Every student knows that there are planets, stars, galaxies, which together with physical laws and constants form the Universe. One of the interesting questions is what is intergalactic space, what does it represent. It is proposed to consider it in more detail.
General ideas about the observable Universe
Before proceeding to consider the issue of intergalactic space, it is necessary to get acquainted with our Universe.
As mentioned above, the Universe is a collection of physical laws, space-time coordinates, various physical constants and matter.
It has now been established that the physical laws known to mankind hold true in all corners of the observable universe, and no place has yet been found in space where these laws would be violated.
As for matter, it is organized in a special way in the Universe: the planets revolve aroundtheir stars, the stars are combined into clusters that are named after galaxies. In turn, galaxies unite into local clusters of galaxies and into superclusters, and already superclusters are scattered throughout the Universe, they are practically independent.
It is also important to know that the main forces acting on a cosmic scale are the forces of gravity. Thanks to these forces, our Earth revolves around the Sun, which, in turn, revolves around the center of our spiral galaxy, the Milky Way.
Galaxies in the Universe
As already noted, all observable matter in the Universe is concentrated in galaxies. This word is understood as giant star clusters that are connected by gravitational forces and that have a certain spatial shape. For example, there are elliptical, spiral, lenticular galaxies, as well as irregular shapes. Galaxies can be small (107 stars) and large (1014 stars). For example, it can be noted that our galaxy contains about 1011 stars.
Galaxies unite into clusters in which they interact with each other thanks to the same gravitational forces. Their various superclusters move away from each other, but inside the clusters they can move towards each other. So, the Andromeda Nebula galaxy is moving towards ours at a speed of 300 km / s, so in the future both of them will merge into one large cluster.
Intergalactic space
Under these wordsrefers to the space separating galaxies. At the same time, the galaxies themselves can be neighboring, such as our Milky Way and the Andromeda Nebula, or distant by millions and hundreds of millions of parsecs.
According to the definition obtained, we can conclude that the space between galaxies is the most empty part of the Universe, which occupies its largest volume, since their size is estimated at hundreds and hundreds of thousands of parsecs, and the distances between them are measured in millions and billions parsec. Recall that the parsec is a unit of measurement of distances in space, which is approximately equal to the distance traveled by light in empty outer space in 3.2 Earth years.
What is in the space between galaxies?
If you answer this question that there is nothing between galaxies, then such an answer will be as close to the truth as possible. According to modern estimates, the average density of matter in the Universe is one hydrogen atom per 1 m3 of outer space. However, this figure does not mean anything if we take into account the non-uniform distribution of matter in the Universe.
Strictly speaking, intergalactic space is not completely empty. It contains charged elementary particles (protons, electrons). Moreover, the space between galaxies is permeated with electromagnetic radiation coming from stars. Thanks to this fact, we can see the galaxies farthest from us. The temperature of the space in question is estimated at 2.73 K.
Based onthe above information, everyone can answer the question of whether there are stars in intergalactic space. Of course, they are not there.
Space in the Universe is expanding
As it was already noted above, galaxies located at large distances from each other are moving away. The rate of this process can be calculated using the so-called Hubble law. Experimental confirmation of the expansion of the Universe was discovered at the end of the 20th century, thanks to the study of the redshift of the electromagnetic spectrum of distant galaxies.
The most interesting thing is that according to Hubble's law, the farther the galaxies are from each other, the faster they fly apart. This means that there are some that are moving away from each other faster than the speed of light! There is no violation of Einstein's theory of relativity in this fact, since it is not the galaxies themselves that are moving faster than the speed of light, but space itself is expanding at tremendous speeds.
The Future of the Universe
As the Universe is expanding and intergalactic space is constantly increasing, then, according to the most popular hypothesis to date, our Universe will eventually freeze and plunge into eternal darkness, since all the matter in it will be completely dispersed, will be represented in form of atoms and subatomic particles.
