The Earth is huge, its surface area is over 500 million square kilometers and it currently holds over 7 billion people. But it’s nothing compared to the solar system, which is billions of kilometers across. And that’s still nothing compared to the Milky Way galaxy. And if we zoom out even more, we can really start to appreciate how huge the universe actually is. But we might be able to take this one step further because we might be living in something called a multiverse, where there’s not just one universe, but potentially an infinite amount of them. And if this is true, some scientists think that we have the Big Bang to thank.
See, for a fraction of a second after the Big Bang, the universe expanded incredibly quickly and then stopped. And over the next 14 billion years, it cooled down and formed stars, galaxies, and eventually life! But there’s reason to believe that there are some pockets of space that haven’t stopped inflating and some others that have at different times.This is called the “eternal inflation” theory and each of these bubbles of space forms it own, isolated universe.
And interestingly, the laws of physics and the fundamental constants might not be the same there. And that got me thinking: what would a parallel universe even be like? Well, in a lot of these universes, you and I might not even exist -- sorry sci-fi fans. See, if the laws of physics were different enough, like if the forces between particles were too weak -- atoms might never form. And that means no molecules, no stars and planets, and no life.
Sounds pretty boring over there. That said, there’s also the possibility that the laws of physics in some of those universes are so close to ours that intelligent life is possible. And if there’s an infinite amount of them, it’s pretty likely that there’s a bubble universe that’s very similar to our own. And interestingly, it is theoretically possible that some of these neighboring universes can collide with each other.
In fact, it’s possible that our universe may have collided with others in the past. The main hypothesis is that a collision like this might have left a mark on the cosmic microwave background that we could detect. But sadly, the researchers haven’t found anything so far and there isn’t any proof that parallel universes even exist. But if they do, and if they contain life, it would be interesting to see what that life was like.
What do you think the life would be like? And do you believe that parallel universes are out there? Let me know in the comments!
