Scientists say this universe is multi-dimensional. It is not a universe, it is multi-verse because it has many layers. Just like in the television there is not just one channel.
In the 1960s and 70s there was only one channel called Doordarshan. There was no other option. Today, there are hundreds of channels. Like that this universe has many layers and knowledge is humongous. There is no end to knowledge.
Do you get all the channels in the same television or different ones