WHAT IS A BUBBLE UNIVERSE?
According to the theory of cosmic inflation – an idea that is accepted by most, but not all, leading cosmologists – the Universe expanded incredibly rapidly in all directions in a tiny fraction of a second following the Big Bang, much like a balloon does as it is blown up. After this initial quick burst, it continued to expand, but much more slowly.
In contrast, the theory of eternal inflation states that following the Big Bang, inflation did cease in some pockets of space, but also continued in others. This means that we could live in a so-called ‘bubble universe’ – an area of slowly expanding space embedded in a much larger, rapidly expanding space that is still undergoing inflation.
What’s more, there might also be countless other bubble universes embedded in this larger space that are being propelled away from us at breakneck speed. In some of these bubbles, the laws of physics could be completely different from those that apply in our own Universe – making these other universes very strange worlds indeed.