One of the functions of the Merkaba is to act as a vehicle of ascension, to transport the body and soul from one dimensional world to another. A fully activated Merkabah field enables you to transcend time and space and travel/bi-locate throughout the Cosmos.
It was believed in ancient times, and even written about by the Hebrews, that the Merkaba could be turned on by certain principles in meditation. This involves breathing changes, and mind, heart, and body changes that alter the way a person perceives the Reality.