SCIENCE, TIME AND MEASUREMENTS IN ANCIENT GREECE

SCIENCE IN ANCIENT GREECE


Eratosthenes
In ancient times sciences such as chemistry, biology and physics did not exist. Philosophy and the sciences were indistinguishable and the prevailing view was that objects were made from earth, air, fire and water. John Wilford Nobel wrote in the New York Times, “By following the historical record” a group of modern-day scientists called the Archimedes researchers “have discovered that the evolution of physics---or, at least mechanics---is based in the interplay between practice and theory, The practical use comes first, theory second. Artisans build machines and use them but do not think why they work. Theorists explain the machines and derive principals that can be used to construct more complex machines.”

The sciences thrived during the Hellenistic period, especially in Alexandria where the Ptolemies financed a great library, quasi-university and museum. Fields of study included mathematics (Euclid's Geometry , 300 B.C.), astronomy (heliocentric theory of Arisrtarchus, 310 B.C., Julian calendar 45 B.C., Ptolemy's Almagest 150 A.D.), geography (Ptolemy's Geography , world map of Eratosthenes 276-194 B.C.), hydraulics (Archimedes, 287-212 B.C.), medicine (Galen, 130-200 A.D.), and chemistry. Inventors refined uses for siphons, valves, gears, springs, screws, levers, cams, and pulleys.↕

The Greek philosophers often equated beauty and mathematics. "Measure and commensurability," wrote Plato in Philebus , "are everywhere identifiable with beauty and excellence." Aristotle wrote "the qualities of numbers exist in a musical scale, the heavens, and many other things. [Source: "The Creators" by Daniel Boorstin,μ]

But science remained less developed than it might have been because science and philosophy remained bound together. The Greeks were astute when it came to applying their knowledge to architecture, art and navigation but the remained locked in the belief that science could be advanced by thinking rather than by experimentation or more hands-on methods.

A surprising number of ancient scientific texts have survived to this day. The Archimedes website lists many of them, including Euclid’s Geometry , Mechanical Problems , once attributed to Aristotle, and Hero of Alexandria’s Roman-era technical manual of crossbows and catapults.

Socrates was among the first speak out against new technologies. He condemned writing and said that relying on written texts over oral tradition would “create forgetfulness in the learner’s souls...they will trust to external written characters and not remember of themselves.”

ANCIENT GREEK TECHNOLOGY (See Separate Article) Also See Philosophers

Muslims and Greco-Roman Science

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Tower of the Winds frieze
In the early Middle Ages, the Muslim kingdoms was the intellectual center of the world. Among other things, the Arabs were very interested in Greek science and philosophy. They were reading Plato and Aristotle when he had long been forgotten in the West.

Arab translators did the world a great service. They translated classical Greek works on philosophy, science, mathematics, medicine, astrology and alchemy. Hunayn ibn Ishaq (808-73), for example, a scholar in Baghdad, translated Plato and Aristotle and Galen's Anatomy . The original Greek versions of these works were lost and probably would not survived were it not for Ishaq's Arabic translations.

The motivations for translating the classical works seemes to have been both practical and scholarly. Knowledge relating to medicine, was particularly in demand. There also seemed to be intellectual curiosity. The great Islamic thinker al-Kindi (801-66) wrote: “We should not be ashamed to acknowledge truth from whatever source it comes to us, even if it is brought to us by former generations and foreign peoples. For him who seeks the truth there is no higher value than the truth itself.”

The Arabs supplied the cultural and scientific link between the Golden of Greece and Rome and the European Renaissance. The medieval European sources of valuable documents by Euclid and Ptolemy and others where Arab manuscripts that were translated into Latin in Toledo.

Some scholars believe that Arab knowledge played a part in triggering the Renaissance and accelerating the pace in the Age of Discovery. The Renaissance began as a rediscovery of classic Greek culture and many say that Arabs were the ones who were responsible for reintroducing writings by Greek authors. Translations of Arabic texts into Latin spread knowledge of instruments such as the astrolabe.

Time in Ancient Greece

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Water clock in
ancient Agora of Athens
Julian Jaynes, a Princeton psychologist, contends that people living when the Iliad was written (the 8th century B.C.) had little awareness of time. The epic poem he says was about people who "did not live in a frame of past happening, who did not have 'lifetimes' in our sense, and who could not reminisce." Concepts of time developed when language advanced to the point where people could describe the past in terms of personal experience. Zeno of Elea, a fifth century B.C. Greek philosopher, was the first man to ponder over the fact that any unit could be subdivided endlessly.╕

The 24 hour day, in the words of one historian, "was the result of Hellenistic modification of an Egyptian practice combined with Babylonian numerical procedures." The Egyptian used sun dials and came up with the idea of hours. These hours, in turn, were organized using Babylonian arithmetic which grouped numbers in denominations of six rather than ten (no one knows for sure why the Babylonians selected six). [Source: "The Discoverers" by Daniel Boorstin,∞]

The word "hour" comes from the Latin and Greek words for “season” or “time of day.” It described a twelfth of the period of sunlight or darkness. Minutes (derived from a Latin word for "small part”) were used to divide the region between lines of latitude and mark locations on a circle during ancient times long before they marked time. It wasn’t until perhaps the 13th century, when the mechanical clock was invented, that minutes were used to divide an hour into sixty units. Seconds were not included until the 16th century when clockmaking technology was significantly improved.

See Sundials and Water clocks

Years, Months and Days in Ancient Greece

The ancient Greeks had no weeks, nor names for the different days. They followed a 12 month calendar similar to the one used by Babylonians with 29 and 30 day lunar months and a 13th month added on the seventh of thirteen years to ensure that the calendar stayed in sync with the seasons. Each city state added the thirteen month at different times to mark local festivals and suit political needs. A complex system of "intercalculating" was employed to decide on meeting times between citizens of different states and to make arrangements for the pick-up and delivery of goods. [Source: "The Discoverers" by Daniel Boorstin,∞]


Ptolemy zodiac

The Romans developed the idea of the week and gave names to the months. They had an eight-day week which they later changed to seven. By the A.D. third century Romans divided the day into only two parts: before midday (ante meridiem A.M.) and after midday ( post meridiem P.M.). Someone was in charge of noticing when the sun crossed the meridiem since lawyers were supposed to appear before noon. Later the day was dived into parts: early morning, forenoon, afternoon, and evening and eventually followed a sundial that marked "temporary" hours.

Ancient Greek Measurements

A cubit, based on the length of a man's forearm, was the unit of measure throughout much of the ancient world. The measurement varied a great deal however. In ancient Egypt, for example, a cubit for a man was 17.72 inches while the cubit for a king was 20.62 inches.

In Greece, a cubit was 18.24 inches. One cubit equaled two spans. One span equaled three palms. Four cubits equaled one fathom and 400 cubits equaled one stadia, which was about 607 feet. An amphora held 44 kotyles . Some have said the Greeks introduced the foot based on the length of Hercules foot.

One talent was equal to 93.65 pounds. For measuring smaller weights, the ancients used grains of wheat or barley corns; the grain to this day is one of the smallest units of weight, 1/7000 of a pound. The carat, used in weighing gems, was derived from the tiny carob seed, prized during antiquity for its uniform weight from seed to seed.

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Aristotle wind rose

Many of the ancient units of measurement were for practical reasons based parts of the body. The digit (width of a finger), the palm (the width of four fingers), the foot and the cubit (the distance from the tip of the middle finger to the elbow) were all measurements of length. The "pace" (the precursor of the yard and meter) was equal to one large step and "fathom" (roughly six feet) was the distance between two outstretched hands. ["The Creators" by Daniel Boorstin]

In ancient times a lot of the standard formulas that modern engineers and architects use to measure stress and balance had not yet been invented. Most building were but together with knowledge learned through trial and error. One of the first scientific principals of architecture---that a the base of column should be equal to one sixth of its height---was based on the observation that the size of a person's foot is one sixth of his height. [Ibid]

Mathematics, Physics, Euclid and Geometry in Ancient Greece

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Euclid and Pythagoras
The Greeks and Romans were unable to make the breakthrough of the concept of zero. The first Old World Culture believed to have figured it out was the ancient Hindus.

The Greeks invented or at least were pioneers in geometry and trigonometry. Diophantus's Arithemtica was an important work.

Euclid is regarded as the father of geometry. Euclidian geometry is still widely studied. Many of his principals still form the basis of high school geometry textbooks.

"Euclid's genius," wrote classicist Lionel Casson, “lay in designing a superbly logical arrangement and in a presentation that was clarity itself...During the first two decades or so of third century B.C. [this] mathematician at Alexandria set himself the task of drawing up a beginner’s manual for learning geometry. He did the job so successfully that his textbook became the longest-lived in history: in the early years of this century English schoolboys were still taught geometry from what was more or less a translation of Euclid's Elements .

See Philosophy

Ancient Greek Atoms

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Most Greeks believed that matter was made up of four elements---earth, air, fire and water. The Greek word atom meant the smallest indivisible unit of matter. The existence of these particles was first proposed by a 5th century B.C. Greek named Leucippus, who found life so amusing he was dubbed the "laughing philosopher." He said the entire universe consisted of atoms and voids, and that atoms themselves were not "infinitely complex but somehow intelligible" and someday "there might be no limits to man's power." This concept of atoms contradicted the “four elements” theory. [Source: "The Discoverers" by Daniel Boorstin,∞]

Democritus wrote in 400 B.C., "Nothing exist except atoms and empty space; everything else is opinion." The Roman poet Lucretius (95-55 B.C.) perpetuated the idea of atoms to waylay man's fear of death and supernatural powers by pointing that nature was governed by it own laws and the soul died with body and wasn't taken to Hades and tortured. The Christian clergy attacked Lucretius and the idea of infinitesimally small particles wasn't resurrected until Descartes wrote about them in the 16th century.∞

The ancient Greeks called amber electron , and we get the word electricity from the fact that when amber is rubbed on wool or silk it produces a static charge. Roman doctors prescribed amber for ear infections and tonsillitis and gladiators wore it as a good luck charm.

Optics in Ancient Greece

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Bronze mirror
The ancient Greeks explained the miracle of sight by stating that perception occurred when "internal fire" from the eye mixed with "external fire" from the object. The intuitive 5th century B.C. philosopher and poet Empedocles suggested that light was substances emitted by the sun that moved so quick people were not aware of it.

The Greeks ascribed light, vision and perception to "fire within the eye," a concept that equated eyes with lanterns. Based on the fact that sometimes people look towards light but fail to notice it immediately Plato and Euclid believed that the eyes produced a visual ray that struck an object before people perceived it. Aristotle and other observed that if this were true people would be able to see in the dark.

Euclid believed that the eye somehow emitted rays which absorbed the object. Plato and the Pythagoreans described the process of seeing as "emanations of the eye which somehow encompassed the object seen." The Atomists were again on the right track when they suggested that emissions from the seen object somehow entered the eye and produced images. But Galen didn't buy this. He pointed out that large images, "like those of mountains, could not squeeze through the pupil of the eye"...In case you forgot vision occurs when the eye perceives the light emitted by an object. [Source: "The Discoverers" by Daniel Boorstin,∞]

Rock-crystal magnifying lenses dating from 1200 B.C. have been found in Crete. The Greek playwright Aristophanes mentioned crystal lens in The Clouds .

Astrology and Astronomy in Ancient Greece

The Egyptians refined the Babylonian system of astrology and the Greeks shaped it into its modern form. The Ancient Greeks were skeptical about astrology. They wondered, for example, why twins born under the same astrological conditions had different fortunes, and why animals weren't ruled by the same cosmic powers as humans. [Source: "The Discoverers" by Daniel Boorstin,∞]

Astrology as we know it originated in Babylon. It developed out of the belief that since the Gods in the heavens ruled man's fate, the stars could reveal fortunes and the notion that the motions of the stars and planets control the fate of people on earth. The motions of the stars and planets are mainly the result of the earth’s movement around the sun, which causes: 1) the sun to move eastward against the background of the constellations; 2) the planets and moon to shift around the sky; and 3) causes different constellations to rise from the horizon at sunset different times of the year.

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Cosmic systems from Ptolemy to Copernicus

In ancient times astrology and astronomy were the same thing. The Babylonians were the first people to apply myths to constellations and astrology and describe the 12 signs of the zodiac. The Egyptians refined the Babylonian system of astrology and the Greeks shaped it into its modern form. The Greeks and Romans borrowed some of their myths from the Babylonians and invented their own. The word astrology (and astronomy) are derived from the Greek word for "star."

The names and shapes of many the constellations are believed to date to Sumerian times because the animals and figures chosen held a prominent place in their lives. It is thought that if the constellations originated with the the Egyptians were would ibises, jackals, crocodiles and hippos---animals in their environment---rather than goats and bulls. If they came from India why isn’t there a tiger or a monkey. To the Assyrians the constellation Capricorn was munaxa (the goat fish).

The Greeks added names of heroes to the constellations. The Romans took these and gave them the Latin names we use today. Ptolemy listed 48 constellations. His list included ones in the southern hemisphere, which he and the Mesopotamians, Egyptians, Greeks and Romans couldn’t see.

Book: Astrology: A History by Peter Whitfield (Abrams, 2001).

Complicated mathematical equations were developed to explain the movements of heavenly bodies in an effort to make astrology seem like a science.

Among Greece's most famous astronomers were Anaximander (611-546 B.C.), who stated all the heavenly bodies were discs; Eudoxus of Cindus (408-355 B.C.), who asserted the planets moved in concentric spheres around the Earth; and Aristarchus (live around 280 B.C.), who hypothesized that the sun not the Earth was the center of the universe.

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Erathostenes map of the world

Ancient Greek Ideas About Earth and the Universe

During Homer's time people thought the Earth was a circular disk surrounded by the river Oceanus. Herodotus (480-425 B.C.) said that this concept was completely wrong: the Earth was surrounded by desert not water. In the late fifth century B.C. Plato and the Pythagoreans argued that the sphere was the most perfect shape and it made sense that man would live on a object with such a shape. Eclipses, boats disappearing over the horizon, and the shape of the moon were all presented as evidence that the Earth was a sphere. [Source: "The Discoverers" by Daniel Boorstin,∞]

The Greeks believed that the Earth was a sphere and the heavens were a rotating spherical dome with the moving stars affixed to it. Beyond the heavenly dome was nothing, not even emptiness, and inside the dome the planets and the sun moved along their own separate paths.

Plato described the world as "round as from a lathe, having its extremes in every direction equidistant from the center, the most perfect and the most like itself of all figures...the like is infinitely better than the unlike." Aristotle aid the heavens were made of a transparent and weightless material known as "Ether" that carried the stars and planets on 55 concentrically organized spheres like "nests." The movements of the planets was described as the motions of the spheres on which the planets rested.∞

Hipparchus

Hipparchus (190-120 B.C.) was the greatest astronomer of the Greek era. He is credited with creating the system of latitude and longitude based on astronomical observation superimposed on an imaginary grid on the Earth. He also discovered the procession of equinoxes, invented trigonometry, and mapped 1080 stars and placed them into six categories of brightness. Ptolemy used his data to show the Earth was the center of the solar system.◂

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ptolemy-tetrabiblos

Hipparchus in 130 B.C. was the first astronomer to note the progression of the seasons changed in relation to the background stars. In the 17th century Sir Isaac Newton deduced that the date of certain historical events could be ascertained by reexamining Hipparchus' calculations, which Newton said were slightly off.

Using Hipparchus’s record Newton was the first to record the major historical events of the Greeks, Egyptians, Persians and the Hebrews's in David and Solomon's reign in the Bible in chronological order. By reexamining calculations made by Hipparchus and comparing them with observations made by other astronomers Newton reasoned that the voyage of Jason and the Argonauts took place 43 years after King Solomon's death. [Source: "The Discoverers" by Daniel Boorstin,∞]

Image Sources: Wikimedia Commons, The Louvre, The British Museum

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, Yomiuri Shimbun, The Guardian, National Geographic, The New Yorker, Time, Newsweek, Reuters, AP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications. Most of the information about Greco-Roman science, geography, medicine, time, sculpture and drama was taken from "The Discoverers" [∞] and "The Creators" [μ]" by Daniel Boorstin. Most of the information about Greek everyday life was taken from a book entitled "Greek and Roman Life" by Ian Jenkins from the British Museum [||].

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© 2008 Jeffrey Hays

Last updated January 2012

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