Many have thought that our universe is the only one. I am going to tell you something that you will likely doubt.
The idea of the multiverse is strictly hypothetical up to this point, even so as to call it science-fiction. If the theory were to be right, however, then the problem with virtual particles would be solved. To clarify Virtual particles are random particles, I’m talking about quantum particles (quarks and antiquarks), that will occasionally pop in and out of our existence. I have a theory that states that these particles are falling into our universe from another higher state. I could also theorize that Kolob (God’s living quarters) could be one of these higher universes. I would call them dimensions, but I cannot because they all have their different qualities that are too similar to that of our universe and our universe is not a dimension. A dimension is only a direction. Space has dimensions, but, it is foolish to assume that the universe is a dimension. I don’t even know if the higher (or lower) universes has to deal with time. Now is the time to mention how the universe works. The universe expands at a 4th-dimensional rate, therefore, no 3rd-dimensional speed could possibly beat it out. If we were to exit the Universe, we would have to go faster than any 3rd-dimensional speed. Going this fast could very well kill us. The other method could be the same as the virtual particles mentioned earlier. The only problem is that to get that small, we would have to go through a black hole. I have a theory that when a particle reaches a certain radius (size) it slips through the dimensional gaps and passes through the universe. That would explain the existence of the virtual particles. We would have to get this small in order to pass. The polar opposite of a black hole would be a white hole. There are theories that state that what goes into a black hole, exits through a white hole. Unfortunately, the size would just be impossible to obtain logically. Side note: That past theory, with the white and black hole resemblance, is what fuels the theory (my theory) that when a particle falls through a black hole, it then combines with other particles in the other universe, and is then made bigger and bigger and bigger until it becomes the matter in that universe. That is my theory of the big bang. It would also mean that our universe is the catalyst for the creation of another universe. There is currently no method of getting through into another universe, but more research will be done on the subject. This is not my photo!