In 1929 astronomer Edwin Hubble discovered that the speeds of distance or recession of galaxies increased with the growth of their distances.
This discovery gave rise to the cosmological theory of the Big Bang, which starts from the hypothesis that all the matter in the Universe was concentrated in an undefined sphere and that, after its explosion, began to expand, creating the space-time binomial.
Today, this theory, although with nuances, is generally accepted by the entire scientific community.
The expansion would continue today and is what astronomers measure in the form of redshift of the spectral bands of distant galactic objects. Apparently, the Universe continues to expand.
Astronomers and physicists order the Universe in a hierarchy of scales or smaller and smaller sizes. The description of the processes at each level is a generalization of the processes that take place at their lower level.
The fundamental laws of Physics are valid (or should be, in that we are) for all scales of organization of matter and all times.
In this chapter, some aspects of the Universe are explained in the form of an article.
In this chapter:Our galaxy, the Milky Way: The Milky Way that we can see in the night sky is actually just one of the spiral arms… Read page Planets in other solar systems: Knowing whether or not we are alone in the universe has been one of the objectives of many philosophers and… Read page Cosmic dust: According to current astronomical theories, galaxies had their origin in large conglomerates of gas and dust… Read page The energy of the stars: The stars emit energy in different ways: 1. In the form of photons of radiation ... Read pageNovas and supernovae: Before the era of astronomy, a star that suddenly appeared where nothing had been seen before, was ... Read page Nebulas: A nebula is a cloud of gas or dust in space. The nebulae can be dark or, if they are illuminated by stars ... Read pageWhat are the pulsars ?: In the summer of 1967, Anthony Hewish and his collaborators at the University of Cambridge detected, by ... Read pageWhat is a black hole ?: To understand what a black hole is, let's start with a star like the Sun, which has a diameter of 1… Read page