Introduction:

Why should you read every story on this website? Well...

The observable universe is decided by the size of our 'Hubble Sphere.' Our Hubble Sphere's size is calculated by the speed of light times the age of the universe. You can't see light rays that haven't reached you yet so anything outside of this sphere is unobservable. But, the Universe is far bigger than just the Hubble Sphere we live in.

The whole universe is about 14 billion years old. That times the speed of light gives us a Hubble Sphere radius of about 4 x 10 to the 26 meters. 10 to the 118 Protons, the subatomic particles that fill up space, can fit into this volume. Now, the possibility of whether or not a proton is present can be described by the number 2 raised to possible number of protons (10 to the 118). This is a very large number, but a finite one. And, it explains every possible configuration of matter, including the present one in our universe.

Now we take that number, of every possible different configuration of matter, and say each one has its own Hubble Sphere. It is more likely that some configurations will repeat than each Hubble Sphere having a completely different one, but we calculate it like this just to be safe. We then take 2 to the 10 to the 118 Hubble Spheres times the size of a Hubble Sphere, which roughly gives us 10 to the 10 to the 118. This is the amount of space before the combinations of matter begin to repeat. We can then say that there is an Identical Parallel Observable Universe 10 to 10 to the 118 meters away. But more likely it is closer.

More importantly, even closer than an Identical Parallel Observable Universe, there are Parallel Observable Universes. These are universes similar to our own, but differ based around choices people have made. This means that somewhere in space, the Hunger Games have probably happened. It means that every child submitted for the reaping was chosen. And in at least one universe, that child was victor. It also means that every story that YOU write, as long as it obeys the rules of physics, has very likely happened no less than 10 to the 10 to the 118 meters away from where you are sitting right now. Or at the very least, your story isn't unique, because an identical you wrote the same story somewhere very far away.

Source: Max Tegmark. Parallel Universes. Scientific American. 2013.