The universe is everything.
There is nothing else, at least, as far as we know.
There are theories that say there are other universes and our universe is part of a much
larger multiverse.
This very well may be true, but so far we don't have strong enough evidence to back
up such theories.
It is however, common knowledge that the universe is expanding.
This is undeniably true.
Scientists have observed the distance between large objects in space, such as galaxies and
have found that the distance between them is increasing; they all seem to be moving
away from each other.
This leaves only one plausible explanation, the universe is expanding.
That means that all the time, new spacetime is being created and the physical size of
the universe is actually increasing.
Just like blowing up a balloon.
Let's just hope this one doesn't go and bloody pop on us.
So that leaves one inevitable, burning question.
If the universe is expanding, what is it expanding into?
Is the universe expanding into a much larger multiverse like some astronomers say or are
we all inside a giant pigeon pie?
Let's find out...
The answer to this age-old question depends entirely on whether the universe is truly
infinite or not.
If you subscribe to the theory that the universe is infinite then the answer to the question
"what is the universe expanding into?"
can only be "nothing".
Because if the universe is expanding, then that means new spacetime is constantly being
added.
It's just like the construction of new real estate in space, but the universe doesn’t
have to apply for planning permission beforehand.
This new real estate is a brand new area of the universe that galaxies can occupy.
But you can't add new space to an infinite area because it's infinite, it continues forever.
It has no end, no boundaries and no measurements.
So if the universe is truly infinite then the universe is expanding into nothing.
It's as simple as that.
Well it can be simple, if you sweep all that bloody complex mathematics under the carpet
and just don't look at it.
But most people have a really difficult time understanding the concept of infinity.
And we have an even harder time understanding the concept of nothing.
Just try and think about nothing for a second.
You can't, it's impossible, you're thinking about thinking about nothing, and that in
itself, is not nothing, it's something.
Kittens!
And now you're thinking about kittens.
My point is, the human brain isn't sufficiently equipped to understand these concepts; it
just doesn't have the necessary tools.
But that's okay, because you may not need to.
Let's imagine for a minute that the universe is finite, it has boundaries.
It might be flat, round or some weird-ass doughnut shape.
But that doesn’t matter, let's just pretend that we know for certain the universe has
an end and we can step beyond that wall and see what's on the other side.
By the way this is totally theoretical now because the current, most widely accepted
notion within the scientific community is that the universe is infinite.
But that means the answer is just nothing, and that's pretty boring, so let's just say
it's not.
After all, the concept of an infinite universe is just a theory, and theories can change
or be thrown out the window, at any moment.
So the universe is finite and it has a boundary, what's would be on the other side?
Well, you’ve really opened the floodgates now, you've let all the wacky, weirdo nut-job
scientists with their theoretical physics degrees and science fiction fetishes in and
they have endless theories.
Seriously there are so many different answers to this question you'll want to travel to
another dimension when you've read them all.
But let's put our objectivity hats on and take a look at a couple of the more popular
theories out there.
One theory is that we are living inside a black hole.
Some believe that every time a new black hole opens a new universe is created at the other
end of it.
For a long time it has been theorised that objects known as white holes exist and they
are essentially the complete opposite of black holes.
A black hole sucks in matter whereas a white hole spews out matter.
Like making a smoothie and leaving the lid off the blender.
To put it simply, shit gets messy.
The theory states that anything that enters a black hole eventually finds itself being
spewed out of a white hole somewhere completely different within the spacetime continuum.
But if white holes do exist they would be extremely unstable and would only last for
a few seconds before disappearing, unlike a black hole, which is considerably more stable.
Some people believe that the big bang was actually a white hole.
Like an exit from a black hole within another universe.
Yep that's right, our entire universe and everything we know, could have been created
as a result of a star dying and forming a black hole in another universe or possibly
even just very, very far away in our own universe.
Which would mean that we are living inside a black hole and our universe is expanding
into an even larger, parent universe.
But that's just one theory.
Another popular theory is the "multiverse theory" which states that our universe is
just one universe amongst many, other, parallel universes.
Like a stack of flat discs, and our entire universe is contained inside just one of those
discs.
If this is true then our universe is expanding into whatever space is surrounding our universe
and our other neighbouring, parallel universes.
Sadly the truth is, we currently have no idea what, if anything lies beyond our universe.
That's because if the universe is finite and it does have a boundary, then we can't detect
that boundary because with our current technology we can only see so far into space.
This is known as the observable universe.
The observable universe is a radius surrounding us in every direction, which is ninety-three
billion light years across.
The light from everything inside that sphere has had enough time to reach our galaxy in
the 13.8 billion years that the universe has been in existence.
But the universe is expanding, so it's highly probable that we will never be able to see
beyond the observable universe because objects beyond the limits of the observable universe
are moving away from us.
That means if the light from those objects hasn't reached us by now, it never will.
So we may never be able to detect the boundaries of our universe, if they exist.
And, unless we find that boundary, we can never know for certain, what lies beyond.
But science and technology is rapidly improving and nobody knows what mind-blowing discoveries
that, previously seemed impossible, will become very real in the near future.
So always keep an open mind and never stop asking questions, because if it weren’t
for that, then the human race wouldn't be where it is today.