The evolution of our understanding of the universe
22 March 2023
Since man became a “sapien,” he has watched the heavens with great interest and wonder. And that’s perfectly normal because what happens above our heads has a significant impact on us. Because he was in constant contact with nature and completely dependent on the birth and death of the Sun, Moon, and stars, which marked the rhythm of day and night as well as the seasons, primitive man had a direct sense of how the heavens affected our lives. Because he needed to know what was going to happen in order to find food and avoid being eaten by other predators, he learned prediction by observing the conditions of the celestial bodies. In addition, we can imagine the stupor and terror our ancestors must have experienced when confronted with the unexpected and dramatic phenomena they were able to observe in the sky: thunder, shooting stars, meteorites, comets, solar or lunar eclipses, the polar aurora, and lightening. They had to have seen them as evidence of much higher beings. Therefore, it stands to reason that they believed their gods resided in the heavens.
Some people quickly came to the realization that gaining great power and stature as divine mediators would come from knowing the secrets of such phenomena and convincing others that they can use them to help or harm one another. Because of this, even the most primitive societies maintained celestial myths, rites, and omens through their priesthoods. Even in the most technologically advanced societies of the twenty-first century, these primitivisms persist in the form of astrology, astral sects, and other forms of deception. In addition, many of the most intelligent people in the world today defend the most complex and speculative scientific theories and cosmological models with a religious-like fanaticism. When trying to provide a concise and understandable overview of what we know about the structure and evolution of the vast universe to which we belong, as I am currently doing, all of this needs to be taken into consideration.
To begin, we must recall and emphasize something that will contextualize the following observations: The entirety of scientific knowledge is tentative and open to revision. In addition, I will attempt to explain what we have observed using the most advanced telescopes and instruments of our time through speculations that are based on rigorous science but are still speculations. We are too small to comprehend the complete and real reality of the vast Cosmos. In conclusion, although we have learned a great deal, we still do not know a great deal. In addition, as I was writing this summary, I was strongly tempted to include each statement’s cluster of unanswered questions. However, such specifics should be left to specialized books.
Having said that, it is even more exhilarating to think about the beautiful and unfinished adventure of humans moving forward blindly but decisively in search of the infinite mysteries, motivated by their natural curiosity and desire to learn. These characteristics have enabled us to surpass our own significant limitations and reach previously unimaginable heights. In the real world, for instance, we have been able to create amazing “prosthetic devices,” or telescopes, despite the fact that we are practically blind, unable to see far away objects, and only able to see a very narrow range of electromagnetic wavelengths. As a result, we are now able to “see” celestial objects that are so far away that we must measure them in thousands of millions of light years.
Our conception of the cosmos has evolved, and this evolution has been particularly significant in recent times (fig. 2). The “Copernican Revolution,” which reduced the Earth to a mere satellite of the Sun and demonstrated that heavenly matter was of the same nature as us—no more divine than the Earth’s own dust—can be traced back only to the Renaissance. We were entertained by the precise mechanics of the heavens as we studied the movement of the bodies that make up our Solar System and were thrilled for a time by such amazing and unexpected things. Consequently, we believed that the universe remained constant and that the cosmic clock was perfect.
This tranquility and perfection came crashing down less than a century ago. We had previously considered the Milky Way to be a singular cluster of stars and nebulae surrounded by an infinite void until science established the existence of numerous other “island universes” outside of it. After that, we realized that their rate of separation increased with increasing distance. As a result, at long last, we were forced to accept that the universe was expanding, that it was getting bigger and colder. To arrive at the original, singular moment and the concept of the “Big Bang,” which was the origin of everything, it sufficed to posit this expansion in reverse. In addition, we were forced to accept that the universe is always evolving when we learned about the energy that makes stars shine. It is neither eternal nor static, and everything it contains, including galaxies and stars, is “alive.” As a result, we are able to observe the ever-evolving birth and death of celestial objects in every region of the universe.
The Universe’s expansion is also accelerating, which surprises us at once! So, our cosmology is changing once more. We are forced to rebuild the cosmic physics structure from the ground up as a result of this global acceleration, imagining a mysterious energy linked to the “vacuum,” which fills and pushes everything. an energy that has such a great strength that it can accelerate the expansion of space and produces anti-gravitational forces that can withstand the inevitable collapse.