The idea of parallel universes is crazy! How can there be more than one of all there is? This video explains the science of parallel universe theories and why we have no idea which is right or not!
There are three main theories surrounding the parallel universe mystery though none have been tried and tested as of yet.
The bubble theory, each ‘bubble’ contains a universe like our own. If each ‘bubble’ had different laws of physics then we can only exist in our own due to the laws our universe follows, and others may be too far away for the light to reach us, or trapped in a black hole, hence why we wouldn’t see or know about others.
The Membranes and extra dimensions theory suggests we exist in a 3D universe or ‘membrane’ embedded into a large ‘super universe’ with 9 dimensions. We wouldn’t see any others but there could be millions more 3D universes embedded into out huge 9D one! Crazy!
The Many worlds picture suggests every possible timeline for the universe exists, but we are stuck in just one of billions available to us. The happenings we exist in are the only ones we can exist in, leaving room for an infinite number of universes we will never cross with!
With science and technology advancing the way it is, it might not be too long until we know if we really are alone!