Understanding Physics: Matter, Energy, and Measurement

Physical science studies the properties of matter and energy, considering the attributes that can be measured. Physics is an empirical science. All that we know of the physical world and the principles that govern its behavior has been learned through the observation of natural phenomena. The ultimate test of any physical theory is its agreement with observations and measurements. Physics is, therefore, essentially a science of measurement. Examples include matter, energy, measurement, and observation.

Key Concepts in Physics

• Matter: The substance that makes up the physical universe, occupying space and existing in many forms perceivable by the senses.
• Empirical: Based solely on observation and factual experience.

Branches of Physics

• Classical Physics: Based on principles established before the advent of quantum physics.
• Modern Physics: Studies changes in atoms, forming particle matter and the forces that govern them.

Classical Physics Branches

• Classical Mechanics: Dedicated to studying the movements and states of bodies (kinematics and dynamics).
• Optics: Treats light as a wave, explaining phenomena like diffraction and polarization.
• Electromagnetism: Studies and unifies electric and magnetic phenomena.

Modern Physics Branches

• Nuclear Physics: Studies the properties and behavior of atomic nuclei.
• Atomic Physics: Studies the properties and behavior of atoms (electrons and atomic nuclei).

Magnitudes and Units

Magnitudes are the properties or attributes of an object that can be associated with a numerical value and, therefore, measured, along with a unit.

Scientific Contributions to Physics

• Thales of Miletus: Asserted that water is the primary universal substance and that the world is encouraging and full of divinities.
• Copernicus: Proposed a new structure for the solar system.
• Democritus: Postulated that atoms are indivisible and are distinguished by shape, size, and order.
• Archimedes: Invented a method for determining the volume of irregularly shaped objects, based on static line tactics and the principle of the lever.
• Newton: Described the universal law of gravitation and established the foundations of classical mechanics.
• Alessandro Volta: Developed electricity in 1800.
• Martín Rees: Investigated high-energy astrophysics and the formation of the structure of the universe.
• Franklin: Primarily studied electrical phenomena.
• Galileo Galilei: Improved the telescope, which helped evaluate metric Astro variations, gave rise to the first law of motion, and provided decisive support for Copernicanism.

Fundamental Units

In physics, there are some basic magnitudes, each with a specific name and symbol, called fundamental units.