8 Theories About Reality That Make You Question Everything

5. We're Just One Bubble In The Multiverse Ocean

One of the more unsettling ideas to wrap your head around, is that we are only really aware of what we call the Observable Universe.

There is a limit to how far we can look into space. This isn't so much to do with how powerful our telescopes are, but rather anything more than about 46 billion light years away from us is invisible as the light from them hasn't had time to reach us yet (this might be counterintuitive as the universe is only around 14 billion years old, but the 46 billion figure accounts for the rate of expansion of the universe).

Anyway, the upshot of this is that we don't actually have a clue as to how big it is, if anything lies beyond, of if this is really all there is. Not through direct observations anyway.

This is where we have to turn detective. Rather than try to get a glimpse of the great cosmic fence at the edge of the universe, we can take some of the weirder cosmic phenomena that don't seem to make sense, and extrapolate until they do. One of these is inflation.

Inflation occurred shortly after the big bang, when to universe suddenly expanded at breakneck speed before settling into its current rate of expansion. Scientists think that they have managed to detect direct evidence for expansion in the form of gravitational waves.

During inflation, some parts of the universe expanded faster than others, creating multiple "bubble" universes. In fact, pretty much all models that involve inflation predict a multiverse of different universes.

As previously mentioned, it's basically impossible to get an objective view of these different universe, but we can still look for the evidence. Some even think that our universe actually shows signs of a collision with another universe, resulting in the cosmic equivalent of a black eye.