Children of the Sun

The following is an attempt to organize some of my thoughts on Alfred Crosby’s Children of the Sun. It essentially summarizes the first six chapters.

Alfred Crosby’s Children of the Sun: A History of Humanity’s Unappeasable Appetite for Energy is a history of humanity’s use of energy. It begins with the transformation of matter into energy through nuclear fusion in the core of the Sun and ends with the current energy crisis and humanity’s efforts to replicate the Sun’s activities by “domesticating” hydrogen fusion—figuring out how to build a power plant whose energy is produced by smashing hydrogen atoms together.

The First Prime Mover: Muscle

The book’s title is derived from a statement by the Russian geochemist Vladimir Vernadsky. (2) Vernaksy was referring to the fact that of the two sources of energy on Earth—radioactive decay of heavy elements in the center of the Earth and nuclear fusion at the center of the Sun—we depend almost entirely on the latter. Aside from a few phenomena, like volcanism, the energy radiated from the Sun powers everything we can think of, from the weather, to our cars, to Alfred Crosby while he wrote Children of the Sun. Gravity smashes hydrogen together at the center of the Sun. Four hydrogen will fuse to form a single helium atom. In the process, some of the matter that composed the hydrogen atoms is transformed into energy. That energy is radiated out into the universe, some of it in the form of light.
 
Around 3.5 billion years ago, the first life forms appeared on Earth. These were single-celled organisms, and all life on Earth would be single-celled for at least the next two billion years; for most of the history of life on Earth, life has been single-celled. An example of the first life forms is blue-green algae, or cyanobacteria. Cyanobacteria contain chlorophyll, which uses energy from the sun to break up water and carbon dioxide molecules to produces simple carbohydrates. (3) At some point, these cyanobacteria became incorporated into other organisms and became known as chloroplasts, producing sugar for their hosts—which we call plants. “Human food chains always ultimately lead down to plants with chloroplasts arranging themselves to catch the sun’s rays.” (3-4) The waste product of photosynthesis is oxygen, which we use to convert food into energy.
 
At this point, Crosby introduces the concept of prime movers. A prime mover is a thing that converts natural energy into work. “I utilize muscle, humanity’s first prime mover (it taps the oxidation of carbohydrates, a natural force), to press down my computer keys.” (4) Crosby’s book is essentially about humanity’s invention of prime movers to tap new sources of energy. The story begins with muscle, which converts the energy stored in plants and other animals into “work,” meaning our activities—running, jumping, talking, fighting, thinking. A later prime mover would be the steam engine, which would convert energy released from coal via oxidation (burning) into the “work” of pumping water out of coal mines. (72-4)
 
Something I was unclear about was this: why isn’t fire a prime mover? To roast a piece of meat over a hearth is to use oxidation to convert the energy within the wood into the work of predigesting the meat, no? I think he conceptualizes fire as a tool that opened up a greater spectrum of energy sources—allowed us to eat a greater variety of foods. “Cooks didn’t invent new prime movers, but they gave us a source of new fuel for the existing prime mover: muscle.” (12)
 
Whether or not fire is to be regarded as a prime mover or not, the first chapter is entitled Fire and Cooking and was of particular interest to me, for as of late I have been especially interested in the history of agriculture and the human diet. When did people start cooking their food? And have they always eaten meat?
 
Crosby’s book touches on these questions. As for how long we have been cooking, it isn’t clear. Homo sapiens appeared 150,000 to 200,000 years ago, and the preponderance of early hearths date from about 50,000 years ago. “Early Homo sapiens bones are not commonly associated with clear evidence of either camp fires or cooking.” (17) “In the Upper Paleolithic [40,000 to 10,000 years ago] the evidence of hearths and cooking becomes, for the first time, plentiful and unambiguous.” (22) So the archaeological evidence suggests we have been cooking since at least the Upper Paleolithic.
 
On the other hand, absence of evidence isn’t evidence of absence, as they say, and anthropologists seem to believe that cooking was important long before 40,000 years ago despite the apparent dearth of early hearths. Homo erectus had a larger brain, smaller teeth, and a smaller gut than its predecessors. Smaller teeth and a smaller gut reduce your spectrum of potential food, whereas an increase in brain size requires the consumption of additional calories. It is inferred from these facts that Homo erectus, who appeared about 2 million years ago, must have cooked, because cooking increases the range of foods available for consumption.
 
In the period known as the Upper Paleolithic, from 40,000 years ago to 10,000 years ago, a period during which humans were still hunter-gatherers, our ancestors utilized the wide spectrum of food (energy) made available in part by cooking to make unprecedented cultural advances, including tools made of myriad materials and the first art, including the famous Venus figurines. “Hominid bodies and behaviors had evolved in crude synchrony before. Now bodies stopped evolving and cultures raced ahead.” (18) “The Upper Paleolithic marked the opening chapter of our transition from being very clever apes to the keystone species of the planet.” (21)
 
A random thought or two—is it assumed that men carved the famous Venus figurines? It’s an interesting assumption if so—the only painters of curvaceous women that I can think of are other women. It has always seemed implausible to me that men’s sexual desires are malleable to the extent that radically different body types would be considered attractive or unattractive at different times. At some point I would like to investigate preferences for body types across cultures. If there is little variation, it would suggest men’s body type preferences aren’t culturally defined and cast doubt on inferences we have made based on the premise that men carved the Venuses and that the Venuses represented sexually attractive body types.
 
If men did carve them, can we assume that they were intended to be sexually appealing? A friend comically suggested that maybe we have it backwards—that the Venuses were used as teaching tools in lessons on moderation. Personally, my intuition is that curvaceous figures are simply more fun to carve—just like some painters find curvaceous bodies more fun to paint.
 
The period between 10,000 years ago and 6,000 years ago is known as the Neolithic, and it is in this period that civilization begins—in particular, the practice of agriculture. Just as fire was not a new prime mover, but simply permitted people to tap into additional sources of fuel for their muscle, farming did not introduce a new prime mover. Human muscle continued to be the means of converting natural energy into work. However, agriculture permitted a more intensive mining of the solar energy (stored in plants and animals) on a given piece of land. This meant more fuel for more human muscle, and human populations increased.
 
It may come as a surprise to the reader that many of the consequences of the shift from a hunting and gathering lifestyle to an agricultural way of life were profoundly negative. Indeed, the authors I have read on this topic explain agriculture as a practice that humans felt compelled to have recourse to because their environment could not sustain them as hunter-gatherers. In other words, while we are likely to assume that the practice of agriculture represented progress—that it was a positive development, that it was clearly preferable to a hunting and gathering way of life—the evidence suggests otherwise.
                  
Hunter-gatherer diets had been varied and richly nourishing—when available. The diets of farmers, of whom there were many more than pastoralists, consisted of cereal grains and roots, with meat or fish only now and then. These diets were much less nourishing, and brought on dental decay, anemia, and other maladies of malnutrition. Added to these disadvantages were the infectious diseases—smallpox, measles, dysentery, cholera—that sedentary life, dense population concentrations, and constant sharing of parasites and germs with dogs, horses, cattle, and pigs encouraged. [40]

A final comment on this section of the book: Crosby brings up an interpretation of the advent of agriculture I have frequently encountered—I think Tom Standage mentioned it, as well as Pollen. It is the notion that plants and animals domesticated humans, or that we at least domesticated each other. In Crosby’s words, “Certain plants and animals evolved to suit humans—and so did humans to suit plants and animals.” In other words, “humans were not leaders but only participants.” (32)
 
When I first encountered such conceptualizations of the evolution of agriculture, I found them thought provoking. I’m increasingly skeptical of them upon reflection, however. Of course it is true that humans changed culturally to suit plants and animals. They adopted news of life in other words—they stopped wandering, they started planting and harvesting, they started grazing animals and milking them. They also changed genetically, though to a minimal degree. For instance, while most people in the world are lactose intolerant as adults, those whose ancestors were dependent upon dairy products for survival are not—in particular, northern Europeans, though others as well.
So we both changed. However, humans make choices, while plants do not. A human chose which seeds to plant. It is creative but imprecise to suggest that plants chose to render their seeds more appealing to human beings. The process by which plants became more useful to human beings was a case of artificial selection—choices made by human beings about which plants to cultivate. They chose to plant the seeds of those plants with the features they most desired. To be almost ridiculous about it: plants lack both the brain structures and physical capacity to make choices about their features and to conform themselves to those choices.
 
Animals at least make choices, but that isn’t really relevant. Are we to imagine that ancient aurochs decided to subject their wild community to artificial selection in order to be more appealing to human passersby? The process leading from auroch to cow was driven by human choices—humans chose those aurochs whose features were most useful to human beings and bred those animals.
 
Humans changed almost exclusively culturally, not genetically, as they adopted agriculture. However, today’s maize does not exist, and could not survive, in the wild. In other words, it cannot survive without humans. If cereal crops disappeared, lots of people would die, but not because we are biologically dependent upon them—indeed, we have no biological requirement for such foods. The scale of human society would change, but humans (some of them) would survive without domesticated crops and animals.
 
For these reason, I think that the characterization of agriculture as a mutual domestication of humans and plants/animals—never mind a plant- or animal-led domestication—is inaccurate.
 
Chapter three describes the Columbian Exchange—Crosby’s most famous work is The Columbian Exchange. The role that the exchange of plants, animals, people, and microbes plays in the history of energy is that it allowed people from all over the world to have access to the full panoply of means of mining solar energy—sugar was introduced to the New World; maize was introduced to the Old World, to give two examples.

Additional Prime Movers: The Steam Engine and the Internal Combustion Engine

Chapter four is entitled Fossilized Sunshine. It describes the tapping of the solar energy stored in long-dead biomass, such as peat, coal, and oil. “Fossil fuels are the tiny residue of immense quantities of plant matter….We are living off a bequest of fossil fuel from epochs before there were humans and even before there were dinosaurs.” (62) In order from the least energy dense to the most energy dense fuel: fresh biomass (wood), peat, coal, and oil. The last three are examples of fossilized sunshine.
 
Crosby does not dwell on the watermill and the windmill. These were new prime movers, converting water and wind energy, respectively, into work. However, “flowing water and wind were far from efficient expressions of sun energy.” (67) These prime movers existed at the time that slavery flourished—elsewhere I have read that as many as 5% of the world population was enslaved at the peak of the Atlantic slave trade in the 18th century. Slavery, from the vantage point of a history of energy, represented the exploitation of humanity’s first prime mover—muscle. Of course, it represented more than that, and I refer to slavery again below.
 
Coal had been used by various societies throughout history long before the Industrial Revolution for heat, light, and cooking. What didn’t happen, however, was the invention of a new prime mover to maximize the exploitation of the energy potential of coal. For instance, China used large amounts of coal to fuel its iron industry in the 11th century. However, “they did not tap the full sun energy of coal, which would have required inventing a new prime mover.” (68)
 
The new prime mover would of course be Thomas Newcomen’s steam engine, first used in 1712 to pump water from coal mines. (72) Great Britain had, like other societies, depleted its timber resources and turned to coal. However, “Britain’s industrial revolution was drowning in utero” because Great Britain is a wet place and its mines often flooded. (70)Newcomen’s engine used heat produced from burning coal to turn water into steam. The expansion and compression of the steam drove a piston, which drove a rocker beam which pulled buckets of water out of the mine. “Thomas Newcomen’s invention was the first machine to provide significantly large amounts of power not derived from muscle.” (74) “It utilized fire—a natural force—to heat water, to make steam, to do work.” (74)
 
Were the first steam engines all utilized to drain coal mines? I think Crosby implies this, but I wasn’t entirely clear on the spectrum of uses to which steam engines were put in the eighteenth century. Whatever the case, it is in the late 18th century that James Watt improves upon Newcomen’s design—to such a degree that Watt is apparently usually cited as the engine’s inventor. (74, 76) By 1800, Watt’s steam engines were being used not only to drain coal mines, but in the production of flour and iron. (76) Further improvements rendered steam suitable for transportation, the result being the locomotive, such a vital factor in the industrialization of the United States. The first ships to cross the Atlantic using steam power crossed in 1838. Whereas these ships’ predecessor required approximately a month to cross the Atlantic, these ships completed the crossing in just over two weeks. (77) Steam would revolutionize not only transportation of course, but industry. The first industry to mechanize was the textile industry. A steam-driven spinning mule was as much as 300X more efficient than its human analogue by 1800.
In addition to wood, humans had burned animal fat for lighting for millennia—at least as early as the Upper Paleolithic, that period between 40,000 and 10,000 years ago when the first art appears. The first streetlights appeared in major cities in the 17th century, fueled by vegetable oils and animal fats. These lamps “didn’t give much light and also smoked and smelled and often went out.” (88)
 
A major innovation in artificial lighting took place at the end of the 18th century. Known as the Argand lamp, it produced more light and less smoke, and it led to an increase in the burning of whale oil, which decimated world whale populations pretty quickly. (89-91) By the middle of the nineteenth century, coal gas (produced by heating coal in the absence of air) was displacing whale oil as the fuel for lighting. (91-92) Next, kerosene, distilled from petroleum, became the primary fuel for lamps. It seems that humanity’s original appetite for petroleum was based on its use as a fuel in lighting. By the end of the nineteenth century, kerosene would no longer be important in lighting, but by that time, humanity had found a new use for petroleum. (92)
 
That new use would be in transportation. Innovators were searching for a way to simplify the steam engine. They wanted to remove steam from the equation. Rather than burn coal to heat water to produce steam to drive the piston, they want to heat coal to produce heat to drive the piston. What was sought was an internal combustion engine, an engine that burned its fuel within the engine. Nikolaus August Otto produced such an engine in the second half of the nineteenth century, and by 1900 there were about 100,000 internal combustion engines being used in machine shops, breweries, and in transportation. (93-4) The internal combustion engine would provide the means for flight. For a century “it has been the most influential contrivance on the planet,” providing millions with transportation in the form of automobiles.
 
I was a little unclear about what these first internal combustion engines used for fuel. Crosby suggests coal gas was used in Otto’s 1863 version; he distinguishes the engines of Benz, Daimler, and Maybach by their use of gasoline. So were the first Otto engines all burning coal gas? That doesn’t sound right.
 
Gasoline is a byproduct of kerosene production. Both are petroleum products. As internal combustion engines proliferated, in particular in the form of automobiles, demand for petroleum dramatically increased. Crosby sums up the geography of this expansion:

The petroleum seekers who had started at Oil Creek field in Pennsylvania rushed on to California, Texas, Oklahoma, and elsewhere in the United States. By 1900, they were pumping oil in Romania, in Baku on the Caspian Sea, and Sumatra, in the Dutch East Indies. By World War I, they had moved on to Mexico, Iran, Trinidad, and Venezuela. In the middle decades of the twentieth century, they were discovering new fields in every continent but Antarctica, most notably in the Middle East, and were even beginning to drill into the sea bottom. [97]

The revolution in transportation brought about by the internal combustion engine enlarged the battlefield when nations went to war. Flight meant bombs could be dropped anywhere on Earth. “The armed forces of World War II were largely propelled by oil burning in the cylinders of ICEs.” (98)
 
Chapter six is on electricity. The problem solved by electricity was the problem of transporting energy. “An engine powerful enough to bend steel girders on this side of town is useless if what you want is to fold newspapers on the other side of town.” (101) There had been some inquiries into the nature of static electricity since at least the time of the ancient Greeks, but it was Alessandro Volta’s invention of the first battery that perhaps best marks the beginning of the history of electrification. (103) This was invented at the end of the 18th century. In the first half of the nineteenth century, Michael Faraday would produce the first dynamo—a device that transforms mechanical energy into electrical energy—in this case, the motion of a crank rotated by hand. (104) It didn’t produce much electricity, but it produced enough to power the telegraph, the first one being sent in 1844. (105) The prime mover for electricity in this instance is still human muscle, electricity is basically embodying and transporting that energy. Eventually, internal combustion engines would be used to produce electricity—I guess this would be a coal power plant, for instance.
         
Additional Thoughts

I acquired Children of the Sun through an interlibrary loan, and when I picked it up, I was also picking up a book on the history of tobacco. The book on tobacco was four or five hundred pages long. Children of the Sun, which describes nuclear fusion and fission, the prime mover concept, the advent of photosynthesis, the domestication of fire, the history of our burning of fossil fuels, electrification, etc., is 166 pages long. I’m at a loss to think of a shorter history, though I can think of no book whose scope is broader. For those who value concision, this book is extremely impressive.

Additionally, I am increasingly interested in the desire of historians to broaden their narratives both in terms of topics and in terms of chronology. This book does that like no other of comparable size.

There is a somewhat disturbing element to the big-picture narratives with which I am familiar however—I have David Christian in mind. I do not lament the minimization of the individual, and Crosby actually counters that issue by ending each chapter with a smaller-scale vignette from the period discussed in the chapter anyway.        
I cannot yet quite define what does bother me about these histories, but it has something to do with their treatment of the darker side of human history. As much as I loved this book, a passage or two verged on distasteful.

For instance, the catastrophic consequences of the arrival of Europeans in the New World for Native Americans included the humiliation, suffering, and death of the vast majority of the continents’ inhabitants. These events are referred to once…in parentheses. “([Europeans] also brought diseases like smallpox and malaria to American for the first time, killing millions. The Native Americans slyly countered with tobacco.)” (48) Analyzing this statement too closely just leads to sounding melodramatic, so let’s just say I find it distasteful.

The chapter that contains the parenthetical comment on the suffering of Native Americans does close with a “coda” on human suffering—the suffering of the Irish. In this passage, Crosby refers to the “horrors of the Potato Famine,” in which a million Irish died. (58) Obviously the Potato Famine was a major tragedy, but why does Crosby speak of “horror” when describing the death of a million Irish, and the deaths of tens of millions of Native Americans are reduced to a parenthetical witticism that evinces not the slightest sense of “horror”?
Slavery shows up in Crosby’s book at least five times—pages 51, 58, 60, 78, and 81. (The page 81 reference does not appear in the index.) Here is what is said on those pages:

·        51: “Europeans developed a sweet tooth and millions of Africans were enslaved and shipped to the New World to work the cane fields to satisfy that taste.”
·        58: “The societies of Western Europe could not reconcile the horror of the Potato Famine with their pride in the humanitarian advances of an era that saw the end of the Atlantic slave trade and, in a few more years, of slavery itself.”
·        60: “The eighteenth was the peak century of the slave trade because Europeans needed more muscle than their home continent could or would supply to exploit their American plantations, so they went to Africa to get it.”
·        78: “Plantations in the southern United States shifted to a monoculture of cotton cultivation, a labor-intensive endeavor. And the power there was still supplied by the primitive prime mover of muscle, in the form of slavery, an institution whose slumping status was revived by the profits to be made from the new textile mills.”
·        81: “Power had been about muscle for all of human history, and the most effective way to marshal it had been by assembling serfs and slaves.”

The absence of any description of the “horror” of slavery, the slave trade, the effects upon the societies from which these people were taken, even of any quantification of slavery and the slave trade’s scale, are disconcerting in themselves, but are more so when contrasted with the description of the Potato Famine. For instance, we know that 1.5 million Irish fled the famine. The slave trade—and the decimation of Native American populations—are only ever quantified more vaguely—“millions.” Crosby also writes, sort of strangely, “We shouldn’t let the numbers distract us from the realization that this was something that happened to individual human beings” (58) when discussing the Potato Famine. No such admonition accompanies the descriptions of the experiences of Native Americans or enslaved Africans—not to speak of the countless other groups throughout history who have experienced large-scale death and enslavement—whose tragedies were of exponentially greater magnitude and duration.

Again, I don’t want to be melodramatic about it. But I’m concerned that important elements of the human experience are being overlooked by some of these larger scale histories, and I do not think this is a deficiency inherent in large-scale histories.

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