What is a parallel world or multiverse?

According to Einstein’s theory of general relativity, high mass can bend spacetime. According to this theory, in the singularity at the heart of a black hole, the mass is so great that the curve of spacetime becomes infinite, thereby violating the laws of physics. This concept has troubled physicists, but based on a hypothesis, the singularity can be replaced with a complete universe, thus reaching the multiverse.

Singularities are unphysical because they cannot be measured. In fact, their existence indicates the flaw of a theory. According to Dr. Nikodem Poplavsky, a theoretical physicist at the University of New Haven:

Because light cannot escape the event horizon of a black hole, these baby worlds are hidden from the observers of the parent universe, and if something crosses the event horizon there is no way back. The fact that nothing can enter the wormhole means that there is no interaction between the parent and child worlds.

However, if two black holes exist in the same universe, and each of them gave birth to a new universe, there is a possibility that these two sister universes will merge with each other. This process is very similar to merging two black holes and creating a new black hole.

So if you’re looking for a similar version of yourself on the other side of the event horizon, don’t look for it in this theory. In fact, there may be no other like you; Because at any time only one object can exist in one universe.

In quantum physics, which deals with physical laws at the subatomic scale, the term multiverse does not exist. In fact, other worlds are called multiple worlds and its concept is different from multiverse.

The hypothesis of many worlds is said to describe the existence of the quantum system in contradictory or superposition states. The most important mental test of this hypothesis is Schrödinger’s Cat by Erwin Schrödinger. Theoretically, suppose there is a cat in an insulated box with a device containing a vial of lethal poison, and if the nucleus of an atom in the box disintegrates, the poison will be released.

The cat and the device in the box are considered as a quantum unitary system. In this example, the two states “alive” and “dead” for the cat, each one is defined based on a wave. Because waves can overlap to form a single wave function, the cat can exist in a kind of superposition of states. As a result, in quantum mechanics, the cat can be considered alive and dead at the same time.

The hypothesis of multiple worlds also ends in superposition. In fact, it shows that instead of opening the box and collapsing the wave function, the measurement causes exponential growth and engulfs the experimenter and eventually the entire universe. As a result, each hit of the light switch can produce infinite worlds. Universes the size of all the possible paths of photons of light in your room.

According to Schrödinger’s cat thought experiment, the experimenter does not open the box to find out whether the cat is alive or dead. Rather, he opens the box to find out which world he lives in? A world where the cat lives on or a world where the cat is dead.

Objects, events and physical records of observers are different in different worlds. This is the world the Eiffel Tower could be in Los Angeles. In this case, all worlds are part of a single world. In fact, this world seems to have been formed from the perspective of our world. This hypothesis is very similar to the hypothesis of parallel worlds and the existence of another version of you in the parallel world.

The mirror universe is another theory for the multiverse, according to which there is a universe exactly beyond the time of the Big Bang, which is an exact mirror image of our universe. According to Neil Turok, a researcher at Perimeter Institute, instead of saying that there was a different world before the Big Bang, in this theory we say that the world before the Big Bang is an exact image of the world after the Big Bang.