Before a physics teacher can ever start discussing about motion, forces, electromagnetism, thermodynamics, optics, or Einstein’s Special Theory of Relativity, he has to answer the question, What is physics?. This is necessary to bring the students into the right mindset.
The topics I enumerated earlier (i.e., motion, forces, etc.) are just branches of physics. Mentioning them or even defining each one of them does not in any way tell them what physics is. So what is physics, really?
Physics is the science of physical quantities. Since it is a science, all the physical theories and principles that exist today have evolved from a systematic knowledge base that involve predictions, mathematical models, experiments, observations, and data analysis. Before they can be accepted for public consumption, they have to be presented in peer-reviewed journals where they are scrutinized by fellow scientists.
Now, lets talk about physical quantities.
A physical quantity is any aspect of nature that can be measured or calculated, i.e., expressed by way of a quantitative description or simply put, in terms of numbers. For example, a qualitative description of the current room temperature would be hot or cold or warm. A quantitative description would be 32ēC. You can be described as tall or short but a quantitative way of describing your height would be 5’8″.
Using a numerical value and a unit of measurement with accuracy and precision to describe something is one of the most important components of physics. That is why physics and math are inseparable. Some say the language of physics is math. In fact, many of today’s observed physical phenomena were long predicted by mathematicians.
Physics is intertwined among a vast range of topics; from the living to the non-living, from the tiniest sub-atomic particles to the colossal superclusters of the Universe. You can use pressures and Bernoullis Principle to explain how roofs are plucked off houses in the midst of strong winds. The same pair can also be used to account for the occurrence of vascular flutter in a human artery.
You can say that physics is the most fundamental of all sciences because many observable facts in biology, medicine, chemistry, engineering, and many others can be explained using physical laws.
Physicists had to take different routes to arrive at their current position. From the deterministic nature of Newtonian physics to the probabilistic one of quantum mechanics, from wave nature of light to the particle nature of light. Despite going in opposite directions, physicists have managed to converge to a common ground.
It is even anticipated that when the Large Hadron Collider becomes operational, particle physics (the study of the very small) and astrophysics (the study of the infinitely large) will finally find unity.
Courtesy by John Carl Villanueva