could take a rocket and find out right?  German physicists Albert Einstein has already deflated that idea, as he says that nothing can travel as fast as light, as it’s mass would become infinite, in his famous equation E=mc².

 But Einstein did have a promising answer to our question. He took a balloon and drew some dots on its surface, to represent stars. He then blew the balloon. All the dots were accelerating away from one another, and what’s more? They are moving away from every reference point! A 3 dimensional surface on which the 3 dimensional universe exists in!

Dimensions. Hmm. There are 4 as we know it. Length breadth, depth and time. But Columbia professor Brianne Greene explains that they're must be 11 dimensions, 9 spatial and 2 time. Let’s hold that horse for a few decades until Doctor Hawking figures that out.

One more thing. Is our universe alone? In his talk ‘questions no one knows the answers to’ Chris Anderson outline the possibilities of multiverses, or multiple universes. Each universe would follow different laws and have different particles. Maybe they too will have an Albert Einstein, a Stephen Hawking, a Neil deGrasse Tyson, a Brian Greene, and a Bill Nye the science guy, all asking the same questions.

I don’t know. Hell, we as a race don’t know. To be fair, it’s difficult to look for answers in vast area like physics, with a constant fear nagging you that you might be looking at the wrong place. The universe is large, it’s startling. It’s exhausting. Your morbid curiosity fuels mankind’s endeavours.

In the next post, I will be outlining how you may have wasted your time reading this post. Stick around for the final instalment of Life, the universe and everything 3: everything. I am Daksh Gupta, and as always, never stop asking questions.

Likes this? Take a look at some of my favourite videos about the universe.

Take a look at all of Doctor Greene’s talks:

TED

Chris Anderson's ‘Questions no one knows the answers to’:

 TEDed

Neil deGrasse Tyson on a history of the universe. I love his voice:

 YouTube

Neil on the purpose of the universe:

YouTube

Neil deGrasse Tyson’s TV show ‘Cosmos’:

Amazon

My favourite TV show as a kid, ‘Into the universe with Stephen Hawking’:

YouTube