# “Newton, the Man”: First of the Age of Reason

Isaac Newton (1642-1727) has often been called the greatest scientist who ever lived. Extremely influential and revolutionary, he represents the pinnacle of the achievement of the Scientific Revolution. Newton’s contributions laid the foundations for classical physics/classical mechanics. Almost singlehandedly he shaped the direction of physics for centuries to come. Another important contribution of Newton’s was his creation of infinitesimal calculus, independently of yet simultaneously with Gottfried Leibniz.

First and foremost, Newton established the basis of classical mechanics, which is one of the two major subfields of physics to this day (the other being quantum mechanics). Classical physics preceded special relativity and quantum mechanics.

One incredibly important idea of Newton’s was his law of universal gravitation. Basically, Newton’s law states that every point of mass in the universe attracts every other point with a force that is directly proportional to its mass. The formula for this, then, is F = G(m1m2/r^2). F is the force of gravity between the masses, G is the gravitational constant, the m’s are the two masses, and r is the distance between the masses. Newton’s law of universal gravitation confirmed heliocentric ideas which had earlier been propounded by Kepler. If gravity is proportional to mass, then it is understandable that the earth would orbit the sun, rather than the other way around. There is a story that Newton had an epiphany about gravity when an apple fell from a tree (possibly landing on his head).

Essential to Newtonian mechanics, which themselves are the fundamental laws of classical mechanics, are Newton’s laws of motion. They are three physical laws which represent Newton’s belief that the universe can be viewed as a collection of forces acting upon a collection of masses. Newton’s first law states that if an object experiences no net force, it is at a constant velocity. This is similar to Galileo’s idea of inertia; basically, that objects at rest tend to stay at rest and objects in motion tend to stay in motion.

Newton’s second law of motion states that, essentially, F = ma (where F is force, m is mass, and a is acceleration). Therefore, the force of an object is the product of its mass and its acceleration. This is an especially interesting and important law because it is an approximation to the equation in relativistic mechanics for the momentum of a particle. This equation is p = (mv)/(sqrt(1-(v^2/c^2))). In this equation, c is the speed of light. Therefore, if the particle’s velocity is negligible comparable to the speed of light, the quotient will be close to zero. Subtracted from one, the difference will still be approximately one, and the square root of approximately one is still approximately one. Therefore, p = mv (approximately). This is the equation which Newton arrived at, and it was a very close approximation to the special relativistic equation.

Finally, Newton’s third law of motion can be summed up by the basic statement that to every action there is always an equal and opposite reaction. The basic equation for this is Fa = -Fb where Fa is the force of the first body and Fb is the force of the second body. The two bodies simultaneously exert equal and opposite forces on one another. These laws make up basic Newtonian mechanics, and, thereby, form the foundation of classical mechanics.

Newton also coined the term “centripetal force” in his manuscript De motu corporum in gyrum (On the motion of bodies in orbit). Centripetal forces are forces which make bodies follow a curved path. Newton described it as a force which causes the body to tend towards a point in a center. Another law Newton developed was his law of cooling. His law states that “The rate of heat loss of a body is proportional to the temperature difference between the body and its surroundings.”

Newton was also highly important to the field of optics. He lectured on optics for two years, and investigated the refraction of light. Newton demonstrated that white light can be decomposed by a prism into a spectrum, and that a second prism can recompose the spectrum into white light. Further observation led him to develop his theory of color, which was that color is the result of objects reflecting more of one color of light than others. Light is colored before it reaches the object.

Newton was arguably one of the greatest scientists of all time. Without a doubt, he has made numerous influential contributions to modern science, especially through his establishment of the foundations of classical mechanics through his laws of motion. His law of universal gravitation was also important in the confirmation of a heliocentric system as the correct model. However, it has been said that some of his ideas, such as his law of universal gravitation, may have been plagiarized (from Robert Hooke, who, granted, was notorious for accusing people of plagiarizing from him). Newton was also deeply religious, and wrote more on religion than he ever did on science and mathematics. He was an unorthodox Christian intensely interested in the occult. Today, however, he is remembered for his immense contributions to modern science and his establishment of the field of classical mechanics.

# The Renaissance and the Scientific Revolution: The Age of Growth

The Renaissance and the Scientific Revolution constituted what was, perhaps, the most significant period of discovery and growth of the sciences in the whole of history. This period preceded the Enlightenment. The Renaissance and Scientific Revolution were responsible for the introduction of ideas such as a heliocentric solar system and laws of planetary motion. Many cite this era as the period during which modern science truly came to fruition, noting Galileo Galilei as the “father of modern science.” This post will cover the contributions of three highly important scientists from the era of the Renaissance and the Scientific Revolution: Nicolaus Copernicus, Galileo Galilei, and Johannes Kepler.

Nicolaus Copernicus (1473-1543) was a Renaissance polymath responsible for what some have called the “Copernican Revolution.” One of the most important contributions of Copernicus was to the field of astronomy. Copernicus placed the sun at the center of the universe, rather than the earth. The previous system, the Ptolemaic system, was geocentric (with the Earth at the center of the universe). In 1543, in his On the Revolutions of the Celestial Spheres he published his theory (which he had formulated much earlier). While he still had the planets moving in patterns of circles rather than ellipses, he postulated that these circles had no one center. He said that the center of the Earth is not the center of the universe, but is the center of gravity and the lunar sphere. He stated that Earth is one of seven planets in the solar system around the Sun, which is stationary. He said that the Earth’s motions include rotation, revolution, and annual tilting of the axis. He concurred with the scientists before him that the distance from the Earth to the Sun is negligible compared to the distance from the Earth to the stars. Tycho Brahe was one of Copernicus’s successors; however, he developed the Tychonic System, an essentially geocentric model which included some mathematical foundations of heliocentric models.

The heliocentric model of Copernicus.

Galileo Galilei (1564-1642) built on the foundations of Copernicus’s work. Also a firm believer in the heliocentric model, Galileo was placed under house arrest for much of his life for his beliefs after standing trial in Rome. He was called a heretic for believing that the Sun, not the Earth, was the motionless center of the universe. In recent years the Church has acknowledged that its handling of the Galileo affair was regrettable. In 1610, Galileo published The Starry Messenger, which reported his discoveries of four of Jupiter’s moons, the roughness of the Moon’s surface, stars invisible to the naked eye, and differences between the appearances of planets and fixed stars. He also published observations on the full set of phases of Venus, and wrote regarding the tides. Galileo’s theory was that tides were caused by the sloshing back and forth of water in the seas at a point on Earth’s surface which speeded up at certain times of day due to the Earth’s rotation. However, this is incorrect (as the tides are caused by the moon). Galileo also importantly put forth the basic principle of relativity (the laws of physics are the same in any system that is moving at a constant speed in a straight line). Galileo was one of the first to observe a sunspot and not mistakenly attribute it to a transit of Mercury. Galileo also demonstrated that falling bodies of similar material but different masses have similar times of descent. In essence, descent time is independent of mass. Galileo also showed that there are as many perfect squares as whole numbers, even though most numbers are not perfect squares; since there are squares and non-squares, and not all numbers are squares, there must be fewer squares than non-square numbers. However, for every number there is a square. Therefore, there is actually a 1:1 ratio of non-squares to squares.

Johannes Kepler (1571-1630) is responsible for creating Kepler’s laws of planetary motion. These laws include that the orbit of every planet is an ellipse with the Sun at one of the two foci, that a line joining a planet and the Sun sweeps out equal areas during equal intervals of time, and that the square of the orbital period of a planet is directly proportional to the cube of a semi-major axis of its orbit. Kepler was one of the first to incorporate the field of physics and the field of astronomy. This caused some controversy, however his ideas became more widely read and accepted after his death. Once Newton derived Kepler’s laws from a theory of universal gravitation, they became part of the theoretical canon of the Scientific Revolution.

In the next and final post, the contributions of Isaac Newton will be considered. Newton, arguably one of the greatest physicists of all time, lived during the late Renaissance and Scientific Revolution. Newton was one of the precursors to the Enlightenment who sparked the ensuing period of incredible intellectual growth.

# Medieval Physics: Transition and Stagnation

Responsibility for the growth of the science of physics moved from Greek physicists to Middle Eastern physicists and Western European philosophers. Greek culture stagnated and intelligent thought began to shift to the Middle East. Western Europe contributed little significant thought to the field of physics before the Scientific Revolution later on, as the West became consumed with religious thought and Scholasticism. This post will cover the scientific contributions of Middle Eastern scientist and polymath Alhazen, as well as the ideas of Western European philosophers and theologians.

Alhazen is arguably the greatest of all of the medieval scientists, at least of the Arabic scientists. Alhazen was often called “Ptolemy the Second,” or, in medieval Western Europe, “The Physicist.” He is most well-known for his contributions to the science of optics, along with physical science and the further development of the scientific method. His most well-known and greatest work is his seven-volume Book of Optics. It had a great influence on scientists for a good time to come, including Johannes Kepler.

The most important and influential theory this work dealt with was the intromission theory of vision, which was also suggested by Aristotle. The dominant theory, however, was the extramission, or emission, theory, purported by Ptolemy, and by Euclid in his Optica. The emission theory of vision was that vision was caused by light emitted from the eyes. Alhazen, however, suggested with experimental evidence in his Book of Optics that vision was actually caused by rays of light entering the eyes, or the intromission theory which is dominant today. Today, of course, we know that light is transmitted through photons which are emitted by a light source, reflected by visible objects, and picked up by a detector like the eye. His argument against emission theory was that rays from our eyes could not reach distant stars the moment we open our eyes, and therefore we wouldn’t be able to immediately see them like we can. Alhazen also pointed out that eyes could be dazzled by looking directly at a very bright light, which likely wouldn’t happen if the eyes emitted rays in order to see.

Not only did Alhazen also prove that rays of light travel in straight lines, he explained the effect of a pinhole camera. This is the effect where an entire image is projected through an aperture, rather than just what can be seen by looking directly through the aperture. Alhazen showed this by being the first to project an entire outdoor image to a screen indoors using a “camera obscura,” which is a room or box with a hole in one side. This aperture allows the light of the surroundings to pass through and be projected onto a screen on the inside.

Alhazen also contributed significantly to the development of the modern scientific method, because he relied on experimentation and controlled testing to explore his scientific inquiries. He was also one of the first scientists to apply mathematics to his theories and experiments. This was a critical inclusion, as it shaped the logical direction of modern science for centuries to come.

Western philosophers became aware again of the works of the Ancients through translations from Arabic to Latin. Earlier, Greek works had been translated to Arabic. This translation allowed the proliferation of Ancient thought throughout the Western world. Ancient philosophy which did not conflict with Christian theology was once again relevant and widely discussed. Where Ancient philosophy did not conflict with Christian theology, the two were reconciled to create the Scholastic school. Especially important to Western European scholasticism were the ideas of Aristotle, which formed the basis of Western philosophy for centuries to come. This embracement of the ideas of Aristotle over Plato marked a revolution in the ideas of Christianity, because, prior to Scholastics such as Saint Thomas Aquinas, Plato was the favored Ancient Greek philosopher of Christianity.

An important medieval physical theory was the theory of impetus. The theory of impetus was based on Aristotelian dynamics, and was introduced in the sixth century by John Philoponus. It was a precursor to modern knowledge of inertia. Initially, it attempted to explain motion against gravity. Philoponus’s theory was that an object can gain forced motion through violent action but that this impressed motion is only temporary and that “natural motion” (gravity) will again take hold. In the fourteenth century, Jean Buridan gave the name impetus to the theory. He also gave the theory the mathematical formula impetus = weight x velocity. His theory was actually very similar to modern ideas of momentum. Buridan made sure to apply his theories to Christianity, as he considered his idea an extension of Aristotle’s theories but was dissatisfied with their lack of Christian ideology. During the Renaissance and the later Scientific Revolution, experimentation would come to form modern ideas of inertia. It is important to note that Asian philosophers BCE formed very accurate ideas of inertia long before any Western philosophers or scientists did. For example, the Mojing stated that “The cessation of motion is due to the opposing force…If there is no opposing force…the motion will never stop. This is as true as that an ox is not a horse.”

John Philoponus

The medieval era was one of slowed intellectual progress, especially in the sciences. However, following the medieval era many of the greatest intellectual minds came to fruition in the Renaissance. These included Galileo, Copernicus, and Kepler. In the next post, the ideas of these scientists will be discussed. Finally, the ideas of Isaac Newton, the last great Renaissance scientist, will be discussed, concluding our journey from the Greeks to the Renaissance.

For a list of sources, or for further reading, see the sources page.

# Archimedes and Ptolemy: Two of the Last Great Greeks

As we near the end of the most significant era of Ancient Greek innovation, there are at least two more Greek philosophers who must be discussed. Archimedes and Ptolemy made a huge impact on the world for centuries to come. Many of Archimedes’ ideas, principles, and inventions are still in use today. Ptolemy did not make many lasting contributions to science, but did make one significant contribution (which he is most known for) which shaped ideas of astronomy for centuries.

Archimedes (287 BC – 212 BC) was a Greek from Syracuse, Sicily. He is widely known for his contributions to physics and engineering, along with his additions to the fields of astronomy and mathematics. He is understood to be one of the greatest mathematicians of all time, and many consider him to be the first scientist. Archimedes was important in the hydrostatics branch of physics, and also created many machines and explained the principle of the lever.

Arguably Archimedes’ most lasting invention is what is today known as the Archimedes screw. Also known as a screwpump, it is used to transfer water from low-lying bodies to irrigation ditches. It is argued that other unknown Greek engineers may have invented it and it was just attributed to Archimedes. However, the story is that Archimedes was contracted by King Hiero II to design the largest ship in classical antiquity for Syracuse. Since the ship was so large and would begin to leak water through the hull, Archimedes supposedly developed the screw to remove this water. The Archimedes screw consists of a spiral around a center shaft encased in a hollow pipe. The screw is operated either manually or by a windmill. The lower part of the spiral picks up some of the water in the body of water it is inserted into, and the turning of the screw carries it up to the top of the screw, where it drops out into the irrigation ditch. Some have even said that this invention was used to irrigate the Hanging Gardens of Babylon. The screw is still used today in various machines, in its original form and in some variants. Also, using the screw in reverse by pouring water into it can power an electrical generator.

Archimedes has created other, more popularly-known inventions. For example, it is said (controversially) that he aligned an array of mirrors on a beach in such a manner as to combust the tar on the decks of enemy ships, burning them. However, the truth of this account is disputed due to the fact that the beach was facing a direction which would not have been optimal for this sort of feat, and that later attempts to recreate it have failed. Another invention of his was the Claw of Archimedes, which he designed in order to defend his home town of Syracuse. The Claw was a large crane with a grappling hook which would be dropped on a boat and then swung upwards, lifting it out of the water or sinking it.

The lever was explained much more thoroughly by Archimedes than any before him. His “Law of the Lever” is that “Magnitudes are in equilibrium at distances reciprocally proportional to their weights.” He is famous for stating “Give me a place to stand on, and I will move the Earth.”

One of his greatest contributions to physics was Archimedes’ principle. Upon his formulation of it, he is said to have shouted “Eureka!”, or “I have found it!”, immortalizing the phrase. The principle is that “Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object. In mathematical terms, density/density of fluid = weight/weight of displaced fluid. With regard to floating objects, Archimedes stated that “Any floating object displaces its own weight of fluid.” It is said that Archimedes used his principle to determine if solid gold was more dense than a golden crown to be given to King Hiero II, but this story, too, is somewhat dubious due to the fact that Archimedes would probably have had to measure the displaced water extremely accurately.

There is much more that could be said about Archimedes, but it is also important to discuss Ptolemy. Ptolemy (90-168) is most known for his treatise known today as the Almagest. This treatise contains the great body of his theories which continued to survive for centuries afterwards. It was his Almagest which contained the geocentric Ptolemaic system of the cosmos. According to Ptolemy, the “celestial realm” is a sphere, similar to that described by Aristotle. It moves as a sphere, and the Earth is a sphere. The Earth is at the center of the cosmos and does not move. In relation to other stars, based on distance, the Earth has no appreciable size and must be treated as a geometric point. The order of the solar system was: Earth, the Moon, Mercury, Venus, the Sun, Mars, Jupiter, Saturn, and then the sphere of fixed and unmoving stars. This was followed by the sphere of the “prime mover” described by Aristotle. Each planet is moved by a system of its deferent sphere and its epicycles. The epicycles required an eccentric deferent and an equant point. The Ptolemaic system was widely accepted for centuries until Copernicus’ heliocentric model came to be more dominant.

In the next post, we will consider the contributions of medieval physicists, including Arabic scientists and the idea of impetus. These laid the foundations for the modern ideas of the Scientific Revolution which began towards the end of the Renaissance era and included Kepler, Copernicus, Galileo, Bacon, Newton, Leibniz, Descartes, and others.

See sources page for a list of sources.

# Natural Philosophy: Aristotle

Aristotle (384-322 BC) established the philosophical basis of physics with his “natural philosophy,” and is also considered one of the greatest philosophers in history.

“In all things of nature there is something of the marvelous.” – Aristotle

As such, much of his work in physics is speculative but offers a great deal of insight. He did contribute real research to several areas of science, and had incredible foresight for an intellectual from the age of classical antiquity.

Significantly, Aristotle espoused a certain belief in inductive reasoning which was not found in his more deductive teacher, Plato. Therefore, Aristotle’s philosophical method at least more closely resembled the current scientific method that did his teacher’s. According to Aristotle, he studied phenomena which were caused by “particular,” which was then a reflection of the “universal,” or the set of physical laws. Aristotle also described “science” as “… either practical, poetical, or theoretical.”

One of the many fields to which Aristotle contributed was the field which he called “natural philosophy.” He regarded “natural philosophy” as a “theoretical” science. Aristotle devoted most of his life to the natural sciences, contributing original research to physics, astronomy, chemistry, zoology, etc. Aristotle expressed an early teleological belief in saying that natural things tend to certain goals or ends. Teleology is the philosophical belief that there are certain final causes in nature. According to Istvan Bodnar, in The Stanford Encyclopedia of Philosophy, “Nature, according to Aristotle, is an inner principle of change and being at rest (Physics 2.1, 192b20–23). This means that when an entity moves or is at rest according to its nature reference to its nature may serve as an explanation of the event.” Essentially, Aristotle believed that reference to the innate qualities of an object (whether it is at rest or in motion naturally) would assist in determining what caused an event. Of course, we now know that objects are set in motion when acted upon by a net force and tend to stay in motion until another net force acts upon it. However, Aristotle made an important point with this idea: that forces acting upon objects can either set them in motion or make them tend towards rest.

One of Aristotle’s more famous ideas of natural philosophy is his addition of the celestial “aether” to the four natural elements suggested by Empedocles. The “aether” is, according to Aristotle, the “greater and lesser lights of heaven.” By this, Aristotle meant the stars of the universe which were visible to him in the night sky. The other four natural elements (fire, earth, air, and water) are able to change and mix, according to Aristotle. This is an early precursor to modern ideas of phase transition. These elements are capable of “generation and destruction,” as opposed to the aether, which is unchanging. Aristotle concludes that these bodies cannot be composed of the four elements, because they are not capable of change. Fire, earth, air, and water are terrestrial elements while aether is a celestial element. The most important point is that Aristotle redefined natural elements to include early ideas of phase transition.

Aristotle also made an important attempt to explain gravity. His theory was that all bodies move toward their “natural place.” Natural places are also based largely on composition (of the natural elements). For example, since many commonplace liquids are composed at least partially of water, they move towards sea-level, where the oceans are, or down towards the ground, where ground water can be found. Or, since smoke is air-like, it moves up into the atmosphere where air is. This was the way in which Aristotle described general motion. Aristotle also believed that vacuums did not exist, but that if they did, terrestrial motion in a vacuum would be infinitely fast.

Aristotle described celestial motion in terms of crystal spheres, which carried the sun, moon, and stars in unchanging endless circular motion. In Metaphysics, Aristotle says “that there must be an immortal, unchanging being, ultimately responsible for all wholeness and orderliness in the sensible world. And he is able … to discover a good deal about that being…” This is his concept of the “unmoved mover,” which is capable of moving other things without being moved. An “unmoved mover” is reminiscent of the modern idea of gravity, which is not actually a physical object but does cause motion without any other motion being necessary.

Highly significant was Aristotle’s argument that the Earth was actually spherical. He believed that the Earth was a small sphere. Since he could see stars in Egypt and Cyprus which he could not see further north, he concluded that this was because the Earth is a sphere and is small because such a significant change in the sky would not happen unless on a small sphere. Based on his theory that the earth element tends towards a center, just as all water heads down to seal level towards the concentrically spherical ocean and all air tends to move upwards to form a concentrically spherical atmosphere, he theorized that the Earth was a sphere. Further evidence Aristotle used to support his round Earth theory was that the shadow the Earth imposes on the Moon during a lunar eclipse is round.

Clearly, Aristotle made some significant contributions to the field of physics. He made several further contributions to physics, cosmology, and astronomy. Aristotle defined the scope with which Western culture would observe nature and theorize about physics for centuries. There would have been no Newtonian physics without the strides made by Aristotle. There are several more contributions to physics which could be covered here, but due to limited space, they must be discounted for now. In the next post, the ideas of Archimedes will be discussed, perhaps along with those of some later Greeks.

For further reading, see the sources page.

# Foundations of Physics: Thales and Euclid

Traditionally, the history of physics begins with the advancements made by Ancient Greek civilization. The Ancient Greeks are widely considered to have been the cradle of Western thought, and to have laid the foundations for modern understandings of mathematics, astronomy, and physics. Indeed, the science of astronomy was a precursor to the birth of physics, and the Greeks had a heavy hand in shaping the progress of astronomy for centuries to come.

There were several Greeks who made important contributions to the field of physics. Some of the first, however, were from the city of Miletus, beginning with the ideas of Thales (624 BCE-546 BCE). Bertrand Russell, the great mathematician and philosopher, is noted as having said that “Western philosophy begins with Thales.” Thales was one of the Seven Sages of Greece, who were revered by Greeks of the following centuries for their insight and wisdom. Thales heavily influenced Aristotle, who described Thales as the first philosopher in the Greek tradition.

Thales was a Milesian philosopher credited with what is often described as the “discovery of nature,” or the realization of the fact that natural phenomena are explicable in terms of matter interacting according to natural laws. This was contrary to the prevailing view that natural phenomena were the arbitrary result of the ever-shifting moods of the gods of the Greek pantheon. Thales ultimately outrightly rejected the idea of mythological explanations for nature, attempting to explain all of his ideas without the use of mythological references. Because of this, his unique ideas became highly influential.

An example of Thales’s more naturalistic, less mythological explanations of nature was his postulation that the flat earth lay on a vast ocean, and that earthquakes were caused by disturbances in the waters of the ocean. The common belief was that earthquakes were caused by the rage of the sea-god Poseidon. A fellow Milesian, Anaximander, later suggested that lightning was caused by wind splitting up clouds, rather than by Zeus.

The take-away point about these ideas is not their level of correctness or incorrectness, but their relative correctness; they were revolutionary ideas in that they did not involve fantastical, mythological explanations. They were also revolutionary in that they were not to be taken as truth. These early scientists admitted incomplete knowledge of the workings of nature, and it was assumed that each new hypothesis was a topic of debate amongst the scientific community. The Milesians, therefore, were an important example of an early culture of rational scientific debate.

Another important contribution by Thales was his methodology. Thales was one of the first to define general principles of science and set forth hypotheses. These critical ideas have led many to dub him the “father of science,” although this is sometimes disputed.

His belief in rational as opposed to mythological explanation was not the only meritorious contribution of Thales. He also was responsible for leaps and bounds in geometry. Thales once said “Space is the greatest thing, as it contains all things.” There is a story in which he calculated the height of a pyramid at the moment when his shadow was the same length as his height. Since Thales understood right triangles, he knew that the distance from the tip of the shadow to the pyramid’s center would have been the same as its height. Thales’s knowledge of triangles allowed him to create Thales’ Theorem: DE/BC = AE/AC = AD/AB.

However, several other Greeks contributed significantly to the development of physics. The most notable, of course, is Aristotle. Aristotle will not be discussed in this post in order to devote the space of a full post to him later on.

Euclid (300BC), however, is worthy of discussion. Euclid’s contributions to geometry are critical for our understanding of space, and thus of all things physical. In particular, his work Elements, consisting of thirteen books, established Euclidean geometry and modern understanding of mathematics. Copernicus, Kepler, Galileo, and Newton were all influenced by Elements. Euclid’s Phaenomena described spherical astronomy. This was crucial, as it is well established that astronomy formed the basis of primitive physics. His work On the Heavy and the Light contains concepts like specific gravity and several propositions. Little is known about Euclid’s life, and he lives on solely in the substance of his works. Many famous physicists, from Einstein (carrying his “little holy book of geometry,” Elements) to Galileo were heavily influenced by Euclid. Even Abraham Lincoln would carry a copy with him in order to sharpen his logical skills as a lawyer “You never can make a lawyer if you do not understand what demonstrate means.”

Many, many Greeks deserve attention as laying some of the earliest (at least Western) foundations of modern physics. However, due to limited space, Thales and Euclid will have to suffice for now. Next, I will examine the fundamental contributions of Aristotle to the creation of modern physics. Aristotle was extremely important, and will be covered in full in the next post.

# Introductory Post

My topic is “The Birth of Physics – Greeks to the Renaissance.”

Aristotle                                        Galileo

Source of photos, and basic background information.