Multiverse/Multiversum and how do we imagine it?

I am and probably still a lot of people who really like to know how the universe began, how the incident in the beginning, and what kind of universe we are in it. Knowledge of the beginning of the universe until now continues to be researched and continue to produce renewal. Until the 20th-century mankind was still struggling with the question of the origin of the universe. The same question has really resonated for hundreds of years. But now the question enters an entirely new chapter, which confirms how the universe began as well as some of the unique phenomena in which it makes no sense at all.

Like a hole without a foothold

In the past the universe was believed to have never been born and would never die in the future, the universe is also still seen as a static and stable universe, the thought lasted until the first quarter of the 20th century. The view remains dominant even though in 1915 an Albert Einstein spawned his revolutionary idea which is now one of the basic bricks of modern science, namely general relativity. General relativity provides a new sense of space, time, mass, energy and (force) of gravity. General relativity offers strange and unreasonable things about our universe. For example, about a beam of light that will slightly turn as it passes near our Sun. Or about the strange motion that Mercury suffered, the closest planet to the Sun in our solar system.

^{Spacetime curvature schematic.wikipedia}

But high-grade astronomical observations made sure Einstein was right. Campaign observation of the Sun Eclipse Total May 29, 1919, prove the path of light is slightly curved when passed near the Sun. Such a large Sun mass produces a gravity that is no less big to bend space-time around it in such a way. Any object, even a beam of light (which is the object with the highest speed in the universe) has no choice but to follow the arch as it passes near the Sun. This is the revolutionary concept of gravity. If in the past we understood the Earth circulating the Sun due to the equilibrium between the force of gravity (which pulls the Earth toward the Sun) with the centrifugal force (which throws the Earth away from the Sun), then according to the general relativity of the Earth around the Sun because the Sun warms the surrounding space-time so that Earth has no choice but to follow the arch.

There are two serious implications of general relativity that were originally ignored even by an Einstein. First, as the dizzying general equations of general relativity are applied in the cosmological domain, the cosmological universe is not static but is expanding. But Einstein's true intuitive and visionary is apparently true the nature of the universe is static. So he considers (and adds) the cosmological constant (lambda constant) as a trait in the spacetime to halt the development, so that the resultant will produce the static universe as it is believed. History finally proves that in just a few years later this assumption was a mess after Edwin Hubble, a boxer who then became an astrophysicist, delivered his hard work in registering the positions and the distance of galaxies other than the Milky Way. It turns out that these galaxies are moving away and steadily away, just as predicted by general relativity before the idea of cosmological consequences arises. Later when visiting Hubble at Mount Wilson Observatory, California (USA), Einstein admitted that cosmological row is "the biggest mistake I ever made."

^{Big bang,wikimedia}

If the current universe is expanding, then obviously in the past all the contents of the universe had gathered at one point the same. This is when the birth of the universe, which in later days popular with the name of the big bang event aka Big Bang. Big bang gets its name because it is then that all the universe of matter, compressed very densely in one point, suddenly expands very rapidly as well as begins to form elementary particles which then rejoin each other to form protons, neutrons, and electrons that become the whole basic brick material. The first big-time boom was first recorded in 1963 as a splash of disturbing radio waves in a continuous microwave spectrum in a radio telescope operated by Penzias and Wilson astronomers no matter where the telescope was directed. This is the cosmic microwave background (CMB) which is also the oldest light trace in the universe since it formed only about 380,000 years after the big bang. Now we know, through the further exploration of cosmic background radiation, that our universe was formed at 13.8 billion years ago and has now expanded so widely that its diameter is 94 billion light-years (1 light year = 63,240 astronomical units = 9, 46 trillion kilometers).

The second serious implication of general relativity is on the appearance of exotic celestial bodies. The light beam slightly curved as it passed near the Sun, with the magnitude of the arch dependent on the mass of the Sun's mass and its distance of crossing to the center of the Sun's mass. If we replace the Sun with another star, it will easily be seen that the greater the mass, the greater the degree of curvature of the light trajectory. A similar phenomenon will also be encountered if the distance is closer. The combination of these two results in extreme situations, where the star has a very large mass and vice versa dimension (diameter) is much smaller than the Sun. Such stars are possible to form as the ultimate product of the evolution of massive star life as demonstrated by quantum mechanics, other basic bricks in modern science. This kind of exotic star has a very large density (mass density) that its gravity not only bends dramatically around the spacetime around it, but even extends it to a 'bottomless well' as a space-time asymptote. This exotic starlight will enter the bottomless well and will never come out of it, nor is the beam of light coming from outside and happens to pass nearby to a certain distance of traffic called event horizon.

^{Simulated view of a black hole in front of the Large Magellanic Cloud. Note the gravitational lensing effect, which produces two enlarged but highly distorted views of the Cloud. Across the top, the Milky Way disk appears distorted into an arc.,wikipedia}

Now we recognize such exotic stars as black holes. And its presence is abundant in our universe, either as part of twin stars or as the inhabitants of the galactic core. Theoretically every star with a mass 3 times the mass of our Sun would be a black hole at the end of its life. As the name suggests, there is not a beam of light emitted from a black hole so no one can see it. Black holes are detected based on their gravitational interactions with their environment. Also how he sucks the material around him, then tears it apart, crushes it and disperses it in certain directions with a peculiar pattern that can only be seen in the spectrum of ultraviolet rays and X-rays. The VLT Telescope at the Paranal Observatory (Chile) shows how a star passing within just a distance of 122 astronomical units (3 times the Sun's distance to Pluto) from the center of the Milky Way galaxy is heavily disturbed by gravity. From the disturbance is known that in the center of the Milky Way we are hidden a giant black hole with a mass between 3.2 to 4 million times our Sun. The mass of it is compressed in a space the size of 1,500 to 1,880 times the size of our Earth. No wonder the gravity is so great that the whole corners of the Milky Way, including our solar system, feel it and are forced to submit under its influence.

As big as a diamond?

Then where does the bottomless well in the black hole end up?

A new history was created on March 17, 2014, when the BICEP2 (Background Imaging of Cosmic Extragalactic Polarization 2) team announced the results of a 9-year study. This announcement reveals one of the most important discoveries for 21st-century science that can be paralleled with the importance of the invention of the Higgs boson. The BICEP2 team, led by John Kovac, an astrophysicist at Harvard-Smithsonian Center for Astrophysics (USA), announced the incontrovertible direct evidence of inflationary ideas in a big bang.

^{History of the Universe - gravitational waves are hypothesized to arise from cosmic inflation, a faster-than-light expansion just after the Big Bang (17 March 2014).,wikipedia}

The idea of inflationary arises more than three decades ago to answer some of the problems that embraced the theory of the big bang. This idea makes us better understand why our universe tends to be flat and homogeneous (equally) on a macroscopic scale. In this idea, when the baby of the universe is still very young, after the big bang, there is a very rapid development so that the dimension (diameter) of the baby universe jumps dramatically many times over. The inflationary took place very briefly after the big bang. But in a very short time that the dimension of the universe swelled greatly from the beginning. So if at first, the baby universe is just a point much smaller than the proton, then post-inflationary after its size has become as big as a diamond.

After the inflationary is over, as the reaction is released the gravitational waves then fill the baby universe (which now has the diamond). And 380,000 years later, when the neutral Hydrogen atoms begin to fully form without being ionized again, the oldest light is formed which then interacts with the post-inflationary gravitational wave to form certain patterns within it. The patterns are still carried in the light even though the universe then matures and ages by expanding so broadly that the wavelength of the oldest light continues to grow until it comes out of the visible and infrared light spectrum and is now within the microwave spectrum. This is the cosmic background radiation.

As with most electromagnetic waves, cosmic background radiation can be polarized. This fact has been found since 2002. Armed with this discovery, the BICEP2 team has begun to examine the polarization properties of further cosmic background radiation by building an Antarctic telescope or SPT (South Pole Telescope) facility working at wavelengths in millimeter / submillimeter order. This study is very difficult. Because to detect polarization in cosmic background radiation, the BICEP team had to build instruments with very high sensitivity so that small fluctuations in cosmic background radiation, corresponding to the fluctuations in the temperature of only 0.1 microkelvins (0.1 mikroCelcius). But hard work since 2005 finally paid off as the BICEP2 team confirmed the polarization of B-mode in cosmic background radiation, a trace that can only be generated from the inflationary stage in the big bang.

Multiverse/Multiversum

The discovery of direct evidence of the inflationary stage leads us to more serious implications. According to quantum mechanics, the inflationary is the result of quantum fluctuations. The same fluctuations will also result in other big bangs that give rise to other time-spaces as well. In other words, the processes that make up our universe through the big bang with the inflationary stage in it can also form other universes. In other words, our universe is not the only universe that exists, but grows and grows with other universes in a multi-universe constellation! Of course, this is still merit.

How many other universes exist outside our universe? On paper, quite a lot, though impossible to prove its existence (at this moment). For the existence of Multiverse / Multiversum is only prominent in our imagination. But if other universes do exist, then their existence may be one of the crucial factors that sustain our universe, especially how our universe has its own fine-tuned parameters on both macro and micro scales so we can observe. In other words, the existence of Multiverse / Multiversum may be the answer to how our universe is so fitting that it allows us, humans, to live in it, albeit only in a small corner called planet Earth. One calculation shows that in order for our universe to exist and to sustain the life of mankind, it takes at least 10 to the rank of 400 other universes!

^{An artist's impression of a wormhole from an observer's perspective,,wikipedia}

Other universes, if any, might also give an answer where the bottomless well of the black hole boils down to. On paper, the bottomless well is the truly invisible tunnel, connecting one point to another in our universe. It can also be a groundless well that is a tunnel that connects one point in our universe with another point in another universe. This is the concept of the wormhole. Though very difficult to prove scientifically, the concept of the wormhole is very popular in fictional tales as a shortcut to get to the true location very far in very short time. For example, the journey of New York - Washington DC must be taken in at least an hour using an airplane. But if the journey takes place with a space-time tunnel in the wormhole concept, then New York-Washington DC can be reached in just a few minutes (even in a few seconds!) On foot, if you know how. For science has warned that this wormhole, if it really exists, is so unstable that the trigger disappears in an instant even when we just put our toes in it. Only if we have exotic material with only negative mass (so it has negative energy) then wormhole can be stabilized and possibly passed.

^{Wormhole visualized,wikipedia}

It is interesting to note how the development of the universe, black hole, bottomless well, inflationary, Multiverse / Multiversum to wormholes bring new implications in understanding. In order for travel can be done, the wormhole needs to be stabilized by exotic materials of negative mass (so negative energy). Such material may never exist in our present universe but may be abundant in other universes. So the journey to the other universes can only take place when the inhabitants wish for it.

What is clear is that today's science has just proved that inflationary is true, it never happened at the beginning of our universe. And the factors that trigger the inflationary can produce other universes. The universe is probably the same as our universe and is controlled by the same laws of nature. But it can also be a universe different from the laws of nature that are completely different from our universe. Yet, though different, other universes remain connected to our universe through a space-time tunnel called a wormhole (it could be).