Every student knows that there are planets, stars, galaxies, which together with the physical laws and constants form the Universe. One of the interesting questions is what is intergalactic space, what is it. 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 already mentioned above, the Universe is a combination of physical laws, spatio-temporal coordinates, various physical constants and matter.
It has now been established that the physical laws known to mankind are fulfilled 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: planets revolve around their stars, stars unite in clusters, which are called galaxies. In turn, galaxies are combined into local clusters of galaxies and into superclusters, and already superclusters are scattered throughout the Universe, they are almost independent.
It is also important to know that the main forces acting on a cosmic scale are gravitational forces. 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 refers to 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 (10 7 stars) and large (10 14 stars). For example, we can note that in our galaxy contains about 10 11 stars.
Galaxies are combined into clusters in which they interact with each other due to all the same gravitational forces. Their various superclusters are moving 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
These words mean the space separating galaxies. At the same time, the galaxies themselves can be neighboring, such as our Milky Way and the Andromeda Nebula, as well as distant for millions and hundreds of millions of parsecs.
According to the definition, it can be concluded that the space between galaxies is the empty part of the Universe, which occupies the 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 of parsecs. Recall that a parsec is a unit of measurement of distances in space, which is approximately equal to the distance traveled by light in empty space for 3.2 Earth years.
What is in the space between galaxies?
If you answer this question that there is nothing between the galaxies, then such an answer will be as close as possible to the truth. According to modern estimates, the average density of matter in the Universe is one hydrogen atom per 1 m 3 of outer space. However, this figure does not mean anything, if we take into account the inhomogeneous distribution of matter in the Universe.
Strictly speaking, the intergalactic space is not absolutely empty. In it there are charged elementary particles (protons, electrons). Moreover, the space between galaxies is penetrated by electromagnetic radiation coming from the stars. Thanks to this fact, we can see the farthest galaxies from us. The temperature of the space in question is estimated at 2.73 K.
Based on the above information, everyone can answer the question of whether there are stars in intergalactic space. Of course, they are not there.
The space in the universe is expanding
As noted above, galaxies located at large distances from each other are removed. The speed 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 away the galaxies are from each other, the faster they fly apart. This means that there are those that move 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 move faster than the speed of light, but space itself is expanding at great speeds.
Future of the universe
Since the Universe is expanding, and intergalactic space is constantly expanding, 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 atomized, will be presented in the form of atoms and subatomic particles .