Chapter 1: Physics

The scientific study of matter, including its fundamental elements, its motion and behavior through space and time, as well as the associated phenomena of energy and force, is referred to as physics. The scientific subject of physics is considered to be among the most fundamental. A scientist who focuses their research and study on the subject of physics is referred to as a physicist.

Physics is one of the areas of study that has been around the longest. Over the course of the last two millennia, natural philosophy encompassed a number of natural sciences, including physics, chemistry, biology, and certain parts of mathematics. However, during the Scientific Revolution, which occurred in the 17th century, these natural sciences began to develop into their own distinct study undertakings. The limits of physics are not strictly defined, and the field of physics crosses with a wide variety of interdisciplinary fields of research, such as quantum chemistry and biophysics. Frequently, new concepts in the field of physics provide an explanation for the underlying mechanisms that are investigated by other scientific fields, and they also propose new areas of investigation in these and other academic fields, such as mathematics and philosophy.

New technologies are frequently made possible by advances in physics. For instance, advancements in the understanding of electromagnetism, solid-state physics, and nuclear physics led directly to the development of technologies that have transformed modern society. These technologies include television, computers, domestic appliances, and nuclear weapons. Additionally, advancements in thermodynamics led to the development of industrialization, and advancements in mechanics inspired the development of calculus.

The origin of the word "physics" may be traced back to the Latin word "physica," which means "study of nature." This term is taken from the Greek word "phusik," which means "natural science." The Greek word "phusik" is derived from the Greek word "phúsis," which means "origin, nature, property."

It is one of the natural sciences that has been around the longest. The Sumerians, ancient Egyptians, and the Indus Valley Civilization were among the early civilizations that possessed a predictive knowledge and a fundamental awareness of the motions of the Sun, Moon, and stars. These civilizations going back to before 3000 BCE came into existence. It was common practice to worship the stars and planets, as it was believed that they represented gods. These early observations created the groundwork for later astronomy, as it was discovered that the stars traveled in large circles around the sky, which could not explain the positions of the planets. Despite the fact that the explanations for the recorded positions of the stars were sometimes not scientific and lacked proof, these early observations laid the framework for contemporary astronomy.

The origins of Western astronomy can be traced back to Mesopotamia, as stated by Asger Aaboe. Furthermore, all Western endeavors in the exact sciences can be traced back to late Babylonian astronomy. The Greek poet Homer wrote about a variety of celestial objects in his Iliad and Odyssey. Later Greek astronomers provided names that are still used today for the majority of the constellations that are visible from the Northern Hemisphere. Egyptian astronomers left monuments that demonstrated their knowledge of the constellations and the motions of the celestial bodies.

Natural philosophy may be traced back to Greece during the Archaic period (650 BCE to 480 BCE), when pre-Socratic thinkers such as Thales rejected non-naturalistic explanations for natural occurrences and asserted that every event had a natural cause. This is when natural philosophy was first established. They provided ideas that were supported by reason and observation, and many of their assumptions were proven correct by experimentation. For instance, the theory of atomism was discovered to be accurate around two thousand years after it was proposed by Leucippus and his disciple Democritus.

The development of natural philosophy in Greece occurred along a variety of avenues of investigation during the classical period, which lasted from the sixth to the fourth centuries BCE, and during the Hellenistic period. The Greek philosopher Aristotle, also known as Aristotéles, lived from 384 to 322 BCE. He was a disciple of Plato.

When he was writing in the fourth century B.C., he covered a wide range of topics, including a major treatise on "Physics." The influence of Aristotelian physics can be traced back approximately two millennia. His strategy consisted of a combination of restricted observation and logical deductive arguments, but it did not rely on experimental verification of claims that were concluded. The basic work that Aristotle did in the realm of physics, despite the fact that it was extremely flawed, served as a framework against which succeeding thinkers further expanded the field. At this point in time, his method is completely obsolete.

Through the notion of the four elements, he provided an explanation for concepts such as motion (and gravity).

The ancient Greek philosopher Aristotle held the belief that each of the four classical elements-air, fire, water, and earth-had a specific natural location. Due to the fact that each element has a different density, it will eventually return to the location in the atmosphere that is most appropriate for it. Due to the fact that fire is heavier than air, it would be placed at the top of the hierarchy, followed by water, and then earth would come in last. As an additional point of interest, he mentioned that when a small quantity of one element reaches the natural position of another element, the element that is less abundant will immediately go towards its own natural place. For instance, if there is a fire on the ground, the flames will rise into the air in an effort to return to their natural location, which is where they should be. His laws of motion comprised the following: 1) heavier items will fall faster, with the speed being proportionate to the weight; and 2) the speed of the object that is falling relies inversely on the density of the object it is falling through (for example, the density of air). He also claimed that when it comes to violent motion, which is defined as the motion of an object when a force is applied to it by another object, the pace at which that item moves will only be as quick or strong as the measure of force that is applied to it. After conducting extensive research on the issue of motion and the factors that contribute to it, he came up with the philosophical concept of a "primary mover" as the ultimate origin of all motion in the world (Book 8 of his work Physics).

A downturn in intellectual pursuits in western Europe occurred as a consequence of the fall of the Western Roman Empire in the fifth century, which was caused by both external invaders and internal decadence. On the other hand, the Eastern Roman Empire, which is more commonly referred to as the Byzantine Empire, was able to withstand the assaults of the invaders and continued to make progress in a variety of academic subjects, including physics.

The Archimedes Palimpsest is a compilation of Archimedes' works that was compiled by Isidore of Miletus in the sixth century. This compilation is considered to be of great cultural significance.

A Byzantine scholar named John Philoponus, who lived in Europe around the sixth century, put Aristotle's teaching of physics under scrutiny and pointed out its shortcomings. The principle of impetus was first presented by him. It was not until the appearance of Philoponus that Aristotle's physics was examined; in contrast to Aristotle, who based his physics on verbal argument, Philoponus relied on observation. Philoponus wrote the following about Aristotle's physics:

However, this is a wholly false assertion, and our viewpoint may be supported by actual observation in a more convincing manner than by any kind of verbal argument. When you let two weights that are many times heavier than the other fall from the same height, you will notice that the ratio of the times required for the motion does not depend on the ratio of the weights, but that the difference in time is a very little one. This is because the ratio of the weights is not the only factor that determines the amount of time required for the motion. Consequently, if the difference in weight is not significant, that is, if one is, for example, twice as much as the other, there will be no difference, or else an undetectable difference, in time, despite the fact that the difference in weight is by no means insignificant, with one body weighing twice as much as the other.

During the Scientific Revolution, which occurred ten centuries later, Galileo Galilei utilized Philoponus' criticism of Aristotelian concepts of physics as a source of inspiration. Galileo made extensive use of Philoponus as a source of evidence in his writings when he argued that Aristotelian physics was incorrect. Jean Buridan, a professor in the college of arts at the University of Paris, is credited with developing the idea of impetus in the time period of the 11th century. The contemporary concepts of inertia and momentum were a step forward as a result of this.

During the Islamic Golden Age, Islamic scholarship pushed Aristotelian physics further, particularly by placing a focus on observation and a priori reasoning, which led to the development of early forms of the scientific method. This intellectual legacy was passed down from the Greeks to the Islamic scholars.

Numerous scientists, including Ibn Sahl, Al-Kindi, Ibn al-Haytham, Al-Farisi, and Avicenna,...