Sleep has plagued the existence
of complex organisms since their evolution early on in the formation of
Earth. Although there are various stages to the sleep cycle, essentially
one falls into a temporary coma for a few hours each day. It seems
totally irrational that evolution would dictate a system where one lets
down their guard for hours every day, leaving one prone to a deadly attack
(this, of course, by no means excludes the violent awakening by a particularly
cruel suite-mate). It seems a fairly logical assumption that sleep
is exceedingly important to life if, in order to get some rest, animals
in the wild irrationally risk their lives. Our bodies are telling
us that they have run at full capacity for long enough, and therefore need
to replenish valuable resources.
In researching sleep, I found "replenish" to be a key word. During the day, one's body is constantly metabolizing ingested food and water, turning them into useful forms of energy. The body depletes a great deal of its energy stores (glycogen, mostly) and also experiences a large buildup of toxic byproducts (lactic acid, for example) during the day.1 Therefore, it is absolutely necessary to replenish these lost stores and get rid of the toxic chemicals coursing through your blood. Four hours seems to be the minimum amount of time one can sleep per night in order to coherently function during the day. A lack of sleep can have grave consequences, greatly caused by the inability of your immune system to work without rest.
Sleep is a multistage cyclic process, involving five steps. Fast waves, called "Beta" waves are those which result from being awake. Once you become sleepy and close your eyes, your body relaxes and your brain waves greatly slow down, becoming "alpha" waves. After approximately five minutes in this relaxed state, your brain waves further slow down to become "theta" waves, transporting you into Stage I sleep. Stage one sleep generally does not last very long, and is accompanied by a lowered pulse rate and slower breathing. After a few minutes in Stage I sleep, Stage II sleep begins, marked by a further slowing of brain waves as well as bursts of electrical activity, called "spindles." These bursts manifest themselves as a sort of twitching. After fifteen to thirty minutes of Stage II sleep, the body moves on to Stages III and IV, the deepest stages of sleep. Brain waves named "delta" waves dominate the brain signals in these two stages. Since "delta" waves are the slowest of the sleep-associated brain waves, these stages are often referred to as Slow Wave Sleep (SWS). After approximately half-an-hour, the brain ascends once again through all the previous stages in order to begin the REM (rapid eye movement) stage, when dreams occur. The length of REM sleep is highly variable, and can last anywhere between a few minutes to an hour. The full sleep cycle generally takes from ninety to one hundred minutes, and occurs four or five times a night.2
Although sleep contains a cycle, it also belongs to a larger cycle involving Circadian Rhythms. Circadian Rhythms is a general term used to describe a variety of cyclic trends that run through their cycle once a day, including body temperature, melatonin levels, and fatigue. It has been postulated that fatigue runs in six hour cycles. Therefore, if you were to wake up at around 8 am, you would hit an alertness peak at around 11 am, three hours later. After that peak, you would become increasingly drowsy, until 2 pm, when you hit your famed "Post Lunch Dip." This ebb inherent in your circadian fatigue rhythm is the culprit behind the dreariness associated with the dreaded 1 pm class (finally, it's not our fault that we fall asleep in class!).2
Several methods have been proposed to "optimize" your alertness throughout the day by cleverly exploiting your circadian rhythms. Anders Sandberg, a research student at the SANS group at NADA at the Royal Institute of Technology, proposed a method that allows for competent daily functioning on five and a half hours of sleep. He suggests sleeping from 3:30 in the morning to 8, and then taking two half-hour naps, one in the afternoon and one in the evening. This method would ideally take advantage of the ebbs of your circadian rhythm without allowing you enough time during your naps to wake up groggy from stage III or IV sleep.3
This method has the potential to be quite beneficial and productive, although it must be followed religiously or it will most likely become detrimental to your health. A friend4 and I have developed a potentially better sleeping method for per capita productivity. Given, this proposal is horribly impractical and too technologically advanced for today's age, but the potential remains nonetheless. The ideal situation for maximum productivity is being able to function on no sleep. The human body alone lacks the capability to cope with absolutely no sleep. Therefore, we propose to introduce a "sleeping chip." It would be like running a gas-powered automobile in that you would start with a full chip, and deplete its capabilities as you went about your daily activities. If the chip were to become "empty," you could transfer it to another person, whose job it would be to sleep and refill the chip. There are, of course, inherent problems with this scheme that would need to be worked out. For example, the chip would have the seemingly impossible task of keeping the body constantly stocked with energy, assuming the body,s immune system would accept the chip in the first place. Another major problem with this plan, as with many scientific theories, involves major ethical issues. The people whose job it would be to restock the chips would have a continuously lowered rate of metabolism, and so they would be quite prone to obesity and other slow metabolism-related problems. On the whole, however, I believe the chip would be benificial to society, as it would aid in its overall productivity. Unfortunately, we do not yet possess the technology to create a sleeping chip, and so we must continue to deal with our coma-induced vulnerabilities...for now.
2. Circadian Learning Center
3. Optimized Sleep
4. Cedar McKay
This paper reflects the research and thoughts of a student at the time the paper was written for a course at Bryn Mawr College. Like other materials on Serendip, it is not intended to be "authoritative" but rather to help others further develop their own explorations. Web links were active as of the time the paper was posted but are not updated.