One of the most fascinating concepts sci-fi movies have ever taken in hands is the concept of parallel universe. There is absolutely no wonder that this concept is widely spoken, because it’s really a fascinating one. The last research paper of Stephen Hawking too, deals with the parallel universe concept, which shows its importance.
So, what is the concept of parallel universe?
Here’s a small introduction to the parallel universe theory, or basically multiverse theory.
Parallel universe concept is a part of the astronomical theory of multiverse. The concept of multiverse starts from the inflation theory, which has its roots inside the big bang theory. Here, let me briefly explain the big bang theory.
According to the big bang theory, the whole cosmos as we see was something infinitesimal and it expanded for about 13.8 billion years to become what we see now and is still expanding, the inflation getting faster with time.
When the big bang started, protons, neutrons and electrons were in their individual states (they did not combine to form atoms). Just like light scatters from a water droplet of clouds, light would have scattered in this state of the universe. Light wouldn’t have reflected and the universe couldn’t be seen.
The temperature would have been about 55 billion degree Celsius.
Some 380,000 years later, these ions decayed, temperature became cooler and formed atoms and that is when light would have shined in the universe. This is called afterglow or to be precise ‘the cosmic microwave background radiation’ (CMB).
Many researches have taken place about CMB and many evidences are found. The background was mapped later and the mapping has led to some mysteries too. That’s a different thing.
According to the big bang theory, CMB will be same wherever you look from, but it isn’t true in some cases. On probing further, researchers have found that most of the cosmos is made of unidentified, unsensed matter and energy, called dark matter and dark energy. It is now known that only 5% of the universe is of sensed matter i.e. planets, galaxies etc.
Another key point of the big bang theory is that, the very first fraction of the second universe was born, it inflated faster than the speed of light itself.
(Note: you would have thought about Einstein’s theory stating that nothing could travel faster than the speed of light. But the theory is for things in the universe, not the universe itself. Einstein isn’t wrong!)
Here comes the multiverse concept. If, in the first ever expansion different parts of space-time expanded at different speeds, what would have happened? Each part would have been separated, and they would be completely different from each other. Just like bubbles, each expanding at their own rate, and separate that there is no interference between each other. Even laws of physics for this bubble (our universe) could be invalid for the other bubble (the other universe, if it is).
And the anomalies of CMB observed during many instances could be the collision made between two bubbles.
And that is the multiverse theory in short.
This is one of the theories of multiverse, commonly known as the bubble universe theory. There are a few other theories too:
- Infinite universes: space-time is considered to be flat and as it goes on, many universes are possible (infinite universes), because the particles constituting the universe can be put together in many ways.
- Daughter universe: this theory is in accordance to quantum mechanics. According to quantum mechanics, each possible outcome (to be simple) of an event occurs. So, if you are thinking whether to take a left turn or a right turn, and if you take a left turn, the you, in a parallel universe will take a right turn at the same point. Sounds cool, right?
- Mathematical universe model: this is a theory by Max Tegmark, which deals with math being the fundamental reality. According to this theory, physical universe is actually a mathematical model, and everything that exists mathematically, exist physically as well. So, there could be many possible mathematical models, so many possible physical universes.
- Parallel universe: just like the infinite universe theory, space time is considered flat. The particles in universe can combine in many ways. There is a probability that they may repeat the same combinations. So, there could exist the same you in a different universe, and someone just one particle different from yours, two particles different from yours and so on.
And there is also a theory called the membrane theory.
These theories cannot be proven experimentally, because our universe is like a fishbowl, (maybe opaque!) you can’t see what’s outside it.
All these theories can be explained, just the way the bubble universe concept was.
Let me just give you all a break and tell that in my next article.