Our present existence is but a cycle of "creation, evolution, and destruction". In astronomy, scientists could observe this "phenomenon" of creation, evolution and destruction of planets and stars. There is no beginning and end. It is a perpetual cycle. It has been like this in time immemorial and will be likewise forever, ad infinitum.
Within one cycle, there is the "creation" of world systems. Life appears from other planes of existence and evolves. The cycle will again go through the stages of "creation, evolution, dissolution, and destruction".
At this point in time, countless world systems go through the different phases of this cycle of existence. Ask any astro scientist and he will confirm this truth. The Buddha, with his mind power (omniscience) could see through all these phenomena.