In the beginning the Universe was created. But the most important question is WHY?
Is there a reason behind its creation? Most people think the reason is a motivation by whom they call GOD. They think so because, they also have motivation to create things.
BUT, very few think, it was the result of some reaction. They are scientists and researchers. They see the reason behind the creation of the Universe being a some kind of trigger at some level of science where both general relativity and quantum mechanics are talking.
They are also searching for some equation that they think is responsible for the creation.
Universe within a larger Multiverse?
It is also sometimes said that our Universe is one among the billions of Universes that exist out there, and the entire setup is called a Multiverse. String Theory says that numerous Universes are constantly created with different values for the physical constants. Most of them are unstable similar to a bubble and die a quick death. Our Universe was a result of this constant creation experiment which happened to find the right values of physical constants for a stable Universe to form and evolve.
Does the question then become WHY was the multiverse created?
But many think that the multiverse always existed and is timeless. After all, for every Universe time starts when it was created. But for a multiverse, no time exists, for it is eternal. Is that so?
So, are the Universes being created in the multiverse or by the multiverse? Or both? Are Universes like the bubbles in the water, they come and go, albeit on large timescales. Most vanish quickly. A few make it for a long time, like our own.
Is the Multiverse a fire cracker world filled with millions of big bangs and big crunches?
Multi-dimensional Universes and Time Travel
So our Universal bubble will burst one day? Our Universe will die? Can we then travel to other Universes to escape the death of ours? Will those other ones have same physical laws as ours? Or are the laws of physics different in different Universes? Does light travel at a different speed there?
It is said that when a Universe is born, equal amounts of matter and anti-matter are created, but ours has only matter. So, does our Universe have a twin companion, an antimatter Universe? Do all Universes then have a twin companion? Are all of them twins?
Even more interesting are the latest developments in String Theory which say that Universes are like n-dimensional stuff called branes and our own Universe is a 3D brane? And an Universe can have any number of dimensions up to 9 dimensions!! Can our brains really understand these branes?