Key Theme 6: Science, Technology, and the Environment
The study of science, technology and the environment has to do with the changing ways in which humans have used the knowledge they share through collective learning to exploit their physical and natural surroundings. As humans have discovered more and more ways of extracting energy and using animals, plants, and minerals for their own purposes, they have begun to change the biosphere at an increasing pace. Though our technological and scientific creativity has allowed our species to multiply, it has also transformed the living conditions for all species on earth. We do not yet know where these accelerating changes will lead. They include, for example, an explosion of genetic knowledge that promises better treatments for numerous diseases. But they also include global warming, which, if it continues, might have devastating effects on humankind’s well-being.
All living creatures survive by extracting energy and other resources from their surroundings. Each animal has its own, distinctive ways of getting what it needs from the environment. Some bacteria, for example, extract energy from nuclear waste products, while others, which existed early in the history of our planet, lived by consuming chemicals such as sulfur generated in hot vents on the ocean floor.
But most animals have a fixed repertoire of survival tricks, determined by their genetic makeup. What makes humans so different is that our capacity for collective learning allows us to continue discovering new ways of getting the energy, food, and materials we need from our environment. Over time, humans have learned to exploit a huge variety of different environments, and with increasing efficiency. Today, though we are only one of millions of species, we may control up to 40 percent of all the energy that enters the biosphere from sunlight.
The environment includes both our biological and geographical surroundings, the foundation for our existence. By “technology”, we mean the various methods, procedures, and tools that humans have used to get food and energy and to change the environment in useful ways, for example, to grow crops, build houses, or communicate through the Internet.
The word “science” is trickier to define. Normally, it refers to the systematic forms of knowledge developed in recent centuries that have enabled modern humans to transform their environments faster than ever before. All human societies, however, have had systematic theories about their environments, often embedded within religious traditions. For example, in the European middle ages most educated Christians accepted the description of the universe that the ancient Greek scholar Ptolemy worked out. He put the earth at the center of the universe. According to him, a series of transparent shells surrounded the earth, and the heavenly bodies were attached them. Though not accepted today, Ptolemy’s elaborate description offered a plausible explanation for the movements of the sun, the planets, and the stars. So we can say that in a sense all human societies have had some form of science, or knowledge system, which supported and explained the technologies they used and the ways they related to their surroundings.
Some time between 250,000 and 100,000 years ago Homo sapiens acquired language, and with it the capacity for collective learning. This meant that members of our species could share complex knowledge with one another, accumulate and store knowledge, and pass knowledge to the next generation. No other species can do these things, except in very rudimentary ways.
For example, with language humans could acquire and share new technological understanding and skill in using a new kind of tool, say, a sharper stone axe. People could:
give a name to that particular kind of axe that could be recognized by hundreds or thousands of other people.
share knowledge of what the axe looked liked and what it could do even if a sample of it were not available.
explain how to use the axe without having to give a demonstration of its use.
discuss how the axe might benefit the welfare of the hunter-gatherer community.
The hand axes to the right were found in southeastern England.
They may be as many as 300,000 years old.
A person could easily grip an axe like this for cutting or chopping.
Dover Museum; Dover, England
Technological knowledge spread from one community to another, sometimes great distances. For example, knowledge of how to make flint tools by flaking them off a piece of rock diffused all the way across Afroeurasia in the paleolithic age. Successful use of flint tools changed the relationship of humans to their natural environment.
In the paleolithic era, all humans lived by foraging, hunting, or fishing. They gathered plants and small animals, and they hunted larger animals. Unlike farmers, they did not feel the need to try to transform their environments. Their numbers were also small, so they had much less impact on the environment than humans did in later eras. This does not mean, however, that hunter-gatherers had no effect on their environment. At times, it could be significant. For example, in many parts of the world, foragers set fire to sometimes large tracts of vegetation to clear undergrowth, encourage new growth, and attract game (which came to eat the new growth). Scholars have called this process “ fire-stick farming.” By firing land, people transformed entire landscapes, encouraging the spread of fire-resistant species of plants and trees (such as the eucalyptus tree, a native of Australia), and narrowing the range of species that lacked resistance to fires.
Early humans also had a huge impact on many species of large animals, or megafauna. This happened especially in the Americas, Australia, and Siberia, where animals encountered human beings only between about 60,000 and 10,000 years ago and therefore had no evolved instincts for avoiding humans when they first appeared. In these regions, humans rapidly hunted to extinction large species such as mammoths, giant kangaroos, and sloths. In short, science and technology left a mark on the environment even in the paleolithic era!
However, about 10,000 years ago, when agricultural societies started to appear, the pace of scientific and technological change sped up sharply. So did human effects on the environment. Early farming was based on new forms of knowledge and new technologies. Agriculture involved a whole set of new techniques for planting, irrigating, harvesting, and processing, as well as a lot of knowledge about how to manage and spread domesticated plants and animals. In order to increase the production of those plants and animals that they found most useful, humans began to remove other plants and animals that they did not need. They got rid of weeds, killed wolves and foxes, and poisoned vermin. They also began to transform the landscape by clearing trees and shrubs, digging irrigation ditches, terracing hills, and draining swamps.
The appearance of agriculture marks one of the most fundamental changes in history, for it allowed people to extract more energy and resources from a given area. As a result, human populations began to rise rapidly. With more people exchanging ideas, knowledge of how to manage the environment accumulated faster than ever before. Humans developed many new technologies. These included new ways of coping with cold environments (for example, making warmer, closer-fitting clothing, or building houses from snow and ice), irrigating land in arid environments, and domesticating new species such as the camel and the ox. As millions of people shared their ideas and techniques, they began to develop new ways of handling materials, learning how, for example, to make textiles, pottery, bronze weapons, and large buildings, such as palaces and pyramids.. They also found ways to exploit new forms of energy, harnessing domesticated animals to carry goods and transport people, taming the power of the wind to propel boats, and using streams and rivers to drive water wheels.
Knowledge systems also became richer and more powerful. In larger-scale societies, leaders had to find ways to coordinate religious rituals, markets, or tax-collecting in many villages and towns. In other words, leaders needed accurate calendars. To invent them people had to acquire more systematic knowledge of the movements of the stars and planets. As wealth piled up in societies, leaders also had to devise new techniques for surveying land and keeping accounts. This need stimulated development of writing systems and mathematics. And, all societies came up with coherent ways of thinking about the world in general, ideas that were usually embedded in religious traditions. Even animism, the idea that most things on earth are animated by spirits of different kinds, can be thought of as a kind of early form of science because it helped people explain the mystery and unpredictability of the real world.
New technologies of transportation and communication were particularly important because they encouraged people to exchange ideas and knowledge over large areas, and stimulated collective learning. In Afroeurasia, people began about 6,000 years ago to use animals for transportation, allowing a great increase in the number, variety, and extent of commercial and cultural contacts among communities. Shipbuilding and sailing technologies multiplied the possibilities for contacts across wide seas, most spectacularly in the Pacific Ocean, where mariners sailed huge distances to settle the islands of Oceania. The ancient Chinese invented the magnetic compass for navigation, and by the thirteenth century this simple device was in use from the East China Sea to the Mediterranean. Inventions such as paper permitted people to communicate in words or pictures over longer distances and to store greater quantities of information.
Revolutions in Transportation
Ways of Moving People and Goods
From about 700,000 years ago
First hominid migrations from Africa
From about 100,000 years ago
Modern humans in southern Eurasia; migrations of modern humans from Africa
From about 60,000 years ago
First migrations by sea to Australasia; earliest seaborne boats
From about 4000 BCE
From about 3500 BCE
From about 1500 BCE
Long-distance ships in Polynesia
1st millennium BCE
State-built roads and canals; coinage
1st millennium CE
Improvements in shipbuilding and navigation
From early 19th century
Railways and steamships
From late 19th century
Internal combustion engine
From early 20th century
From mid 20th century
Table adapted from David Christian,
Maps of Time: An Introduction to Big History
(Berkeley: University of California Press 2004), 307.
As knowledge reached larger areas, it tended to become more general. For example, it was no longer
sufficient for a farmer to ask how large a particular field was. It became necessary to compare it
with other fields, and that required the construction of abstract units of measurement, leading to early
forms of geometry and mathematics. As people encountered many different types of societies, they had to
begin asking what it was that all humans had in common. Did they have the same gods? Did they believe
in the same values? What, in short, was it that all humans shared? Early notions of economic value
reflected the spread of markets and the need to develop uniform monetary values.
In some regions, such as ancient Greece, or the early Islamic world, the search for general ways of describing reality led to forms of philosophy that begin to look remarkably like modern forms of science.
Technological advances contributed to the emergence of more complex social inequality because not everyone benefited equally—or benefited at all—from technological change. Control over sophisticated technologies, such as writing systems, the manufacture of metal tools and weapons, or the flow of irrigation water, granted great power to some. Those who controlled those technologies typically dominated those, usually the great majority, who did not. Access to advanced technologies, particularly for military or commercial purposes, goes a long way to explain why some groups managed to conquer and repress others. As a general rule, those leaders who possessed the most advanced technologies were likely to have the greatest impact on historical change in a region. In some times and places those leaders used superior weaponry and communication networks to build great empires.
In the millennia following the invention of farming, advances in science and technology had increasing effects on the physical and natural environment. These advances allowed humans to populate the earth in much larger numbers, raise agricultural production, build great cities, and experiment with many new forms of social and political organization. The spread of farming and metal-working industries, however, also contributed to forest cutting on a larger and large scale, and with it erosion and loss of productive hunting and crop-growing land. In some places humans caused environmental changes that led to social catastrophe. In Mesopotamia in the late third millennium BCE, too much irrigation and buildup of salt deposits (salinization) undermined the productivity of the soil, leading to sharp decline in population in much of the region. In Mesoamerica towards the end of the first millennium CE, the Maya civilization collapsed, probably also as a result of over-exploitation of the land. In towns and cities around the world, the burning of wood and other fuels, as well as tanning and metal-work industries created extremely polluted environments, which seriously reduced life-expectancies.
As communications and transportation technologies developed, exchange networks knitted large areas of the world together, until by the sixteenth century all the major land areas of the world, excepting Australia until the late eighteenth century, were brought within a single global web of trade and cultural interaction. The fashioning of this global network gave a huge impetus to the development and spread of new technologies and new forms of knowledge. Information from all parts of the world contributed to a single global system of ideas, skills, and techniques.
For a time, Europe found itself at the centre of this system because its fleets dominated so many international trade routes. As a result, Europe and, more broadly, the Atlantic region had an early advantage in benefiting from access to the existing global inventory of new ideas and technologies. This may be one reason why so many of the core ideas of modern science emerged in Europe between the sixteenth and eighteenth centuries, the era of what we call the scientific revolution. In the eighteenth and early nineteenth centuries, this concentration of scientific knowledge underpinned the industrial revolution, which got underway in Europe but shortly involved the entire world in many ways.
A product of modern science and technology.
The chronometer that the Englishman John Harrison invented in 1760 for use
in reckoning longitude at sea.
National Maritime Museum, Greenwich, England Photo by R. Dunn
At the heart of the new industrialization was the fossil fuel revolution. Coal, oil, and natural gas are called fossil fuels because they are made from fossilized plants and bacteria that contain much of the energy they stored from sunlight when they were alive. In burning fossil fuels, we are using sunlight energy that has been stored in natural "batteries" for several hundred million years. By the eighteenth century, the growth of world population and the further spread of farming accelerated the pace of deforestation so much that a global energy crisis loomed. However, new machines such as the steam engine and the railway locomotive allowed humans to tap into the huge amounts of energy stored in fossil fuels. For example, miners used steam engines to pump water out of underground shafts and tunnels, allowing extraction of coal on a much larger scale than ever before. And steam locomotives carried coal relatively inexpensively from mine to factories and homes.
The dangers of rapid technological change, however, have accelerated along with the benefits. Industrialization and the accompanying rapid growth of world population have speeded up deforestation, leading to over-exploitation of land. Burning vast quantities of fossil fuels worldwide has begun to transform the atmosphere in ways that may lead to catastrophic climatic change in the near future. New forms of social inequality have emerged because those nations and peoples that first acquired advanced machines and weapons gained military, economic, and political advantages over societies that lagged behind technologically. Indeed, the concentration of technological and scientific skill in Western Europe, North America, and Japan beginning in the mid-nineteenth century allowed the peoples of those regions to politically and economically dominate the rest of the world for about a century and a half.
The patterns of power in the world have changed significantly in recent decades, but the social and economic chasms have on the whole been getting wider. For example, the furious pace of advances in computer technology has already created a “digital divide” separating people in the highly industrialized countries from the great majority everywhere else. Innovations in weaponry have also made it possible to wage wars on a scale of destruction unimaginable before the nineteenth century. The nuclear weapons first invented in the mid-twentieth century have the explosive and toxic power to annihilate much of the biosphere in just a few hours. Indeed, the resentments and conflicts created by extreme social inequalities in the world increase the chances that such weapons will be used.
Chart adapted from David Christian, Maps of Time: An Introduction to Big History (Berkeley: University of California Press 2004), 458.
This essay reminds us that the human species is astonishingly inventive. The benefits of scientific and technological advances have been immense, in global communication, farm productivity, medical treatment, useful genetic modification, availability of material goods, and, for hundreds of millions, higher standards of living than humankind could have dreamed of just 200 years ago. But our inventiveness has also brought gaping social and economic imbalances in the world and an array of new dangers from extinction of animal species to nuclear terrorism. Unless we seriously address these threats and inequalities and begin to solve the worst of our problems, we could conceivably set our species back hundreds or thousands of years, just as excessive exploitation of the land ruined great societies in ancient Mesopotamia and Mesoamerica.
Why Do We Need to Understand This
Humans are living creatures and, like all of them, they need to draw energy and resources from their environment. How humans have done this from paleolithic times to the present is one of history's dramatic stories. Science and technology have transformed, and continue to transform, the daily lives of all peoples. Because of the scientific and technological achievements of the past 200 years, Americans as a whole enjoy unprecedented standards of living and life expectancy.
Making some sense of the world around us and understanding how and why we live the way we do-as individuals, families, employees, and citizens-require at least a modest grasp of the immense changes that have occurred in the world in the past two centuries, which is barely a page in the long chronicle of human history. For example, the world's human population could never have reached its current level of about 6.4 billion without the mastery of nature that science and technology have afforded. Simply feeding this many people has depended upon the continuous accumulation of new ideas and techniques for irrigating land, mechanizing farming, genetically modifying seeds, moving goods from place to place, and organizing business and finance. History shows us, however, that these systems might be more fragile than we think. Therefore, we cannot ignore the history of humankind's changing relationship to the natural and physical world.
Human systems of knowledge are utterly unlike those of other organisms because humans seem to have a never-ending capacity to add to and transform them. This explains why humans have had such a huge impact on the environment and on one another. In exploring Key Theme 6, we are really exploring what it is that makes human beings so special.
Landscape and Closeup Teaching Units
that Emphasize Key Theme 6: