Day 51 : Book Excerpt : Maps Of Time

Thirteen billion (13,000,000,000) years ago there was nothing. There wasn’t even emptiness. Time did not exist, nor did space. In this nothing, there occurred an explosion, and within a split second, something did exist. The early universe was fantastically hot—a searing cloud of energy and matter, much hotter than the interior of a sun. For a trillionth of a second it expanded faster than the speed of light, growing from the size of an atom to the size of a galaxy. Then the rate of expansion slowed, but the universe has continued expanding to the present day. As the early universe expanded, its temperature dropped. After about 300,000 years, it was cool enough for atoms of hydrogen and helium to form. Within about a billion years, huge clouds of hydrogen and helium began to gather and then collapse in on themselves under the pressure of gravity. As the center of these clouds heated up, atoms fused together violently like vast hydrogen bombs, and the first stars lit up. Hundreds of billions of stars appeared, gathered in the huge communities we call galaxies. The early universe consisted of little more than hydrogen and helium, but inside stars, and in the violent death agonies of large stars, new elements were created. And over time, more complex elements began to appear in interstellar space. Our own sun was formed about 4.5 billion years ago from a cloud of gas and matter that contained many of these new elements, in addition to hydrogen and helium. The planets of our solar system were formed at the same time as the Sun, from the debris left over from the Sun’s creation.

The early earth was a dangerous place, bombarded by meteorites and so hot that much of it was molten. Over a billion years, however, it began to cool, and as it did so, water rained down on its surface to create the first seas. By 3.5 billion years ago, complex chemical reactions, probably taking place around deep-sea volcanoes, had created simple forms of life. Over the next 3.5 billion years, these simple, single-cell organisms became more and more diverse, evolving through natural selection. Quite early, some learned to extract energy from sunlight through the process of photosynthesis. As other organisms began to feed on the photosynthesizers, sunlight became the main “battery” of life on earth. Powered by the Sun, living organisms spread through the seas and eventually over the land, creating an interconnected web of life that had a profound impact on the atmosphere, the land, and the sea. From about 600 million years ago, there began to appear larger organisms, each made up of billions of individual cells. A mere 250,000 years ago, our own species appeared, having evolved from apelike ancestors through the same unpredictable processes of natural selection.

Though they evolved in the same way as other animals, humans turned out to be unusually good at extracting resources from the environment. Their advantage lay in their ability to share information and ideas with a precision that no other animal could match. And over time, their shared knowledge accumulated, enabling each generation to build on the knowledge of earlier generations. The number of humans grew as they learned how to live in more and more diverse environments, first in Africa; then in Eurasia, Australia, and the Americas; and eventually in the myriad islands of the Pacific. These global migrations took many tens of thousands of years. Eventually, beginning a mere ten thousand years ago, humans in some parts of the world began to manipulate their environments so successfully that they could produce ever greater amounts of food from a given area of land. Using the technologies we refer to as agriculture, they began to settle down in small village communities. As populations grew, the number and size of villages also grew until the first large cities appeared, about 5,000 years ago. These large, dense settlements required new and complex forms of regulation to prevent disputes and coordinate the activities of many people living at close quarters. In this way there appeared the first states, groups of powerful individuals capable of regulating the activities of the community as a whole. Conflict appeared both within and between communities, as different groups competed for resources and power. But as communities also exchanged information, the technological resources available to humanity as a whole continued to accumulate. Over several thousand years, the size, the reach, and the populations of societies with states expanded, until eventually most humans were living within state-based societies with cities and some form of agriculture. As their numbers and technological skills grew, so did their impact on the biosphere—the community of other organisms on earth. In some regions, the impact of human activities such as irrigation or deforestation proved so damaging that the local environment could no longer support large human populations, and entire civilizations collapsed.

As technologies of communication and transportation improved, more and more communities came into contact with each other. About 500 years ago, for the first time, these changes connected human communities in all parts of the world. For many communities this coming together was disastrous; it brought conquest, disease, and exploitation, sometimes of the most brutal kind. But the merging of regional communities also helped trigger new technological breakthroughs that could now be shared throughout the world. In the past two centuries, new technologies, beginning with the harnessing of steam power, have given human societies access to the vast sources of energy locked up in fossil fuels such as coal and oil. Human populations have grown more rapidly than ever before, and the problems of administering these huge communities, and coping with conflicts between them, have demanded the creation of even more powerful and complex state systems. Today, human numbers are so great, and the impact of humans on the biosphere is so significant, that we are in real danger of doing serious damage to the environment that is our home. Such damage could lead to a global collapse of human civilizations and have devastating effects on other organisms as well. At the same time, the ability of humans to share knowledge is now greater than ever before, and it may be that new technologies and new ways of organizing human societies will enable us to avoid the dangers created by our ecological virtuosity.

~~Maps Of Time: An Introduction to Big History -by- David Christian