It is believed that if antimatter were present in large quantities in the Universe, then at the boundaries of the world, consisting of matter, and the antiworld, annihilation of particles and antiparticles would occur continuously. The quanta with an energy of 0.5 MeV arising in this process would fill the entire space. However, observations in the y-band did not reveal quanta with such an energy.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.