Pranks on colleagues at work. Office pranks: lighten the mood
Looking at the starry sky at night, you involuntarily ask yourself: how many stars are there in the sky? Is there still life somewhere, how did it all come about, and is there an end to it all?
Most astronomers are confident that the Universe was born as a result of a powerful explosion, about 15 billion years ago. This huge explosion, usually called the “Big Bang” or “Big Impact”, was formed from a strong compression of matter, dispersed hot gases into different directions, and gave rise to galaxies, stars and planets. Even the most modern and new astronomical devices are not able to cover the entire space. But modern technology can catch light from stars that are 15 billion light years away from Earth! Perhaps these stars are long gone, they were born, grew old and died, but the light from them traveled to Earth for 15 billion years and the telescope still sees it.
Scientists of many generations and countries are trying to guess, calculate the size of our Universe, and determine its center. Previously, it was believed that the center of the Universe was our planet Earth. Copernicus proved that this is the Sun, but with the development of knowledge and the discovery of our Milky Way galaxy, it became clear that neither our planet nor even the Sun are the center of the Universe. For a long time they thought that there were no other galaxies besides the Milky Way, but this was also denied.
Famous scientific fact says that the Universe is constantly expanding and the starry sky that we observe, the structure of the planets that we see now, is completely different than millions of years ago. If the Universe is growing, that means there are edges. Another theory says that beyond the boundaries of our space there are other Universes and worlds.
The first who decided to prove the infinity of the Universe was Isaac Newton. Discovering the law universal gravity, he believed that if space were finite, all her bodies would sooner or later attract and merge into a single whole. And since this does not happen, it means that the Universe has no boundaries.
It would seem that all this is logical and obvious, but still Albert Einstein was able to break these stereotypes. He created his model of the Universe based on his theory of relativity, according to which the Universe is infinite in time, but finite in space. He compared it to a three-dimensional sphere or, in simple language, with our globe. No matter how much a traveler travels across the Earth, he will never reach its edge. However, this does not mean that the Earth is infinite. The traveler will simply return to the place from which he began his journey.
In the same way, a space wanderer, starting from our planet and crossing the Universe on a starship, can return back to Earth. Only this time the wanderer will move not along the two-dimensional surface of a sphere, but along the three-dimensional surface of a hypersphere. This means that the Universe has a finite volume, and therefore a finite number of stars and mass. However, the Universe has neither boundaries nor any center. Einstein believed that the Universe is static and its size never changes.
However, the greatest minds are not above delusions. In 1927, our Soviet physicist Alexander Friedman significantly expanded this model. According to his calculations, the Universe is not static at all. It can expand or contract over time. Einstein did not immediately accept this amendment, but with the discovery of the Hubble telescope, the fact of the expansion of the Universe was proven, because galaxies scattered, i.e. were moving away from each other.
It has now been proven that the Universe is expanding at an accelerating rate, that it is filled with cold dark matter and its age is 13.75 billion years. Knowing the age of the Universe, we can determine the size of its observable region. But don’t forget about constant expansion.
So, the size of the observable Universe is divided into two types. The apparent size, also called the Hubble radius (13.75 billion light years), which we discussed above. And the real size, called the particle horizon (45.7 billion light years). Now I’ll explain: you’ve probably heard that when we look at the sky, we see the past of other stars and planets, and not what is happening now. For example, looking at the Moon, we see as it was a little more than a second ago, the Sun - more than eight minutes ago, the nearest stars - years, galaxies - millions of years ago, etc. That is, since the birth of the Universe, no photon, i.e. light would not have time to travel more than 13.75 billion light years. But! We should not forget about the fact of the expansion of the Universe. So, by the time it reaches the observer, the object of the nascent Universe that emitted this light will already be 45.7 billion light years away from us. years. This size is the horizon of particles, it is the boundary of the observable Universe.
However, both of these horizons do not at all characterize the real size of the Universe. It is expanding and if this trend continues, then all those objects that we can now observe will sooner or later disappear from our field of vision.
On this moment The most distant light observed by astronomers is the cosmic microwave background radiation. These are ancient electromagnetic waves that arose at the birth of the Universe. These waves are detected using highly sensitive antennas and directly in space. By peering into the cosmic microwave background radiation, scientists see the Universe as it was 380 thousand years after the Big Bang. At this moment, the Universe cooled down enough that it was able to emit free photons, which are detected today with the help of radio telescopes. At that time, there were no stars or galaxies in the Universe, but only a continuous cloud of hydrogen, helium and an insignificant amount of other elements. From the inhomogeneities observed in this cloud, galaxy clusters will subsequently form.
Scientists are still debating whether there are true, unobservable boundaries of the Universe. One way or another, everyone agrees on the infinity of the Universe, but interprets this infinity in completely different ways. Some consider the Universe to be multidimensional, where our “local” three-dimensional Universe is only one of its layers. Others say that the Universe is fractal - which means that our local Universe may be a particle of another. Don't forget about various models Multiverse, i.e. the existence of an infinite number of other universes beyond ours. And there are many, many different versions, the number of which is limited only by human imagination.
Universe distance scale
Because the Universe is expanding, the question of distances to very distant galaxies is difficult to answer. It all depends on your point of view.
Omega Nebula
Eagle Nebula
Antlia Cluster
That's the problem with determining distances in an expanding universe: two galaxies are close to each other when the universe is only 1 billion years old. The first galaxy emits a pulse of light. The second galaxy does not perceive this impulse until the Universe is 14 billion years old.
At this point, these galaxies are separated by about 26 billion light years; a light pulse travels for 13 billion years; and the picture that people get in the second galaxy is an image of the first galaxy at a time when it was only one billion years old and when it was only 2 billion light years away.
In cosmology, four different distance scales are generally accepted:
(1) Photometric distance - DL
In an expanding universe, distant galaxies are much more difficult to see than might be expected as photons of light are stretched and spread out over a wide area. This is why huge telescopes are required to see very distant galaxies. The most distant galaxies visible through the Hubble Space Telescope are so faint that they appear to be about 350 billion light years away, even though they are much closer.
The photometric scale does not reflect actual distance, but it is used to determine how dim very distant galaxies appear to us.
(2) Angular diameter distance - DA
In the expanding universe, we see galaxies at the edge of the visible universe when they were very young, about 14 billion years ago, because light took about 14 billion years to reach us.
However, the galaxies at that time were not only young, but also located much closer to us.
The faintest galaxies visible through the Hubble Space Telescope were only a few billion light years away when the light was emitted.
This means that very distant galaxies appear much larger than one would expect, as if they are about 2 or 3 billion light years away (Although they also appear very, very faint - see "Photometric distance").
Angular diameter distance - good indicator(especially in a flat galaxy like ours) how close a particular galaxy was to us when it emitted the light we currently see.
(3) Follower distance - DC
The accompanying distance scale expands along with the Universe. It gives us an idea of where galaxies are currently located, even though we are seeing a distant galaxy as it was when it was much younger and smaller. On this scale, the farthest edge of the visible Universe is currently 47 billion light-years away, although the most distant galaxies visible through the Hubble Space Telescope would be about 32 billion light-years away.
The comoving distance is the opposite of the angular diameter distance.
This distance shows where the galaxies are now, not where they were when they emitted the light we see now.
(4) Aberration distance - DT
Aberration distance refers to the length of time it takes for light from distant galaxies to reach us. This is what is meant when they say that the visible Universe has a radius of 14 billion light years.
The meaning of this statement: the age of the Universe is about 14 billion years, but light from more distant galaxies did not have enough time to reach us.
Aberration distance is as much a measure of time as it is a measure of distance. The main benefit of this scale is that it gives us an idea of the age of the image of a given galaxy that we currently see.
For small distances (about 2 billion light years or less), all four distance scales are combined and repeat each other, so it is much easier to determine the distances to galaxies in the local Universe surrounding us.
Below are all four distance scales superimposed on the redshift. Redshift is a measure of the stretching of light caused by the expansion of the Universe: a galaxy with high level redshift is further away than a low-redshift galaxy. The most distant galaxies visible through the Hubble Space Telescope have a redshift of 10, while the most distant protogalaxies in the Universe probably have a redshift of about 15. The edge of the visible Universe has a redshift of infinity. By comparison, a typical portable telescope cannot see objects with a redshift significantly greater than 0.1 (about 1.3 billion light years).
Photometric distance (DL) demonstrates why it is so difficult to see distant galaxies: a very young and distant galaxy at redshift level 15 appears to be 560 billion light-years away, although angular diameter distance (DA) shows that at the time the galaxy emitted light , which we see now, it was actually about 2.2 billion light years old. Aberration distance (DT) shows that light from a given galaxy has traveled 13.6 billion years from the time it was emitted until now. Composite distance (DC) shows that the same galaxy today, if we could see it, would be 35 billion light years away.
What do we know about the universe, what is space like? The Universe is something difficult to comprehend by the human mind. limitless world, which seems unreal and intangible. In fact, we are surrounded by matter, limitless in space and time, capable of receiving various shapes. To try to understand the true scale of outer space, how the Universe works, the structure of the universe and the processes of evolution, we will need to cross the threshold of our own worldview, look at the world around us from a different angle, from the inside.
Education of the Universe: first steps
The space we see through telescopes is only part of starry universe, the so-called Megagalaxy. The parameters of Hubble's cosmological horizon are colossal - 15-20 billion light years. These data are approximate, since in the process of evolution the Universe is constantly expanding. The expansion of the Universe occurs through propagation chemical elements and cosmic microwave background radiation. The structure of the Universe is constantly changing. Clusters of galaxies, objects and bodies of the Universe appear in space - these are billions of stars that form the elements of near space - star systems with planets and satellites.
Where is the beginning? How did the Universe come into being? Presumably the age of the Universe is 20 billion years. Perhaps the source of cosmic matter was hot and dense proto-matter, the accumulation of which exploded at a certain moment. The smallest particles formed as a result of the explosion scattered in all directions, and continue to move away from the epicenter in our time. The Big Bang theory, which now dominates scientific circles, most accurately describes the formation of the Universe. The substance that emerged as a result of the cosmic cataclysm was a heterogeneous mass consisting of tiny unstable particles that, colliding and scattering, began to interact with each other.
The Big Bang is a theory of the origin of the Universe that explains its formation. According to this theory, there initially existed a certain amount of matter, which, as a result of certain processes, exploded with colossal force, scattering the mass of the mother into the surrounding space.
After some time, by cosmic standards - an instant, by earthly chronology - millions of years, the stage of materialization of space began. What is the Universe made of? The scattered matter began to concentrate into clumps, large and small, in the place of which the first elements of the Universe, huge gas masses—nurseries of future stars—subsequently began to emerge. In most cases, the process of formation of material objects in the Universe is explained by the laws of physics and thermodynamics, but there are a number of points that cannot yet be explained. For example, why is expanding matter more concentrated in one part of space, while in another part of the universe matter is very rarefied? Answers to these questions can only be obtained when the mechanism of formation of space objects, large and small, becomes clear.
Now the process of formation of the Universe is explained by the action of the laws of the Universe. Gravitational instability and energy in different areas triggered the formation of protostars, which in turn, under the influence of centrifugal forces and gravity, formed galaxies. In other words, while matter continued and continues to expand, compression processes began under the influence of gravitational forces. Particles of gas clouds began to concentrate around an imaginary center, eventually forming a new compaction. The building materials in this gigantic construction project are molecular hydrogen and helium.
The chemical elements of the Universe are the primary building material from which the objects of the Universe were subsequently formed
Then the law of thermodynamics begins to operate, and the processes of decay and ionization are activated. Hydrogen and helium molecules disintegrate into atoms, from which the core of a protostar is formed under the influence of gravitational forces. These processes are the laws of the Universe and have taken the form of a chain reaction, occurring in all distant corners of the Universe, filling the universe with billions, hundreds of billions of stars.
Evolution of the Universe: highlights
Today, in scientific circles there is a hypothesis about the cyclical nature of the states from which the history of the Universe is woven. Arising as a result of the explosion of promaterial, gas clusters became nurseries for stars, which in turn formed numerous galaxies. However, having reached a certain phase, matter in the Universe begins to tend to its original, concentrated state, i.e. the explosion and subsequent expansion of matter in space is followed by compression and a return to a superdense state, to starting point. Subsequently, everything repeats itself, the birth is followed by the finale, and so on for many billions of years, ad infinitum.
The beginning and end of the universe in accordance with the cyclical evolution of the Universe
However, omitting the topic of the formation of the Universe, which remains open question, we should move on to the structure of the universe. Back in the 30s of the 20th century, it became clear that space divided into regions - galaxies, which are huge formations, each with its own stellar population. Moreover, galaxies are not static objects. The speed of galaxies moving away from the imaginary center of the Universe is constantly changing, as evidenced by the convergence of some and the removal of others from each other.
All of the above processes, from the point of view of the duration of earthly life, last very slowly. From the point of view of science and these hypotheses - everything evolutionary processes happen quickly. Conventionally, the evolution of the Universe can be divided into four stages - eras:
- hadron era;
- lepton era;
- photon era;
- star era.
Cosmic time scale and evolution of the Universe, according to which the appearance of cosmic objects can be explained
At the first stage, all matter was concentrated in one large nuclear droplet, consisting of particles and antiparticles, combined into groups - hadrons (protons and neutrons). The ratio of particles to antiparticles is approximately 1:1.1. Next comes the process of annihilation of particles and antiparticles. The remaining protons and neutrons are building material, from which the Universe is formed. The duration of the hadron era is negligible, only 0.0001 seconds - the period of explosive reaction.
Then, after 100 seconds, the process of synthesis of elements begins. At a temperature of a billion degrees, the process of nuclear fusion produces molecules of hydrogen and helium. All this time, the substance continues to expand in space.
From this moment, a long, from 300 thousand to 700 thousand years, stage of recombination of nuclei and electrons begins, forming hydrogen and helium atoms. In this case, a decrease in the temperature of the substance is observed, and the radiation intensity decreases. The universe becomes transparent. Hydrogen and helium formed in colossal quantities under the influence of gravitational forces turns the primary Universe into a giant construction site. After millions of years, the stellar era begins - which is the process of formation of protostars and the first protogalaxies.
This division of evolution into stages fits into the model of the hot Universe, which explains many processes. The real reasons The Big Bang, the mechanism of expansion of matter remains unexplained.
Structure and structure of the Universe
The stellar era of the evolution of the Universe begins with the formation of hydrogen gas. Under the influence of gravity, hydrogen accumulates into huge clusters and clumps. The mass and density of such clusters are colossal, hundreds of thousands of times greater than the mass of the formed galaxy itself. The uneven distribution of hydrogen observed at initial stage formation of the universe, explains the differences in the sizes of the formed galaxies. Megagalaxies formed where the maximum accumulation of hydrogen gas should exist. Where the concentration of hydrogen was insignificant, smaller galaxies appeared, similar to our stellar home - the Milky Way.
The version according to which the Universe is a beginning-end point around which galaxies rotate on different stages development
From this moment on, the Universe receives its first formations with clear boundaries and physical parameters. These are no longer nebulae, accumulations of stellar gas and cosmic dust (products of an explosion), protoclusters of stellar matter. These are star countries, the area of which is huge in terms of human mind. The universe is becoming full of interesting cosmic phenomena.
From point of view scientific justification And modern model Universe, galaxies were first formed as a result of the action of gravitational forces. There was a transformation of matter into a colossal universal whirlpool. Centripetal processes ensured the subsequent fragmentation of gas clouds into clusters, which became the birthplace of the first stars. Protogalaxies with fast period rotations evolved over time into spiral galaxies. Where the rotation was slow and the process of compression of matter was mainly observed, irregular galaxies were formed, most often elliptical. Against this background, more grandiose processes took place in the Universe - the formation of superclusters of galaxies, whose edges are in close contact with each other.
Superclusters are numerous groups of galaxies and clusters of galaxies within the large-scale structure of the Universe. Within 1 billion St. There are about 100 superclusters for years
From that moment on, it became clear that the Universe is a huge map, where the continents are clusters of galaxies, and the countries are megagalaxies and galaxies formed billions of years ago. Each of the formations consists of a cluster of stars, nebulae, and accumulations of interstellar gas and dust. However, this entire population constitutes only 1% of the total volume of universal formations. The bulk of the mass and volume of galaxies is occupied by dark matter, the nature of which is not possible to determine.
Diversity of the Universe: classes of galaxies
Thanks to the efforts of the American astrophysicist Edwin Hubble, we now have the boundaries of the Universe and a clear classification of the galaxies that inhabit it. The classification is based on the structural features of these giant formations. Why do galaxies have different shapes? The answer to this and many other questions is given by the Hubble classification, according to which the Universe consists of galaxies of the following classes:
- spiral;
- elliptical;
- irregular galaxies.
The first include the most common formations that fill the universe. Characteristics spiral galaxies is the presence of a clearly defined spiral that rotates around a bright core or tends to a galactic bar. Spiral galaxies with a core are designated S, while objects with a central bar are designated SB. Our Milky Way galaxy also belongs to this class, in the center of which the core is divided by a luminous bridge.
A typical spiral galaxy. In the center, a core with a bridge from the ends of which spiral arms emanate is clearly visible.
Similar formations are scattered throughout the Universe. The closest spiral galaxy, Andromeda, is a giant that is rapidly approaching Milky Way. The largest representative of this class known to us is the giant galaxy NGC 6872. The diameter of the galactic disk of this monster is approximately 522 thousand light years. This object is located at a distance of 212 million light years from our galaxy.
The next common class of galactic formations are elliptical galaxies. Their designation in accordance with the Hubble classification is the letter E (elliptical). These formations are ellipsoidal in shape. Despite the fact that there are quite a lot of similar objects in the Universe, elliptical galaxies are not particularly expressive. They consist mainly of smooth ellipses that are filled with star clusters. Unlike galactic spirals, ellipses do not contain accumulations of interstellar gas and cosmic dust, which are the main optical effects of visualizing such objects.
A typical representative of this class known today is the elliptical ring nebula in the constellation Lyra. This object is located at a distance of 2100 light years from Earth.
View of the elliptical galaxy Centaurus A through the CFHT telescope
The last class of galactic objects that populate the Universe are irregular or irregular galaxies. The designation according to the Hubble classification is the Latin symbol I. The main feature is an irregular shape. In other words, such objects do not have clear symmetrical shapes and characteristic patterns. In its shape, such a galaxy resembles a picture of universal chaos, where star clusters alternate with clouds of gas and cosmic dust. On the scale of the Universe, irregular galaxies are a common phenomenon.
In turn, irregular galaxies are divided into two subtypes:
- irregular galaxies of subtype I have a complex irregular shape structure, high dense surface, distinguished by brightness. Often this chaotic shape of irregular galaxies is a consequence of collapsed spirals. A typical example of such a galaxy is the Large and Small Magellanic Cloud;
- Irregular, irregular galaxies of subtype II have a low surface, a chaotic shape and are not very bright. Due to the decrease in brightness, such formations are difficult to detect in the vastness of the Universe.
The Large Magellanic Cloud is the closest irregular galaxy to us. Both formations, in turn, are satellites Milky Way and may soon (in 1-2 billion years) be absorbed by a larger object.
Irregular galaxy Large Magellanic Cloud - a satellite of our Milky Way galaxy
Despite the fact that Edwin Hubble quite accurately classified galaxies into classes, this classification is not ideal. We could achieve more results if we included Einstein’s theory of relativity in the process of understanding the Universe. The universe is represented by a wealth of diverse forms and structures, each of which has its own characteristic properties and features. Recently, astronomers were able to discover new galactic formations that are described as intermediate objects between spiral and elliptical galaxies.
The Milky Way is the most famous part of the Universe
Two spiral arms, symmetrically located around the center, make up the main body of the galaxy. The spirals, in turn, consist of arms that smoothly flow into each other. At the junction of the Sagittarius and Cygnus arms, our Sun is located, located at a distance of 2.62·10¹⁷km from the center of the Milky Way galaxy. The spirals and arms of spiral galaxies are clusters of stars whose density increases as they approach the galactic center. The rest of the mass and volume of galactic spirals is dark matter, and only a small part is accounted for by interstellar gas and cosmic dust.
The position of the Sun in the arms of the Milky Way, the place of our galaxy in the Universe
The thickness of the spirals is approximately 2 thousand light years. All this layered cake is in constant motion, rotating at a huge speed of 200-300 km/s. The closer to the center of the galaxy, the higher the rotation speed. It will take the Sun and our Solar System 250 million years to complete a revolution around the center of the Milky Way.
Our galaxy consists of a trillion stars, large and small, super-heavy and medium-sized. The densest cluster of stars in the Milky Way is the Sagittarius Arm. It is in this region that the maximum brightness of our galaxy is observed. The opposite part of the galactic circle, on the contrary, is less bright and difficult to distinguish by visual observation.
The central part of the Milky Way is represented by a core, the dimensions of which are estimated to be 1000-2000 parsecs. This brightest region of the galaxy is concentrated maximum amount stars that have different classes, their own paths of development and evolution. These are mainly old super-heavy stars in the final stages of the Main Sequence. Confirmation of the presence of an aging center of the Milky Way galaxy is the presence in this area large number neutron stars and black holes. Indeed, the center of the spiral disk of any spiral galaxy is a supermassive black hole, which, like a giant vacuum cleaner, sucks in celestial objects and real matter.
A supermassive black hole located in the central part of the Milky Way is the place of death of all galactic objects
As for star clusters, scientists today have managed to classify two types of clusters: spherical and open. In addition to star clusters, the spirals and arms of the Milky Way, like any other spiral galaxy, consist of scattered matter and dark energy. As a consequence of the Big Bang, matter is in a highly rarefied state, which is represented by tenuous interstellar gas and dust particles. The visible part of the matter consists of nebulae, which in turn are divided into two types: planetary and diffuse nebulae. The visible part of the spectrum of nebulae is due to the refraction of light from stars, which emit light inside the spiral in all directions.
It is in this cosmic soup that ours exists. solar system. No, we're not the only ones in this huge world. Like the Sun, many stars have their own planetary systems. The whole question is how to detect distant planets, if distances even within our galaxy exceed the lifetime of any intelligent civilization. Time in the Universe is measured by other criteria. Planets with their satellites are the smallest objects in the Universe. The number of such objects is incalculable. Each of those stars that are in the visible range can have their own star systems. We can see only the existing planets closest to us. What is happening in the neighborhood, what worlds exist in other arms of the Milky Way and what planets exist in other galaxies remains a mystery.
Kepler-16 b - exoplanet double star Kepler-16 in the constellation Cygnus
Conclusion
Having only a superficial understanding of how the Universe appeared and how it is evolving, man has taken only a small step towards comprehending and comprehending the scale of the universe. The enormous size and scope that scientists have to deal with today suggests that human civilization is just a moment in this bundle of matter, space and time.
Model of the Universe in accordance with the concept of the presence of matter in space, taking into account time
The study of the Universe goes from Copernicus to the present day. At first, scientists started from the heliocentric model. In fact, it turned out that space has no real center and all rotation, movement and movement occurs according to the laws of the Universe. Even though there is scientific explanation processes taking place, universal objects are distributed into classes, types and types, not a single body in space is similar to another. Dimensions celestial bodies are approximate, as is their mass. The location of galaxies, stars and planets is arbitrary. The thing is that there is no coordinate system in the Universe. Observing space, we make a projection onto the entire visible horizon, considering our Earth as the zero reference point. In fact, we are only a microscopic particle, lost in the endless expanses of the Universe.
The Universe is a substance in which all objects exist in close connection with space and time
Similar to the connection to size, time in the Universe should be considered as the main component. The origin and age of space objects allows us to create a picture of the birth of the world and highlight the stages of the evolution of the universe. The system we are dealing with is closely related to time frames. All processes occurring in space have cycles - beginning, formation, transformation and ending, accompanied by the death of a material object and the transition of matter to another state.
