Energy to burn: conserved, consumed, or converted, it's the engine that drives every event

The word "energy" pops up everywhere nowadays. Did you have enough energy to get out of bed on time this morning? Does that vitamin-charged, candy-colored sports drink deliver the energy promised in the ads? How much energy do you spend chasing your kids? Are your energy costs going up this winter? Will new sources of renewable energy alleviate the new energy crisis?

Words that get used in many different ways tend to invoke elusive or imprecise concepts. In spite of some abuses within the New Age movement, "energy" is not that kind of word. What it describes is real and measurable. Energy drives everything that has ever happened in the universe. Without it, nothing would move, no tasks would ever be started or finished, and no events would ever take place.

Across the cosmos, energy takes on multiple identities and spans a staggering range of strengths. At the lowest end, though not quite at zero, is the so-called quantum vacuum, also known as the zero-point field. It's the closest possible approximation of total lethargy offered by the universe. (Paradoxically, the zero-point field of the entire cosmic vacuum may account for the mysterious acceleration of the universe.)

Individual electrons are a few steps up the energy scale. They whirl around the protons and neutrons of the atomic nucleus at assorted energy levels that trace concentric clouds. Once every 10 million years or so, the lone electron in any given hydrogen atom in interstellar space does a stately "spin flip," which shifts it to a slightly lower energy and releases a radio wave--a big event in the life of that atom, but nothing you'd write home about.

Take a big leap up the scale, and you get to the destructive potential of the thousand-foot-wide asteroid 99942 Apophis, which has Earth in its path and enough impact energy to wipe a major city clean of all its structures and inhabitants. Unlike friendly asteroids, with friendly names like 445 Edna or 1060 Magnolia or even 13123 Tyson, asteroid Apophis bears the Greek name of the Egyptian god of chaos, darkness, destruction, and evil.

Stronger still is the raging furnace in the Sun's core, which generates enough nuclear energy in one second to supply the needs of every person on Earth for a trillion years. Up near the high end is the omnipresent cosmic microwave background; although weak and harmless locally, in its entirety it holds some ninety powers often more energy than the hydrogen spin flip. Way at the top of the scale is the big bang: the sum total of all the cosmic energy that ever was or will be, and the beginning of everything we know and love.

What we on Earth commonly rank as high-energy events--hurricanes along the Gulf Coast, nor'easters in New England, volcanic explosions in the Cascades, earthquakes in the Indian Ocean--rank rather low on the cosmic energy scale, even though such events take a horrific toll on lives and property. Yet in none of those natural disasters is the energy high enough in any single spot to disturb an atomic nucleus.

What about the energetic domains beyond the natural but limited range available on our own planet? In the 1930s, physicists succeeded in concentrating energy into a very small space for a very short time. They did it by smashing atomic nuclei together in particle accelerators, then watching what took place during the collision. Ever since, with each new generation of technology, increasingly powerful accelerators have slammed subatomic particles together at ever higher speeds, focusing ever more energy into ever smaller volumes. This exercise in energy leapfrogging has pushed physicists to probe regimes of energy that greatly exceed the centers of the hottest stars. The most powerful accelerators probe key episodes in the formation of the universe itself.

Yes, particle physicists do have an occasional twinge of energy envy, the your-smasher-is-bigger-than-my-smasher kind. But building huge accelerators is the only way to cozy up to the building blocks of matter. The latest-generation machine is the Large Hadron Collider at CERN (the European Organization for Nuclear Research), scheduled to be turned on in 2007. Three hundred feet underground at the border between France and Switzerland, inside a tunnel seventeen miles long, two beams of protons will collide with a total energy of fourteen teraelectronvolts. That's the level of collision energy you'd find among particles in a gas heated to a toasty 200 quadrillion (2 x [10.sup.17]) degrees. The last time anyplace in the universe reached such soaring temperatures was a trillionth of a second after the big bang.

The quest to explore, control, and ultimately transcend the realm of earthly energy enjoys a history almost as old as civilization. The ancient Greeks, as usual, had something to say about the subJect. Energeia is their word, usually translated as "activity." To Aristotle the word signified work, movement, or concrete, tangible change. Energeia contrasted with dynamis, "potentiality," which signified the ability, capacity, or power to do something. Back then, however, neither energeia nor dynamis was something you measured.