There’s a new scientific theory in the limelight — it’s called the ‘Many-Interacting Worlds Theory’ and it talks about stuff that science fiction movies are made of. Authored by Professor Howard Wiseman (from Griffith University’s Centre for Quantum Dynamics), Dr. Michael Hall (also from Griffith University’s Centre for Quantum Dynamics), and Dr. Dirk-Andre Deckert (from the University of California), the theory claims that our universe is only one among many universes that exist.
Interestingly, these multiverses exist on the same space, on the same timeline, and occasionally interact when they bump into each other. Moreover, these other universes are also supposed to be governed by the same laws of physics that our universe follows. If this theory — presented through a paper published in the Physical Review X journal — is correct, it means what we know about space and time is inaccurate, and that travelling through time is in fact possible.
And so the concept of going back in time or going forward in time to change the present will no longer be just a movie plot but a very real scenario. And the world we know can easily become an altered version where dinosaurs still exist (because the historic giant asteroid missed our planet and struck some other universe) and the lost city of Atlantis is not a myth but a real city that still stands because the gigantic tsunami that was supposed to have buried it deep under water hit some other city.
According to Professor Wiseman, the parallel universes can best be imagined as ‘ghost universes.’ The ‘ghost’ part is the fact that they exist, but they can’t be seen because they interact with our universe under conditions that we can only speculate about. Supposedly, the interaction happens through a force that acts on similar particles that exist within the different universes. However, the interaction is almost negligible that it can’t be noticed, but is enough to explain how quantum mechanics works.
The researchers demonstrated their theory by using the classic double-slit experiment. What they do is fire individual photons at a screen at different times. Between the screen (that functions as a detector) and the source of the photons is a black material with two slits that is intended to absorb the photons.
If photons are simply particles, they should spread evenly in space. But they didn’t. What happened instead was that the photons piled on top of each other in strips following a specific pattern. The same result is seen when photons pass through the double slit as waves. The conclusion? A photon is not just a particle; it’s also a wave.
This wave-particle duality has been referred to as the ‘central mystery’ of quantum mechanics. In the context of the ‘Many-Interacting Worlds Theory’, the photon should only go through one slit when it passes through by itself. However, something else happens when the photon bumps into its counterpart from a mirror universe; some kind of pattern emerges. And that’s how we’ll know our universe isn’t the only one out there. And that’s also our cue to start thinking about how we can travel through time.
“And so the concept of going back in time or going forward in time to change the present will no longer be just a movie plot but a very real scenario.”
No. This seems to be a common misunderstanding. If you go backward in time to another universe then you’re in that universe and no longer in the one with the present you wish to change. Any changes you would make there would have nearly 0% probability of changing the present in the universe from which you traveled. When you travel back to the future, if you’re lucky and precise enough to land in the same universe in which you started, nothing will be different.