Examine the existence of Multiverse

Is it possible that the universe is not alone? Is there another universe?

We used to think that the Earth is alone. But the development of knowledge and technology brings people to see the existence of other planets that become the family of the Solar System and open our horizons to the vastness of the universe. The earth is no longer itself. The planets in the Solar System are no longer alone. Outside there are other stars that are also found to have planets just like the Sun.

And humans are brought to understand the beginnings of the universe from light stories that come from the past. If we first asked whether there is another planet in another star, then there is nothing wrong with another question arises. Is there a universe other than the universe that we have not yet fully recognized?

The hypothesis of multiverse states that we live in a parallel universe in which more than one universe exists. Simply put, multiverse is an infinite collection of universes.

The multiverse hypothesis is believed to be true by a number of theoretical physicists because it is still a theory that has not been proven. Even the multiverse theory still invites debate. For his supporters, this theory is a further step for the story of universal inflation while for opponents, the multiverse theory is not physics and unscientific but a metaphysical realm that can not be tested. Keep in mind, science is always based on data collected and predictions that can be tested. Now how to test the existence of multiverse?

For this reason, Matthew Johnson and his colleagues from the Perimeter Associate Faculty conduct research to bring the multiverse hypothesis into the realm of testing.

What is multiverse like?

According to Johnson, the inflation model of the universe opens up space for the existence of multiverse. Inflation is a period of expansion of the universe in an instant that is even faster than an eye blink. In the period of inflation, the universe expands or expands from smaller sizes of atoms to the size of a galaxy in an instant. If inflation happens when there is a theory that also says that inflation will never stop, known as eternal inflation. In eternal inflation, there is a medium filled with inflation which is the energy that causes the universe to accelerate in the expansion.

In the multiverse model, it was originally a hollow medium that was then boiled down by the energy inside. Energy is in the form of dark energy, vacuum energy, the field of inflation, or also by the Higgs field. Just as water is boiled in a pan, the high energy then evaporates and forms a bubble. Each bubble is another vacuum with a lower energy. Existing energy causes bubbles to expand and grow.

As the bubble expands, the bubbles of the universe will be separated by the expansion of space. As a result, in multi-universe models, the universe's bubbles can be very rare because they are far apart from each other, or even solid like foam.

The bubbles are universes in a multiverse where one of them is the bubble of the universe where we are.

Bringing the Multiverse Theory in the Testing Sphere

In his research, Johnson built a rare case where our universe bubbles collided with other universe bubbles. He simulates the entire universe and starts with a multiverse that has 2 bubbles of the universe in it. Both bubbles then collide and of course leaving a bruise or a sign of injury due to the collision. This sign is then sought as evidence of the existence of multiverse.

The marks or bruises produced in the universe bubble collisions are circular bruises in a background cosmic microwave background (CMB). The circular bruise can be seen as a disc on a CMB map where the intensity of the light is slightly different.

But keep in mind, the multiverse simulations and the existence of the universe bubble do not include and take into account all the atoms, stars, or galaxies in them. That is, modeling is done only on a large scale where gravity and other required forces are taken into account.

It seems that this is only a small step in terms of computational simulations. But this small step is actually a big leap for multiverse cosmology. With this modeling, the multiverse is no longer a hypothesis and a theory but has entered the testing phase. Not only that, according to Johnson, the modeling he made has already reached the ability to override certain multiverse models if the model is not able to show what should be seen as predicted.

^{Illustration of the collision of the universe bubble caused a bruise,pixabay.}

For example, a collision of a bubble universe with other bubbles will leave a bruise on the CMB. If it turns out that a circular bruise is not found on the CMB, then obviously some models cannot be said to be valid to be taken into account in multiverse models.

Departing from the modeling, Johnson and his team began to search for traces of collision relics between bubbles that might be left. Although there is no concrete evidence of the presence of the circular bruise disk found in the CMB, it is for the first time a multiverse theory brought to the scientific realm to be tested and searched for its signs.

What is the significance of multiverse? Does this signify that we are really not alone and there is another life in the other universe? Maybe! Because if indeed multiverse is true and there are other universes besides our universe, then of course hopefully there will be other planets there who know can have a life. But it's still too far away. Because the multi-universe theory itself has not been widely accepted and can not be proven through observation whether it is true we are just one of the bubble of the universe. According to Johnson, with the simulations he does, we can know if we are in a bubble of the universe.

But keep in mind, too, Johnson himself began the simulation by assuming a multiverse that has two bubbles of the universe that then collide. From that collision, there are the remaining bruises that are expected to stick in the footsteps of our universe. But what if the multiverse had bubbles that never even met each other? Or what if the multiverse starts with a lot of bubbles of the universe and the bubble of the universe we never bubble other let alone collide?

There is no answer at this time. And when it comes to talking about us we are not alone then ... indeed today we are not alone even in our own universe considering there are thousands of planets that have been discovered and will continue to be found that have the possibility to shape life. thanks

Best regard @ aneuktulot

references and related reading :

https://en.wikipedia.org/wiki/Multiverse
https://www.space.com/32728-parallel-universes.html
https://www.space.com/31465-is-our-universe-just-one-of-many-in-a-multiverse.html
https://www.space.com/18811-multiple-universes-5-theories.html
https://www.worldscientific.com/doi/abs/10.1142/9789814504782_0040
http://adsabs.harvard.edu/abs/2013prst.conf..364H
https://insidetheperimeter.ca/universe-bubble-lets-check/
https://www.sciencedaily.com/releases/2014/07/140717124800.htm