Sizes of the Universe: from the Milky Way to the Metagalaxy
Each of us at least once thought about what a huge world we live in. Our planet is a crazy number of cities, villages, roads, forests, rivers. Most of his life does not have time to see half. Imagining the grand scale of the planet is difficult, but there is a task even harder. The size of the universe - that is, perhaps, not the strength to imagine even the most advanced mind. Let's try to figure out what modern science thinks about it.
The Universe is all that surrounds us, of which we know and guess what it was, is and will be. If we reduce the heat of romanticism, then this concept defines everything in science, physically existing, taking into account the time aspect and the laws governing the functioning, interrelation of all elements, and so on.
Naturally, to imagine the real size of the universe is quite difficult. In science, this issue is widely discussed and there is no consensus yet.In their assumptions, astronomers rely on existing theories of the formation of the world, as we know it, and also on the data obtained as a result of observation.
Various hypotheses define the Universe as dimensionless or inexpressibly huge space, about the most part of which we know little. The concept of metagalaxy was introduced to clarify and discuss the area available for study. This term refers to the part of the universe that is available for observation by astronomical methods. Thanks to the improvement of technology and knowledge, it is constantly increasing. Metagalaxy is part of the so-called observable Universe - the space in which matter during its existence has managed to reach its present state. When it comes to understanding what the dimensions of the Universe are, in most cases they speak of Metagalaxy. The current level of technological development allows us to observe objects located at a distance of up to 15 billion light years from Earth. Time in the definition of this parameter plays, as can be seen, no less a role than space.
Age and size
According to some models of the universe, it never appeared, but exists forever. However, the dominant theory of the Big Bang sets our world "starting point". According to astronomers, the age of the Universe is approximately 13.7 billion years. If you move back in time, you can go back to the Big Bang. Regardless of whether the dimensions of the Universe are infinite, its observable part has borders, since the speed of light is finite. It includes all those locations that may affect the earth observer from the time of the Big Bang. The size of the observable universe increases due to its constant expansion. According to the latest estimates, it occupies a space of 93 billion light years.
A bunch of
Let's see what the universe is. The dimensions of outer space, expressed in dry numbers, are amazing, but difficult to understand. For many, it will be easier to realize the scale of the surrounding world, if they find out how many systems like the solar one fit in it.
Our star and the surrounding planets are only a tiny part of the Milky Way.According to astronomers, the galaxy has about 100 billion stars. Some of them have already discovered exoplanets. It is not only the size of the Universe that is striking - the space already occupied by its insignificant part, the Milky Way, inspires respect. It takes a hundred thousand years for the light to pass through our galaxy!
Extragalactic astronomy, which began to develop after the discoveries of Edwin Hubble, describes many structures similar to the Milky Way. Its nearest neighbors are the Andromeda Nebula and the Large and Small Magellanic Clouds. Together with several other “satellites” they form a local group of galaxies. About 3 million light-years separate it from a neighboring similar formation. It is even scary to imagine how much time it would take a modern plane to cover such a distance!
All local groups are separated by extensive space. Metagalaxy includes several billion structures similar to the Milky Way. The size of the universe is really amazing. The light beam requires 2 million years to overcome the distance from the Milky Way to the Andromeda Nebula.
The farther away from us is a section of space, the less we know about its current state. Because of the finite speed of light, scientists can get information only about the past of such objects. For the same reasons, as already mentioned, the region of the Universe accessible to astronomical research is limited.
However, this is not all the information striking imagination that characterizes the Universe. The dimensions of outer space, apparently, significantly exceed the metagalaxy and the observed part. The theory of inflation introduces such a concept as the Multiverse. It consists of many worlds, probably formed at the same time, not intersecting with each other and developing independently. The current level of technology development does not give hope for the knowledge of such neighboring universes. One of the reasons is the same finite speed of light.
The rapid development of space science is changing our understanding of how large the Universe is. The current state of astronomy, its constituent theories and calculations of scientists are difficult for the uninitiated person to understand. However, even a superficial examination of the question shows how huge the world is, of which we are a part, and how little we still know about it.