Our universe is unimaginably big. Hundreds of billions, if not trillions, of galaxies spin through space, each containing billions or trillions of stars. Some researchers studying models of the universe speculate that the universe’s diameter could be 7 billion light-years across. Others think it could be infinite.
Science fiction loves the idea of a parallel universe, and the thought that we might be living just one of an infinite number of possible lives. Multiverses, real scientific theory explores, and in some cases supports, the case for universes outside, parallel to, or distant from but mirroring our own.
Perhaps there are other universes, even with different versions of ourselves, different histories and alternate outcomes, than our own. When it comes to physics, this is one of the most exciting possibilities of all. Here’s what the science actually says about whether this could be true or not.
Multiverses and parallel worlds are often argued in the context of other major scientific concepts like the Big Bang, string theory and quantum mechanics. Around 13.7 billion years ago, when the Big Bang theory, it burst into action, inflating faster than the speed of light in all directions for a tiny fraction of a second. As the inflation slowed the flood of matter and radiation creating to began and form the atoms, molecules, stars and galaxies that populate the vastness of space that surrounds us.
The reason the universe appears finite in size to us is we can’t see anything that’s more than a specific distance away isn’t because the universe is actually finite in size, but is rather because the universe has only existed in its present state for a finite amount of time.
But this in no way means that there isn’t more universe out there beyond the portion that’s accessible to us. In fact, we have every reason to believe there’s plenty more, and perhaps even infinitely more. That mysterious process of inflation and the Big Bang have convinced some researchers that multiple universes are possible, or even very likely.
Some researchers base their ideas of parallel universes on quantum mechanics. In quantum mechanics, multiple states of existence for tiny particles are all possible at the same time. However, when we actually look, we only ever observe one of the possibilities. This is a branching arrangement, in which instant by instant, our perceived universe branches into near-infinite alternatives. Those alternate universes are completely separate and unable to intersect, so while there may be uncountable versions of you living a life that’s slightly or wildly different from your life in this world, we would never know it.
Some physicists believe in a flatter version of multiple universes. That is, if the universe that we live in goes on forever, there are only so many ways that the building blocks of matter can arrange themselves as they assemble across infinite space. Eventually, any finite number of particle types must repeat a particular arrangement. In a big enough space, those particles must repeat arrangements as large as entire solar systems and galaxies.So, our entire life might be repeated elsewhere in the universe, down to what we ate for breakfast or what we did yesterday.
Countless works of myth and fiction draw from ideas of parallel universes and the multiverse. Overlapping worlds make appearances in Norse mythology as well as in Hindu and Buddhist cosmology.
Nearly every “Star Trek” series incorporates some form of mirror universe. And comics, as well as their corresponding movies, delve deeply into the idea of parallel worlds. Recent Marvel Comics’ storylines, DC’s Flashpoint arc explore multiple universes and the intersections between them. There is an incomplete list of some appearances of multiverses, split-timeline universes and parallel universes in fiction.
No matters what for some of us, the idea of parallel universes spark our wildest dreams. If there are other universes where certain events had different outcomes is one of the most exciting and enticing topics to speculate about the idea of our reality.
Visual by: Kunal Kaustav Duwarah
Article by Niladri Sekhar Dutta, The North-Eastern Chronicle