“In the beginning there was nothing, which exploded”
That’s how the great Terry Pratchett described the beginning of the universe; the legendary
big bang.
The majority of modern physics comes from the understanding that everything started
out as one tiny tiny point that blew up, expanded and created all of the wonderful things around
you like galaxies, stars, planets and bacon sandwiches.
As a planet, we’re pretty set on this concept but that’s not to say it’s the only possibility
that’s been suggested.
Obviously you have the many religious creation stories but even within the scientific community,
a few other options have been suggested.
So if you’ve ever wondered whether our universe is actually all a cat’s dream, a marble
in the hand of a giant alien or a simulation that has some worrying coding errors, well
then here are some alternative and entirely possible theories to the big bang.
Our first idea was born out of string theory and popularised by Steinhardt and Turok, who
sound like a German techno duo.
String theory is basically an attempt to connect the ideas of general relativity with the bizarre
and confusing world of quantum mechanics.
The idea is that there are many more dimensions than the ones we can observe and that something
that might look like a point from our perspective, is actually joint a part of a long string,
like you are looking at a bit of spaghetti dead on and mistaking it for a tiny speck.
Steinhardt and Turok proposed an idea called the Incredible Bulk.
It’s not been entirely rejected by the physics community, but possible because they are afraid
of making the incredible bulk angry, you wouldn’t like it when it’s angry.
It suggests that rather than there being one big bang, our observable universe is like
a sheet of paper drifting in a multi-dimensional soup.
Theorists call these sheets branes, short for membrane.
Occasionally our brane collides with another brane and there is a big release of energy.
There is an endless cycle of collisions and expanding branes.
Mmm brane soup.
Sean Carrol has been obsessed with time since he was young, probably as a way to explain
why he was always late for dinner.
His trouble with the big bang was not that it came at the beginning of time but that
time itself has a beginning and end; why does time only move in one direction?
Well what if there were multiple universes and in some of them, time runs backwards?
In the Multiverse theory, a universe can spring up from the random fluctuations in dark energy,
which appears throughout what we think of as empty space.
Dark energy is like glitter, it gets bloody everywhere.
Sometimes the universes wouldn’t really get going and they’d collapse into a black
hole.
But occasionally one takes off and expands rapidly.
It keeps expanding forever and eventually becomes so thinned out that it is now the
empty space where another universe can form.
One of the confusing things about the universe is that it looks basically the same in all
directions, no matter where you’re looking from.
Since we know the universe is expanding, we tend to think of it as a balloon but for most
of us, this give the idea of a centre and an edge, which is not really the case.
Fred Hoyle tried to explain this similarity of all parts of the universe with an idea
called Steady State.
If you want to keep the density of stuff the same in an expanding space, surely you need
to keep adding things.
It’s like a house party, if people keep arriving, you’re going to need to keep adding
booze, otherwise everyone will either start getting bored or possibly drinking all your
perfume and cleaning products and that won’t end well.
In order to keep the density up, matter would need to be spontaneously created.
And before you start picturing random bubbles of hydrogen appearing all around you, the
amount suggested was about one atom a year within each cubic kilometre, so no need to
squeeze up just yet.
Speaking of running out of space, in Christoff Wetterich’s theory, we are all heading towards
a big game of galactic sardines, since rather than expanding, the walls are actually closing
in.
He called it the cold bang.
One of the big observable factors for why we believe the universe is expanding is the
Doppler Effect, or red shift.
We noticed that very distant galaxies seemed to be redder than closer ones, and this was
true whichever way we looked.
So unless we were surrounded by a gigantic red light district, there must be some reason
for this.
And there is.
If an object is giving out a wave, like light or sound, then its movement affects how you,
the observer receives that wave.
If it’s moving towards you, then the waves are pushed together at a higher frequency.
If the object is moving away, then they are stretched out.
You can hear this effect with a police siren, the pattern repeats quicker as the siren comes
near, and then seems to slow down as it moves off into the distance, unless you’re being
arrested, in which case you’ll only get the first part.
So, if the universe is expanding, then light from distant objects is being stretched since
they are moving away, so it has a longer wavelength, making it redder.
Wetterich countered this by saying that as the universe closes in, the light would be
affected by the greater mass of the universe.
The benefit of his theory is that ait voids the need for everything starting from a singularity.
The problem with it is that there is going to be much less space on the beach in a few
trillion years.
Another factor of existence that is difficult to explain is why everywhere is a relatively
even temperature.
Sure, it may not feel like that on earth where you can get brain freeze from ice cream before
burning your mouth on apple pie.
But on a general level, like if you cut the universe up into cubic light years, they are
all roughly the same temperature.
The reason this is strange is that 14 billion years may seem like a long time for us but
on a cosmic scale, the universe is still a toddler, wetting the bed and drawing all over
the walls in crayon.
The big bang was astonishingly hot so you’d expect there to be more hot pockets, and I’m
not talking about that snack that sort of resembles food.
Some theorist have wondered if maybe there is some unknown energy that caused an expansion
faster than the speed of light, which would explain how the temperature evened out so
quickly.
Niayesh Afshordi and his team came up with the idea that perhaps our 3D universe was
not only in a 4D bulk universe but one that created 4D stars.
And if you have 4D stars, these can collapse into 4D black holes so perhaps we are like
sheet of paper, wrapped around the event horizon of one of these black holes, sucking up the
enormous energy that would be surrounding us.
Thanks to the work of great minds all over the world, we are learning more and more about
what is out there and how it began; from the quantum madness of the Large Hadron Collider
to the gravitational waves of dancing black holes found by the advanced LIGO project.
But perhaps the true origins of the universe are something we will never be able to prove
and maybe we don’t really want to know.
I mean, how would you feel if you knew that we were just a tiny, insignificant planet,
in one of many tiny insignificant universes?
Or if the big bang was just the sneeze of some 8 dimensional cat… actually I’m pretty
fine with that last one.