Human civilization

Human civilization interferes more and more with the cycles that cormect land, water, and atmosphere, and pollution seriously affects water quahty. In order to assess the stresses caused to aquatic ecosystems by chemical perturbation, the distribution of pollutants and their fate in the environment must be investigated (see Air pollution). 

Biomass is generally made up of polymers, oligomers, monomers, and other nonpolymerizable simple organic compounds, including metallic salts and complexes [17,29,30]. Polymers are, of course, the major components and have been serving human civilizations from time immemorial. The literature on natural polymers is vast and only a few reviews and books are cited here for further reference [3,17,18,24,29-31,37-53]. The outstanding aspect of natural polymers is their wide variety, which provides innumerable opportunities for structural modifications and utilization. 

Through time, human civilizations have repeatedly made the same critical error the excessive exploitation of forest resources or the failure to practice forestry on a sustainable basis. The earliest recorded cases of excessive deforestation occurred approximately 5,000 B.P. in the very cradle of western civilization, Mesopotamia 19), Since that period, abusive levels of forest exploitation have severely degraded or caused the complete disappearance of forests in regions of Europe, Africa, Asia, Australia and the Americas. Truly, the negative consequences of excessive levels of deforestation is a lesson that has been learned by few civilizations. 

The advances of human civilization can be viewed as the results of people figuring out how to increase the availability of energy. As Figure 6-21 shows, the amount of energy used per person per day has multiplied by ore than a factor of 100 as humans moved beyond the application of their own muscles, by making use of animals, water power, fossil fuels, and nuclear energy. 

Metallurgy is the production and purification of metals from naturally occurring deposits called ores. It has an ancient histoiy and may represent the earliest useful application of chemistry. Metallurgical advances have had profound influences on the course of human civilization, so much so that historians speak of the Bronze Age (ca. 

The Iron Age was a phase of human civilization (in Europe from about 1000 BC to 100 AD), characterized by the introduction and development of iron tools and weapons it followed the Bronze Age. 

Many activists and environmentalists believe that climate change is the major threat facing human civilization in the 21st century and that institutions are doing little to battle the problem. 

In recent years we have been faced by the possibility or perhaps the probability that human civilization as we know it may be shattered if not pretty well destroyed. In view of this it seems not inopportune to remind those who work in ivory towers that the possibilities of applied human biology should be looked into. Possibly it holds the key to the solution of more human problems than we dream of. There comes a time when pure scientific curiosity as the sole object of scientists devotion may be inadequate and even, in effect, destructive. 

Although human civilization has been experimenting and consuming drugs for many centuries, it is only in the past hundred years that the foundation was laid for the systematic research and development of drugs. Readers are referred to Appendix 1 for a brief description of the history of drug development since ancient times. 

The following are some snapshot examples of how drugs were discovered from the early human civilizations. 

Pain is a basic sensory, emotional, and cognitive phenomenon that signals some type of harm to the organism. It is practically universal to human experience, and although it is initially adaptive, it frequently outlives its usefulness and impedes one s ability to function. Accordingly, plants that alleviate pain have become essential to human civilization. 

Grass predates human civilization and occupies places well... 

Our relationship with grasses is therefore prehistorically deep and turfgrass cover has been with human civilization for a very long time, in some form or another. The term turf is derived from the Sanskrit word darbha, meaning tuft... 

Back to the future. The situation with regard to human testing today is vastly different. Considerations of human civil rights (some of them seeming to be included in the name of what some call political correctness ) now cause conscientious investigators to ask themselves many questions before submitting a proposal. 

The voice of the teacher spoke in my mind. "You ve found it. This is it. It s all over now. There is no more. Within a few hours, the superstructure of earthbound, human civilization is going to collapse and your species will depart. First you will go to Jupiter and then to Alpha in Sagittarius. A day of high adventure dawns at last for the human beings."... 

The search for chemicals that will provide relief from pain, cure disease and infection, and offer an escape from the real world has been a part of virtually every known human culture. In the earliest period of human civilization, plants, animal products, and minerals were the major source from which such chemicals were obtained. Many of those products—ranging from natural poisons obtained from frogs and certain types of plants to rocky minerals such as compounds of arsenic to mind-altering substances derived from mushrooms and cacti—are still used in at least some parts of the world as a means of capturing prey, for the treatment of disease, or for recreational purposes. Indeed, many pharmaceutical chemists believe that the natural world contains an almost endless supply of yet-to-be-discovered chemicals that will significantly augment the world s supply of drugs. 

Environmentalists and ecologists, however, oppose constmction of any new incinerators and landfill facilities. They would like to close all existing incineration and landfill facilities, if possible. They are wrong. Unless human civilization is to go backward, there will always be hazardous and infectious wastes produced by industry. These wastes must go somewhere. A solution must be found. 

We can also be proud of the entire scientific endeavor. The scientific enterprise in this country, indeed the world at large, represents some of the best attributes of human civilization. Nobel Laureate Robert Wilson spoke around 1969 about basic research in the Fermi lab This new knowledge has all to do with honor and country, but it has nothing to do directly with defending our country except to make it worth defending. ... 

The story of opium is one of both individual and global conflict. It is a story of alleviating pain and inspiring genius, of addiction, escape, and freedom, of contradictions and mystery. Above all, the story of opium is one of constant mutation within the instability and evolution of human consumption and addiction. The story is as relevant today as it was during the great opium wars of the mid-nineteenth century, yet it stretches back into the far reaches of human civilization. 

Early human civilizations used stone, bone, and wood for objects. Approximately ten thousand years ago, metals first appeared. The first metals used were those found in their native form, or in a pure, uncombined state. Most metals today are acquired from an ore containing the metal in combination with other elements such as oxygen. The existence of native metals is rare, and only a few metals exist in native form. Iron and nickel were available in limited supply from meteorites. The first metals utilized widely by humans were copper, silver, and gold. Pure nuggets of these metals were pounded, in a process known as cold hammering, with stones into various shapes used for weapons, jewelry, art, and various domestic implements. Eventually, smiths discovered if a metal was heated it could be shaped more easily. The heating process is known as annealing. Because the supply of native metals was limited, metal items symbolized wealth and status for those who possessed them. 

Alkanes such as ethane are relatively unreactive and reactions involving alkanes require high-energy atoms or free radicals. Three general types of reactions involving alkanes are combustion, halogenation, and pyrolysis. The most common reactions of alkanes involve combustion. Combustion of alkanes has been the primary source of heat for human civilizations throughout... 

Ar human civilization. Indeed, archaeol-Y ogists organize early human history in terms of materials—the Stone Age, in which only natural materials such as wood and stone were available the Bronze Age, in which implements were made of copper alloyed with tin and the Iron Age, in which ornaments, weapons, and tools were made of iron. Copper and iron are still of enormous importance. Copper is used to make electrical wiring, and iron is the main constituent of steel. 

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