| Star Flight and the Deep Sleep |
| Call me a chicken, I don't care. Cryogenic "suspended animation" makes me nervous, even with cyroprotectant chemicals in my blood that I would not like being injected with to begin with and nanobot repair systems in my body. Hypothermia and hibernation unnerve me also. It seems though that some form of hibernation will be necessary for star travelers. During multi-month long jaunts in pods that decelerate/accelerate from/to star ships flying by stellar systems this may be necessary. Even during flight on large star ships with plenty of amenties it will be useful to kill some of the time and reduce LSS requirements by using rotating hibernation shifts with some of the passengers in deep sleep while others are awake and enjoying a less crowded ship, all taking turns in the biostasis chambers. It might not be necessary to sleep in the deadly cold. Humans might be able to estivate. This is a condition of reduced metabolism used by animals in warm climates to escape from summer heat, dryness and reduced food supplies. The fat tailed dwarf lemur, a primate and closer kin to humans that crocodiles or lungfish which estivate, can go into a torpor as long as seven months a year in warm tropical Madgascar while tucked away in a hole in a tree. Could humans do the same, perhaps with a little genetic modification? Hypometabolism does not necessarily go along with low body temperature. If ambient temperatures are warm the hibernating or estivating creature will exhibit a greatly slowed metabolism without going into hypothermia. Crocodiles can reduce their metabolic rate by 90 to 95%. Humans will probably never be able to reduce their metabolism that much because our huge brains use 18% of all oxygen in the body as well as similar amounts of kilocalories and blood even during sleep. If we can reduce our energy consumption during some kind of deep sleep induced by drugs or electrodes attached to the head that use pulsating electric currents to induce "alpha sleep" to the basal metabolic rate we will use less energy. BMR consumes about 70% of all calories consumed just to keep the heart beating, lungs breathing, etc. A simple formula is: Body weight in pounds X 10 kcal/lb. = BMR So a 200 pound man uses about 2000 kcal a day just to stay alive and a 120 pound woman about 1200 kcal/day. Determining BMR is actually more complex and depends on many factors including age, body fat percentage, etc. but this is close enough for discussion. Perhaps people of tomorrow wil be genetically enhanced to have more efficient metabolisms and use less energy or at least make more efficient use of the food they do eat. Anyhow, if a 200 pound man went into a deep sleep of some kind for four months and burned 2000 kcal a day, and one pound of fat contains 4500 kcal, then he would lose about 53 pounds. It's possible that he could be fed intravenously but I hate needles and catheters. Perhaps he could consume some special food substance that was digested very slowly that contained mucho calories. The intestines can handle a volume of about seven quarts of food and liquid! Also, space travelers don't need to remain in a constant torpor. They could wake up every few days, stretch, consume some special nutrient mixture, evacuate and go back to sleep. It might be desirable to take a quick shower every few days with a good meal of concentrated space food. I've experimented by living on nothing but milk and honey for a whole week and sometimes I practically live off peanut butter! I once experienced a severe depression that lasted for six months. During this time I slept constantly, woke up every day for a little while, took a bite to eat, and every few days went to a nearby restaurant for a good dinner. Naturally I used up all my savings during this experience as I was not working, got some help from relatives, and when I came out of it had gained five pounds and got a job doing hard physical work and had not weakened significantly. I think fears of muscular atrophy are over blown. Either that or I have some kind of unsual ability to go into a torpor, and that I doubt. Bears don't actually hibernate and many animals that do wake several times during their seasonal slumber. Buddist monks can reduce their metabolic rates and live off very little food. So we don't absolutely have to freeze people or induce hypothermia. The main reason for going into some kind of deep sleep, in addition to reducing food and water intake and making room aboard ships, in my estimation is psychological. It could kill time on long voyages and make several months in a small pod tolerable. I think people might estivate like the fat tailed dwarf lemur. Archaic genes for hibernation have been found in humans since we have lower mammalian ancestry. Perhaps these genes can be reactivated somehow. Mice which ordinarliy do not hiberate have been caused to hibernate by breathing air with 80 ppm hydrogen sulphide, a terribly foul smelling gas. Humans of the future will have more time to develope their minds and bodies with robots doing most of the work, thus, even without genetic enhancement there could be people who master some of the abilities of Buddist monks and yogis famed for their ability to go long periods without much food or water in a meditative trance. That doesn't mean I beleive in some of these stunts pulled by magicians! If one can live off a can of liquid nutrition every day and have a real meal every few days and remain in a trance state or deep sleep with the help of drugs or electrodes that induce certain brain wave patterns the rest of the time and not go stir crazy during a 120 day pod journey then this challenge is defeated. With genetic enhancement the ability to go into a state of estivation with greatly reduced metabolic rate in special chambers that are warm and germ free after a thorough cleansing of the body that would be sufficient. Hypothermia could be avoided because of its dangers. As for drugs that induce a hypometabolic sleep, I don't mean opiates or sedatives which can be deadly and addictive. Perhaps melatonin or a derivative, a hormone secreted by the pineal gland that has been shown to induce hibernation in some animals and used as a sleep aid by humans would be safe. Since the human brain uses so much energy, even in deep sleep, there will be a limit to how much the human basal metabolic rate can be slowed. Crocodiles and many other lower animals don't have to support so much brain tissue so going into a torpor without food or water is not as difficult for them. |
| some links to more information: Brain Estivation Torpor hibernation BMR |
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