Respuesta :

Informer
There are many things that they assume, the assumption that it is expanding, it is more than 13 billion years old
The universe happened with a big bang, is a theory suggested by Stephen hawking an Astro scientist. According to scientists the universe is expected to get crunched, freeze or get ripped, that how it would end or probably start again with a bang.
There is also a theory of Multiverse, which means parallel universe, universe above universe or many universe.

Explanation:

Different scientist gave  different theories about universe.

According to Big Bang theory, scientists assumes that universe was about 13.8  billion years ago, universe was centered at a point and its temperature of over a trillion degrees. Due to really high temperature it took place an explosion. In this process a  tremendous amount of energy was released and  it also created different galaxies like Milky way, Andromeda, and Whirlpool galaxy. Which was the beginning of our universe. Big Bang was the most common theory of the universe.