The Multiverse and Time Travel: From Comics and Movies to Theoretical Physics (I)

There is a concept that will be familiar to any comic book fan, at least for those who follow those of the two major publishers of this type of publications, Marvel and DC Comics, which, to reconcile the variety of series, characters, scenarios and sometimes versions of the same characters and scenarios, that exist between the pages of their series, have adopted the concept of the multiverse. A concept that we are now also beginning to see represented in their productions for the small and big screen.

This concept, together with time travel, has been the leitmotiv that has served to explain and amend any irreparable situation in the plot of many stories, and in many cases, the very core of the motivations that guide the events.

But what does science say about the possibility of a multiverse, it is possible that there could be different versions of us, existing out of our sight.

In this regard, theoretical physics gives us different approaches to the idea of multiverses, all of them are mere speculations, which in the first instance cannot be proven, hence their hypothetical character. In this article I will discuss one of these hypotheses and in subsequent publications I will continue to expand on the subject.

The Interpretation of Multiple Worlds (IMM)

Much has been said about Schrödinger's cat experiment as a way to explain the superposition of states in the quantum world. Suppose that in a box we introduce a cat, a sealed container with a poisonous vapor and a device that will break the container when it detects the emission of an alpha particle from a radioactive isotope; we seal the box so that we cannot see what is happening inside, and after waiting a few minutes, enough for the isotope to have a 50% probability of having emitted the particle, we ask ourselves, without opening the box, in what state is the cat?

Ignoring the ethical implications of killing an innocent cat, this experiment aims to show us, taking to the macro world, what happens with particles at the quantum scale; a phenomenon called superposition, we do not know for sure if the cat is alive or dead, we can only say that its state is equally likely for both cases, that is, it suffers from a superposition of states.

At the quantum level the state of a particle is defined by the so-called wave function, which is nothing more than a probabilistic interpretation of the state of the particle, so, for example, the position of an electron at a given time, can only be defined as a probability expressed by the function, as well as the state of life or death of our cat. The only way to know what happens to the cat, is to open the box and verify it, which in quantum physics is called collapsing the wave function, when this happens, we can know, for example, if the electron is in a place or not. This impossibility of knowing the exact state of a phenomenon at all times, gives a random character to the events in the quantum world.

This is how the perspective of quantum physics, on multiverses, is a direct product of the random nature of quantum phenomena, and is expressed in the Interpretation of Multiple Worlds (IMM) of the American physicist Hugh Everett; from this position, any possible result of a quantum phenomenon, regardless of its probability, exists somewhere, as a classic example of this is the aforementioned experiment of Schrödinger's cat.

From the IMM position, actually when opening the box, there would be a bifurcation, in which both states would be occurring in parallel, in two different universes, so there would exist somewhere a universe where the cat would be alive and another where it would have died poisoned.

In this interpretation, the random nature of quantum physics would make possible the existence of infinite universes in which each event, subject to quantum randomness, generates bifurcations that give rise to parallel universes.

The IMM gives an interpretation of quantum physics in which the discrete phenomena of each universe can be explained by classical physics, while the randomness of the multiverse requires quantum physics.

These universes would coexist in the same Hubble volume, or space that could be reached by an observer located at the center of an imaginary sphere; beyond this limit, objects move faster than light and would be unreachable. Consequently, these universes would share the same physical constants and laws as the other volumes of the bubble, while their configuration would depend on how randomly distant they are from the bifurcation that gave rise to them.

This concept of multiverse, we can see it expressed, for example, in movies like Avengers: End Game, of course, not without escaping the inevitable time travel. When each of the infinity gems are removed from different moments in time, it forces the creation of different timelines, which are nothing more than universes, bifurcated by the disappearance or not of the respective gem, always keeping as the object of our attention in the film, the universe in which the gem was not extracted, and disappearing the bifurcation, when they are again returned to their original time. That is the explanation of why Captain America could age in the same timeline in which the snap occurred, obviating of course, the paradox that there have been two captains all the time.

For Dragon Ball fans, this is also the explanation why Trunks from the future cannot change the events of his time, because no matter how much he tries to modify the past, this would only start new timelines, universes, that would not affect what happened in his own universe.

In a future article, I will explain other interpretations of physics regarding the concept of the multiverse, thank you for your attention.Click to Source

Sources

• Redacción EC, ¿Qué son los universos paralelos? La última teoría de Stephen Hawking, El Comercio.

• Rodríguez, G., Universos paralelos: explicando la teoría, VIX

• Tegmark, M., Universos paralelos, Investigación y Ciencia

• Vera, B., Las teorías de los universos múltiples, N+1

• Wikipedia, Multiverso, Wikipedia

• Wikipedia, Universos paralelos, Wikipedia