Physics

Physics is the scientific discipline that explores natural phenomena through observation and experimentation, seeking to describe them using mathematical laws. It focuses on understanding the properties of matter, energy, and their interactions, both at the macroscopic and microscopic levels.

As a fundamental science, physics helps us comprehend the universe, from the fall of an apple to the interactions between subatomic particles.

Physics is a quantitative science because it deals exclusively with the measurable characteristics and properties of natural phenomena. What does this mean? Simply put, physics revolves around numbers, measurements, and relationships. Everything in physics can be measured and quantified with great accuracy. In other words, physics doesn't settle for describing something as "big" or "small," "heavy" or "light." It seeks to know exactly how big and precisely how heavy, often with an almost obsessive attention to detail. If something can’t be measured, it can't be studied in physics.

For instance, it's not enough to say the Earth is "very large." Physics demands to know exactly how large, telling us that the Earth's radius is approximately 6,371 kilometers. Saying it's "many kilometers" isn’t sufficient; we need an exact figure. Without quantification, we'd still be speculating about the speed of lightning or the weight of a star without arriving at useful conclusions. Thanks to physics, we now know exactly how fast lightning travels and how much a star weighs.

The characteristics and properties of objects or natural phenomena that can be measured and quantified are referred to as physical quantities. Physics measures these quantities with precision, allowing them to be compared, added, subtracted, and, most importantly, used to predict future outcomes.

The history of physics

The history of physics is a long journey, from the philosophical observations of antiquity to the groundbreaking discoveries of the 20th century. Initially, with Aristotle, physics was qualitative, based on observations without experimentation. Explanations of the world relied on philosophy, without precise measurements or rigorous experiments.

Classical physics (17th–19th century)

This began to change in the 17th century with Galileo Galilei, who introduced the scientific method, and Isaac Newton, who formulated the laws of motion and universal gravitation, laying the foundation for classical mechanics. During the 18th and 19th centuries, disciplines like thermodynamics, electromagnetism (thanks to Maxwell), optics, and acoustics were developed, forming what we now call classical physics (17th–19th century).

Modern physics (20th century)

The 20th century brought a revolution in physics with Einstein's theory of relativity and quantum mechanics, which explain phenomena at both the grandest and smallest scales. New fields like atomic physics, nuclear physics, particle physics, astrophysics, and cosmology emerged, significantly expanding our understanding of the universe. Physics shifted from describing the motion of bodies to probing the fundamental particles and the universe itself.

Where classical physics dealt with tangible concepts like the motion of objects and the propagation of sound, modern physics ventures into exploring the universe's boundaries and the complex structure of matter. Today, physics is no longer limited to describing observable reality; it seeks to explain the most mysterious and enigmatic phenomena of the cosmos.

Branches of physics

The key branches of physics are:

• Classical mechanics: Studies the motion of objects and the forces acting upon them. For example, it analyzes why a ball thrown into the air follows a parabolic trajectory.
• Thermodynamics: Examines the thermal properties of matter and the processes of heat transfer. For instance, it explains why hot coffee cools down when left on a table.
• Electromagnetism: Investigates phenomena related to electric and magnetic fields. For example, it explains how a magnet attracts a paperclip.
• Quantum mechanics: Explores the behavior of particles at the subatomic level. For example, it explains the behavior of electrons within atoms.
• Relativity: Studies the behavior of matter and energy at speeds approaching the speed of light. A practical application of relativity is the GPS system, which requires relativistic corrections to function properly.

Physics isn’t just theoretical; its practical applications are all around us. Without physics, many modern technologies we rely on every day wouldn’t exist. For example, in engineering, constructing bridges and skyscrapers requires a deep understanding of classical mechanics and fluid dynamics.