Is the universe Infinite?

Space is really really big, the known universe is home to billions of galaxies each with 10x or 100x of billions of stars and each of those stars with planets of their own, maybe some of them even support life like Earth does. Beyond the known, the universe is the unknown universe, an expanse so vast and mysterious that we can't even begin to understand many of its properties. 

How far does it reach? 

Is there an end? 

What's beyond the end?

What if there's no end at all?

We are going to assume that the universe is infinite and look at a few of the implications before we consider what the infinite universe would mean for our existence. 

We need to understand how it could work in the first place?

 

At first glance, it would seem like an infinite, the universe would conflict with the Big Bang Theory,

Before the Big Bang, all the matter of the universe was condensed in one, the infinitely dense point. After the Big Bang, the matter begins to spread apart or rather the distance between the matter begins to expand, the matter didn't blast away from this infinitely dense point as the term Big Bang would have you believe because it wasn't an explosion. There is no empty space created in the event but rather space itself expanding infinitely away from its origin, 

But what is it expanding into?

If it has the room to expand that means it's contained within something. This is really hard for humans to understand, but we can try another analogy 

Imagine a deflated balloon, there's nothing inside or outside the balloon, just the two-dimensional surface of the rubber representing our the three-dimensional universe, as the balloon inflates every point on the rubber expands away from every other.

If you imagine some dots on the surface of the balloon, as the balloon inflates those dots will move away from each other. This is a good approximation of how our universe works as far as we can tell since the Big Bang every point in the universe has been expanding away from every other.

The rubber of the balloon is the actual fabric of space which means there's no empty space as we think of it.

The very stuff of space is expanding. So, to recap if we assume that the universe is infinite which means at one point it was infinitely dense and close together, then began to expand infinitely away from itself from every point. So, wherever you are in space you'll observe everything else moving away from you forever.

Now that we understand how an infinite universe would work. 

What would that mean for us?

Well, nothing in the short-term. Let's fast forward to when we have more advanced technology, space vessels capable of interstellar travel, that can support multiple generations of humans. Say we take off from Earth in the year thirty nineteen no matter how far we travel, no matter how many generations and, no matter in which direction we would never reach any sort of edge of the universe, no matter how many billions of light-years we are from Earth.

Everything will still look the same. 

The fabric of space expanding away from us in all directions, it's kind of scary to think about but also somewhat reassuring even if you completely screw up your life here on earth it has absolutely zero cosmic significance in an infinite universe and odds are someone somewhere has screwed up even worse because an infinite the universe would also include infinite other intelligent civilizations whether there would be infinite copies of each and every individual person is up for debate because technically with infinite time and matter the permutation that led to you or me would appear an infinite number of times, but it wouldn't exist in the same time in a place. So, would it really count as you of the countless intelligent civilizations out there.

Somewhere most of them would never encounter another intelligent species simply because of the sheer scale of the universe and the fact that everything is expanding away from everything else at a speed we likely couldn't match. 

The universe is full of life but we'll never see most of it or possibly any of it. It's unfathomably vast but we'll never be able to travel even the tiniest the fraction of it. It seems to have an age but we can't tell what came before and we don't know how long it will continue to expand or what will happen if it stops. There's a whole lot of we don't know involved when you're talking about the far reaches of the universe even if it's not infinite the observable universe the part we can see only makes up a tiny per cent of what we know is out there. 

There are at the very least hundreds of patches of the universe, the size of our visible home region possibly thousands millions or billions but we can't tell the light hasn't reached us yet and for most of these far-off regions humans will be long gone before it ever does.

Long story short we'll never be able to map the entire universe with a fleet of super-advanced starships, we might be able to get a good estimate of the size of the universe or at least whether or not. It's infinite by continuing to observe and come up with new equations that can keep up with the mind-boggling complexities of the final frontier you know what else is almost infinite.

- Ankur Duhan