Earth Science: Exploration

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Earth Science: Exploration

Introduction

Motivations for exploration have ranged from a nation's quest for territory and power to an individual's desire for religious fulfillment, economic prosperity, or scientific discovery. From the ancient Phoenicians to the robotic Mars missions, sociocultural factors have mingled with the desire for knowledge in voyages of discovery.

Historical Background and Scientific Foundations

Although prehistoric indigenous peoples colonized the American continent, Asia, and the Arctic tundra, the first written account of exploration comes from ancient Egypt. The walls of the tomb of Harkhuf (fl. 2290–2270 BC) described a trading journey in which he went to Nubia “with three hundred asses laden with incense, ebony, heknu, grain, panthers… ivory, [throwsticks], and every good product.” Over time, Egypt became a crossroads of trade for Mediterranean and African “good products,” exporting them to Cyprus, Crete, Greece, Syro-Palestine, Punt, and Nubia.

Phoenician explorers in the first millennium also sailed the Mediterranean in search of trade. Phoenicia's rough and hilly climate meant that it could not sustain itself on domestic agriculture alone, so it exported cedar wood, glass, and murex (a beautiful and expensive purple dye obtained from snails). With limited goods to offer, the Phoenicians became masters at copying other people's arts and selling them at lower prices, using their adaptive skills to create sailing ships that used both Greek keels and Egyptian ribs and cross-braces. The Phoenicians were the first people to use the pole star for navigation and to sail by tacking—sailing diagonally left and right to catch prevailing winds and move in a desired direction.

With their ships and navigational techniques, the Phoenicians left the Mediterranean, and under the leadership of Himlico (fl. 5th c. BC) went to Britain in 500 BC to trade for tin. He and his crew may also have visited the southwest coast of India and Sri Lanka; the Greek historian Herodotus (c.484–430/420 BC) records that in 600 BC they sailed around Africa, hugging the coast as they went, since navigating in open waters was still perilous. The Phoenicians also founded colonies, such as Cades (now Cadiz) on the coast of Spain, and Carthage in North Africa. Controlling the passage between the eastern and western Mediterranean, Carthaginians traded olives and olive oil, wine, wheat, linen, cotton, and expensive spices from Asia. By the fourth century BC, the ancient Greeks challenged the Phoenician's naval dominance, and in 146 BC the Romans destroyed Carthage in the Third Punic War, ending Phoenician exploration.

The ancient Greeks had long practiced apoikia, or colonization, since the dry rocky soil of their islands could not support a large population. Between 650–600 BC settlers populated points as far afield as the Black Sea, Sicily, southern Italy (known as Magna Graecia or Greater Greece), and the coasts of France and Spain. It was little wonder that the ancient poet Homer's tales of discovery and conquest, the Odyssey and the Iliad, were centrally important in Greek culture.

The Greeks also began extensive trade with the Near East, exporting olive oil and wine. They imported not only luxuries such as spices, but Eastern myths and artistic motifs as well. Figures of gorgons, sphinxes, and griffins appeared on their famous red- or black-painted pottery, and Greek statuary adopted the monumental style of Egyptian sculpture. The Greeks also incorporated near-Eastern philosophy into their science. Scholars believe that the Greek philosopher Pythagoras (c.580–c.500 BC) traveled to Egypt and Mesopotamia, bringing back their methods in early geometry and astronomy to his philosophical school based in Croton in southern Italy. Pythagoras recognized that the laws of nature were written mathematically, and devoted his school to the search for empirical verification of such laws via experiments in music and sound as well as number theory.

In addition to their travels to the Near East, Greek explorers also seem to have explored the Atlantic. Pytheas of Marseilles (380–310 BC) seems to have reached Britain either via naval voyage from Marseilles, or by crossing France on foot to Bordeaux and sailing from there in the 320s BC. Pytheas also seemed aware of Ireland, as well as the Hebrides and Orkneys, and may have even reached Iceland and the Gulf of Finland.

Like Phoenicia and ancient Greece, the growth and consolidation of the Roman Empire was built on exploration and colonization. Successful Roman military conquest of France, Britain, Spain, North Africa, and Germany quelled most border disturbances by the reign of Augustus (63 BC–AD 14). Increasing economic prosperity and the subsequent demand for luxury goods prompted voyages to Southeast Asia and Africa. In 145 BC Greek historian and explorer Polybius (c.200–c.118 BC) was sent to investigate the west coast of Africa south of Gibraltar by the Roman general Scipio Africanus (236–183 BC). Polybius reached Senegal, where he saw crocodiles and hippopotamuses swimming in the river. Later Roman emperors tried to repeat this success and sent several expeditions to the northern oceans, known to be rich in fish, but the loss of several ships due to storms ended their efforts.

Roman contributions to geography were also significant. Claudius Ptolemy's (AD c.90–c.168) Geographia (AD 150) was one of the first works to utilize map projections with a grid of latitude and longitude. An earlier map of the Roman Empire was made by Marcus Agrippa (c.63–12 BC), a Roman war hero during the reign of Augustus. He summoned leading geographers to Rome and provided them with the archives of field and coastal coordinates gathered by the Roman army and navy. The resulting map was 60 feet (18 m) long, was either painted or inlaid in stone, and occupied a public colonnade in Rome. The map illustrated the famous Roman highway system, and was accompanied by a geographical commentary by Agrippa that provided the physical dimensions of provinces, the lengths of important rivers, and the distances between cities.

Such geographical accomplishments meant that wealthier Romans became some of the first tourists. Romans toured the Parthenon, took boat rides down the Nile, visited the Pyramids, and were led by professional tour guides called mystagogi (those who show sacred places to foreigners). In their own manner of cultural exploration and assimilation, they also bought souvenirs such as painted glass vials showing the lighthouses of Alexandria and miniature statues of Apollo, and they watched floor shows where Egyptian priests fed pet crocodiles and polished their teeth.

The Fall of Rome to the Renaissance

After the fall of Rome's western empire in the fifth century, European expansion and colonization quickly came to an end. Roman contributions to geography and cartography did, however, survive in the Byzantine (eastern) region of the empire, where they were adopted by Islamic scholars. The rise of Islam in the seventh century and the founding of the capital of Baghdad in the eighth century by Abbasid Caliph Harun al-Rashid (c.766–809), led to renewed trade with the East Indies, Persia, and China.

The most remarkable Islamic geographer was Ibn Battuta (1304–c.1368) who over the course of 30 years visited the lands of every Muslim ruler in his time, traveling 75,000 miles (120,700 km) in the interior of Africa, India, China, and what is now Turkey. He was a keen empiricist (observer), and recorded his observations, providing a unique ethnographic glimpse into the culture of the medieval East. He described geography, social and religious customs, and even food. In a book detailing his travels, translated by H.A.R. Gibb, he describes the importance of the betel plant (containing a mild stimulant similar to caffeine) in India:

Betel-trees are grown like vines on cane trellises or else trained up coco-palms. They have no fruit and are only grown for their leaves. The Indians have a high opinion of betel, and if a man visits a friend and the latter gives him five leaves of it, you would think he had given him the world, especially if he is a prince or notable. A gift of betel is a far greater honour than a gift of gold and silver. It is used in the following way: First one takes areca-nuts, which are like nutmegs, crushes them into small bits and chews them. Then the betel leaves are taken, a little chalk is put on them, and they are chewed with the areca-nuts.

By the ninth century the Vikings were the primary explorers of the early Middle Ages, making voyages to trade iron ore for glass and woolens from Ireland and Russia. In the process, they developed impressive ships with strong keels that could handle rough northern waters. They journeyed from Scandinavia into Britain, Greenland, and likely Iceland around AD 1000, and also mounted expeditions of conquest, creating fortified harbors in Ireland from which they could raid farther south and east into England and France.

Normandy (“land of the Norsemen”) was a Danish colony in the tenth century. In England, the Vikings demanded extortionate bribes, called “Danegeld,” from the Anglo-Saxons; the Vikings ruled England briefly from 1016 until 1042, when the Anglo-Saxons regained control for an even shorter period. Excavated ruins and Nordic sagas show that Vikings like Leif Eriksson (fl. 11th century) reached North America (Newfoundland) 500 years before Columbus. In 1960 a Scandinavian settlement was discovered in L'(A)nse aux Meadows, Newfoundland, proving that Vikings had indeed been in North America.

By the late twelfth century, there was a renewed emphasis on European exploration. The Crusades brought Westerners into contact with the Middle East, and the rise of cities encouraged exploratory voyages to increase trade. Venetian adventurer and merchant Marco Polo's (c.1254–1324) account of his visit to China was enormously popular, as was Sir John Mandeville's (fl. 14th century) more fanciful book The Voyage and Travels of Sir John Mandeville, Knight. This gave rise to the legend of the kingdom of Prester John, a mythical Christian king in India or central Asia who would aid Crusaders in their fight against Islam and whose realm contained a fountain of youth.

Such travel tales made the Portuguese realize the wealth to be gained via trade with the East, and they devoted their energies in the fifteenth century to determining the most efficient sea routes around Africa to India and China. Under the leadership of Henry the Navigator (1394–1460), the Portuguese government mapped the coast of Mauritania, discovered the Azores, and mounted several expeditions to Africa and Asia in their sleek caravels (single-stern ships). Bartolomeu Dias (1450–1500) circumnavigated Africa around the Cape of Good Hope. In 1498 Vasco da Gama (1460–1524) became the first sailor to travel from Portugal to India, where he attempted to secure Calcutta under Portuguese dominion. The opening of a sea route to India created a monopoly for the Portuguese.

Other European powers who wanted to cash in on the lucrative trade with India and China attempted to find a westward route. To this end, the Spanish government backed Christopher Columbus (1451–1506) who, motivated by a combination of missionary zeal and desire for personal glory, discovered Hispaniola, the Bahamas, and Cuba, although he thought at first that he had reached the Chinese mainland or another point in Asia.

The encounter between the Old and New Worlds, while a triumph of technology and navigation, was an environmental catastrophe. New European species wiped out native flora and fauna, and European diseases like smallpox nearly destroyed entire races of Native Americans. The strange peoples, plants, and animals brought back to Western Europe from the New World engendered a renewed intellectual appreciation for the “wonders of nature.” Scholars have speculated that such encounters spurred a desire to observe and classify nature, which became part of the basis for the Scientific Revolution in the seventeenth century.

Voyages to the New World continued in the sixteenth and seventeenth centuries. The Pacific Ocean was discovered by Spanish conquistador Vasco Nuñez de Balboa (1475–1519) in 1513. Portuguese navigator Ferdinand Magellan (c.1480–1521), launched an expedition in 1519 that became the first to circumnavigate the globe. (Magellan himself was killed in the Philippinesin 1521, and did not live to see the mission completed.) The Aztec and Incan Empires were discovered and conquered by Spanish explorers Hernán Cortés (1485–1547) and Francisco Pizarro (1471–1541), respectively. Cortés and Pizarro were driven by a lust for gold, territory, and a hope of finding el Dorado (“the gilded one”) a variation on the legend of Prester John. Their expeditions also had far-reaching economic effects. The opening of wildly productive silver mines in Peru by Spanish conquistadors using Native American slave labor brought so much bullion to Western Europe, that the last part of the sixteenth century saw tremendous inflation in the prices of food and durable goods.

From the Enlightenment to the Modern Era

The encounters between the Old and New Worlds led to some of the first comparative anthropological and sociological studies of culture, primarily in the eighteenth century. French philosopher Charles-Louis Montesquieu in his Spirit of the Laws (1748) discussed the effect of climate, primarily heat and cold on the human body and on the intellectual outlooks of society. He espoused “geographical determinism”: the belief that certain climates were superior to others. The temperate climate of France, he said, was ideal; races living closer to the equator were “hot-blooded,” and those in northern countries “stiff.” Montesquieu also claimed hot southern or eastern climates led to despotisms (absolute rule/tyranny), and moderate western climates to constitutional monarchies such as those in England and France.

As western Europe began to colonize Africa and the Middle East in the late eighteenth and nineteenth centuries, their policy makers relied on theories such as Montesquieu's to impose governments on native peoples who were “under the sway” of their “inferior” climates.

European colonialism also gave impetus to exploration of those areas of the world that remained unknown to the West, such as Australia, New Zealand, and the African interior. The voyages of Captain James Cook (1728–1779) and Sir Joseph Banks (1743–1820) to Australasia and the Pacific led to a program of economic botany in the British Empire. Indigenous plants were sent back to the Royal Botanic Gardens at Kew, investigated for possible uses, and then exported to colonial plantations. In this manner, tea plantations using Chinese plants were established in the British colony of India, so Britain did not have to pay to import Chinese tea.

The expansion of British whaling ships and seal traders into the Arctic and Antarctic led to an interest in

reaching the North and South Poles. In 1828 Sir William Parry (1790–1855) nearly reached the North Pole, a goal that was finally accomplished by American explorer Robert Peary (1856–1920) in 1909. The first scientific expedition to survey Antarctica was led by British explorer James Ross (1800–1862) in 1839–1843, which further whetted appetites to explore the region. In 1895 the Sixth International Geographic meeting in London adopted a resolution that “the exploration of the Antarctic Regions is the greatest piece of geographical exploration still to be undertaken.” Though the Congress recommended that “this work should be undertaken before the close of the century,” it was not until 1911 that Norwegian explorer Roald Amundsen (1872–1928) reached the pole. An expedition by Ernest Shackleton (1874–1922) subsequently made heroic yet tragic efforts to cross the continent from 1914–1917.

The Antarctic Treaty of 1959 prohibits any one from staking territorial claims on Antarctica, designating it for scientific purposes only. Presently, the Antarctica research station is taking ice core samples to monitor global warming; it is also the darkest place on Earth and thus ideal for astronomical research.

Modern Cultural Connections

Those who plumb the depths of the sea and engage in manned or robotic missions to the stars are the last explorers. Using seismometers at the bottom of the ocean, robotic divers, and deep sea submarines, scientists in the Deep Ocean Exploration Institute at Woods Hole Oceanographic Institution investigate the planetary forces and phenomena that generate earthquakes and tsunamis, support communities of life of the ocean floor that hold key clues to the evolution, and that forge large offshore mineral, oil, and gas deposits. Under the leadership of Dr. Bob Ballard (1942–), Woods Hole was also responsible for the discovery of the shipwrecked RMS Titanic in 1985.

As does deep ocean exploration, space exploration has scientific, economic, and geopolitical facets. Space exploration began in the late 1950s with the launch of the Soviet Union's Sputnik satellite on October 4, 1957, the first manmade object to orbit Earth. Responding to the Cold War—induced “space race,” the United States made the first manned moon landing by Apollo 11 on July 20, 1969.

After the first 20 years of exploration, NASA's budgetary cuts shifted emphasis to renewable space hardware (such as the Space Shuttle and instrumentation such as the Hubble Telescope). The end of the Cold War also saw partnerships in space with the former Soviet Union, exemplified by the International Space Station with entrepreneurs such as Sir Richard Branson (1950–) of Virgin Group, Ltd., forming the Spaceship Company in 2005 to promote space tourism, build suborbital spaceships, and launch aircraft. The price for a two-hour space ride is projected to be $200,000. NASA has advocated manned lunar and Mars missions after 2010 not only due to gains in scientific knowledge, but out of pragmatic concerns. With the onset of global climate change, humans may be forced to colonize space to ensure their survival.

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Fara, Patricia. Sex, Botany, and Empire: The Story of Carl Linnaeus and Joseph Banks. New York: Columbia University Press, 1994.

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Perrottet, Tony. Pagan Holiday: On the Trail of Ancient Roman Tourists. Westminster, MD: Random House, 2003.

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Roller, Duane W. Through the Pillars of Herakles: Greco-Roman Exploration of the Atlantic. London: Routledge, 2006.

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Van Pelt, Michel. Space Tourism: Adventures in Earth Orbit and Beyond. New York: Springer, 2005.

Wertheim, Margaret. Pythagoras' Trousers: God, Physics, and the Gender Wars. New York: W.W. Norton and Company, 1997.