Unlike most writers in the renewable energy field who promote idealized and unrealistic solutions for our energy problems to a largely uninformed public, Mr. Smith provides the reader with a cogent and realistic evaluation of our energy alternatives. He clearly and simply explains many of the technical and economic concepts associated with energy and its utilization, and provides the reader with a brief and concise historical perspective on the development and evolution of energy systems. From the book, we learn that almost all energy systems both past and present take advantage of either energy of motion or heat energy to provide some form of useful work to society. Because we can not direct, store and completely capture heat energy and must use heat immediately at the point where it is generated or captured, scientists view it as a low-grade energy source. Unlike heat energy, electrical energy is considered among scientists to be a high grade energy source because it can be directed, stored and used far from where it has been captured or generated. Lastly, one can derive electrical energy from either the conversion of heat energy or energy of motion, but as Smith tells the reader, conversions between the two energy forms can never be perfect, and likewise while one can generate one form of energy from another, one can never create energy from nothing.

From the text, we also learn that energy is not free in the economic sense. You must always pay something to gather and convert energy. There are three key costs associated with energy- economic, environmental and energetic costs. When evaluating energy systems, one must ask two (2) pertinent questions. The first question asks what one can do with the system, while the second question asks what one must do in order to get useful work out of the system. Thus, the evaluation of energy systems not only hinges upon how much energy is obtained from the process/system, it more importantly rests upon the amount of effort and resource expenditure that is required to obtain the energy. As such, proper evaluations of energy systems must look at not only the economic cost, but also the convenience of such systems for doing useful work. Every attempt must be made by the scientist, the politician, the environmentalist, and the concerned citizen to gauge and assess the practical limitations imposed by processes to produce energy.

For many reasons, efficiency- defined as the ratio between useful work output and energy input, is not a good indicator of an energy system's practical utility. Efficiency measures can only tell you how much of the available energy is lost, or how much of it is actually useful. Furthermore, efficiency numbers can be easily manipulated up or down to suit the whims of proponents or detractors, and thus it is very important to know the basis for their calculation. All energy systems, especially those for electricity generation, require considerable amounts of supporting infrastructure. Furthermore, from an environmental standpoint, many of the best places to produce renewable energy are also the most ecologically fragile and environmentally sensitive locations on the planet. Readers of this text inexorably learn that every single energy system known to man has an environmental impact, and these systems only differ in their degree of environmental impact.

However, Smith conveniently skirts the social and political problems associated with various energy systems such as nuclear and fossil fuels, and fails to adequately present some of the thornier problems associated with nuclear energy, such as the proliferation of waste and bomb-grade material, as well as the unfavorable economics of the power source. He also neglects to delve into the issues of energy supply and demand in a meaningful way. Although he readily concedes that our global supply of fossil fuels will eventually run out, and that steps to conserve energy are helpful in the short and long-term, he astutely avoids answering the question of when the eventual depletion of fossil energy will occur.

In one small volume, the author accurately dispels the 'free' energy myth so often touted by proponents of renewable and pseudo-scientific alternative energy schemes. Using very understandable language, he skillfully discusses the practical limitations of various energy systems, and tells the reader why we have not switched wholeheartedly to renewable energy systems for our needs. We can not fancifully wish our way out of our energy problems, nor can we freely choose to ignore the practical limitations of the various energy systems. As a result, from all of this, the reader learns that energy is not easy indeed.

This book is an excellent introduction into metals. The book covers everything from smelling ores to the atomic structures of metals. Ever wonder why when you bend a spring too far it refuses to return to its original shape? Well, it's in here. Ever wonder why metal makes an excellent conductor, whereas other materials don't? That's in here too. How about why certain materials weigh more than others? See chapter 5.

My point is that this book really does answer all of your questions about metal. It is written in an easy to understand manner, explaining molecular structure in a way that a neophyte like myself can understand. This is a great book, and I recommend it 100%!

This book is excellent for learning more about specific trees of the Great Lakes Region. It goes into much more detail than any field guide will ever tell you. The book spends 2 pages per tree, detailing the life history characteristics and typical habitats that the trees will be found in. I particularly like the fact that for each tree you can see a photo of the entire tree, as well as close ups of the bark and leaves (sometimes fruit too). The book provides satisfactory descriptions for identifying trees; however, does not provide any way to "key out" trees, so you must have some idea what you are looking at before you refer to the book. As a student in Ecology, I have found this book ten times more valuable than the price; however, I found that I needed an additional field guide to key out unknown trees in the field.