PERPETUAL MOTION MACHINES 259
HISTORY VIEWED THROUGH
ENERGY
Energy is vital to civilization. In fact, all of human history can be
viewed through the lens of energy. For 99.9 percent of human existence, primitive societies were nomadic, scratching a meager living
scavenging and hunting for food. Life was brutal and short. The energy
available to us was one-fifth of a horsepower-the power of our own
muscles. Analyses of the bones of our ancestors show evidence of
enormous wear and tear, caused by the crushing burdens of daily survival. Average life expectancy was less than twenty years.
But after the end of the last ice age about ten thousand years ago,
we discovered agriculture and domesticated animals, especially the
horse, gradually raising our energy output to one or two horsepower.
This set into motion the first great revolution in human history. With
the horse or ox, one man had enough energy to plow an entire field by
himself, travel tens of miles in a day, or move hundreds of pounds of
rock or grain from one place to another. For the first time in human
history, families had a surplus of energy, and the result was the founding of our first cities. Excess energy meant that society could afford to
support a class of artisans, architects, builders, and scribes, and thus
ancient civilization could flourish. Soon great pyramids and empires
rose from the jungles and desert. Average life expectancy reached
about thirty years.
Then about three hundred years ago the second great revolution in
human history took place. With the coming of machines and steam
power, the energy available to a single person soared to tens of horsepower. By harnessing the power of the steam locomotive, people could
now cross entire continents in a few days. Machines could plow entire
fields, transport hundreds of passengers thousands of miles, and allow
us to build huge towering cities. Average life expectancy by 1900 had
reached almost fifty in the United States.
Today we are in the midst of the third great revolution in human
history, the information revolution. Because of an exploding population and our ravenous appetite for electricity and power, our energy
needs have skyrocketed and our energy supply is being stretched to
HISTORY VIEWED THROUGH
ENERGY
Energy is vital to civilization. In fact, all of human history can be
viewed through the lens of energy. For 99.9 percent of human existence, primitive societies were nomadic, scratching a meager living
scavenging and hunting for food. Life was brutal and short. The energy
available to us was one-fifth of a horsepower-the power of our own
muscles. Analyses of the bones of our ancestors show evidence of
enormous wear and tear, caused by the crushing burdens of daily survival. Average life expectancy was less than twenty years.
But after the end of the last ice age about ten thousand years ago,
we discovered agriculture and domesticated animals, especially the
horse, gradually raising our energy output to one or two horsepower.
This set into motion the first great revolution in human history. With
the horse or ox, one man had enough energy to plow an entire field by
himself, travel tens of miles in a day, or move hundreds of pounds of
rock or grain from one place to another. For the first time in human
history, families had a surplus of energy, and the result was the founding of our first cities. Excess energy meant that society could afford to
support a class of artisans, architects, builders, and scribes, and thus
ancient civilization could flourish. Soon great pyramids and empires
rose from the jungles and desert. Average life expectancy reached
about thirty years.
Then about three hundred years ago the second great revolution in
human history took place. With the coming of machines and steam
power, the energy available to a single person soared to tens of horsepower. By harnessing the power of the steam locomotive, people could
now cross entire continents in a few days. Machines could plow entire
fields, transport hundreds of passengers thousands of miles, and allow
us to build huge towering cities. Average life expectancy by 1900 had
reached almost fifty in the United States.
Today we are in the midst of the third great revolution in human
history, the information revolution. Because of an exploding population and our ravenous appetite for electricity and power, our energy
needs have skyrocketed and our energy supply is being stretched to