About billions of years ago the universe was created which is still not explored by our scientists. The size of the universe is still not defined, it might be infinite in extent. Some parts of the universe are too far for the light emitted since the Big Bang to have had enough time to reach the space-based elements. We all know with some certainty that there is some more universe out there which is beyond the boundaries. It always comes to mind what comes outside the universe.
So today we will talk about the five theories that lie outside the observable universe.
The theories of our universe that we are going to discuss today are:
1. Hubble Volume Theory
In modern cosmology, the shape of the universe is flat. In between the closed space and flat space, there is one compromise, that is ‘Hubble Volume’. Even though the Hubble volume is virtual in the flat universe, by considering the product of critical mass density and the Hubble volume, one can estimate the Hubble mass. Since 1998 we have come across the expansion of the universe accelerating, and the number of galaxies within the Hubble volume decreasing. The Hubble volume is approximately equal to 1031 cubic light years.
We know with some certainty that there is more universe out there beyond the boundaries. Astronomers think space might be infinite having kinds of stuff like energy, galaxies, stars, and many more such things distributed in the observable space. If we go far, we will find another solar system with all the planets and stars.
Hubble’s law simply says that a galaxy’s velocity is directly proportional to that of its distance. It also tells something important about the state of the universe. If the universe is static and unchanging, there should be no correlation between distance and velocity.
2. Infinite Bubbles Theory
Discussing things that are outside of the Hubble volume might be a bit of unfairness since it is the same universe, just the part of it which is not visible to us. Post-Big Bang expansion of the universe caused “bubbles” to form in the structure of space. Each bubble is an area that stopped stretching along with the rest of the space and formed its universe, with its laws.
The bubble theory arises from the nature of cosmic inflation, which views the universe as expanding exponentially in the first tiny fraction of a second after the Big Bang. In the concept of the multiverse, some parts of space-time expanded faster than others, and this created bubbles of space-time. Each bubble contained a vacuum simmering with energy. That energy caused the bubbles to expand. Unavoidably, some bubbles collided with each other because of that some secondary bubbles also started producing. Each of these was a universe in its way. These various bubbles developed into universes that were different from each other. The theory tells us about the explosion thrust matter in all directions and expanded space.
3. Dark Flow Theory
Astronomers discovered something very strange and unexpected, that is galactic clusters. These were all streaming in the same direction at immense speed, over two million miles per hour. After two years they observed the confirmed phenomenon which was known as Dark Flow. The movement defies all predictions about the distribution of mass throughout the universe after the Big Bang. This was caused by something beyond the limit of our observable Universe.
In astrophysics, dark flow is a theoretic non-random component of the peculiar velocity of galaxy clusters. This is being caused by something beyond the limit of our observable Universe. In 2008, astronomers discovered something weird and unexpected after a few years in 2010 they conclude and confirmed the phenomenon as Dark Flow. This theory is a little controversial because the distribution of matter in the observed universe cannot be counted for this theory.
4. Black Hole Spawning theory
A theory named fecund universe theory suggests that every black hole in our universe causes the formation of a new universe. Each of them has a slightly different physical law than the forerunner universe. In this theory, a star burns through the last of its fuel and the object may collapse or fall into itself. Cosmologists speculated that the universe is formed from the debris ejected when a four-dimensional star collapsed into a black hole. Black holes are some of the strange objects in space. They are extremely dense having a strong gravitational attraction force. The Milky Way could contain over 1000 million black holes. In the middle of the Milky Way, a supermassive black hole lies.
The theory of the fecund universe was proposed by physicist Lee Smolin which suggests that every black hole causes the formation of a new universe. In this way, he also suggested a sort of natural selection for universes, as laws that lead to the frequent formation of black holes lead to the creation of more and more universes. This theory has since been discounted by Smolin himself and some others.
5. The Parallel Universes theory
These parallel universes are also known as parallel dimensions or alternate reality. There are a lot of theories about parallel universes, and the most accepted one from them nowadays involves an evolution of the ideas of string theory to involve membranes that vibrate in other dimensions. The parallel universes are the hypothetical self-contained planes of existence, co-existing with the universe. As it is an idea that arises from the multiverse theory, which suggests that our universe is one of many existing universes. Dr. Michio Kaku has suggested that if these ideas become reality, there will be virtual copies of every individual in some other region of space. Our universe is very huge where hundreds of billions and trillions of galaxies spin through space which contains trillions of stars in it.
Around billions of years ago, everything was just an infinitesimal singularity. Then, according to the Big Bang theory, it burst into action. That mysterious process of the Big Bang convinced researchers that multiple universes are possible. According to theoretical physicist Alexander Vilenkin of Tufts University, inflation did not end everywhere at the same time. This theory was called the theory of eternal inflation. He mentioned that “as inflation ends in a particular place, a new bubble universe forms”.
These were the theories about What Lies Outside the Observable Universe.
Image courtesy: https://www.space.com/whats-beyond-universe-edge
