One of the unwritten rules of physics says you can't get
something for nothing; at best, you can manage a fair exchange
rate between how much energy you pump into a system and how much
you coax out of it. Consider your car: On average, only 12.6
percent of the chemical energy you pump in at $3.50-plus (or
whatever you pay) per gallon translates into motion. The rest
goes to overcoming drag, inertia and other mechanical
inefficiencies, with a whopping 62.4 percent consumed by engine
friction, air pumps and waste heat [source: California Energy
Commission]. Heat crops up in all sorts of systems. Like an
energy embezzler, it skims off the top of chemical reactions,
physical systems and electrical circuits. Whether it's the
consequence of lost efficiency or its cause, the upshot is
you're taking a loss in the deal. Heat is why we can't achieve
perpetual motion (or movement that never ceases). It's also the
reason power plants must amp up current to high voltages when
transmitting it across country: to overcome en