Sometimes, when reading an article on the subject of space, it becomes extremely difficult to understand at least something in it, without knowledge in the field of physics and cosmology.
On the one hand, the awakened craving for knowledge does not give rest, and on the other hand, while reading complex terms, the gravitational force attracts the head to the pillow.
In this article, we tried as simple, interesting and phased as possible to come to what has been so exciting for scientists over the years — to the multiverse.
What are multiverses?
The process, called the Big Bang, which created our spacious Universe, can create another infinite number of universes. That is, the multiverses are a hypothetical indefinite set of all possible existing universes.
The multiverse hypothesis is uncountable. There may be a copy of you enjoying a cup of coffee in the morning, or maybe, on the contrary, a copy of you hates coffee and has breakfast with freshly squeezed juice. What if you are not there at all? Yes, and a world like this simply does not exist there?
Nothing comes from nothing
When we try to imagine the Universe, then most likely, a visualization of some kind of black enclosed space where some objects are located (galaxies, star clusters, planets, etc.) will come to mind.
We cannot imagine anything without boundaries. And even more so, we cannot imagine and accept that we and other objects in the Universe are in a “suspended” state.
Something is happening around us, somewhere in the distance something merges or stops close “contact”, various chemical reactions and laws of physics are “raging” around. Anyway, the more we learn, the more questions appear the answers to which are in the same “suspended” we state.
Each time, visualizing the Universe in the head as some kind of space, we try to find its end and immediately visualize another space in which ours is located. And so on ad infinitum — in our understanding, it simply cannot be otherwise. It’s as if we are creating new universes in our heads.
In the world of science, you can offer your own versions of the origin of the universe, but each is obliged to explain the results of processing a variety of collected data.
They, in turn, fit easily into the mighty Big Bang. The evidence for this theory is based on the work of three scientists. Each of them is incredibly talented in the field of science to which he has devoted his life.
We are sure that many, not even avid fans of outer space, have heard their names.
Problems of Distance
Until today, determining the exact distance to stars is a rather difficult task for astronomers. A distant and bright star may look just like a dim star. Analyzing a photograph of the Andromeda nebula, Edwin Hubble discovered a variable star (Cepheid) within it. These are stars that constantly, at certain intervals, either become brighter or fade.
The time of one full cycle of a star depends on its brightness. The more “saturated” it is, the longer will be the period of its pulsation. By calculating the duration of its cycle, you can find out the brightness and, subsequently, the distance to it.
Realizing that the star is far beyond the “native home” called the Milky Way, Hubble was very inspired by this discovery. Studying the remaining spiral galaxies, the great scientist concluded that they are also not part of the Milky Way. Moreover, Hubble realized that our home is one of many galaxies.
The universe became larger in his eyes instantly. We just need to imagine his feeling at the moment when he made this greatest discovery.
The beginning of the Miss Universe and Hubble constant
After examining 24 galaxies, Edwin Hubble discovered that the farther away a galaxy is, the faster it moves away. The ratio of speed to distance is approximately constant. This expression of the expansion rate of the universe was called the Hubble constant.
But if the Universe expands, it is logical that it should have a beginning, from where the expansion comes. It is the Hubble constant that helps to calculate the age of this modest Miss Universe, which, as carefully as a true lady, tries to hide her years.
After all, knowing the rate of expansion, scientists can calculate the reciprocal and then the approximate time when the explosion occurred.
Bought a balloon filled with helium — acquired atoms formed in the first minutes after the Big Bang
Walking in the footsteps of Edwin Hubble, George Gamow set out to find evidence proving that once there was a Big Bang. It cannot be said that this was something very promising for Gamow.
Gamow’s next greatest contribution to physical science was the discovery of nuclear reactions. Today, this discovery is called “nucleosynthesis.” The theory is that there is an unbreakable chain of elements starting with hydrogen.
It can only be built by sequentially adding particles to the hydrogen atom. Gamow suggested that the plurality of elements that make up our universe was created precisely at the time of the Big Bang.
The very birth of the Universe was so hot that a fusion took place between protons and neutrons, which formed helium atoms. By the same principle, further collisions of hydrogen with helium generated other elements.
A powerful explosion managed to generate so much helium that its percentage of the entire mass of the Universe is about 25%. Looking at the stars and galaxies, we understand that they are 75% hydrogen and 25% helium and other trace elements.
But, despite all the coherence, problems nevertheless arose. His theory was considered true only for light neutrons. Since the Universe consists of heavier elements that have much more particles than light ones with 5 and 8 protons and neutrons, unable to be stable and serve to create elements with numerous neutrons and protons, it became unclear how they formed during the explosion.
George Gamow, being an assertive man, was not going to give up. Then he got the idea that since the explosion was so hot, then his residual heat should remain. And if this was a true thought, then this “heat” could be considered something like a recording of an explosion.
He suggested that the Big Bang is an explosion of a super-hot neutron nucleus. This was a reasonable assumption at that time, given that little was known about other particles except for the electron, proton, and neutron.
A few years later, Gamow managed to prove that the radiation of this super-hot core would work as “radiation of a completely black body.” What is it?
Radiation of a black body is a special type of radiation given off by a hot object, where the light incident on this same object is completely absorbed, giving off radiation in a different way.
To make it clearer, try to imagine a kiln, where the product, as its temperature rises, changes color from red to white. Knowing the color of a hot object, you can understand its approximate temperature. And vice versa.
Then Gamow suggested that the radiation of the Big Bang could have the radiation of a completely black body, and since the radiation temperature was the most important feature, the scientist had to calculate it.
In 1948, Gamow’s graduate students, Ralph Alfer and Robert Herman showed work where they presented arguments that the radiation temperature after the explosion should have been 5 degrees above absolute zero.
Amazingly, their number is very close to what scientists have now — 2.7 degrees Kelvin. Microwave radiation was still supposed to “plow” through the universe, filling the cosmos with “afterglow.”
After the Big Bang, for many years, the temperature was so high that every newly formed atom was torn apart immediately. For this reason, free electrons scattering light are formed. Any ray of light moving through such a hot universe was absorbed.
Thus, the universe looked foggy. After another year, when the temperature became much lower, the atoms stopped breaking and their formation began.
The rays of light were no longer absorbed but could move during light-years. So space became transparent, and radiation, which henceforth was not absorbed instantly, continues to wander through the expanses of our days.
Put forward another proof of the Big Bang, trying to expose it?
Fred Hoyle did not accept the Big Bang Theory and found the “evidence” empty. One of the drawbacks of this theory was the fact that Hubble incorrectly calculated the age of the universe. Therefore, Fred Hoyle, enlisting the support of colleagues, Thomas Gold and Herman Bonley, began to reflect on their theory.
The theory was that the universe has no beginning or end. It expanded, creating new matter from nothing. Hoyle and his colleagues could not explain where the new matter was created, but their theory gained many supporters who also fiercely entered the battle with those who adhere to the Big Bang
Theory. It was much easier for Fred Hoyle to accept that something could come from nothing than if it was due to an exploding cataclysm.
An interesting fact is that it was Hoyle who gave the name to Gamow’s theory. Although the followers of the Big Bang Theory later tried in every possible way to come up with a different name, even competition was held, but they could not pick up anything else.
We want to note that the name of the theory should not be taken directly. There was no big bang, as such, because there was no air in space, and it couldn’t be big.
Oh, this restless Fred…
Hoyle did not see peace. He was so enthusiastic about his idea that the elements of the Universe were formed not from the brazier of the Big Bang, but in the core of the star.
Indeed, the need for Gamow’s theory fell away by itself. And the main question about elements with a mass number above 5 and 8, which baffled Gamow, would seem to have been resolved.
But, alas, even such a blazing hell inside the stars was not enough for such “hot cakes” as copper, nickel, zinc, and uranium to be prepared. For such elements, at least a supernova explosion is needed.
But, alas, even such a blazing hell inside the stars was not enough for such “hot cakes” as copper, nickel, zinc, and uranium to be prepared. For such elements, at least a supernova explosion is needed.
In 1957, in collaboration with Margareti, Jeffrey Burbidzhi and William Fowler published a work that presented all the steps necessary to create elements in the Universe, having such significant arguments that even Gamow reluctantly admitted that his rival provided a fairly convincing essence of nucleosynthesis.
Ah, Hoyle… what a pity…
Over the years, in all areas of science, more and more denials of the mischief of Mr. Hoyle have been collected, but one cannot but give him credit because he is truly a brilliant scientist.
According to Hoyle’s theory, it was called the “Stationary Universe”, the Universe could not evolve. In her leadership was only the creation of new matter, which meant the identity of the early and present Universe. All objects visible to us should have been similar to those that are already billions of years old.
An unpleasant moment was the quasars discovered by scientists in the 1960s. Now, probably, there is no such person who at least once has not heard of them. Quasars generated incredible amounts of energy and were characterized by a redshift, which meant that they were very far from us. They also lit up the still very young Universe.
To date, scientists have no evidence of the existence of quasars in our time, but according to Hoyle’s theory, they must still be. Yes, and helium, as scientists have found out, is too much, and this does not fit into the theory of the stationary Universe.
But the most decisive blow to theory was the detection of a strange noise.
Great job!
Gamow, so assertively developing the Big Bang Theory, and Hoyle, so furiously trying to trample it, all the same, we can say, worked together. They gave us a complimentary picture of nucleosynthesis.
Today, scientists have found that light elements weighing up to 5 and 8 still arose as a result of the Big Bang, as George Gamow had suggested. And heavier elements originated in the nuclei of stars, as Hoyle asserted confidently.
Nevertheless, in this scientific battle, the victory was for George Gamow, because in 1965 something happened that George and his colleagues predicted back in the 1948s.
Arno Penzias and Robert Wilson, working with a radio telescope in Bell’s laboratory, spotted a strange radio noise. Thinking that it was some kind of awkward interference, they cleared the mouthpiece.
The noise came evenly from all directions, and not from some object. It so happened that they stumbled upon microwave relic radiation. For such an important discovery, they were awarded the Nobel Prize in 1978. It is impossible not to say that Hoyle almost sent this news to the next world, but he did not continue to argue further, admitting his defeat.
Unfortunately, the same Gamow, albeit being right, was no less upset than his rival Hoyle. His work, as well as the works of his colleagues, were hardly mentioned. The opening championship was given to Penzias and Wilson.
Launched in 1989, the satellite COBE, spacecraft for the study of CMB radiation, measured many parameters that confirmed the work of Gamow and his colleagues. And in 1998, stormy applause was accompanied by photographs taken by the satellite that the temperature of the relict radiation was 2.728° K.
Looking back, it would be wrong not to recall the gathering of Hoyle with Gamow. Once meeting, discussing the relict radiation and its temperature, Gamow told Hoyle that he had performed the calculations and found out that it should be about 50 degrees.
Hoyle, hearing the words of Gamow, shared information that he knew the work that had not found recognition, written by Andrew McKellar in 1941, which stated that the radiation temperature could not be higher than three degrees Kelvin, because at high temperatures new reactions would occur. So, if two great scientists had not fought their foreheads with each other, the history of cosmology would have been a bit different.
The Big Bang Theory is good, but something is missing…
Seamlessly, we are already approaching the most interesting. A thrilling discovery was thrilled by Alan Gut, stumbling upon one of the greatest theories of cosmology. As a brave man of science, he decided for the first time in 50 years to reconsider the Big Bang Theory.
Then Gut concluded that he could solve some puzzles and give answers to a lot of questions, suggesting that the Universe underwent hyperinflation (accelerated expansion) at the time of its appearance.
The latest cosmological data and the results obtained by the WMAP satellite indicate that Alan Gut accomplished a revolution in cosmology with his theory. Such a laconic theory solved many non-laconic questions, one of which concerned the almost zero curvature of the Universe.
Having gone outside, it seems to you that the earth is flat because you are too small to see the opposite. So it is with the universe. We are unable to see this very “curvature” because we are like a point on a huge ball. Gut’s theory explains this by the fact that inflation has “stretched” space and time so much that it seems flat to us.
Gut also applied the world of quantum theory and elementary particle physics to the study of the Universe. This was a historic moment since now the deepest puzzles would otherwise be impossible to solve.
We bring the universe into action
In order not to put readers into a state of sleep, we will not go into details very much, but only “go over” superficially.
Scientists, conducting many studies over many years, found that the Universe is driven by four main forces: gravitational interaction, electromagnetic, weak and strong nuclear interactions. They all differ from each other, have their characteristics and advantages.
Joining forces, as an idea, looks pretty good. The forces looked like superheroes in one team — without each other, it was somehow not right.
However, even though our Universe arose in the state of solidarity of this team, as it cooled down, the forces “related” to each other “cooled down”, gradually ceasing interaction with each other.
For clarification, scientists often cite two water conditions as an example. Being in a liquid state, water is “elastic” and homogeneous. As soon as it freezes and turns into ice, its “elasticity” is broken, a lot of bubbles and crystals appear.
Such an example is given to make it clear that our universe is damaged. Being already cold and, to put it mildly, aged, we observe how heterogeneous, asymmetrical it is and this, anyway, is still beautiful and surprising.
What makes the universe expand so fast?
How is this a false vacuum? Imagine a raging river and a dam on it. Despite the current and waves beating along it, it seems to you that it is in a state of stability. But in reality, the dam suffers every second from a high level of pressure on it. If it gives slack, then a huge stream of river energy will be released.
Similar to the example of a dam on the river, our Universe also arose from the very beginning in such conditions. The forces were united in a single whole, but suddenly something happened and the unity collapsed. The energy of a false vacuum expands the universe at an incredible speed.
What explains inflation?
The Big Bang Theory could not explain the plane of the Universe and this fact very worried scientists. Gut saw his theory solve these concerns. Inflation simply made it so for us, so the Universe became too wide for us to see anything else.
Inflation, too, did not forget to solve another problem — the horizon problem. Wherever we look, it seems to us that the whole Universe is homogeneous. The problem is that for the entire existence of the Universe, light could not pass from one part to another. Since microwave radiation in different parts has the same temperature, we can conclude that they had a contact at the very beginning.
Returning to the moment when only 380,000 years passed after the Big Bang and when radiation was only just formed, looking at the opposite parts of the Universe, we will see that absolutely everything is homogeneous. If we take into account the speed of light, then this is impossible. Light is unable to travel 90 million light-years in 380,000 years.
Then what would the universe look like? It can be assumed that she would have looked … strange enough. Its parts could not be in contact with each other, and indeed, all of it would consist of lumps. Then how did it happen that it looks uniform? The answer to this question is inflation. According to Gut, it was she who suddenly incredibly quickly expanded the universe, making it homogeneous.
Other scholars were not so enthusiastic about Gut’s theory, considering that there was a lot of confusion in inflation. In the following years, more than a thousand works were devoted to inflation research, it was criticized and admired. Gut, despite all the talk, believed that once it would be confirmed that the Universe was indeed flat.
Imagine a kettle
A good known example is the teapot example. Let’s pretend that you turned on the kettle. You do this every day and find nothing unusual in it.
Every time the water is about to boil, it goes into a state of high energy. She wants to boil, but she doesn’t succeed. For the formation of bubbles, she needs some kind of unevenness, something else. In the usual manner, bubbles form, merge and the kettle is filled with uniform steam.
In the idea of Gut, each bubble was a kind of particle of the universe. After calculating, he found that the bubbles do not merge. Transfer this idea to the Universe and you will understand that it was a cluster of parts that could not merge. Gut was in a deplorable state because of his “teapot.”
In 1981, Andrei Linde and Andreas Albrecht resolved his problem. If any single bubble of the false vacuum begins to expand for too long, then, in the end, it will fill with itself the entire space of the “teapot,” that is, the Universe. Then you do not need numerous bubbles, because only one will be enough, but with the condition that it will expand for a long time.
Randomly expanding…
Andre Linda, a cool physicist, proposed a new version of inflation, which, it would seem, does not contain any problems of previous versions. He presented the Universe as a rather spontaneous and characteristic miss.
In his view, spontaneous disturbances occur in different temporal and spatial segments. At each such point, a universe is created that begins to expand. To a greater extent, the expansion is insignificant, but since the process itself is disordered, a “bubble” is formed, the expansion of which lasts a very long time. So long that this is enough for our universe to appear.
It follows that expansion is eternal, big explosions occur constantly, some universes “flow” from others. Such a process can occur anywhere and thanks to it, another one will occur from our Universe. Thus, the formation of the “Multiverse” occurs.
Visiting another Universe
Well … the multiverse is very cool and interesting. But if they are, these very “other worlds,” then how do we get there? The first, most likely, black holes come to mind.
Back in 1783, the astronomer John Mitchell wondered what would happen if a star increased so much that even light could not “escape” from it. John Mitchell knew that every object has its own “runaway” speed (the speed to overcome gravitational pull). He was extremely curious about what would happen if the mass of the star becomes so huge that even the speed of “runaway” becomes equal to the speed of light.
The gravity of such a star will become so large that even the light will not be able to leave its domain. To an outside observer, such an object will appear black. Mitchell’s thoughts were remembered only after a century and a half. In 1916, physicist Karl Schwarzschild found a solution to Einstein’s equations for a massive star. Einstein, in turn, was amazed at the core, because the Schwarzschild decision had its special moments.
What Einstein was especially grateful for was the fact that the Schwarzschild solution was effective for the gravity of an ordinary star. And the physicist, also famous for his unusual hairstyle, was able to use it to calculate the gravity of the Sun and to verify his calculations.
Moving on, Schwarzschild proved that a massive star is surrounded by an imaginary sphere with unusual abilities. It is a point of no return. Anything that passed through this sphere would instantly be pulled by gravity into a star and the object would disappear forever.
Schwarzschild, not knowing it himself, stumbled upon Michell’s reflections, referred to as “dark stars.” After, Schwarzschild managed to calculate the radius of the sphere, called the radius of the Schwarzschild. Later physicist Johannes Droste made the statement that the rays of light would be significantly curved, approaching such an object.
прThus, at a distance of 1.5 Schwarzschild radius, the rays of light would begin their journey in the orbit of the star. He also added that if you decided to approach the sphere, then the person who was watching you would calculate your watch as slowing down and so on until they would completely freeze. At that moment, you would “hit” the object itself. Thus, your observer would see you froze at the moment you approach the sphere.
Cosmologist H.P. Robertson, studying the statements of Droste, found that time stops only for the observer. It would take you a second for gravity to suck you in and crash to death. An observer would have to contemplate this process for thousands of years.
Approaching a black hole, you would be able to see the light captured by it many years ago when the hole was just formed. When approaching, tidal forces would tear apart your constituent parts into atoms, and the atoms themselves would begin to resemble elongated spaghetti. Once there, traveling back would be impossible, since you would have to develop a speed exceeding the speed of light, which is impossible.
Today, this area is called the “event horizon.” What does it mean? The word “horizon” denotes the farthest point that we could see. In this case, it refers to the point that the light could reach.
Einstein did not like all this, and he did his best to challenge the existence of “dark stars.” He argued that stars are formed by gravity, which attracts dust, gas, and various other “small” objects. The next step was to show that such a cluster never collapses to the Schwarzschild radius. With the best outcome, the mass of particles would reach a radius of 1.5 Schwarzschild, and therefore the formation of a black hole is impossible because it would have to develop a speed greater than the speed of light.
In 1939, at the same time that Einstein challenged the existence of “dark stars” with his work, Robert Oppenheimer and his student Heartland Snyder proved that black holes could form. And not only to form but also to serve as the endpoint of the life of giant stars.
How? Let’s say that in front of us there is a huge star that has survived the allotted to it. Its mass is 40 solar masses. It spends all of its fuel and is compressed by gravity to a Schwarzschild radius of 130 km. In this situation, she would have no choice but to collapse into a black hole.
Bizarre black holes
Einstein will continue to regard black holes as something strange and unnatural. But, according to all the laws of the irony of fate, he also tried to explain the possibility of wandering with the help of them.
In 1935, he, along with his student Nathan Rosen, introduced the theory of portals to the world of physics. They had a brilliant idea to imagine an electron, usually considered a small point without structure, like a black hole. They started with a solution for a standard black hole that resembles a vase with a large long neck. After they “removed” this neck and then attached it to the turned upside down.
According to Einstein, such a configuration would be balanced, and therefore free from a singularity, which, according to the scientist, had no place, since he saw it rather meaningless. Also, such a configuration could, according to the scientist, act as an electron. Alas, his vision of an electron as a black hole failed.
Einstein, resigned to such a fate, was still not quite positive in his mood. He was sure that let the portals exist and that nothing of the living could pass through it and stay alive. Today, cosmologists believe that such a kind of Einstein-Rosen bridge could well serve as a gateway between two universes.
The mathematician Roy Kerr, unlike Einstein, was not such a gloomy person concerning to black holes. In 1963, he found perhaps the most accurate solution to Einstein’s equations for dying stars. Due to the conservation of the kinetic momentum, a star collapsing under the influence of gravity begins to rotate even faster.
Having exploded, the star forms a ring of neutrons, which remained stable due to centrifugal force. She, in turn, pushes them out and balances the force of gravity. Kerr’s black hole would not let you die, on the contrary, it would lead you through the Einstein-Rosen bridge into a parallel universe. But, alas, you would not be able to return due to insufficiently strong gravity, which in this case is not able to lead you back.
The opinions of scientists were divided into countless numbers. Someone was wildly delighted with such a development of events, someone was looking for more loopholes in every possible way, and someone simply categorically denied everything written above.
It is a pity that to this day we are not able to make sure that anyone is right.
See you all next Monday!
