Blunders of Ancient Science
This list is our first prize winner for the site launch competition. Congratulations to the author, Tristan Bradshaw. One of the most tempting mistakes in studying history is to judge the past by modern standards. Nowhere is this more easily seen than in the contributions of ancient science. When we laugh at geocentric cosmology, or the theory of four elements, we fail to realize that, while the theories were certainly wrong, they still advanced scientific knowledge. This list explores 10 such contributions.
Ptolemy
Ptolemy (born A.D. 90), was an astronomer whose model of the universe became the standard geocentric theory, until Copernicus. Ptolemy's writings proved influential in early astronomy, and he was revered throughout the Middle Ages in Europe and Arabia. He also provided the most authoritative compilation of constellations in antiquity. Although he helped to discredit Aristarchos' heliocentric universe (more on that later), and ensured the geocentric model would be universally accepted for the next 1,000 years, Ptolemy did much to raise the standard of astronomy. Ptolemy did this by highlighting the disjunction between mathematical models and actual, observed patterns in the stars. Because planets actually follow ellipses (a fact not proven until Kepler), ancient astronomers relied on epicycles (circles within circles within circles) to explain the motion of the planets. Epicycles can be quite accurate, but they are never perfect. Ptolemy's work on astronomy did much to highlight the problems of epicycles, ensuring that later astronomers continued to search for better explanations.
Euclid
Euclid (born c. 330 B.C.), is most famous for his contributions to geometry, but he also wrote treatises on astronomy and optics. Euclid's treatment of optics reflects his love of geometry. Euclid argued that vision occurs when rays emit from the eye to form a cone. From there, Euclid proceeds geometrically. Everything the rays touch is seen. If one reduces vision to a geometric exercise, Euclid's treatment of optics is profound. Issues such as medium, light and whether there was a physical connection between the eye and the viewed object were passed over. Nevertheless, Euclid's treatment of the subject would be influential until the age of Ptolemy.
Galen
Galen, born in A.D. 129 in Asia Minor, was the second most revered physician in antiquity, after Hippocrates. He served as the court physician for three Roman emperors and was one of the most prolific writers in the ancient world. His contributions to medicine, anatomy and physiology are numerous and profound. Not unlike the fictional Gregory House, Galen was known for being more interested in understanding the cause of a disease than the comfort of his patients, whom he tended to treat as specimens. The contribution to science that puts Galen on this list is not for any particular discovery or theory, but the absolute rigor and high standard he applied to developing medical knowledge. Human dissection was outlawed in Rome, so Galen used pigs and monkeys to understand anatomy. His careful and meticulous dissections revealed many anatomical features that had been missed by others, such as his discovery that arteries contain blood. His theories of human physiology and disease were based directly on this research, leading to conclusions difficult for critics to dispute. Unfortunately, Galen's careful research led him to conclude that excess blood was frequently the cause of diseases and he helped to popularize bloodletting, a traditional medical practice in the Eastern Mediterranean, that had never gained popularity in Italy. Modern medicine has shown that, except in a small number of situations, bloodletting is useless and actually harmful, but Galen's authority and defense of the practice ensured bloodletting would become an accepted procedure until the 19th century. His careful work, while wrong in its conclusions, raised the standard of medical theory immeasurably.
Herophilos and Erasistratos
Herophilos was born in 335 B.C. - almost 500 years before Galen - in Asia Minor. He founded a school in Alexandria, Egypt, where he entered the service of the Ptolemaic dynasty. With Ptolemaic patronage, Herophilos and his students were permitted to violate the sanctity of the dead and dissect humans. Throughout antiquity, Mediterranean cultures maintained a strong taboo against cutting or dissecting the dead. Herophilos and his students were the first-known Greeks to violate this taboo in order to study anatomy. They may have even dissected condemned prisoners while they were still alive (which is known as vivisection).Herophilos' findings did much to advance knowledge of human anatomy. Much of the terminology he coined is still used in modern medicine. His student, Erasistratos, built on Herophilos' findings and argued that "pneuma" ran through arteries and nerves. Pneuma ("breath" in Greek) was a substance imagined to be the life force that enables much of the body to run. Erasistratos hypothesized that pneuma was pulled from the air via the lungs and sent through the arteries. It finally arrived at the brain, which refined the pneuma and sent it through nerves to control the body and feel sensations.
Empedocles
Empedocles (born c. 490 B.C.), was among the last of the Presocratics, philosophers before Socrates who wrote in verse. It was Empedocles who first hypothesized the classic four elements: fire, earth, water and air. Empedocles argued that all material is a mix of these four elements. Wood, for example, is made primarily of fire and earth. Burning wood separates the fire, leaving only earth (ash) behind. His notion that all physical material can be broken down into just mixtures of earth, water, air and fire seems hopelessly naive, but the idea had a profound impact on the physical sciences.
Empedocles' true contribution to science, however, was not what he was arguing for, but, rather, what he was arguing against. Empedocles was attacking the philosophies of Heraclitos and Parmenides. Heraclitus argued that reality is perpetually changing, and that material must come into and out of existence for change to exist. Parmenides argued that all change is an illusion, including time and movement (his student, Zeno, illustrated this with several famous paradoxes). Empedocles' theory of four elements was his attempt to show that material, in its elemental form, cannot be destroyed or created. Change is a result of things being mixed together or separated. Empedocles' ideas anticipated the first law of thermodynamics by more than 2,000 years, and his notion that material is comprised of indivisible elements has proven invaluable to the physical sciences.
Hippocrates
Hippocrates (born c. 460 B.C.), is perhaps most famous for the oath that bears his name. It is difficult to separate what Hippocrates believed versus what his students believed. Since many of the texts that he supposedly wrote differ greatly in style and date of composition, none can be definitively identified as coming from him direct