The outstanding figure of the scientific Revolution, Isaac Newton, was born on January 4, 1643. His place of birth is the small British village of Woolsthorpe, located in the county of Lincolnshire. A frail, prematurely abandoned boy from his mother’s womb came to this world on the eve of the English Civil War, shortly after his father’s death and shortly before the celebration of Christmas. The child was so weak that for a long time, he was not even baptized. The father of the future genius scientist was a small farmer but quite successful and wealthy. After the death of Newton Sr., his family received several hundred acres of fields.
When Isaac was 16 years old, his mother took him back from school to the estate. However, the guy was only engaged in constructing ingenious mechanisms. The young man’s school teacher, his uncle, and his acquaintance (a member of Cambridge Trinity College) from Grantham, where the future world-famous scientist attended school, persuaded Newton’s mother to allow her son to continue his studies (West, 2020). As a result of collective persuasion, Isaac completed his studies and successfully passed the entrance examinations at the University of Cambridge. As a student, Newton had sizar status. This meant that he did not pay for his education, but he had to do various jobs at the university or provide services to more affluent students.
The powerful apparatus of Newtonian mechanics, its versatility, and its ability to explain and describe the broadest range of natural phenomena, especially astronomical ones, had a tremendous impact on many areas of physics and chemistry.
Newton wrote that it would be desirable to deduce other natural phenomena from the principles of mechanics. When explaining some optical and chemical phenomena, he used a mechanical model. In-depth studies of the natural sciences and mathematics were combined with religiosity in Newton. Newton wrote an essay about the prophet Daniel and an interpretation of the Apocalypse. After Newton’s death, a scientific and philosophical trend emerged, which received the name of Newtonianism.
The main questions of mechanics, physics, and mathematics developed by Newton were closely related to the scientific problems of his time. Newton began to be interested in optics as a student; his research in this area was associated with the desire to eliminate the shortcomings of optical devices. In the first optical work he reported to the Royal Society of London in 1672, Newton expressed his views on the “corporeality of light” (corpuscular hypothesis of light). This work caused a stormy controversy, in which R. Hooke opposed the corpuscular views of Newton on the nature of light (at that time, wave representations dominated). Newton formulated a hypothesis that combined corpuscular and waves concepts of light.
Newton was the first to consider the primary method of describing any physical activity through the medium of force. Defining the concepts of space and time, the scientist separated “absolutely stationary space” from limited movable space, calling it “relative,” and uniformly flowing, absolute, true-time, calling it “duration,” from relative, apparent time, which serves as a measure of “duration. “. These concepts of time and space formed the basis of classical mechanics. Then the scientist formulated his famous “axioms, or laws of motion”: the law of inertia (Newton’s first law). He formulated the law of proportionality of momentum to force (Newton’s second law), and the law of equality of action and reaction (Newton’s third law.). From the 2nd and 3rd laws, he deduces the law of conservation of momentum for a closed system. All these laws the scientist outlined in work called “Principles”.
Newton’s laws – depending on which angle people look at them – represent either the end of the beginning or the end of classical mechanics. In any case, this is a turning point in the history of physical science – a brilliant compilation of all the knowledge accumulated by that historical moment about the motion of material bodies within the framework of physical theory, which is now commonly called classical mechanics. We can say that the history of modern physics and the natural sciences, in general, began with Newton’s laws of motion. Newton’s three laws gave physicists the tools necessary to begin a comprehensive observation of all phenomena occurring in the universe.
The most important achievement of Newton was the formulation of the three laws of motion. Newton’s first law states that a body moves rectilinearly and uniformly relative to inertial reference frames or is at rest if the sum of the forces acting on it is zero. Newton’s second law establishes a connection between a force and the acceleration caused by it: the force acting on a body, regardless of its nature, is equal to the product of the body’s mass by the acceleration imparted by this force. Newton’s third law indicates that the action of one body on another has a mutual character: bodies act on each other by forces of the same nature, equal in magnitude and opposite in direction. Newton’s laws allow people to solve any problem in mechanics (Permana et al., 2021). If the forces applied to the body are known, one can find the acceleration of the body at any moment, at any point of its trajectory.
Acceleration is found in the known forces and mass of the body. Its speed and displacement are calculated for any period and, finally, the coordinates of the body at any moment. For this, the “initial conditions” must be known – the initial position and the initial velocity of the body. For example, the scientists directing a spacecraft’s flight, of course, need to know in advance the spacecraft’s position at any given time. In this case, scientists need to use Newton’s laws. Scientists know the initial position of the ship on the launch pad and its initial speed. They also know the forces that act on the ship at any point on the trajectory. Using these data, they solve the problem of mechanics as applied to space flight.
“Mathematical Principles” are rightfully considered one of the most important works in physics in the entire history of humanity. Newton’s new approach made it possible for the first time to explain how, taking into account the force of gravity, the planets move around the Sun in elliptical orbits (Schilt, 2020). Scientists believe that physical laws are valid for everything in the universe. Newton described how the movement of a body changes under the influence of gravity. Much later, Einstein improved this knowledge and showed that the motion of the planets is influenced not by any particular force but by the curvature of space-time.
Thanks to Newton, the movements of bodies on Earth and in space were explained due to the same laws, which was the birth of a new physics and astronomy. The scientist influenced chemistry: his idea of attraction as the basis of chemical affinity determined the development of theoretical thought in this science. Newton’s work is now considered the culmination of the early modern scientific revolution. Although his predecessors – Copernicus, Galileo, and Kepler – laid the foundation for this path, describing the phenomena they observed, Newton changed the very subject of natural philosophy – what we now call physics – by searching for universal laws of nature at the forefront.
In “Principles,” Newton investigated the motion of bodies in a continuous medium (gas, liquid) depending on their movement speed and gave the results of his experiments on studying the swing of pendulums in air and liquids. Here he considered the speed of sound propagation in elastic media. Using mathematical calculations, Newton proved the inconsistency of Descartes’s hypothesis, which explained the motion of celestial bodies with the help of the concept of various vortices in the ether filling the Universe. Newton found the law of cooling a heated body. In the same work, he paid considerable attention to the law of mechanical similarity. In “Principles,” for the first time, a general scheme of a rigorous mathematical approach to the solution of any specific problem of terrestrial or celestial mechanics is given.
Newton’s theory of the motion of celestial bodies, based on the law of universal gravitation, was recognized by the most prominent English scientists of that time and was powerfully negatively met on the European continent. The opponents of Newton’s views (particularly on the issue of gravitation) were the Cartesians, whose views dominated Europe, especially in France, in the first half of the 18th century. A convincing argument in favor of Newton’s theory was the discovery of the flattened nest of the globe at the poles, calculated by him – and this is instead of the bulges expected by Descartes’ teachings.
In the 17th century, Newton was not the only person who contemplated the force that causes bodies to fall to Earth and objects in space. A contemporary of Newton, Robert Hooke, also explored these questions. But Newton was the first to give the correct answers. Isaac Newton was a deeply religious person who believed that objects exist in space (which is absolute) because they live in the divine mind. The basis of space, according to Newton, is hidden from our eyes and is given in sensation only to God. The scientist thought a lot about the issues of immortality, and Newton’s biographers still argue whether he can be considered an alchemist.
Isaac Newton was a mysterious and controversial figure. But one thing can be said for sure: for the first time in history, a scientist discovered the laws of nature, which obey all moving bodies in the Universe. The work of A.C. Clairaud played a special role in strengthening the authority of Newton’s theory by taking into account the disturbing action of Jupiter and Saturn on the motion of Halley’s comet. The successes of Newton’s theory in solving problems of celestial mechanics were crowned with the discovery of the planet Neptune (1846), based on calculations of perturbations in Jupiter’s orbit.
References
Permana, H., Khotimah, S. H., Muliyati, D. & Fauzi, B. (2021). Augmented reality in the poster: Introduce sir Isaac Newton in the study of mechanics. AIP Conference Proceeding, 2320 (1), 123-128. Web.
Schilt, C. J. (2020). Created in our image: How Isaac Newton was fashioned as a scientist and forgotten as a scholar. The University of Chicago Press Journals, 5(1), 217-225.
West, B. J. (2020). Sir Isaac Newton Stranger in a Strange Land. Entropy, 22(11), 1204. Web.