During the 16th century, as the Copernican model of the universe became increasingly accepted, astronomers focused their attention on producing more precise measurements of the stars and planets. The greatest observer of this per-telescopic era was Tycho Brahe (1546 – 1601), born to a Danish noble family, where he rejected a career in politics and instead dedicated his life to astronomy after witnessing a solar eclipse in 1560 that hooked his attention to the sky.
Brahe is best known for his meticulous astronomical observations that he recorded in his observatory granted to him by King Frederick II, on the island of Hven (now called Ven) near Copenhagen. The observatory had some of the finest instruments of the time, its own printing press, was a frequent destination of visiting scholars, and became a training station of a generation of young astronomers.
The completeness and accuracy of his observations cemented his legacy as one of the greatest astronomers of his era. The breadth of data compiled in the observatory is no small feat – he accurately plotted the position of nearly 800 stars all without the assistance of a telescope. Famously, the observational data compiled at the observatory assisted Johannes Kepler in calculating the elliptical orbits of the planets.
The Earth-centered universe was the prevailing wisdom of Medieval Europe until a Polish scholar named Nicolaus Copernicus suggested otherwise in his 1543 book, On the Revolutions of Celestial Spheres. Copernicus was not the first person to suggest a heliocentric model of the universe; 1800 years prior Aristarkhos of Samos suggested this same idea. However that idea never took hold among most scholars and was never able to compete with the geocentric model championed by Ptolemy and laid out in his popular treatise known as the Algamest. The Algamest was to become the dominate cosmology of Europe for over a millennia.
The 16th century marked a turning point in history where long held beliefs about the universe first seriously began to be questioned. The discovery of the new world at the end of the prior century no doubt had an impact on people questioning the ancient and authoritative accepted wisdom of the time. If the Earth wasn’t like people thought it was, maybe the celestial sphere above us wasn’t either?
A Radical Astronomical Idea Ahead of it’s Time
The fact of the heliocentric solar systems seems common knowledge to everyone today but we must remember the technological limitations of the period in which this writing took place. Prior to the invention of the telescope astronomers had to rely on naked eye observations. This method was very imprecise and led many to believe that the sun, moon, and stars revolved around the earth. It took the unique imagination and creative mind of Copernicus to suggest a different model of the solar system.
Copernicus was a student of history. He studied many previous works of astronomy and he even mastered the Greek language to read parts of Ptolemy in Greek. In 1514 he had written a brief outline of his work devoid of any mathematics which he showed to a few close acquaintances. In the proceeding years he continued to gather additional data to support his theory. He did not publish his work for nearly 30 years until two friends encouraged him to finally publish it. His delay in publishing was due to his well founded fears that his work would create a controversy within the Catholic Church.
This treatise itself is divided into six sections, closely mirroring Ptolemy’s Algamest. Copernicus made his heliocentric argument from a mathematical perspective rather than as a physical truth. Some of his immediate predecessors such as Tycho Brahe seems to agree. Brahe stated that he believed in the mathematical superiority of the Copernicus model however he doubted its physical truth in reality. Copernicus also relied on the conventional wisdom of the time that all heavenly bodies revolve in perfect circles and so he continued to use the epicycles, additional series of circles, also used in the Ptolemaic system.
The Heliocentric Solar System
On the Revolutions of Celestial Spheres is treatise is about astronomy, but it also impacted the philosophical view of humanity. It was a radical break from the traditional thought of the time as Copernicus indicates in the passage below.
I therefore took this opportunity and also began to consider the possibility that the Earth moved. Although it seemed an absurd opinion, nevertheless, because I knew that others before me had been granted the liberty of imagining whatever circles they wished to represent the phenomena of the stars, I thought that I likewise would readily be allowed to test whether, by assuming some motion of the Earth’s, more dependable representations than theirs could be found for the revolutions of the heavenly spheres.
Nicolaus Copernicus
A Prelude to the Scientific Revolution
The book was published in the same year of Copernicus’ death, just before he died. We know that Copernicus had refused to publish his ideas earlier due to fear of persecution from the Catholic Church, and the books dedication to Pope Paul III was in attempt to assuage the church. Sadly, this yet another tragic example of dogmatic religious belief hindering the progress of truth, knowledge and the advancement of science.
Although hindered by the church, Copernicus’ model was later confirmed by Galileo Galilei after he observed the moons revolving around Jupiter and the phases of Venus. Even then it did not become fully accepted by scholars until Isaac Newton formulated his Law of Gravity in 1687. Additionally Copernicus’ book was largely ignored by scholars and by the church in the decades after its publication. It took the church over seven decades before it issued a decree to suspend its publication.
Despite its relatively insignificant influence in the years after its publication it can be said that this now famous work is when the Scientific Revolution in Europe began. It did not spark and immediate change in thinking and the progress in scientific advancement was gradual. Many other scientists amended and improved his ideas. But it challenged people to think differently about the accepted wisdom of the day and paved the way for other scientists to publish and produce their own original work and discoveries.
If there is one person who could be credited with establishing the principles of science and ushering in the era of the Scientific Revolution it would be Francis Bacon (1561 – 1626). Bacon argued for a new way of learning and collecting knowledge, one of forming observations, formulating hypothesis to explain the observations, then testing the hypothesis by rigorous experimentation.
Francis Bacon was born in London in the winter of 1561, home-schooled in his early youth and entered Trinity College at the age of 12. Although he excelled in the traditional medieval curriculum, he came to the conclusion that the methods were flawed. The medieval curriculum was dominated by the thinking of Aristotle. Bacon was impressed by Aristotle’s intellect but he believed that his methods stood in the way of scientific progress.
After his schooling he spent much of his life working in the British government before publishing his great philosophical work, Novum Organum (New Instrument), where he laid out his method of inductive reasoning and the scientific method. Bacon believed that the new body of scientific knowledge should be based on experimentation and observation and not on philosophical arguments or logic.
As an ambitious man Bacon had a very successful career in British politics and he rose to great heights within the government. His career saw steady progression, highlighted by being knighted by King James I in 1603 and culminating with the position of Lord Chancellor in 1618. Sadly his career ended in disgrace when he was charged with bribery and corruption charges in 1621. He was fined and sentenced to some time in prison, ending his political career. He spent his remaining days studying and writing before he died on pneumonia in 1626.
Bacon had an enormous impact on a generation of scientists, most notably in Robert Boyle. He was also an influential proponent in the concept of establishing scientific organizations, where information could be shared and ideas debated. It was in the Baconian spirit that the British Royal Society was formed in November 1660, with Boyle being one of its founding members. It is the oldest scientific society in existence today.
Referred to by many as the founder of modern anatomy, Vesalius (1514 – 1564) was born in Brussels, studied medicine in Paris, and finally settled in Italy as the Chair of Surgery and Anatomy at the University of Padua, which he earned the first day of receiving his medical doctorate from the University. He published his famous works on human anatomy, On the Fabric of the Human Body, a collection of seven books presenting a modern anatomical view of the complete human body, rife with many detailed drawings of the human body.
Vesalius was so influential because he was able to correct the errors of earlier anatomists due to his direct observation of the body through the dissection of executed criminals. The detailed illustrations were drawn by artists present at the dissections and provided a valuable resource for medical students to reference. The improved printing technology of the Renaissance helped preserve and distribute these drawings.
Later in life, Vesalius joined Charles V court as a doctor, leaving his post in Padua. After serving a little more than a decade in the imperial court Vesalius embarked on a pilgrimage to the Holy Land where on his return he was shipwrecked on an island and soon died. He was 50 years old at the time of his death but his influence on anatomy would be permanent.
A vital precursor to the scientific revolution, the invention of the printing press changed the way information spread across the world by in two important ways; by improving its fidelity and by hastening its rate of reproduction. Within years after its invention an increasing numbers of books of increased accuracy quickly spread across Europe and the globe providing the medium for a diffusion of ideas to a growing literate population.
The Print Revolution
The Printing Press
The invention of the printing press is widely regarded as one of the most influential inventions in history. It drastically changed the way information was shared around the world. Prior to the printing press information had to either be spoken and memorized or hand-written onto papers and books. Writing offered a cleared benefit to limited and imperfect memory. However very few people could write (and only a few more could read) and the process was long and tedious. Most scribes could only produce several pages of manuscript per day. The process of creating a single book could take months, or even years. Although a copied text is more reliable than memory, errors are still inevitable in the coping process.
In 1450 a new invention called the printing press offered a new way to create text. The printing press was the creation of the German inventor Johannes Gutenberg, whose creative insight was to combine movable type with a pressing mechanism to create the Gutenberg press. Simple, yet revolutionary. Block printing was not an original idea of Gutenberg. The Chinese used wooden blocks coated in ink to copy religious texts centuries as early as 200 AD. Since the Chinese language contained over 40,000 different characters, movable block printing was not very practical to Chinese printers. It was the idea of block printing and not movable type that was transferred East to West along the Silk Road.
Gutenberg created his movable type casting letters in lead. Once he had an array of letters he could create a page for printing by arranging them in line on a rack on a wooden tray. In order to print a page you first line up the metal type, apply ink, place the paper on top then apply the press. Many pages could quickly be printed and then the rack was cleared for the next page to be printed. What once required hours to copy by hand was reduced to minutes with the printing press.
Changes in the Post Printing Press World
The printing press allowed for the mass reproduction of printed material. Printing spread at a remarkable rate, driving up literacy rates with it. Within a few decades hundreds of presses were active in hundreds of cities around Europe, and this basic method of mass production of printing did not change much until the late 18th century.
Martin Luther Hammers his 95 Theses to the Church Door (Credit: Wikimedia Commons)
Printings impact was far reaching, influencing religion, science, and government. Early on its most important impact was religious. Gutenberg’s most famous work, the Gutenberg Bible, is considered a triumph of early printing. It was in circulation by around 1455 and and allowed for broader access to the Bible than ever before. The emerging middle class – merchants and trade professionals – now had access to the Bible in their vernacular language, rather than in Latin. The rapid reproduction and widespread distribution of religious ideas was not all good news for the church, however. In 1517 Martin Luther famously nailed his 95 theses to the door of All Saints’ Church, and other churches in Wittenberg, Germany. Luther’s 95 theses were a list of propositions criticizing the Catholic Church for the sale of indulgences and other corrupt practices. These ideas were rapidly reprinted and spread like wildfire across the European continent, sparking the Protestant Revolution.
Centuries later the printing press would initiate a new type of revolution known as the scientific revolution. It began simply by helping to revive some of the lost knowledge from antiquity. Rare and long forgotten books of the Greeks and Romans could be copied quickly and distributed to more people. In pursuit of ancient wisdom, new wisdom also began to flourish. Information about the observed and natural world could now be shared me quickly and easily. New ideas began to overthrow old ideas, and soon people began to question everything they they thought they knew about the world, including their form of government. The radical, new ideas of the Enlightenment were critical in forging the French Revolution. Newspapers, books and pamphlets were published in numbers never before seen. The French government censured the printing of many of these books however they were printed outside of the country and smuggled in. An explosion of opinion and debate ensued further resulting in even more printed material. All of this printed material contributed to the spread of the new revolutionary ideas of democracy and republicanism. These ideas moved thorough Paris, into the provinces and inspired the passions of the French people to overthrow their monarch and institute a new form of government.
There is yet one more profound change caused by the invention of the printing press. Since spread information could be shared like never before, it also created a new sense of community by allowing others to read together. Most people preferred to read in their local dialect as opposed to Latin. The natural result was the creation of new languages as certain dialects and regional variations became standardized thanks to the distribution of printed text. A national identity sprang up all across Europe and eventually the rest of the world, creating unified nations. In this sense and many others we can literally say the invention of the printing press created our world as we know it today.
A dazzling display of colorful fireworks can always delight a crowd and put everyone in attendance in good spirits. The shrieking boom of a cannon delivers the opposite reaction. That is the paradox of gunpowder, the invention that is responsible for both of these powerful and spectacular activities.
Discovery and Spread
Gunpowder
Gunpowder was discovered in China around the year 900 during the Tang Dynasty. As with so many civilizations of the time, alchemy was a thriving occupation. The Chinese alchemists were working on an elixir of life when they stumbled upon the formula for an elixir of death. They called their formula fire medicine and soon found a variety of uses for the explosive material such as in fireworks and in military weaponry.
A powerful military technology could not stay isolated for long, but it did take the knowledge of gunpowder around 350 years to spread to the Middle East. Soon after arriving in the Middle East it quickly made its way into Europe by 1300, now nearly 400 years after its invention. William of Rubruck is likely responsible for bringing gunpowder back to Europe after his encounters with the Mongols, although there is little direct evidence for this. The earliest European reference to gunpowder is found in Roger Bacon’s great work Opus Majus (Opus Majus literally means Great Work in Latin) in 1267.
Its impact in warfare was substantial and almost immediately felt on the battlefield through infantry weapons, having a devastating effect on the knightly class. Although this was a setback for the nobility they still had their walled castles. Even those castles would soon succumb to the power of gunpowder.
Impact on Warfare
Chinese Fire Arrow (Credit: Wikimedia Commons)
Fire arrows were the initial military weapon for gunpowder. A small pouch of gunpowder was attached the arrow resulting in open fires upon impact. Other incendiary devices such as bombs and fire lances were soon widely deployed. Many proto-gun and proto-cannon designs were experimented with in the 12th and 13th century. During the later part of the 13th century, the Mongols were using a hand cannon, something we can definitively call a firearm. It took until the 1320s for guns to catch on in Europe as a form of weaponry but they soon rapidly spread across the continent. Within twenty years larger artillery weapons were arriving on the battlefield. The strategies of warfare were on the verge of being revised.
Artillery weapons powered by gunpowder, initially unreliable but once perfected, made once impenetrable walled castles vulnerable. Sieging a castle in the Middle Ages was a long and arduous process. Techniques involved tunneling under walls, ramming down walls, starving out the inhabitants, all of which could take weeks or even months. However with the invention of cannons firing their devastating projectiles from a safe distance, a castle could be taken within a single day.
No other example illustrates the power of cannons than the fall of the city of Constantinople to the Ottoman Turks in 1453. Certainly the city’s downfall was the result of many factors – a weakened Byzantine state and Western Europe’s reluctance to provide assistance to name a few. But one undeniable factor was the effective Ottoman use of cannons.
A Cannon Used by the Ottoman Turks to Pummel the Walls of Constantinople (Credit: Wikimedia Commons)
The walls of Constantinople were considered to be impenetrable. Five meters thick and 20 meters high, they stretched over four miles long from the Golden Horn to the Sea of Marmara. Much of it was double walled with some area’s having up to five walls deep. These walls had held off dozens of sieges for over 1,000 years. The Ottomans employed around 60 cannons which battered and weakened the walls for the duration of the siege. The final assault by the Ottoman’s was focused on the section of the wall most damaged by cannon fire and was eventually breached by the invading Turks.
The Chemistry of Gunpowder
Gunpowder consists of a mixture of saltpeter (potassium nitrate), charcoal, and sulfur. Early on this proportion was experimented with until a 75% saltpeter, 15% charcoal, 5% sulfur solution was determined to be most effective. The sulfur and charcoal act as the fuel, with saltpeter acting as an additional oxidizer creating a stable chemical reaction with the rapidly expanding gases resulting in the propelling motion. This was the only known chemical explosive until the middle of the 19th century. Since that time gunpowder has been replaced by other means in military weaponry but it is still used in fireworks today.
Antikythera Mechanism, National Archaeological Museum, Athens (Credit: Wikimedia Commons)
One valuable technology in assisting people do to work was the invention of gears. Gears consist of a system of cogs that takes energy from an input source, such as flowing water, and convert it to an output source, such as a pump. The oldest archeological evidence for gears dates to about 230 BCE in China, however evidence of geared technology prior to that time is referenced from ancient Imperial Chinese manuscripts.
A Brief History of the Invention of Gears
Reconstruction of the Antikythera Mechanism (Credit: Wikimedia Commons)
The invention of gears are a natural extension from the invention of the wheel. They appear to have been invented in China but it was the Greeks who demonstrated their widespread use. Archimedes is believed to have used gears in his constructions and in the 4th century BCE Aristotle provided one of the earliest descriptions of gear-like devices. By 100 BCE they were being used across much of Greek civilization.
The discovery of the Antikythera mechanism, dubbed the worlds first analogue computer, is one of the earliest examples of a complex mechanism using a combination of gears. This device was discovered in 1901 from a shipwreck off the coast of the Greek island Antikythera. The instrument was used to predict astronomical positions. It is a complex, hand-wound device consisting of 30 bronze gears. Like a clock, it had a circular face with several hands that displaced times of celestial objects such as the Sun, Moon, and known planets. Winding the device forward or backward would move the hands at various speeds thought the interconnecting gear train. Not all of the pieces have been fully recovered so the precise mechanisms and exact purpose of the device is not fully understood, but it does unequivocally show that gears were being used in complex devices by 100 BCE.
A Remarkable Level of Flexibility Leads to a Remarkable Level of Functionality
Several Types of Gear Designs
There are many ways to design and combine gears making them extremely versatile. The various different types of gears can be broadly classified by the orientation of their axes. There are other characteristic differences such as gear tooth design and gear shape.
The first category is parallel axes. Spur gears and helical gears have parallel axes. This design is easy to manufacture and produces efficient power and motion transmission. The next category is intersecting axes. Gears such as plain bevel and spiral bevel have intersecting axes. These also have high transmission efficiencies. A final category that is non-parallel and non-intersecting such as worm gears. These typically have lower motion and power efficiencies than the prior two categories. Each type provides a unique set of advantages and disadvantages. Some operate more smoothly and quietly while others provide strength and durability where needed. Ease of manufacturing, which is related to costs, also varies across the different types of gears.
Putting Gears to Use
The earliest gears had a few broad applications. They were used in large machinery such as water mills and irrigation systems where they were needed to transmit considerable power. Water mills were increasingly used from the time of the Romans all the way through the Middle Ages of Europe. A secondary application of gears were also used in small, precise devices usual focused on astronomy and the calendar.
Some gears were constructed of wood and others constructed with various types of metals. The material used depended on its use. As the centuries passed gears continued to find uses in new inventions. The first clocks incorporated very precise systems of gears. During the Industrial Revolution a multitude of machines would not be able to operate with out properly working gears.
Gears feature predominately in today’s world, especially in transportation. One modern transportation invention using gears was the bicycle, whose modern form was developed in 1885. The bicycle caused a bicycle craze in the late 19th century and many people became wealthy manufacturing bicycles. The Wright Brothers constructed their gliders and the first airplane, The Wright Flyer, from the bicycle factory they owned in Ohio. After the widespread use and adoption of the bicycle gears became used in a newer type of transportation, the automobile. The automobile uses a system of gearboxes in the transmission system to transmit power from the engine to the wheels. Today gears are used in nearly all transportation systems including railroads and airplanes, as well as other common appliances and industries such as pumps, power plants, energy systems, lifts, and elevators.
There was no other ancient thinker who held a greater influence over European medieval intellectual life more than Aristotle (384 – 322 BCE). It’s easy to see why, giving his prolific writings and interests in a wide range of topics that included physics, cosmology, biology, zoology, geology, psychology, mathematics, logic, metaphysics, politics, ethics, justice, and rhetoric – to name a few. Over 150 books are attested to be authored by Aristotle, although only 30 or so of his works survive to the modern day.
Aristotle was born in Stageria, Macedon, was orphaned at an early age and raised by his uncle. At age 17 he went to Athens and joined Plato’s Academy where he spent 20 years studying and earning his reputation as one of Greek’s great philosophers. After his time at The Academy he ended up in King Philip of Macedon’s court, where he tutored his 13 year old son, Alexander, who grew up to be Alexander The Great. During his time at the Macedonian court Aristotle also tutored two future kings and successors to Alexander’s empire, Ptolemy and Cassander.
When Aristotle did not receive headship of the Academy in Athens due to political reasons, he started his own establishment around 335 BCE with encouragement from Alexander called The Lyceum. It is during his time at The Lyceum, from around 335 BCE to 323 BCE, when he composed most of his works. Aristotle was forced to leave The Lyceum and Athens again due to political reasons after Alexanders death. He died shortly after by natural causes.
Aristotle’s impact and legacy in western philosophy is immense. He was one of the first great figures in the history of science, influencing scientific thought for well over a millennia. Some of Aristotle’s works were preserved through the fall of Rome. They were well read in Byzantium and in the Islamic empire but were virtually forgotten in Western Europe. Then, in the 13th century, much of his work was reintroduced into Western Europe through the work of Thomas Aquinas and others, and a synthesis of Aristotelian philosophy and Christian theology held supreme for over three centuries. This Aristotelian influence was not to last forever as the dawn of the scientific revolution burst onto the world scene in the 16th century and permanently changed how humans viewed themselves and their world.
