pielou - the energy of nature (chicago, 2001)

[...]... underfoot or the drumming of rain, the babbling of a stream, the calls of birds, the hum of insects Sound is much more noticeable on a windy day, with the roar of wind and waves at the beach and the snapping of tree branches in the forest The stormier the weather, the more obvious the energy Lightning gives a glimpse of yet another of energy s many forms— electrical energy Movements, sounds, and the occasional... are merely the more attention-getting forms of energy The warmth and brightness of sunshine and the growth of plants illustrate how the sun’s energy empowers life and action at the surface of the earth; energy from the sun comes as electromagnetic radiation, and plants grow because they can convert the radiant energy into chemical energy Energy in a multitude of forms is as much a part of our surroundings... rays); this energy leaves the sun in all directions as electromagnetic energy, a small fraction of which strikes the earth Suppose some of this solar energy falls on a tract of grassland The grass uses the solar energy to create sugars by the process of photosynthesis That is, the chlorophyll in the grass converts electromagnetic energy into chemical energy The grass grows—entailing a whole series of conversions... temperature and the subjective sensation of temperature holds only if the density (or pressure) of the air is what we are accustomed to Recall that the temperature of the air is a measure of the average kinetic energy of each molecule, regardless of the number of molecules in a given volume Now imagine two parcels of air, one at ground level and the other 300 km up, and suppose they are at the same temperature... that the total energy in the parcel at ground level far exceeds the total energy in the high-altitude parcel, because the former contains so many more molecules than the latter; it is the total energy, not the energy per molecule, that determines how the air “feels,” either warm or cold Thus the statement that at an altitude of 300 km the air temperature is 1,500°C, while true, gives no idea of how the. .. lead to the inescapable conclusion that although the total energy of the universe remains forever the same, the fraction of it that is entropy forever increases 20 chapter three Another way of saying the same thing is, first, to contrast “ordered energy, ” such as the kinetic energy of a moving macroscopic object, with “disordered energy, ” namely thermal energy, the disordered, random motion of individual... much higher temperature than the comparatively cool steam discharged from the funnel All the same, the cool steam carries away a proportion of the heat supplied by the firebox This is the crux of the matter: high-temperature heat yields a mixture of mechanical energy and low-temperature heat; the latter is wasted energy, but waste cannot be avoided The thermal efficiency of any heat engine is defined... energy, the energy of movement Eventually a coyote catches and eats the jackrabbit; this requires a fairly lavish conversion of chemical energy into kinetic energy by the coyote, since the jackrabbit will no doubt resist Both the animals are warm-blooded, and to keep their temperatures at the physiologically correct level, they must also convert some of their chemical energy into thermal energy Death... within the cylinders The movement of the pistons is converted by camshafts and linkages into the rotary motion of the wheels Indirectly, therefore, heat from the burning coal turns the locomotive wheels Only a fraction of the heat supplied is turned into mechanical energy, however; most of the rest is lost in the steam escaping into the atmosphere; note that the heat put in from the firebox is at a much... complete: the bob’s KE has decreased to zero so that it is momentarily stationary, and its gravitational PE has increased to a maximum Then the whole process happens again, from right to left The total energy remains the same all the time, never dwindling; it is the sum of the KE and the PE, known as the mechanical energy of the pendulum As an equation, mechanical energy = potential energy + kinetic energy . alt="" THE ENERGY OF NATURE THE ENERGY E. C. Pielou the university of chicago press • chicago and london OF NATURE E.C. PIELOU, former professor of mathematical ecology and Killam Pro- fessor. 0-2 2 6-6 680 6-1 (cloth) Library of Congress Cataloging-in-Publication Data Pielou, E.C. The energy of nature / E. C. Pielou. p. cm. Includes index ISBN 0-2 2 6-6 680 6-1 (alk. paper) 1. Force and energy. . with the roar of wind and waves at the beach and the snapping of tree branches in the forest. The stormier the weather, the more obvious the energy. Lightning gives a glimpse of yet another of energy s