1543: On the Revolutions of Celestial Spheres

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On the Revolutions of Celestial Spheres
On the Revolutions of Celestial Spheres

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
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.

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Francis Bacon

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“Knowledge itself is power.” – Francis Bacon

Francis Bacon portrait
Francis Bacon

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.

Andreas Vesalius

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Andreas Vesalius portrait
Andreas Vesalius

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.

1450: The Printing Press

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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 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 or moved around the world. Prior to the printing press information slowly – it had to either be spoken and memorized or hand-written onto papers and books. The invention of writing in the 4th millennium BCE offered a cleared benefit to our limited and imperfect memory. However up to the middle of the 15th century, 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, as is evident in the myriad changes made to the Bible in its millennium long copying process up to the middle of the 15th century.

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
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 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.

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900: Gunpowder

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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

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

Fire Arrow
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
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.

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800 BCE – 200 BCE: Gears

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Antikythera Mechanism
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
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

Types of Gear Designs
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.

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Aristotle

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Aristotle portrait
Aristotle

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.

Pythagoras

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Pythagoras portrait
Pythagoras

One of the most famous mathematicians of the ancient world was Pythagoras of Samos (570 – 495 BCE).  Much mystery surrounds the early life of Pythagoras and it is sometimes difficult to separate fact from legend.  It is believed that around the age of nine, Pythagoras may have traveled to Miletos where he was taught by the famous Greek philosopher Thales and his pupil Anaximander. Later on, around 535 BCE, it is likely that he traveled to Egypt and Babylon where he was taught geometrical principles that laid the foundation for many of his theorems.

In about 518 BCE Pythagoras settled in Cronton, a Greek seaport in southern Italy, where he founded a school dedicated to studying mathematics.  The school provided a way of life for him and his followers that included rules on diet and behavior, but also placed a primacy on mathematics and numbers.  They believed that everything in the universe was related to numbers.  Therefore symmetries and sequences held deep meaning where they turned up in nature, including in the study of music.  Since Pythagoras traveled widely in the ancient world it likely that he incorporated many ideas of the Egyptians and Babylonians into his school’s philosophy.  Indeed, the school was part philosophy, part mysticism, but its influence was profound and was clearly a source of inspiration for future generations of Greek mathematicians and thinkers.

During his lifetime Pythagoras made several discoveries in mathematics.  The one which he is most famous for and bears his name is the Pythagorean Theorem.  It states that for any right sided triangle the square of the length of the hypotenuse is equal to the sum of the square of the length of the two legs.  He is also alleged to have been one of the first people to teach that the Earth was a sphere.  The exact details of his death are unclear but his school expanded rapidly after 500 BC preserving his philosophy, ideas, and legacy for future generations.

3000 BCE – 600 BCE: Early Medicine and the Hippocratic Oath

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Disease is humanity’s oldest and most feared enemy. It harasses us constantly in a multitude of vicious ways through methods that have only recently been discovered. Medicine is our primary defender against this ever-present, ever-evolving, enemy. It is the science of diagnosis, prevention, and treatment against the oldest and most dangerous threat to our lives.

Early Medical Practices

Rod of Asclepuis
Rod of Asclepius

The earliest forms of prehistoric (before the written word) medicines were various herbs used to heal the diseased person.  We may think of the tribal medicine man or shaman as an early doctor but it is likely that many prehistoric healers were women. Women were heavily involved in gathering plants for food and cooking meals for the group. This experience provided an opportunity to gain knowledge about the affects of many types of plants, and to apply that knowledge medicinally to their community.

Stone Age Mortar and Pestle
Stone Age Mortar and Pestle
(Credit: Wikimedia Commons)

Plants were not the only treatments available to people living in the prehistoric world and early civilizations. There is evidence of surgical procedures being attempted in the prehistoric ages, Mesopotamia, Indus Valley civilizations, and in Ancient Egypt. The code of Hammurabi, written in 1754 BCE, sets out guidelines for surgical fees and physician malpractice. Fire was likely used for sterilizing and closing wounds.

Some of the earliest known medical texts date are from China, India and Egypt around 3000 BCE. The texts from Egypt, for instance, focus on a variety of ailments – problems associated with the hair, blood, digestive system, headaches and toothaches. Many of the remedies for these ailments are grounded in superstition. Evil spirits and gods were thought responsible for them and magical incantations are recorded as being part of, or the whole treatment. Still, it was beneficial for medical advancement to record these treatments and observe which ones worked more consistently that others.

Edwin Smith Papyrus - a medical document from Ancient Egypt
Edwin Smith Papyrus – a medical document from Ancient Egypt

There are however a few notable examples of medical texts grounded in rational observation. One such example is a series of medical texts known as the Edwin Smith Papyrus, named after the dealer who purchased it in 1862. It contains medical observations and advice on 48 different injuries ranging from injuries to various parts of the body to gynecology. The document contains instructions for an appropriate examination of the patient, then provides a diagnosis and prognosis, and potential treatments. This incredible document was written in hieratic script in Ancient Egypt around 1600 BCE and is thought to be a copy of an even older document.

Hippocrates of Cos and the Hippocratic Oath

Hippocrates of Cos, The Father of Medicine
Hippocrates of Cos, The Father of Medicine

In the 8th century BCE the first Greek medical school opened at Cnidus.  To their credit the Greeks placed a strong emphasis on diet, lifestyle, and hygiene, continuing the tradition of the Egyptians and Indians.  The prevailing Greek medical doctrine was humorism. This holistic approach to medicine declared there were four humors were linked to four bodily fluids, blood, black bile, yellow bile, and phlegm, which were linked to the four elements. Disease was caused by an imbalance of the humors. Treatment was predicated on restoring this balance.

The most famous Greek doctor was Hippocrates of Cos, born in 460 BCE.  Hippocrates founded the famous Hippocratic School of Medicine and is largely referred to as the Father of Medicine. He is credited with forming the Hippocratic Oath – a guiding set of duties that is widely taken by physicians to this day. The Hippocratic Corpus is a collection of around 60 medical treatises attributed to Hippocrates, although it is the work of many different authors. The salient point is not who wrote these treaties but that Hippocrates and his students broke with the ancient tradition of ascribing disease to magic or evil deities. They instead focused on discovering the natural processes of disease through experimentation and data collecting.

The Hippocratic Oath, practiced by Hippocrates and his followers and summarized as “Do No Harm”, prescribes more conservative methods for treatment. He urged his citizens to avoid faith healers and quack physicians, recommending instead that they seek out doctors whose practice was grounded in science and observation. A strong emphasis was placed on prevention by encouraging the body to build up resistances to disease. This was accomplished primarily through diet and exercise, and supplemented by techniques such as massages and hot baths. Various foods could treat and cure a whole host of health problems ranging from infections, constipation, and blood clotting. He recognized that heat could reduce pain. He even warned against making any sudden significant lifestyle changes as detrimental to ones health. From Hippocrates through the Middle Ages of European history the influence of Hippocrates reigned supreme on the practice of medicine.

Modern Medicine

The Italian Renaissance marked the period in which the influence of Hippocrates began to wane and new medical developments and insights began to emerge. A renewed emphasis was placed on observation and experimentation leading to discoveries. Andreas Vesalius, deemed the Father of Anatomy, was one such person in the new army of meticulous observers in medicine. In 1543 he published his influential book On the Fabric of the Human Body, a ground breaking work correcting many errors of his predecessors and complete with detailed anatomical illustrations. Soon new discoveries such as the circulation of blood, the presence of biological cells, and vaccines were happening. The pace of discovery soon hastened.

Gene Therapeutic Programs from Sangamo Therapeutics
Gene Therapeutic Programs at Sangamo Therapeutics
These Programs are Gene Therapy, Gene-Edited Cell Therapy, Genome Editing, and Gene Regulation
(Credit: Sangamo Investor Presentation Slidedeck)

In the middle of the 19th century the most important advance towards modern medicine occurred when Louis Pasteur formulated the Germ Theory of Disease. Germ theory states that microorganisms are responsible for certain diseases and this provided tremendous insight into prevention and treatment techniques. Medicine now had a new and more accurate framework from which to build upon. Today, we are making still more incredible advancements in fields such as gene-editing techniques. These new technologies give us the potential power to edit life in whichever way we choose to. Hopefully, we choose wisely.

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3500 BCE: The Wheel

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Wheels appear everywhere in today’s world. It is impossible to imagine civilization as we know it without them. The idea seems quite simple and given the number of wheels we see in the world today, almost obvious. However, wheels are a rather recent actor to appear on the worlds stage. Whereas many ideas’ stem from things found in nature, there are no wheels in the natural world. Evolution by natural selection would never select for it. The Earth’s natural landscape rigid and rough, not paved and flat.

The idea of the wheel developed in ancient Mesopotamia, which in time proved highly effective and rolled on throughout the Old World. There is no evidence of the wheel being used in the America’s prior to European contact despite the highly advanced civilizations of the Mayans, Aztecs, and Incas.

Stove Carving of a Chariot
Stone Carving of a Chariot

The Wheel’s Unexpected First Use

ancient potters wheel
Illustration of a Foot-turned Potters Wheel

Most people think of the wheel as a component in a transportation device. Less people associate the wheel with pottery, its actual origination. The wheel was invented and first used by ancient Sumerian potters (the same Sumerians who invented writing) during the late Neolithic period at around 3500 BCE. This exact date of its original use is a little uncertain, as is with many things in ancient history. It’s possible the idea was hit upon centuries earlier, but since nobody was around keeping detailed records we can’t be absolutely sure when it was first invented. However by 3500 BCE it was certainly in use in that region of the world. The device was extremely practical and quickly spread through cultural diffusion, however the Chinese also came across the idea of the wheel around 2800 BCE.

As valuable to civilization as the wheel is, one might think that it was of the first invention of human civilization But this isn’t the case, as this simple invention occurred well into the Bronze age. By this time more complex technologies like metallurgy were already established as an increasingly sophisticated, 2000-year-old science.  Even pottery as a craft had been around for tens of thousands of years. So this is where the story of the invention of the wheel begins, as an artifact assisting in making pottery. The potter’s wheel was not a wheel used for rolling or moving things. It laid horizontally on its side while pottery was spun on top of it. The potter’s wheel was typically made from solid wood or stone and attached to a fixed axle, allowing for smooth, slow and controlled rotation.  

The potters wheel quickly found new uses and it adapted those used to the urgent needs of civilization. During the late Neolithic period human societies were increasingly settling into agricultural communities and the need for more effective methods of labor and transportation became apparent.  After the invention of the potters wheel, it only took another few centuries of innovation before the next generation of people assembled two wheels, rotated 90 degrees and placed an axle through the center of each. This process did not happen overnight, as in one swift stroke of genius. It was a gradual process that began with a rolling log and culminated with a rudimentary wheel and axle device. 

However by around 3400 BCE the wheel was likely being used for transportation, at least in one part of the world. The first depictions of a wheeled vehicle were found in 1974 during an excavation of a neolithic village near the present day village of Bronocice, Poland. Found in a pit among animal bones was an artifact that has come to be known as the bronocice pot. The bronocice pot is a ceramic vase showing what appears to be a wheeled vehicle. The discovery shows that wheeled wagons were in use in Central Europe by this time. They were likely drawn by aurochs, the wild ancestor of domestic cows, as auroch remains were found in the same area. Clay tablets found in around 3200 BCE in Urak – present day Iraq – also show depictions of wheeled vehicles.

A Drawing of the Wheeled Vehicle from the Bronocice Pot
A Drawing of the Wheeled Vehicle from the Bronocice Pot
The Bronocice Pot Showing the First Known Depiction of a Wheeled Vehicle
The Bronocice Pot Showing the First Known Depiction of a Wheeled Vehicle

Once the wheeled vehicle arrived on the scene, the innovations continued. It could be connected to carts and eventually larger transportation vehicles called chariots. The transformation of the potter’s wheel to a transportation device was now complete. The transformation from a solid wooden wheel to today’s rubber tire was just beginning.

The Evolution of the Wheel

The wheel has evolved substantially over its 5000 year history. It has become thinner and stronger, and has developed into different types. One of the first such evolution’s of the wheel was a plank wheel. The plank wheel is made from wooden planks rather than being one solid log of wood. As societies advanced the wheel continued to evolve to meet the needs and demands of society. Some wheels had parts of it that were able to be removed, making it lighter. The next major steps were hollowing out the center of the wheel and adding spokes radiating from the axle. The use of spokes reinforced the structure of the wheel and reduced its weight. It is believed to have originated in ancient Sumer around 2000 BCE. The spoked wheel eventually became used in chariots.

Additional features of the wheel continued to be modified or added to improve its performance. The concept of the rim, an outer edge of a wheel that holds it in place, dates back to ancient times as well. Rims provide structural support to make the wheels more durable. Early rims were made of wood or metal, and as metal-working become more sophisticated various other materials such as iron and steel were used. The wheel and axle also went through some changes. Originally the two were fixed, meaning that they rotated as a single unite. The design is simple but does not allow for much maneuverability. The fixed axles were modified into pivoting axles where the wheels can move independently of each other, increasing the vehicle’s maneuverability.

The biggest change in the evolution of the wheel came many thousands of years after its first use as a form of transportation, during the Industrial Revolution. The manufacture of wheels improved as cast iron, and later steel wheels greatly enhanced their performance, durability, and load capacity. This era also found many new uses, such as for trains or for components in factory machinery. The modern wheel of the 21st century continued to evolve as manufacturing techniques continue to improve and technology advances at a breakneck pace. Wheels were now mass produced for a variety of new vehicles such as cars and airplanes, and made from a variety of materials such as aluminum and rubber. The digital age has transformed wheeled vehicle technology and features such as traction control, anti-lock breaking systems, and advanced driver-assistance systems are becoming commonplace in vehicles. Currently, we are seeing the concept of “smart wheels” that incorporate electronic systems using sensors that monitor conditions such as tire pressure, tread wear, and temperature. New technologies like robotics are making wheeled robots a common sight in manufacturing plants and warehouses, and even in advanced space agencies such as NASA. As human civilization continues to push the limits of technology, the wheel will undoubtedly continue to be an integral part of that process.

Evolution of the wheel
Evolution of the Wheel
(Credit: www.123rf.com)

The Power Behind the Wheel

There are two main reasons why wheels make moving loads easier than pushing or pulling loads.

  1. Decreased friction – Only a small part of the wheel is in contact with the ground leading to increased efficiency and reduced wear and tear. Decreased friction also increases maneuverability making it easier to change directions. There are many methods to decrease the friction of the wheel such as optimizing the wheels design and materials used in construction, using lubricants, and minimizing the roughness of the surface that the wheel is being used on.
  2. Increased leverage – Wheels elevate the load reducing the angle at which force is required to move the load. Additionally, the rim of the wheel turns more distance than the axle of the wheel. Turn the wheel at the rim and more force is applied to the axle. Turn the wheel at the axle to create more speed.

The Wheel’s Impact on Early Civilizations

The wheel has played a significant part in shaping history and had a variety of early uses and forms. The first use was for pottery making – the pottery wheel. Although the most important use was for transportation. For thousands of years people dragged heavy things on sledges. Wheels changed this, and subsequently altered our terrain. Wheels work best when they have a smooth surface to roll on. The Romans were the first to institute large scale road construction to connect their large empire. They constructed thousands of miles of straight roads, some of which are still in use today.

The agricultural process also benefited from wheels in the form of improved food production, transportation, and distribution. The invention of wheeled plowing and tilling revolutionized the preparation of soil for planting.  Carts and wagons allowed farmers to transport crops, seeds, and other agricultural goods over long distances with ease. With transportation now easier than ever, farmers had access to larger markets and an expansion of trade markets.  The significant boost the invention of the wheel gave to agricultural production allowed for larger food surpluses, thus increasing population in urban centers.  

People continued to find new and innovative uses for the wheel.  They harnessed the energy of water and wind in the form of the waterwheel and the wind turbine. They added teeth to the wheel and created gears, an essential component in many mechanical devices.

The Glade Creek Grist Mill In West Virginia
A Waterwheel at Babcock State Park in West Virginia
(Credit: Jim Vallee)

For such a simple device, the evolution of the wheel keeps on spinning. Bicycles, trains, and automobiles all rely on the wheel for movement. But the wheel can be adapted for uses other than movement. Automobile engines depend on many wheels. One part of the engine is a crankshaft – a wheel with an off-center axle. This is spun to power the engine that spins the road tires. The wheel – found nowhere in nature – is certainly human’s greatest yet simplest innovative achievement.

Continue reading more about the exciting history of science!