How do we know if we live in 'multiverse'?

Multi-universe is a hypothesis that has been long established by scientists, but to prove it is not easy.

The existence of parallel universes seems to be a more familiar concept for science fiction works than real life, but the idea of 'multi-universe' has long been considered a possible possibility. out, although it is still a controversial topic in academia. The outstanding problem is now finding evidence, anything that can prove that other universes exist.

Remember, the multi-universe view is not a hypothesis, in fact, it is a consequence of our current understanding of theoretical physics. Between these two concepts is quite a distance away. This idea does not suddenly come from nothing, instead, it comes from modern theories like string theory and quantum physics.

Are we living in a "multiverse" ?

Multi-universe analysis

You may have heard about the experiment on Schrodinger's cat , experimenting with a cat that was locked in an iron box, along with the following devices (which the cat could not touch): a Geiger counter and a sample of radioactive material is so small that within an hour it is only 50% of the probability that it emits a radiation. If there is radiation, the Geiger counter will receive a signal and drop a hammer that breaks the poison hydrocyanic acid in the iron box and the cat will die. If there is no radiation left within an hour, the cat will still live. The wave function of the system will be a superposition of both the live cat state and the dead cat and both overlapping states of equal amplitude.

Schrodinger's cat experiment showed that both states could happen, from which the multiverse hypothesis was proposed.

The state of the cat, described according to Copenhagen's understanding of quantum mechanics, is a superposition of life and death, until someone opens the box. But intuitively, in the macro world, cats can only be in one of two basic states, either alive or dead.

However, according to multiverse theory, all events are branch points . The cat's life and death state lies on two branches of the universe, both branches are real, but do not interact with each other. Both of these states, whether living or dead, we can only observe a single state. We can accept that all of these possibilities are real, and they exist in another universe of multiverse models.

String theory

String theory is the theory that promises the most potential in integrating gravitational theory and quantum mechanics theory. This is extremely difficult, because gravitational force is difficult to describe on micro scales like atomic and subatomic particles - the main components of quantum science.

But with string theory, the theory that all particles are made up of one-dimensional strings, it is capable of describing all natural forces, including gravity, electromagnetic force and nuclear force.

10 dimensional space?The limits of humanity are still unable to discover all these mysteries of the universe.

However, to be able to mathematical string theory, it needs at least 10 dimensions of space while we have only four dimensions: length, width, depth and time. If this theory is correct, the remaining dimensions are questions that need to be answered.

To be able to use this theory to explain immediate physical phenomena, these dimensions are thought to have been 'compressed' by bending in different ways, so that they become too small for the eye. of ordinary people. Perhaps, at some point in this four-dimensional space, there are always six other dimensions that we have not yet realized?

However, the question is: where do we stand in the multitude of possibilities of this multiverse model? The string theory does not provide any predictive mechanism, so we cannot test it. However, the idea of ​​cosmic formation will most likely bring about a possible answer.

Early universe model

In the early universe, before the Big Bang, the universe experienced a period of increasing expansion. This expansion is primarily given to explain the cosmic uniformity that we are observing.

However, this theory also predicts a range of thermal fluctuations around this equilibrium point, and this prediction was later tested by observations from many spacecraft such as Cosmic Background Explorer, Wilkison Microwave. Anisotropy Probe or PLANCK.

The Big Bang explosion occurred 13.7 billion years ago, forming the universe today.

The details of this theory are still a hot topic of debate, however, the expansion of the universe is approved relatively widely. Accordingly, somewhere in this universe will still exist the parts that are still expanding.
However, due to the quantum vibrations of space - time, some parts of the universe will never actually reach the final state of the expansion process. This means that the universe, according to our current understanding, will forever be in a state of expansion. Some parts, therefore, will become other universes, and this is the mechanism to create a multitude of different universes that exist in parallel and independently of each other.

By combining this perspective with string theory, it is possible that each universe will possess a different type of compression for the remaining six dimensions, and therefore, they will possess physical laws. different.

Test hypothesis

The multiverse model from string theory and cosmic expansion coexists in a physical space, they can overlap or collide. Obviously, their collision is inevitable, and this will create the astronomical signs that we are trying to find.

Does that much Earth exist in parallel with us?

What exactly do these signs look like? This depends mainly on the structure of the cosmic models, from hot or cold points in the universe to the giant vacuum spaces in the galaxy. However, when the collision with other universes is required to occur, we will expect any sign to break the identity of the universe.

Scientists are still actively looking for these signs. Some search for direct imprints in the universe, such as luminescence residues after the Big Bang, others seek indirect signs, such as gravitational radiation, to help prove survival. in the theory of expansion, thereby strengthening the doctrine in favor of the existence of a multiverse model.

Can we prove the existence of other universes ? That is a very difficult question to answer. But the presence of a multitude of phenomena, suggestions of a great discovery - is certainly a worthy mystery for exploration journeys.

Multiverse is the hypothesis of the existence of parallel universes (including the universe we live in), which includes everything that exists and can exist: space, time, things substance, energy and physical laws. The term was born in 1895 by American psychologist and theorist William James. The universes that coexist in a multiverse are called parallel worlds .