Dark matter is the most mysterious and inertsubstance in the universe. Its gravitational effects explain the rotation of galaxies, the movement of clusters and the largest structures in the entire Universe. But on a smaller scale, it is too small to affect the movement of the solar system, the substance of the Earth, or the origin and evolution of man. At the same time, the gravity provided by dark matter is absolutely necessary for the raw ingredients that form life like us and a planet like Earth. Without dark matter in the Universe there could have been no life at all.
Stars produce 100% of the light we see inUniverse, but only 2% of its mass. When we look at the movements of galaxies, clusters, etc., we find that the amount of gravitational mass outweighs the stellar mass by 50 times. One would think that other types of ordinary matter could explain this difference. In the end, we discovered many other types of matter in the universe, not counting the stars:
- the remains of a star like white dwarfs, neutron stars and black holes;
- asteroids, planets and other objects whose mass is too small to be stars;
- neutral gas in galaxies and the space between them;
- light blocking dust and foggy regions;
- ionized plasma, which is a lot in the intergalactic environment.
All these forms of ordinary matter - or matter,which originally consisted of the same things that we do: protons, neutrons and electrons - really do their part. Gas and plasma, in particular, contribute more than the sum of all the stars in the universe. But even if we summarize all these components together, we get only 15-17% of the total amount of matter that is necessary to explain gravity. For the rest of the movement that we see, we need a form of matter that not only differs from protons, neutrons and electrons, but also does not correspond to any known particle of the Standard Model. We need in some way dark matter.
A small group of scientists opposeadding some invisible source of mass, but for changing the laws of gravity. A similar model has difficulties, including the inability to reproduce the full set of observations, including the motion of individual galaxies in clusters, the cosmic microwave background, collisions of galactic clusters, and the giant space network of the observed large-scale structure of the Universe. There is also another important piece of evidence that points to the existence of dark matter. You will be surprised, but this is our existence.
You will probably be surprised that we do not just needdark matter to explain astrophysical phenomena like galactic rotation, the movement of clusters and their collisions, but also to explain the very origin of life.
To understand why, you need to remember thatThe Universe began with a hot and dense state - the Big Bang - when everything was in the form of a practically homogeneous sea of separate, free, high-energy particles. As the Universe cools and expands, protons, neutrons, and lightest nuclei (hydrogen, helium, deuterium, and a little lithium) are formed, but nothing else. Only tens or hundreds of millions of years ago, this matter collapsed into sufficiently dense regions to form stars and, finally, galaxies.
All this would have happened, albeit in a slightly different way, withdark matter or without it. But for the elements necessary for life to proliferate in abundance - carbon, oxygen, nitrogen, phosphorus, sulfur - they must be smelted in the nuclei of the most massive stars in the universe. It makes us neither hot nor cold; In order for solid planets, organic molecules and life to form from them, they first need to throw these heavy atoms into the interstellar medium, where they will again become stars, the next generation. This requires a supernova explosion.
We watched these explosions to the smallestwe know the details, in particular, how quickly this material is ejected from the stars in their dying rales: thousands of kilometers per second. (Cas A supernova remnants threw material at speeds of 5000 and even 14 500 km / s!). Although this number may seem small, especially against the background of the speed of light, do not forget that our own star rotates in the Milky Way at a speed of only 220 km / s. If the Sun rotated at least three times faster, we would already be outside the gravitational attraction of our galaxy - we would be thrown out.
Supernova remnants throw heaviermatter, but thanks to the powerful gravitational attraction of the diffuse, elongated halo of dark matter, we will hold most of this mass inside our own galaxy. Over time, the substance will return to the usual regions rich in normal matter, form neutral molecular clouds and form the basis of subsequent generations of stars, planets and, most interestingly, organic molecular combinations.
But without the additional attraction of a massive haloof dark matter surrounding the galaxy, the vast majority of the material ejected from the supernova would forever leave the galaxy. It will always float in an intergalactic environment, but will never become part of future generations of stellar systems. In a universe without dark matter, we would have stars and galaxies, but the planets would be only gas giants, no solid worlds, no liquid water and no life. Without an abundant amount of heavy elements supplied by generations of massive stars, life based on molecules would never exist.
It turns out a massive halo of dark matter,the surrounding galaxy, which allowed the emergence of carbon-based life, which chose Earth as its home - or some other one - should be thanked for all this. As we dive deeper into the principles of the universe, we realize that dark matter is absolutely necessary for the emergence of life. Without it, there would be no chemistry, complex elements, biology, solid planets, life - and us.