Chapter 11 -- Energy

Chapter 11 -- Energy - THE THIRD PLANET E R SWANSON spring...

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THE THIRD PLANET E. R. SWANSON – spring 2009 ENERGY Introduction – History Our early ancestors discovered how to use fire from energy sources such as combustible wood or from dung if the region was dry and lacking in wood. Wind, water and solar might sound like modern energy sources but they have actually been used for centuries if not for millennia. Wind power has a long history of being captured by sails hoisted on ships and on windmills. The power of running water was eventually harnessed by water wheels to power grinding wheels and various machines or to lift boats up in locks along ship canals. Solar power, when you think about it, has had a long history of being used for many things such as drying clothes, preserving meat and to make salt from saltwater. In a way, all of the energy sources mentioned above could be considered nuclear power. Nuclear fusion powers the Sun and it is the Sun’s energy that drives atmospheric circulation, evaporates ocean water and powers the water cycle. Nuclear fission gives the Earth its internal heat, so that geothermal energy is also ultimately nuclear. As for the chemical energy locked in fossil fuels, that too is the result of nuclear powered solar energy that grew plants that later became fossil fuels. Early individual energy requirements were modest and easily supplied by nature. Greater energy needs were commonly supplied by the first alternative energy source – muscles. The muscles used may have been from one of our larger fellow mammals, the so-called “beasts of burden” like horses, oxen, donkeys, camels, elephants, llamas, sled dogs, etc. The muscles of our fellow humans were also put to use, voluntarily or involuntarily. Slavery has a long history of being an inhuman source of energy employed by humans (or was it a human source of energy employed by inhumans). The Industrial revolution relied on steam power, and that started in England. The invention of the steam engine ultimately relieved some pressure on the exploitation of muscle power, but it did require enormous amounts of fuel that stripped the English countryside of forests. England then went after the fossil energy of ancient forests trapped in beds of coal. The internal combustion engine required petroleum products, or was it the discovery of petroleum products that allowed the widespread use of the internal combustion engine? Eventually nuclear power tapped forces found in the nucleus of atoms as it converted mass into energy through nuclear fission and nuclear fusion. The changing choice of fuels in the U.S. is reflected in its history. In 1850 the U.S. was an agricultural nation with 90% of its energy needs met by wood. By 1880, industrialization and coal mining caused coal and wood to be about equal in terms of the energy they provided. By 1920, coal met 75% of U.S. energy needs and the use of petroleum was in its infancy. The 1950s saw the use of petroleum draw even to and then surpass the use of coal. That decade also so the dawn of the nuclear power era. Today
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This note was uploaded on 09/09/2009 for the course GEO 301 taught by Professor Long during the Spring '07 term at University of Texas.

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Chapter 11 -- Energy - THE THIRD PLANET E R SWANSON spring...

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