I often find myself thinking the impossible and i am wondering:

what is the size of the universe?

It strikes me that although mainstream science is happy to model the universe as being infinitely big, and that it is expanding all the time, no-one seems to arrive at the conclusion that it still must be expanding into something, and that something is infinitely bigger. 

You may think that this is proposterous and just wrong, but i'm a firm believer in the idea that if you look for it, you will find it, no matter how big or how small.

So I find that it is not too much of a leap of faith to think that there may be other universes expanding into this something as well, and this something could be called a "multiverse".

For example; if when it is raining you find yourself looking at a puddle outside, should we believe there is only a single expanding ripple in the water when as the rain hits it? No, many drops will hit the pool and many ripples will form and grow, and interact with eachother. 

So it is with our Galaxy, so it is with the Universe, so it should be with the Multiverse.