Matter and antimatter. Why are we here?

The matter making the solar system, the Earth, all living beings and ourselves, is made up almost entirely of atoms which, in turn, are based on three elementary particles: protons, neutrons and electrons. For each of these particles, as well as for many others, not usually part of atoms, there is an antiparticle. Therefore, there could be antimatter antiatoms, made of antiprotons, antineutrons, and antielectrons (positrons).

An interesting property of matter and antimatter is that they cannot be together. As soon as they come into contact, they completely disintegrate, transforming into energy. Everything suggests that our galaxy (the Milky Way) is made up almost exclusively of matter. There is also some antimatter, in the form of antiparticle clouds, outside the galaxy, close to it and attracted by its gravity, but in such a small quantity, compared to the mass of the galaxy, that for practical purposes it can be ignored. It has also been said that there could be some (but very few) anti-stars.

Influence of aesthetic ideas in physics

The Birth of Venus by Botticelli

In a previous post I reviewed the new book in Spanish by Francisco José Soler Gil, entitled The enigma of the natural order. Its third chapter, whose title is Aesthetic ideas in physics, which reproduces a lecture given by the author at the Faculty of Chemistry of the University of Seville, has provided me with matter for this post in my blog.

The influence on physics of aesthetic ideas is very old, perhaps as old as physics. One of its oldest precursors is Pythagoras, who proposed the concept of the harmony of the celestial spheres, according to which the distances between the planets would reproduce harmonious musical intervals.