|The Martial Bioengineering of "Old Man's War"
||[Feb. 20th, 2012|10:09 pm]
The central premise of the mil-SF novel Old Man's War (John Scalzi, 2005) is that future humanity, in its fight against alien races for interstellar territory, has found it expedient to create synthetic bodies for its soldiers, and to transfer the minds of septuagenerian recruits into those bodies. The novel's protagonist, John Perry of Ohio, learns that his new Colonial Genetics Defender Series XII "Hercules" body (CG/CDF Model 12 Revision 1.2.11) features a BrainPal™ neural prosthetic, UncommonSense™ sensory enhancements, nanotech SmartBlood™ with increased oxygen capacity and immunity, HardArm™ musculo-skeletal boosts, and KloraDerm™ skin with photosynthetic abilities (and green color).|
That an oldster is magically granted a shiny new youthful body is a power fantasy, and hardly a unique one in SF. Likewise it's the rare novel whose engineering can't be improved. Scalzi's SmartBlood is conservative, KloraDerm is pointless, and the CDF soldier's sex life needs a rethink.
Blood that's smart, but not capacious?
SmartBlood™ is a suspension of nanomachines that can, among its other abilities, instantly clot severe wounds. It has an increased oxygen-carrying capability, four times greater than ordinary human blood. In this, Scalzi is being very conservative. The "respirocytes" designed by Robert Freitas (1998) are cell-sized pressure tanks that can carry thousands of times the oxygen of an equivalent volume of erythrocytes. But perhaps the CDF doesn't possess full Drexlerian diamondoid nanotech.
KloraDerm: Power plant or uniform?
KloraDerm™ acts as a photosynthetic energy-gathering supplement (and the CDF war suit is translucent in that band). A BOTE calculation shows this to be impractical. Earth's "solar constant" (the maximum intensity of sunlight at the top of the atmosphere) is 1,400 watts per square meter; on the ground, at noon, it's reduced to 700. A typical human has 1.5 to 2.0 square meters of skin, of which no more than half will be facing the sun. Today's photoelectric systems have an efficiency of about 25%, but chlorophyll photosynthetic efficiency (i.e., conversion of photon energy to stored chemical energy) is under 10%. The CDF soldier will gather energy at 70 watts or less, whereas basal metabolism is 90 watts -- let alone strenuous physical activity. Fiddling with the error margins doesn't improve things much.
KloraDerm might prove useful if the soldier lies injured in the open air, without rations and waiting for rescue; but otherwise, the green coloration is more immediately useful to differentiate CDF members from the human population. Also, since human skin coloration is due in part to the blood within, and SmartBlood is grey, it presents a zombie-like complexion.
And the dangly bits
CDF bodies are incapable of reproduction among themselves or with baseline humans -- partly because the genetics are incompatible, and partly because they're copyrighted. The bodies do, however, have fully functional genitals -- deemed necessary for the soldier's psychological well-being during the period of service. (A recruit signs up for two years in the infantry, usually extended to ten, and may remain in the CDF for decades afterward. Upon departure, a soldier's mind is transferred to a new human body cloned from the original.)
However, external genitals are a drawback for a infantryman (as any human male reading this can well imagine) and their inclusion by Colonial Genetics is shortsighted. Human external testes are sensitive to impact; they're external only because the development of spermatozoa requires a lower temperature; CDF bodies cannot reproduce; hence, testes are unnecessary; moreover, the balance of seminal fluid is secreted by glands located safely inside the abdomen. Assuming a scrotum is also psychologically necessary, it can be filled with insensitive tissue. A more complete redesign would be retractable, as with whales. (The CDF bodies already have catlike eyes.)
(The inconvenient placement of male genitals vis-a-vis the legs -- i.e., they can be squashed by many postures -- is one of those details that Nature overlooked when migrating humans from a quadrapedal to bipedal stance, along with the dynamic load on knees and the weight of the fetus during pregnancy.)
Similar arguments apply to the breasts of female soldiers (see also: sports bras). A sensible pair of modifications would be that, first, regardless of the genetic predisposition of the recruit (CDF bodies are based partially on the donor), breasts be limited to a reasonable size; and second, that internal supplements be added to suppress parasitic vibration. (One of Peter F. Hamilton's novels featured a courtesan with breasts modified in this way; he later expanded the idea to "nanonic supplement membranes" that protect during high-gee maneuvers. Natural human viscera are supported by little more than their blood vessels.)