Multiverse theory posits the existence of multiple, possibly infinite, universes that exist parallel to our own, collectively forming what is known as the "multiverse." The origins of this theory are rooted in quantum mechanics and cosmology. In 1957, physicist Hugh Everett III proposed the "Many-Worlds Interpretation" of quantum mechanics, suggesting that all possible outcomes of quantum measurements are realized in some "world" or universe, leading to a vast number of parallel universes. In cosmology, theoretical models involving inflation (a rapid expansion of the universe after the Big Bang) suggest that different regions of space could stop inflating at different times, creating separate "bubble universes" with potentially different physical properties.
There are various types of multiverses proposed by scientists. A Level I multiverse includes regions beyond our observable universe, where regions sufficiently far away might have different physical conditions and histories. A Level II multiverse consists of universes with different physical constants and laws of physics, arising from different inflationary conditions. The Many-Worlds Interpretation of quantum mechanics is considered a Level III multiverse, where every quantum event branches into new universes. A Level IV multiverse encompasses universes with fundamentally different mathematical structures, including all possible mathematical realities.
