Nova
07-10-06, 01:30 AM
Any comments ?
Why do we sleep ?
Excerpt taken from book: The Physics of Consciousness
by Evan Harris Walker
Pgs. 240-244
Obvious answers to this question immediately leap to mind. We sleep because darkness inhibited the day time activites of the aboriginal man. We sleep because our body is tired; we sleep to restore the chemical balance our body needs to function efficiently.
Because sleep does occur, the body certainly makes use of it to knit up the raveled sleeve of care, to rest the machine, to restore the chemical balance in the body.
But the heart does not sleep. It slows down. It takes advantage of sleep. But it does not stop and rest for some eight hours. The brain also slows down, but it doesn not cease its function. It would seem that the pressures of evolution would have wiped away sleep as the most hazardous of all possible behaviors. Surely the body should rest at night, and the brain should think at a pace consistent with what we find in the sleeping brain.
But how could the pressures of evolution permit the existence of such a hazard as the complete lapse of attentiveness that turns the body into nothing more than an awaiting meal for any wild beast ? Why do we need sleep so desparately ? It must be that sleep is vital as life itself; it must be vital to the very existence of consciousness.
The answer to the puzzle of sleep lies in the fact that the mechanism of consciousness that we described in the last chapter cannot go on indefinitely without periods of restoration. Consciousness has to pause. Every time another synapse enters into the quantum mechanical consciousness mechanism that couples distant synapses, some 200,000 electrons begin their hopping conduction into the brain’s sea of soluble RNA. A few of these electrons will play a part in firing synapses immediately. The brief presence of these electrons on the soluble RNA disturbs nothing. They disappear from the original synapse and reappear in the synapse they fire. In between, they behave in that mysterious quantum mechanical way: Although they need the stepping stones to make the journey, they are never in the space between.
But the many of the 200,000 electrons that start out never finish the journey. Their presence helps to smooth out the transition from one intersynaptic event to the next, smoothing out the consciousness experience so that the briefest consciousness interval is greater than the time required for a synapse to fire. But if this outpouring from excited synapses were permitted to continue uninterrupted, if there were nothing to drain off these excess electrons, consciousness would become one grand blur until the glut of electrons choked off consciousness altogether.
And this is where melanin comes to play. To prevent an excessive blurring of the consciousness interval, melanin is present in the outer layer of the brain. There it absorbs some of these electrons-some of this excess energy. Of course, just the right amount of melanin must be present there. Too much, and the melanin damps out the consciousness itself. Too little, and consciousness blurs.
If the quantum mechanical interconnection of synapses were limited to the average synaptic delay time during firing, our minimum conscious experience would be as brief as 0.3 millisecond-clearly shorter than we ordinarily experience it to be. Allowing for the full range of synaptic firings would give as much as about 1 to 3 milliseconds for the minimum consciousness time interval.
But there is only a small amount of melanin present. The cortex is only a pale gray. It absorbs only about 10% of the radiations that falls on it, and so we can estimate that perhaps only about 10% of these electrons will be absorbed during the interval of 1 to 3 milliseconds. For the melanin to to damp out most of the activity from any synapse, it requires 10, 20, or 30 times as much time. As a result, the characteristic time interval for consciousness is not 1 millisecond, but more like 30 or even 40 milliseconds.
During this time, 80% to 85% of the excess electrons are absorbed. This, then, agrees with the time interval of about 0.04 second that we previously found for the minimum time of consciousness- the length of the tick of the consciousness clock.
This is another point of agreement between theory and the way we actually experience our own conscious existence. Everything fits. Everything is tied to the way everything else works. The machinery that runs our consciousness is a finely tuned engine. The strange presence of a ‘tan’ on the brain, the minimum time interval we consciously experience, and the quantum mechanical nature of consciousness are all woven together into this silken fabric of reality.
But something else can also happen to the hopping electrons. They can stop on one of the stepping stones. And when one of the electrons ceases to stop hopping and stops on a given RNA molecule, that stepping stone is no longer in the game. It is no longer available to help maintain consciousness. If this goes on long enough, the RNA stepping stones become used up and consciousness stops.
Sleep comes and continues until this excess energy clogging up the engine of consciousness is bled away by chemical or other means that can restore these radicals (the excited RNA molecules) to their normal ‘ground’ state. This process takes hours-much too much time for it to occur while the brain is conscious and continuing to use up the supply of unexcited RNA molecules.
During the conscious state, we have 23.5 trillion synapses, each of which fires an average of once every 67 seconds, with about 200,000 electrons being released to the RNA each time a synapse fires. At this rate, the 745 billion billion soluble RNA stepping stones would be occupied-used up-in only 3 hours.
The presence of the melanin significantly reduces this problem. The fact that we can stay awake 16 to 20 hours without difficulty reflects the fact that the melanin damps out between 80% and 85% of this electron activity. But the remaining 15% to 20% continues to use up the available material necessary to maintain the synaptic intercommunication of the quantum mechanical consciousness. As more and more of the molecules are used up, the brain reaches a condition in which consciousness can no longer be maintained. The brain must sleep.
Sleep has to begin so that these excited RNA molecules can make their natural transitions back into their unexcited states. By morning they will have to support consciousness again. If the brain doesn’t sleep, the supply of ‘stepping stone’ RNA disappears and unconsciousness eventually results.
In addition, the brain must also quiet down. It has to reduce the rate of its synaptic firings. This means that two things must happen during sleep: Consciousness has to stop, and the level of synaptic firing must diminish to permit restoration of the pool of soluble RNA back to the ‘ground’ state.
With this rather simple idea in mind, it is straightforward to show in detail how sleep works. The rate at which we lose the RNA (that is, the rate at which an electron gets stuck on one of the molecules, removing it from the game) depends on the rate at which synaptic firing is pumping out electrons into the sea of 7.45 x 1020 RNA molecules and also on the rate at which the RNA molecules is recovered. This recovery rate for the RNA (the number of RNA molecules that return to being normal, per unit of time) depends only on the number of excited-state RNA molecules in the brain at any particular time.
Thus, beginning with the level of available RNA at, let us say, 90% of the total, and with a level of brain activity at twice the minimum needed to just maintain consciousness, the supply slowly drops. The minimum synaptic firing rate that just maintains consciousness depends on how much RNA is available.
If we have the total supply available to serve as stepping stones, then we calculate the minimum firing rate to be about 0.015 per second (once ever 67 seconds on average). If during our waking hours we maintain a level of activity twice this (0.03 per second, or once ever 33 seconds for the synaptic firing rate), then consciousness can be maintained until we have “used up” half of the RNA, which will require 16 or so hours. After 16 hours, when the amount of available RNA begins to drop below the 50% level, a synaptic activity of 0.03 firing per second will no longer support consciousness.
Sleep comes, and in order to restore the available RNA, the brain drops back to a level of activity of about 0.01 firings per second, or about once every 100 seconds for the average synapse. This constinues for 6 to 8 hours, after which time most of the supply of RNA has become available to support consciousness again.
Thus, the presence of melanin and the natural transitions from the excited to the unexcited state of the RNA build up the supply of these molecules over the next 8 hours or so of sleep, restoring the RNA supply to its initial level. At this point, the cycle can repeat.
Many people, especially “night people”, run on a different cycle. These people do not start the day at an activity level like the 0.03 firings per second for the average synapse. Rather, their morning activity level barely rises above the minimum to achieve consciousness.
If that describes you, you will spend most of the day operating on half your cylinders. You will be conscious, of course, but with just a small drop in the level of the available RNA, you just might drop back below the level of consciousnesss- back to sleep.
Toward the end of the day, however, night people still have a large reserve of conscious activity because of the available RNA. If you are one of them, that’s when you enter a period of heightened conscious activity. For a few hours you really feel alive, sharp, and bright. But of course, all that extra nighttime sharpness rapidly uses up the rest of your reserve. At one or two o’clock, finally, you can fall asleep.
There is another scenario. It is also possible to force extended consciousness. Say one begins the day at an average synaptic activity of 0.03 firings per second, when half the available RNA is used up, this level of activity is then the minimum that sustains consciousness.
By applying further stimulation-drinking quantities of coffee, perhaps, or experiencing a heightened level of sensory excitement (say to a level that corresponds to an average synaptic activity of 0.04 firings per second)- one can still maintain consciousness even when the available RNA sinks below the 50% level, to as low as, say, 38%, or lower.
This heightened synaptic activity compensates for the drop in available RNA molecules so that consciousness can be sustained, extending consciousness for hours more before sleep becomes necessary. We have all experienced the fact that excitement can overcome even severe drowsiness.
Of course, this is not all there is to how sleep works. In reality, the brain has many special structures, such as the thalamus and the reticular formation, that monitor and coordinate the brain’s levels of activity, controlling the brain so that it will efficiently carry out these requirements of the physics of consciousness.
Why do we sleep ?
Excerpt taken from book: The Physics of Consciousness
by Evan Harris Walker
Pgs. 240-244
Obvious answers to this question immediately leap to mind. We sleep because darkness inhibited the day time activites of the aboriginal man. We sleep because our body is tired; we sleep to restore the chemical balance our body needs to function efficiently.
Because sleep does occur, the body certainly makes use of it to knit up the raveled sleeve of care, to rest the machine, to restore the chemical balance in the body.
But the heart does not sleep. It slows down. It takes advantage of sleep. But it does not stop and rest for some eight hours. The brain also slows down, but it doesn not cease its function. It would seem that the pressures of evolution would have wiped away sleep as the most hazardous of all possible behaviors. Surely the body should rest at night, and the brain should think at a pace consistent with what we find in the sleeping brain.
But how could the pressures of evolution permit the existence of such a hazard as the complete lapse of attentiveness that turns the body into nothing more than an awaiting meal for any wild beast ? Why do we need sleep so desparately ? It must be that sleep is vital as life itself; it must be vital to the very existence of consciousness.
The answer to the puzzle of sleep lies in the fact that the mechanism of consciousness that we described in the last chapter cannot go on indefinitely without periods of restoration. Consciousness has to pause. Every time another synapse enters into the quantum mechanical consciousness mechanism that couples distant synapses, some 200,000 electrons begin their hopping conduction into the brain’s sea of soluble RNA. A few of these electrons will play a part in firing synapses immediately. The brief presence of these electrons on the soluble RNA disturbs nothing. They disappear from the original synapse and reappear in the synapse they fire. In between, they behave in that mysterious quantum mechanical way: Although they need the stepping stones to make the journey, they are never in the space between.
But the many of the 200,000 electrons that start out never finish the journey. Their presence helps to smooth out the transition from one intersynaptic event to the next, smoothing out the consciousness experience so that the briefest consciousness interval is greater than the time required for a synapse to fire. But if this outpouring from excited synapses were permitted to continue uninterrupted, if there were nothing to drain off these excess electrons, consciousness would become one grand blur until the glut of electrons choked off consciousness altogether.
And this is where melanin comes to play. To prevent an excessive blurring of the consciousness interval, melanin is present in the outer layer of the brain. There it absorbs some of these electrons-some of this excess energy. Of course, just the right amount of melanin must be present there. Too much, and the melanin damps out the consciousness itself. Too little, and consciousness blurs.
If the quantum mechanical interconnection of synapses were limited to the average synaptic delay time during firing, our minimum conscious experience would be as brief as 0.3 millisecond-clearly shorter than we ordinarily experience it to be. Allowing for the full range of synaptic firings would give as much as about 1 to 3 milliseconds for the minimum consciousness time interval.
But there is only a small amount of melanin present. The cortex is only a pale gray. It absorbs only about 10% of the radiations that falls on it, and so we can estimate that perhaps only about 10% of these electrons will be absorbed during the interval of 1 to 3 milliseconds. For the melanin to to damp out most of the activity from any synapse, it requires 10, 20, or 30 times as much time. As a result, the characteristic time interval for consciousness is not 1 millisecond, but more like 30 or even 40 milliseconds.
During this time, 80% to 85% of the excess electrons are absorbed. This, then, agrees with the time interval of about 0.04 second that we previously found for the minimum time of consciousness- the length of the tick of the consciousness clock.
This is another point of agreement between theory and the way we actually experience our own conscious existence. Everything fits. Everything is tied to the way everything else works. The machinery that runs our consciousness is a finely tuned engine. The strange presence of a ‘tan’ on the brain, the minimum time interval we consciously experience, and the quantum mechanical nature of consciousness are all woven together into this silken fabric of reality.
But something else can also happen to the hopping electrons. They can stop on one of the stepping stones. And when one of the electrons ceases to stop hopping and stops on a given RNA molecule, that stepping stone is no longer in the game. It is no longer available to help maintain consciousness. If this goes on long enough, the RNA stepping stones become used up and consciousness stops.
Sleep comes and continues until this excess energy clogging up the engine of consciousness is bled away by chemical or other means that can restore these radicals (the excited RNA molecules) to their normal ‘ground’ state. This process takes hours-much too much time for it to occur while the brain is conscious and continuing to use up the supply of unexcited RNA molecules.
During the conscious state, we have 23.5 trillion synapses, each of which fires an average of once every 67 seconds, with about 200,000 electrons being released to the RNA each time a synapse fires. At this rate, the 745 billion billion soluble RNA stepping stones would be occupied-used up-in only 3 hours.
The presence of the melanin significantly reduces this problem. The fact that we can stay awake 16 to 20 hours without difficulty reflects the fact that the melanin damps out between 80% and 85% of this electron activity. But the remaining 15% to 20% continues to use up the available material necessary to maintain the synaptic intercommunication of the quantum mechanical consciousness. As more and more of the molecules are used up, the brain reaches a condition in which consciousness can no longer be maintained. The brain must sleep.
Sleep has to begin so that these excited RNA molecules can make their natural transitions back into their unexcited states. By morning they will have to support consciousness again. If the brain doesn’t sleep, the supply of ‘stepping stone’ RNA disappears and unconsciousness eventually results.
In addition, the brain must also quiet down. It has to reduce the rate of its synaptic firings. This means that two things must happen during sleep: Consciousness has to stop, and the level of synaptic firing must diminish to permit restoration of the pool of soluble RNA back to the ‘ground’ state.
With this rather simple idea in mind, it is straightforward to show in detail how sleep works. The rate at which we lose the RNA (that is, the rate at which an electron gets stuck on one of the molecules, removing it from the game) depends on the rate at which synaptic firing is pumping out electrons into the sea of 7.45 x 1020 RNA molecules and also on the rate at which the RNA molecules is recovered. This recovery rate for the RNA (the number of RNA molecules that return to being normal, per unit of time) depends only on the number of excited-state RNA molecules in the brain at any particular time.
Thus, beginning with the level of available RNA at, let us say, 90% of the total, and with a level of brain activity at twice the minimum needed to just maintain consciousness, the supply slowly drops. The minimum synaptic firing rate that just maintains consciousness depends on how much RNA is available.
If we have the total supply available to serve as stepping stones, then we calculate the minimum firing rate to be about 0.015 per second (once ever 67 seconds on average). If during our waking hours we maintain a level of activity twice this (0.03 per second, or once ever 33 seconds for the synaptic firing rate), then consciousness can be maintained until we have “used up” half of the RNA, which will require 16 or so hours. After 16 hours, when the amount of available RNA begins to drop below the 50% level, a synaptic activity of 0.03 firing per second will no longer support consciousness.
Sleep comes, and in order to restore the available RNA, the brain drops back to a level of activity of about 0.01 firings per second, or about once every 100 seconds for the average synapse. This constinues for 6 to 8 hours, after which time most of the supply of RNA has become available to support consciousness again.
Thus, the presence of melanin and the natural transitions from the excited to the unexcited state of the RNA build up the supply of these molecules over the next 8 hours or so of sleep, restoring the RNA supply to its initial level. At this point, the cycle can repeat.
Many people, especially “night people”, run on a different cycle. These people do not start the day at an activity level like the 0.03 firings per second for the average synapse. Rather, their morning activity level barely rises above the minimum to achieve consciousness.
If that describes you, you will spend most of the day operating on half your cylinders. You will be conscious, of course, but with just a small drop in the level of the available RNA, you just might drop back below the level of consciousnesss- back to sleep.
Toward the end of the day, however, night people still have a large reserve of conscious activity because of the available RNA. If you are one of them, that’s when you enter a period of heightened conscious activity. For a few hours you really feel alive, sharp, and bright. But of course, all that extra nighttime sharpness rapidly uses up the rest of your reserve. At one or two o’clock, finally, you can fall asleep.
There is another scenario. It is also possible to force extended consciousness. Say one begins the day at an average synaptic activity of 0.03 firings per second, when half the available RNA is used up, this level of activity is then the minimum that sustains consciousness.
By applying further stimulation-drinking quantities of coffee, perhaps, or experiencing a heightened level of sensory excitement (say to a level that corresponds to an average synaptic activity of 0.04 firings per second)- one can still maintain consciousness even when the available RNA sinks below the 50% level, to as low as, say, 38%, or lower.
This heightened synaptic activity compensates for the drop in available RNA molecules so that consciousness can be sustained, extending consciousness for hours more before sleep becomes necessary. We have all experienced the fact that excitement can overcome even severe drowsiness.
Of course, this is not all there is to how sleep works. In reality, the brain has many special structures, such as the thalamus and the reticular formation, that monitor and coordinate the brain’s levels of activity, controlling the brain so that it will efficiently carry out these requirements of the physics of consciousness.