There were times when the world of people was limited to the surface of the Earth, which is under their feet. With the development of technology, mankind has expanded its horizons. Now people are thinking about whether our world has boundaries and what are the dimensions of the universe? In fact, no one can imagine its real size. Since we do not have suitable guidelines. Even professional astronomers draw for themselves (at least in the imagination) models that are much smaller. The principal thing is the exact correlation of the dimensions that the objects of the Universe have. And when solving mathematical problems, they are generally unimportant, because they turn out to be just numbers that the astronomer operates on.
About the structure of the solar system
To talk about the scale of the universe, you first need to figure out what is closest to us. Firstly, it is a star called the Sun. Secondly, the planets that revolve around it. In addition to them, there are satellites moving around some space objects. And do not forget about the asteroid belt.
The planets in this list have been of interest to people for a long time, since they are the most accessible for observation. From their study, the science of the structure of the Universe - astronomy - began to develop. The center of the solar system is recognized as a star. She is also her largest object. Compared to the Earth, the Sun is a million times larger in volume. It only seems relatively small, since it is far removed from our planet.
All the planets of the solar system are divided into three groups:
- Earthly. It includes planets that are similar to the Earth in appearance. For example, these are Mercury, Venus and Mars.
- Giant objects. They are much larger in comparison with the first group. In addition, they contain a lot of gases, so they are also called gas. These include Jupiter, Saturn, Uranus and Neptune.
- Dwarf planets. They, in fact, are large asteroids. One of them, until recently, was included in the composition of the major planets - this is Pluto.
Planets "do not fly away" from the Sun due to the force of gravity. And they cannot fall on a star because of high speeds. Objects are really very “smart”. For example, the speed of the Earth is approximately 30 kilometers per second.
How to compare the sizes of objects in the solar system?
Before you try to imagine the scale of the universe, it is worthwhile to deal with the sun and planets. After all, it can also be difficult to relate them to each other. Most often, the conditional size of a fire star is identified with a billiard ball, whose diameter is 7 cm. It is worth noting that in reality it reaches about 1400 thousand km. In such a "toy" layout, the first planet from the Sun (Mercury) is at a distance of 2 meters 80 centimeters. In this case, the ball of the Earth will have a diameter of only half a millimeter. It is located from the star at a distance of 7.6 meters. The distance to Jupiter on this scale will be equal to 40 m, and to Pluto - 300.
If we talk about objects that are outside the solar system, then the closest star is Proxima Centauri. It will be removed so much that this simplification is too small. And this despite the fact that it is located within the Galaxy. What to say about the scale of the universe. As you can see, it is virtually limitless. One always wants to know how the Earth and the Universe are related. And after receiving the answer, one does not believe that our planet and even the Galaxy are an insignificant part of the vast world.
What units are used to measure distances in space?
A centimeter, a meter, and even a kilometer - all of these values turn out to be insignificant already within the limits of the solar system. What to say about the universe. To indicate the distance within the galaxy, a value called the light year is used. This is the time it takes the light moving for one year. Recall that one light second is almost 300 thousand km. Therefore, when converted to familiar kilometers, the light year is approximately equal to 10 thousand billion. It is impossible to imagine it, so the scale of the Universe is unimaginable to man. If you need to specify the distance between neighboring galaxies, then the light year is insufficient. An even larger value is needed. It turned out to be a parsec, which is equal to 3.26 light years.
How is the galaxy arranged?
She is a gigantic entity made up of stars and nebulae. A small part of them is visible every night in the sky. The structure of our Galaxy is very complex. It can be considered a strongly compressed ellipsoid of revolution. Moreover, the equatorial part and the center are distinguished from it. Equator Galaxies are mostly composed of gas nebulae and hot massive stars. In the Milky Way, this part is located in its central region.
The solar system is no exception to the rule. It is also located near the equator of the Galaxy. By the way, the bulk of the stars form a huge disk, the diameter of which is 100 thousand light years, and the thickness is 1,500. If we return to the scale that was used to represent the solar system, then the dimensions of the galaxy will be commensurate with the distance from the earth to the sun. This is an incredible figure. Therefore, the Sun and the Earth turn out to be crumbs in the Galaxy.
What objects exist in the universe?
We list the most basic:
- Stars are massive self-luminous balls. They arise from an environment consisting of a mixture of dust and gases. Most of them are hydrogen and helium.
- Relict radiation. They are electromagnetic pulses propagating in space. Its temperature is 270 degrees Celsius. Moreover, this radiation is the same in all directions. This property is called isotropy. In addition, some mysteries of the Universe are associated with him. For example, it became clear that it arose at the time of the big bang. That is, it exists from the very beginning of the existence of the Universe. It also confirms the idea that it expands equally in all directions. Moreover, this statement is true not only for the present. So it was at the very beginning.
- Dark matter. That is the hidden mass. These are those objects of the Universe that cannot be investigated by direct observation. In other words, they do not emit electromagnetic waves. But they have a gravitational effect on other bodies.
- Black holes. They are not well understood, but very well known. This happened due to the mass description of such objects in science fiction works. In fact, a black hole is a body from which electromagnetic radiation cannot propagate due to the fact that the second cosmic velocity on it is equal to the speed of light. It is worth remembering that it is the second cosmic velocity that must be communicated to the object so that it leaves the cosmic object.
In the Universe, in addition, there are also quasars and pulsars.
Mysterious Universe
It is full of what has not yet been fully discovered, not studied. And what was discovered, often throws up new questions and related mysteries of the Universe. They can even include the well-known theory of the Big Bang. It is really only a conditional doctrine, since mankind can only guess how it happened.
The second riddle is the age of the universe. It can be calculated approximately from the already mentioned relict radiation, observation of globular clusters and other objects. Today, scientists agreed that the age of the universe is approximately 13.7 billion years. Another secret - if life on other planets? After all, it was not only in the solar system that suitable conditions arose, and the Earth appeared. And the Universe, most likely, is filled with similar formations.
One?
And what is outside the universe? What is there where the human eye has not penetrated? Is there anything beyond this border? If so, how many universes exist? These are questions that scientists have yet to find answers to. Our world is like a box with surprises. Once it seemed that it consists only of the Earth and the Sun, with a small number of stars in the sky. Then the worldview expanded. Accordingly, the borders have moved apart. Not surprisingly, many bright minds have long concluded that the Universe is only part of an even larger entity.