It is demonstrated that parallel universes forming the multiverse, according to the hypothesis suggested herein, actually exist and are accessible for people to visit, because they comply with the similarity principle. According to this principle, laws of nature governing different universes are identical or similar, but certain differences are also possible. For example, time in them can flow in any directions with respect to the time in our universe. The suggested hypothesis of the multiverse is based on the adjusted special theory of relativity, where statements on an unbreakable light speed barrier and lack of physical meaning of imaginary numbers are removed from the second postulate. Furthermore, the principle of physical reality of imaginary numbers is proven both theoretically and experimentally. In line with this principle, all the relativistic formulae of the special theory of relativity are adjusted accordingly. The reality of this multiverse is confirmed by the existence of dark matter and dark energy.

multiverse, parallel universes, complex numbers, imaginary numbers, special theory of relativity, dark matter, dark energy