ENERGY - A Unifying Concept

By Jim Disbrow
U.S. Department of Energy

Whatever moves or changes in our world takes work. If work is to be done, force needs to be applied. Forces are essential in science, engineering, social systems, and education. Since very force has a energy behind it, energy can serve nicely as a concept that unites all of these.

If every thought we have of science starts from energy, a pattern emerges showing how everything in science is related or unified. We can start from a historical point of view, looking at the path from the greatest events of each century to where we are today. In the 18th century, Benjamin Franklin figured out the nature of electricity, leading to lightening rods and electric lights. In the 19th century, Maxwell’s Four Equations showed that electricity, magnetism and light were all forms of electromagnetism.

Alternating current allowed large islands of stability for electric utilities. Radios changed the way we spread information. Computers reflect the laws of electromagnetism. With Lorentz's "Force" formula, electromagnetism's conversion into mechanical forces led to electrical machines that power industry. Tesla's inventions led the change into the second phase of the Industrial Revolution. In the 20th century, e=mc² unified energy and mass with electromagnetism, leading to nuclear medicine - and a longer life span, to nuclear power - and commercial nuclear electricity, to astrophysics - and a different view of the universe, and to nuclear weapons.

We could start with the science of patterns and explain the interrelationships with equations, just as Einstein did in his 1906 seminal treatise on Special Theory of Relativity. These mathematical equations provided the starting point for many aspects of today’s comfort and our progressively longer lives. These patterns include the notion that energy is neither created nor destroyed, but can be transformed between each of its forms.

Energy basics - virtually everything everyone should know about energy and why we need it - need to be kept in perspective. Energy is close to the root of theoretical and applied physical and life sciences (e.g., electricity, materials research and bioscience research), engineering (e.g., power for the future), economics (e.g., forecasting future prices), and local/global politics (e.g., nuclear weapons).

Energy is basic to a broad spectrum of important theoretical scientific concepts: heat flows, kinetic energy, enthalpy, entropy, the Law of Conservation of Energy, and the Laws of Thermodynamics. Electrical energy and magnetic energy can be converted back and forth. Through e=mc2 the ideas of mass and energy are unified - mass and energy can be converted into each other. Energy comes in a variety of forms: heat, light, mechanical, electrical, chemical, and atomic - and some can be transformed into another. Before 1997, the concept of "dark energy" did not exist, but now its influence on the expansion of the universe is being explored. Energy is integral to understanding the physical sciences, life sciences, and engineering. Energy in astrophysics, quantum theory and atomic blasts are expressed with exotic math symbolism (e.g., Riemann vectors/tensors), while the trajectories of spacecraft relies on fuel energy inputs to calculations using Newtonian physics and calculus.

Energy affects us economically on a daily basis through our food, weather, employment and transportation. Energy impacts all sectors of all economies. Adequate, safe and inexpensive energy resources and production are available in the U.S., but this is not true everywhere. Energy resources will be needed for the future - more so in some ways and places than others. Conservation and efficiency affect our environment and the life styles of future generations of kids. "What's hot" is an energy term that will continue to change its meaning while rippling through our language and history.

The Earth's surface has received most of its energy from the sun. Through photosynthesis, solar energy was stored millions of years ago into fossil fuels that serve as today's energy resources. As these nonrenewable fuels are mined and burned by engineers, the heat is used directly or converted into electricity. Solar energy is now used in areas with no electrical distribution system. Renewable fuels (e.g., solar energy, biomass) have limitations that make them useful in niche markets, but keep them from having a dominant share of the market for electricity. In Fourth World Nations, wood and biomass still supply most of the energy to residences, while right now natural gas is the most widely burned residential fuel in the U.S.

Finite resources are depleted as fossil fuels are consumed/ burned - and waste products are created. The products of combustion affect our environment (e.g., as precursors to ozone - a health hazard) and global warming (from carbon dioxide and water vapor). Waste products/pollutants may be diluted and dispersed, disposed of, isolated behind engineered barriers or converted into something useful. Oil spills waste a finite resource while polluting the environment. Energy conservation is important.

Energy conservation has ripple effects. Energy audits of homes identify ways to use energy more wisely - and reduce expenses. Switching from private vehicles to public transportation conserves energy - and reduces personal flexibility. Recycling energy-intensive items (e.g., aluminum cans, homes, cars) conserves energy and saves on natural resources - but requires additional attentiveness and rethinking of old habits. Cogeneration facilities save money by generating both electricity and hot water for nearby commercial and industrial companies; normally, large-scale electricity generation plants waste two-thirds of the energy by dissipating it. Pollution reduction often requires more energy than before, but new equipment may be both more efficient and less polluting. Corporate profits may increase as energy-efficient technologies are put into place - but these profits may decrease as emissions controls are implemented and energy consumption grows. Exchanges between two companies, "green twinning", may send one's waste streams to the other company's nearby plant for use as a resource, saving both companies money while reducing waste.

We put energy into our work and play. When we run out of energy at the end of a wearying day, we sleep. The Earth, however, is far from running out of energy. Advanced natural gas and coal combustion technologies are significantly more efficient than they were a few years ago. Cogeneration plants are saving money and fuel. Solar energy is good for five or so billion years. Alternative transportation fuels are being developed. Fuel cells are being tested in cars, buildings and buses. Nuclear fusion is getting closer to the goal of being sustainable. While the extent of oil reserves are being debated, enhanced recovery of both oil and natural gas is happening. Gas hydrate resources dwarf all other known fossil fuels - but it may take more energy to get them than they are worth. Geothermal energy is available for heat pumps everywhere. Renewable energy may get a boost as consumers demand "green electricity" in the deregulated electricity industry. Wind power is a fast-growing source of electricity. Most fuels should be available for at least the next decade or two before becoming dramatically depleted.

Work is important to all sectors of our economy (i.e., residential, commercial, transportation, industrial and government sectors). Households consume electricity, natural gas and other fuels to heat, cool, and cook. Commercial markets keep farm products cool, extending their shelf life. Demand for gasoline and diesel fuel has led to a dependence on imported petroleum. Profitable industries have been developed just to find, transform, and market energy resources. Stock market prices fluctuate as oil prices go up and down. Governments have fought wars to acquire and protect energy resources. Politicians have curried votes by promising to keep energy taxes at bay. Federal and State laws have been passed to ensure employee safety (e.g., in coal mines), plan for future energy supplies, and fund energy research (e.g., fusion).

Economic theory mandates that personal, local and national economies depend on natural resources, labor, capital, and energy (not always in that order). If one of the four is unavailable, unreliable - or becomes too expensive, life gets tougher as productivity slows down and incomes decline. No energy means no jobs. The U.S., with 5% of the world’s population, consumes about 25% of the world’s annual energy supply, while the poorest countries (with 64% of all people) consume less than 5%. Average U.S. per capita consumption of energy exceeds that of all others - while U.S. gasoline taxes and prices are the lowest of all industrialized nations.

Energy is very personal, supplying fuel to our bodies, hand held games and air conditioners. Energy cleans and pumps our drinking water, makes fertilizer for crops, powers plowing of fields, and then transports our food to supermarkets. Energy makes our lives comfortable. Work (i.e., whatever moves or changes in our world) does so by the use of a force we call energy. Cheap and readily available energy allows work to be done efficiently, safely and quickly. Research into energy supports growth in this direction, as does education about efficient consumption of energy - and minimization of waste. Energy life-cycle roadmaps plan the development of infrastructures - from the beginning of a fuel cycle to the end use of each new energy source and the disposal of associated waste. Implementation of each aspect calls for unifying a broad range of scientific and engineering knowledge, skills and abilities.

Footnotes:

1. Definition: en-er-gy (en'er-ge) n. pl. -gies. 1. a. Vigor or power in action. b. Vitality and intensity of expression. 2. The capacity for action or accomplishment: lacked energy to finish the job. 3. Physics. The work that a physical system is capable of doing in changing from its actual state to a specified reference state, the total includes, in general, contributions of potential energy, kinetic energy, and rest energy. 4. Usable heat or electric power [LLat. energia < Gk. energeia <energos, active: en-. at + ergon, work.].

2. Heat from coal, natural gas and nuclear energy can be transformed into electricity. The electrons are transported and delivered to remote locations by electrical distribution systems.

3. National Research Council of the National Academy of Sciences, "National Science Education Standards", (1996, National Academy Press, ISBN 0-309-05326-9)

4. Structure of atoms; structures and properties of matter; chemical reactions; motions and forces; conservation of energy and increase in disorder; and interactions of energy and matter.

5. The cell; molecular basis of heredity; biological evolution; interdependence of organisms; matter, energy and organization in living systems; and behavior of organisms.

6. Torques, stresses, impulses - both physical and electrical.

7. Energy has a variety of units of measure (e.g., calories, temperature, Btu) expressed in different systems (i.e., Metric and British/American), with some terms having different meanings in different systems (e.g., how big is a barrel?).

8. Unless, of course, there is some major oil or economic disruption.

As of February 18, 2003.

In addition to his work at the Energy Information Administration, Jim Disbrow appears from time to time as “Energy Ant,” complete with antennae, at science teacher workshops, school gatherings, parades and other civic functions, where he talks about energy and the EIA Kid’s Page. If you’d like a visit (Maryland, Virginia and Washington, DC areas only, please), e-mail him at Energy.Ant@eia.doe.gov.