Parallel Universes: What the future holds ?

Is the concept of parallel universes going to remain as a mere sci-fi movie plot? And on what scientific grounds do we say that parallel universes exist after all?

It may be hard to believe, but the idea of multiverse or parallel universes, was one of the  genuine and plausible results that physicists considered (at least some of them). And that was because of its possibility in quantum mechanics - a giant branch of physics, that deals with properties of subatomic particles like electrons, quarks etc.

But what made the multiverse theory even more popular was some of the ideas and theories that were put forward by some of the famous 20th century physicists like Erwin Schrodinger and Richard Feynman - the Schrodinger’s cat paradox and Feynman’s interpretation of many worlds. Both of the theories very reasonably predicted the existence of multiverse or parallel universes, where each of them had a different state of being, with their own probability.

Despite its consistency with the quantum world, the idea of parallel universes was abandoned! The reason being that it only remained as a theoretical model, and we’ve never been able to observe one in the real world, directly or indirectly. 

Another reason was that it was developed on the sole basis of quantum mechanical principles, which didn’t coincide with that of classical physics or General Relativity - which is another giant area in physics, that deals with the macroworld and gravity. 

And since there’s no existing link that combines quantum mechanics and general relativity to this date, the multiverse theory also seems impractical in today’s world.

But we can’t completely deny the fact that parallel universes are not going to exist ever. With the advancement of science and technology in the next decades, we might be able to crack the code on the true reality of our universe… and possibly other universes!!!