Modern Physics and the Evolution of the Universe

The Modern Scientific Worldview

Until the 19th Century, the scientific process was dominated by the conceptual schemes of Isaac Newton and Galileo Galilei. Many scientists felt they were nearing a point where no significant new laws remained to be discovered. However, two new branches of physics would completely transform our worldview, affecting both the macrocosm and the microcosm: the theory of relativity and quantum physics.

The Theory of Relativity: Revolution in the Macrocosm

Albert Einstein published the theory of special relativity in 1905. It posits that there is no absolute space or time independent of the subject who experiences them. Instead, space and time are relative to speed. Time elapses differently for two observers traveling at different speeds, creating an interdependence between temporal and spatial dimensions. Together, space and time form a four-dimensional continuum.

Nothing can travel faster than the speed of light, not even gravitational interactions. Consequently, Einstein developed the theory of gravitation under this limitation, introducing the concept of a gravitational field. According to this idea, matter warps the geometry of space around it, influencing the bodies within it. Where space is more curved, time elapses more slowly, explaining the orbital motions of planets. An unintended consequence of this theory is that the universe is in a process of expansion.

The Expansion of the Universe

Einstein initially believed there must be a mistake in his theory, as he thought the universe was static. However, Edmund Hubble proved that the universe is indeed in a process of continuous expansion. Hubble discovered that the Milky Way galaxy is not alone in the universe, forcing scientists to rethink the dimensions and static nature of the cosmos.

The Big Bang Theory

This theory proposes that the universe formed from a vast explosion that occurred approximately 15 billion years ago. From this explosion, atoms of hydrogen, helium, and lithium were formed. This theory has been confirmed by the detection of background radiation from Earth, which serves as the traces left by the initial explosion.

The Big Crunch Theory

According to the Big Bang theory, the history of the universe involves a slowing process of the expansion that began with the initial explosion. There are several possibilities for the future:

• The Big Crunch: Gravitational action will eventually stop the expansion of the universe and result in a contraction process. This will lead back to the initial moment, after which there may be a new Big Bang, and so on.
• Indefinite Expansion: The expansion continues indefinitely, and the universe will "die" by cooling as energy disperses across an ever-larger and colder area.