Physics

Muslim scientists studied acoustics, its origin and its transfer. They were the first to understand that sounds are affected by the bodies that cause them and that these sounds transfer in the air in the form of circular waves. Muslim scientists were also the first to categorize sounds into different types; they expounded that the sounds of animals differ according to the length of their necks, the width of their throats and the structure of their larynx.

Abu al-Fath Abd al-Rahman Mansour al-Khazini was an incomparable physicist, particularly in relation with dynamics and hydrostatics to the extent that the succeeding researchers have been startled. His theories in the field on kinetics are still been used in schools and universities up till now. Among these theories are the Theory of Obliquity and Inclination and the Theory of Impulse. Al-Khazani pointed out that air had weight and power to boost things suspended in it, adding that the weight of the object in the air weighs less than its actual weight and its condensed weight depends on the density of air. It is worth of note that these studies paved the way for the inventions of the barometer (pressure measurement), air vacuums and pumps among others. A lot of historians in the field of science regard Al-Khazani the physicist of all physicists.

Ibn Al-Haitham (965 – 1040) known in the West as Alhazen was the mathematician and physicist who made the first significant contributions to optical theory since the time of Claudius Ptolemy. In his treatise on optics, translated into Latin in 1270, he published theories on refraction, reflection, binocular vision, focusing with lenses, the rainbow, parabolic and spherical mirrors, spherical aberration, atmospheric refraction, and the apparent increase in size of planetary bodies near the Earth’s horizon. He was the first to give an accurate account of vision; correctly stating that light comes from the object seen by the eye.

Laws of motion

The importance of the laws of motion lies in the fact that they are viewed as the backbone of contemporary civilization. For example, the sciences of mobile machinery nowadays starting from the car, train, plane, space rockets, and transatlantic rockets, among others rely on these laws. They have aided man to invade the outer space and to land on the surface of the moon. Moreover, they are deemed the basis for all physical sciences which depend on motion. It is well known that these laws were described by the English scientist, Isaac Newton. But in the beginning of the 20th century, a group of contemporary physicists, mostly, prominent Professors of Mathematics examined these laws. They checked the accessible body of Islamic manuscripts in this field and came up with the fact that Muslim scientists were the first to discover these laws seven centuries before Newton was born. All what Newton did was to collect what had been written on these laws and formulated them in a mathematical form.

First Law of Motion

Newton stated that, “In the absence of force, a body either is at rest or moves in a straight line with constant speed.” Incidentally, Ibn Sina (Avicenna) in his book, Isharat wa Tanbihat (Insinuations and Notices) identified the same law in his own words: “You know if the object is left unaffected by external influence, it remains as it is.” It is clear this statement of Avicenna regarding the first law of motion excelled that of Isaac Newton who appeared centuries later.

Second Law of Motion

According to Newton’s mathematical formulation, he stated that, “A body experiencing a force, F will have an acceleration ‘a’ related to F by F = ma, where m is the mass of the body. Alternatively, force is proportional to the time derivative of momentum.” When it comes to Muslims, Hebattullah bin Malaka Al-Baghdadi (1087 – 1164) indicated in his book, Al-Moatabar fil Hikma (The Considered in Wisdom) that, “The faster the speed, the stronger the power. The stronger the power that pushes the object, the faster the speed of the object at move, and the shorter the time spent for covering the distance.” This is exactly what Newton mathematically formulated and named the second law of motion.

Third Law of Motion

The third law of motion says that if two objects interact, the force the first object exacts on the second object (called the power of the action) is equal to the force the second object exacts on the first, but it holds the opposite direction. This power is called the Force of the Reaction. Newton mathematically formulated this law as follows: “Every action has a reaction which is equal in magnitude and opposite in direction.” The same concept has been asserted by Ibn Al-Haitham (Alhazen) in his book, The Scenes. He pointed out that “The moving object is encountered by an obstruction, and if this forces remains, this moving object retreats in the opposite direction in the same speed practiced by the first object and according to the power of obstruction.”