Modern Physics and Ancient Science: A Comparative Study
Theory of Relativity
Albert Einstein, after discovering the photoelectric effect, concluded that light behaved as both a wave and a particle, with a constant speed. This was the beginning of the theory of relativity. According to this theory, there is no absolute motion or fixed reference point, unlike Newtonian physics. Time and space are intertwined. Mass and energy are interchangeable. This theory explains the accelerated motion of bodies and gravity as a curvature of space-time.
Quantum Theory
This theory seeks to explain the structure of matter at the atomic and subatomic levels. In 1900, Planck demonstrated that matter absorbs energy in discrete units called quanta. Later physicists stated that matter is made of atoms, and these are made of smaller particles very near the limit of what is observable. These particles have a dual nature: sometimes they behave as mass points and other times as waves, expressible only by a mathematical formula. Heisenberg described the unspecified nature of the subatomic world with the principle of uncertainty, which states that we can predict either the speed or the position of a particle, but not both. This marked the end of determinism.
The Big Bang and the New Face of the Universe
The challenge of contemporary physics is the unification of quantum theory and relativity. The quantum revolution brought about the discovery of two new forces: the weak nuclear force, which acts inside protons and neutrons in the nucleus, and the strong nuclear force, which holds together the nuclei of atoms. The strong force involves an extraordinarily concentrated energy with a limited scope, operating inversely to gravity, and is the most powerful force. The electromagnetic force maintains the cohesion of atoms through the attraction and repulsion of protons and electrons (electricity). These are called the four fundamental forces. Superstring theory attempts to describe the entire universe as consisting of abstract entities like strings, which are infinitesimally small, vibrating and gyrating under tension. Particles would be vibrational nodes of these strings. The most consistent theory of the origin of the universe is the Big Bang. George Gamow, based on studies of the background radiation of the universe, proposed an image of this initial moment of expansion. It was a huge explosion of a primary point of almost infinite energy, subject to high temperatures near absolute zero and high density. Space-time originated in the same explosion, and the first particles and nuclei of hydrogen and helium were constituted in a trillionth of a second. Atoms, under the pull of gravity, formed stars and planets. The universe could continue to expand or end in a “Big Crunch,” where all components would shrink to merge back into the initial particle.
Two Positions in Modernity
The modern approach to knowledge understands it as a process involving two elements: a knowing subject and an object known.
Empiricism
Knowledge begins and ends with experience, based on information provided by the senses. It starts from the idea that the mind is like a blank page on which all knowledge is printed from contact with reality. Hume distinguishes two types of perceptions: immediate impressions, which are the object of observation, and simple ideas, which are copies of impressions. More complex and abstract ideas are formed from the association of simpler ones, according to certain laws.
Rationalism
Seventeenth and eighteenth-century rationalists share confidence in reason as the instrument for humans to discover the processes that occur in reality. Senses have a secondary role. The mind constructs reality through the activity of reason, developing innate ideas. Descartes distrusts sensory information and seeks true knowledge based on innate ideas.
Ancient Science
The universe is seen as a large, closed space, hierarchical and differentiated in its parts. It is conceived as finite, with Earth at its center (geocentric). It is a dynamic universe where everything that moves is moved by something else; ultimately, everything is attracted by an unmoving first engine. This universe is hierarchical, orderly, and gifted with a purpose (teleology). In the second century, Ptolemy attributed a double orbit to the planets. This system persisted until the Renaissance, assimilated by Christianity. The first engine of Aristotle became the supralunar God, and the world was identified with heaven. This formed the medieval interpretation of the world, focused on God and the supralunar world (theocentrism).
The New Science
The Renaissance brought a new perspective with the following features: heliocentrism, the discovery of mathematics, and an attitude of methodical observation of nature. The new science arose, measuring and establishing laws to control nature. Ancient science contemplated the qualities of nature; the new science removed them.
Newton’s System
The entire universe is subject to the law of universal gravitation, according to Newton. The final image is that of a great clockwork regulated by necessary laws, where space and time are absolute references governing all motion. This is determinism.
Definitions
- Universe: Plurality of objects. Also used as synonyms are the terms cosmos, insofar as it relates to an ordered whole, and world, if it relates to the human realm.
- Dynamics: The part of physics that studies the relationship between forces and movements.
- Teleology: The part of philosophy that studies the nature of purposes. The teleological conception of the universe defends the existence of order or purpose in a structure.
- Particle: Elementary component of matter. It is not representable but a mathematical construct, for a particle is far from a radiation.
- Emergent Properties: New qualities acquired by a system, irreducible to previous ones. They occur in open systems.
- Black Hole: Space-time deformation caused by a dying star, which upon cooling results in a high gravitational field.
- Experience: Capturing information through the senses.
- Object: Everything that can be a matter of knowledge or awareness on the part of a subject.
- Phenomenon: That which is perceived by the senses and organized according to the structure of the subject’s sensitivity.