The minimum work principle is the force used on deeper levels (the maximum economy principle in other words). According to this, every action in the book of the universe is completed in a fashion to cause minimal energy consumption in the present binding conditions. The term binding condition refers to conditions that are mandatory (forced) for the system here. For instance, the total energy of a gas in a container that is perfectly insulated from the external environment is constant and therefore when we are investigating this gas, we should not overlook the conservation of total energy as a binding condition. Therefore, even for tiny actions, from the swing of a tree leaf with the wind to the flight of a dust particle in the air, the lowest energy consumption is essential in terms of present binding conditions.

We can make the topic easier to understand via short cut events of circuit boards. The reason behind a short cut is the conduction of electrical charges by the route with the least consumed energy. If even multiple short cuts are designed to attract electrical charges in an electrical circuitry, these charges are conducted via the route that requires the lowest energy.

It is all right, but how do electrical charges know this route? It is possible to ask a similar question about the orbit a ball follows when we throw it forward in a horizontal direction. The thrown ball continues on the orbit with the lowest amount of energy consumption depending on the present binding conditions (such as wind direction, strength, and the ball’s geometry). This is all well and good, but how does the ball know it will exert more energy on another trajectory?

Light follows the path where it moves fastest in the environment. In physics, “Fermat’s principle” states that when light is passing from one environment to another, it will be refracted not in the shortest path, but in the fastest direction of travel in the new environment (Figure 2). Therefore Fermat’s principle is the projection of the minimum energy principle on optics. In other words, the least amount of energy is spent by light on the path in which it will move fastest. However, for light to determine the direction that will be fastest, does it not have to first display refraction in all angles to identify the fastest path?

For science historian James Gleick it is impossible for physicists to discuss the minimum energy principle without giving the ball some type of willpower; the ball seems to choose its own orbit, as if it has knowledge of all the possibilities ahead of time.

A nice example in the living world for the minimum work principle is the similarity of ant behavior to the maximum economy principle. When some groups of the ant colony set out to forage, they communicate with pheromone hormones amongst each other. An ant that has found food leaves pheromones on the ground – indicating the quantity and quality of food – to guide others.

Another ant that follows this pheromone trace reaches the food, and marks the surface on the path back to nest with the pheromone by assessing the amount and quantity. Pheromones in spots that are not renewed by the ants within a certain time frame evaporate. Upon investigation of the ant routes, they are always found to follow the shortest path in between the food and nest, and leave pheromone tracks accordingly. For instance, when an asymmetric obstacle is positioned on the ant route (Figure 1), ants after a certain time are able to locate the shortest route again.

However, a more interesting case is the movement of the ant species named Wasmannia auropunctata when they are passing from one environment to another (Figure 3). It’s based on Fermat’s principle.

Not only ants, but also humans display trends that follow Fermat’s principle. For example, an emergency worker trying to rescue a drowning swimmer adheres to the most suitable strategy to reach the person at sea: When the beach and sea are considered as two different environments, first the rescuer runs to the nearest point to the swimmer on the beach, then reaches swimmer by entering the sea. Since humans move at different speeds on sand and at sea, if rescuer tried to reach the swimmer by entering directly into sea, it would take longer to reach the swimmer.

As seen in the above principle, the natural order of the world is created with incredible wisdom, without wasting any energy. Each truth has different projections on each existence and event. However, this distance in between the events or existences feels very far to us, therefore it is necessary to look more carefully to notice this relation among different projections.

There are also projections of this minimum work principle in our personal lives too. During the position of prostration in prayer, which can be considered as the humblest state of being when one feels closest to the Divine, the head, the highest point of body, is brought down to the level of the feet to compose a potentially lower energy status. This, in terms of the physical sciences, is the situation with the lowest work achievement capability, and can be seen as a status in which human deficiency and weakness as opposed to the infinite power of the Almighty are declared.

The minimal work principle can also be adopted in shaping the methods and style of providing services to other people, especially in the service of faith. Humans are the sons of their ages. Each age can be defined as a different environment. Therefore, when humans interpret their experiences, the socio-cultural environment where one is born and the specifics of their period must be considered. The shortest cut to people’s hearts and minds with minimal work principle is possible when the conditions of the time are taken into consideration. Said Nursi once said if he were to live in the time of Rumi (13th century), he would have written the Mathnawi, rather than his magnum opus the Risale-i Nur, and Rumi would do the same if he lived during his time. The Mathnawi eight centuries ago was and the Risale-i Nur today is the safest, shortest, and widest public avenue of faith and reflected the zeitgeist of their respective periods in history, Nursi argued.

References

1. James Gleick, Genius, Richard Feynman and Modern Physics, Abacus, London, 1993.
2. Jan Oettler, Volker S. Schmid, Niko Zankl, Olivier Rey, Andreas Dress, Jurgen Heinze, Fermat’s Principle of Least Time Predicts Refraction of Ant Trails at Substrate Borders, PLoS ONE 8(3): e59739. doi:10.1371/journal.pone.0059739

The heart is composed of four compartments: two atriums and two ventricles. The blood that reaches the heart first accumulates in the atriums. From here, it is sent to the ventricles. Afterwards, it is redistributed to the body by the contractions of the ventricles. The harmony of this process depends on the electrical currents in our hearts.

How is the electrical current formed?

There is a particular region in the heart called the sinus node. The sinus node is strip of a muscle that is 15 mm in length, 3 mm in width, and 1 mm in thickness, and is located in the right atrium of the heart. The cells of this strip are responsible for producing electrical currents, and are created in a different fashion from the rest of the cells that are responsible for producing contractions. This is where the electrical currents in our hearts are periodically produced. Every cell in the body contains elements such as sodium, calcium, potassium and chlorine that are electrically charged. The elements which are electrically charged are called ions. These ions also exist in the extracellular environment. The intra cellular and extra cellular concentrations of these ions are different from each other. This situation causes a difference in the electrical potential between the interior and exterior of a cell. This difference is called a membrane potential. Periodically, the membrane potentials of the sinus cells show sudden jumps – meaning they suddenly increase and then suddenly decrease. Since the cells are in close contact with each other, such a jump in the membrane potential of one cell triggers a jump in the membrane potential of another cell. The electrical currency that enables the contraction of the heart is produced by this continuous triggering of cells. On average, 70 electrical currents per minute are produced in the sinus node. These currents start being produced while a person is in the womb of their mother and continues their whole lifetime. The heart of an embryo starts beating while it is only 22 days old. However, the height of the embryo at this point has not even reached 1 cm. Isn’t it an amazing force that creates the beating heart of such a small embryo and keeps it going a lifetime?

How is the electrical current distributed?

Another node called the atrio ventricular node was created in between the atriums and ventricles in our heart. While the current coming from the sinus node is spread to the whole of the atrium, it is by this node that the current is sent to particular fibers. The task of this node is to hang on to the current coming from the sinus node for a while. Why does the current need to be held on to? Because blood can only enter the ventricles while it is resting and by holding on to it, the contraction of the ventricles is disabled while the contraction of the atriums is taking place. By this process, the blood coming from the atrium can enter the ventricle. Therefore, the blood fills in the ventricles and can be distributed throughout the body. The blood circulation is enabled in a flawless manner by allowing the atriums to do their duty while the ventricles wait.

After passing through the atrio ventricular node, the electrical currency eventually goes through the purkinje fibers. These fibers surround the ventricles like a web and are composed of cells that can conduct electrical current in a very fast manner. Compared to the atrio ventricular node, the electrical current can be conducted 150 times faster in the purkinje fibers. Therefore, the current reaches every point of the ventricles in a very short period of time. Every muscle in the ventricles contracts in a time shorter than one tenth of a second.

The muscles in the ventricles rapidly contract, one by one, depending on when the current reaches them. The contraction starts at the end of the ventricles and carries on towards the main veins exiting the heart. By this orderly and harmonious contraction, the blood is pumped from the end of the heart towards the main veins exiting the heart to be distributed among the body. Because all the ventricle muscles are stimulated very fast, the contraction also happens very fast, resulting in a strong pumping effect. The design of this system is incredibly wise, right down to its most minute detail.

Movement in heart muscle potential

As all cells in our body, the cells in the heart also have a membrane potential. We had stated before that this membrane potential is the result of the difference in intra and extra cellular ion concentrations. The charges of these ions are different from each other. For example, sodium and potassium have plus one (+1) charges, calcium has a plus two (+2) charge, and chlorine has a negative one (-1) charge. The resting potential of a cell is negative. This means that there are more negative ions within the cell when compared to its environment. Sodium, calcium, and potassium ions are mobile through the membrane. While sodium and calcium have a higher concentration outside the cell, potassium has a higher intra cellular concentration compared to its environment. There are channels created on the cell membrane that allow ions to pass through the membrane. The sudden increase in the membrane potential that was explained before causes a sudden rush of sodium ions inside the cell. This is such a rapid movement that it is concluded in a tenth of a second. Right after the entrance of the sodium ions, calcium ions also enter. Because these ions are positively charged, the membrane potential becomes positive.

With the entering of calcium ions into the cell, calcium ions are also released from the storages within the cell. By triggering the protein necessary for these contractions, the calcium ions become a means for the contraction of the heart muscles. Meanwhile, the potassium channels open and these ions within the cell pass to the extra cellular environment. The loss of positive ions results in the membrane potential being negative again. Therefore, the sudden jump in membrane potential that is the basis for the electrical current is created.

However, at this point there are extra amounts sodium and calcium within the cell and extra amounts of potassium outside the cell. The concentrations need to be returned to their original values for the next jump in the membrane to be possible. This task is given to a protein called the sodium-potassium pump that pumps out sodium from the cell and pumps in potassium. If this pump had not been created, the ion balance in any of the cells within the body would be impossible to re-establish. As a result, the life of the cells would come to an end. However, because of the remarkable intricacy of our cells, life is made possible for us.

Afterwards, some amount of the calcium ions are pumped out of the cell with a similar pump, while the rest are stored within the cell. The decrease in the concentration of calcium relaxes the muscle. Now the heart muscle has gone into relaxation and therefore is ready for the next contraction.

If the movement of the ions becomes unbalanced, the rhythm of our heart is disturbed. The unbalance in the ion movements or blockage in heart veins can be reasons for heart rhythm disorders. Even small heredity-based defects in the ions pumps affect the movement of these ions and can cause heart rhythm disorders. This situation shows that nothing is created by coincidence.

Movement in the sinus node

The jump in the membrane potential of a heart cell depends on the membrane potential jump of the previous cell. Through the gaps in between the cells that are in contact with each other, the positive ions that exit a cell reach the membrane of the cell next to it and trigger the opening of its ion pumps. As a result, the membrane potential of that cell starts changing. At this point, you may have this question: how does the electrical current start in one end of the sinus node that is not previously triggered by any cell?

This concept is explained by the ion transfer mechanism of the node cells being different than the muscle cells. Before explaining this, it should be noted that even while resting, a mechanism for allowing an ion exchange of the cell with its surrounding has been created. In the node cells, this exchange while at rest has been created in a way that the sodium and calcium exchange is larger and the potassium exchange is lower compared to the muscle cells during resting conditions. Therefore, the membrane potential of the node cells is less negative and slowly increases with time. As a result of this slow but steady increase, after a while it reaches a threshold. When it reaches it, the calcium channels in the membrane suddenly open and there is a rush of calcium ions into the cell. Thus, the jump in the membrane potential is created independently from another cell.

As it can be observed, even a single contraction of our heart depends on a very detailed, delicate, and complex system. Moreover, this system is repeated over a hundred thousand times within one day. After reflecting on this, how can we claim this system runs by coincidence or chance?

(continued from the previous issue)

Using the distinct groves and folds on the hemispheres as a guideline, a map drawn on the cortex identifies focal points, where the various senses are concentrated, and activities in particular regions. Each of these different colored schematic centers has a specific name and performs specific functions. For example, the region above the neck at the back of the head (occipital lobe) is the field of sight; the sections that coincide with the temporal region is the field of hearing; immediately in front of this, on the left, is (generally) the field of speech; in the forehead region (frontal lobe), on the anterior wall of the middle canal is the initial center of planning of movement; on the top section of the front region is the field of complex movement; immediately behind here, in the middle-side region, is the field of simple movement; the area behind this, next to the hearing field and extending upwards, is defined as the touch receptive field. However, these areas are not confined, but rather spread out, and have a very complex connection network. The duty of the adjoining areas of these regions is to display and decipher the meaning of the signals received from the nerves. As the received signals regenerate past experiences and memories, the object or event sending the signal is recognized. To perform voluntary complex movements, the plan of movement must initially be defined in the mind and then the combination of this plan is conveyed through my nerve fibers to the movement regions. As complicated activities in humans, such as talking, and activities that involve the sensory integration mechanisms are miracles in themselves, it is quite astonishing that certain people claim that humans evolved from apes, later learning how to speak. The spinal cord (medulla spinalis) that extends from the skull in the form of a long cord, is the central nervous system sending signals to the body regions under the neck. The grey matter of the brain is located on the surface, while the white matter lies beneath the cortex; however with the spine, the butterfly shaped grey matter is inside, and the white matter on the surface covers the grey matter. In this central nervous system, all of the sensual messages that are received from the entire peripheral system, in particular from your skin and muscle, are immediately connected with the synapses or connections of the movement cells, and thus a spinal reflex is produced. As a section of the connecting cells (synapses) responds with a reflex, the other section transmits the signal to me to determine the appropriate voluntary response. For instance, if you tread on a nail, as the nail goes into the foot, a signal is transmitted by the sensor fibers to the spine, and to avoid a loss of time, the spine immediately signals the movement nerves before me, and a command is transmitted to your muscle you to raise your foot. And after your foot is saved by instant reflex, you begin to perform the other conscious activities, for example; you avoid putting weight on the foot, and bandage the wound if it is bleeding.

31 pairs of nerves (right and left) emerge from the spinal cord; 12 pairs from the brain area lay beneath the skull. These are all nerves that emerge from the central nervous system, and are distributed to various organs of the peripheral nervous system. All of the head nerves that emerge from the skull, with the exception of the tenth nerve, called the vagus nerve, control activities related to movement and senses in the head and neck region. Each of the 31 nerves exit from a space in the side of the vertebrae, and each of these nerves has two roots, an afferent nerve (sensual nerve), and an efferent nerve (movement nerve). These roots join immediately outside the spinal cord, and form the cords that carry the sensual and movement nerve fibers. These nerve cords are distributed in a plan and system that is specific for each organ. For example, the receptor sensor cells that sense a needle pricking your finger transmits this signal to the spinal cord through the receptor cell of the arm. The responsive reflex of pulling the hand away, a reflex from the spinal cord, is sent to the arm and hand muscles, and you pull your hand away. This is an example of a simple reflex. The movement nerve cells of the peripheral nervous system are divided into two, the somatic nervous system, which is distributed to the skeletal muscles, and the autonomic nervous system, which is distributed to the inner organs. Whilst the majority of the activities of the somatic systems occur voluntarily at the conscious level, the activity of autonomic systems is mainly involuntarily, or below the level of consciousness. The autonomic nervous system controls the smooth muscles of the heart, glands, blood vessels, respiration, digestion, urination and reproduction systems without our even realizing it. Dear Peter! Could you manage to do all this if you were in control? Your self control can only intervene until you place food in your mouth. Then the digestive secretions, the stomach and bowel activity, and the excretion of waste are all conducted automatically, totally beyond your control. Your breathing continues while you sleep, your kidneys never cease to function, your heart never rests, and your liver never relaxes while you sleep; your pancreas continues to produce insulin. All of your internal organs and blood vessels continue to function with the smooth muscles whenever necessary. And all this activity is conducted without you even being aware of it. If you tried to do all this, you would become exhausted within five minutes, lose interest and become unable to cope.

The nerve cords of the autonomic nervous system are divided into two, the sympathetic and the parasympathetic. These two systems have been created in such a way that they respond in opposition to one another, and every organ is provided with a stem from both. Therefore, no organ of the body is left uncontrolled. Whilst one signals and encourages the organ to function quicker and generate more outcomes, the other acts to the contrary, sending signals that encourage the organ to slow down. In which case, with these two contrasting signals, the organ protects its optimal functioning tempo according to the situation and conditions. The sympathetic system generally responds in cases of stress and shock, preparing the body for the effects of such situations. For example, an increase in your blood pressure, blood-sugar level, and perspiration, the dilation of your pupils, and an increase in the flow of blood in your muscles all occur from the effect of the sympathetic fibers. The parasympathetic system sends adverse signals, such as reducing blood pressure and so on, so that the organs return to their neutral state and continue their normal functions.

From the very beginning I have described many of my sections and signals, but I have not yet told you about my key to life, my nerve cells, and how my nerve cells function. 30 billion cells, known as neurons, are the actual units that function in every part of my system. A neuron has a cell body and emerging filaments like tree branches. The single thicker filament like the tree trunk is called the axon, and the thinner filaments that emerge in larger quantities like tree branches are called dentrites. The nerve signals advance from the axon to the dentrite in the form of an electrical pulse. In the space between the connection point (synapses) of a nerve cell axon and the other cells, the dentrite, a chemical substance, called the neurotransmitter, is released. When these substances, in the form of neuropeptides, amino acids, acetylcholines, and monomines, reach the wall of the opposite cells, it an electrical pulse is immediately ignited in the dendrite. Just like a row dominos, falling down one after the other, or football fans performing the Mexican wave, a wave-like effect is generated and these electrical messages are fired with great speed from one end of the cell to the other, advancing in the form of tiny electrical pulses to be transmitted to neighboring cells. While a cell at rest has a potential of 70m V, the action potential of up to +30 – +40m V can transmit all types of information. Every cell can transmit up to 1,000 signals per second.

While you still do not recognize the true value of what you call the memory, which records hundreds of experiences every day, various theories are presented regarding how this bank which stores information in your brain actually functions. But we all know that the answer to this question lies within the millions of neurons that constitute me. Just as all of the senses, thoughts and actions occur from electrical and chemical signals that are transmitted from one cell to another they are presumably recorded in the same way, that is, with electrical and chemical signals.

It is difficult to define a precise center for the boundaries of the memories in me; memory could be interconnected with all of my regions. The storing of certain memories, some voices, visions, smells, or dreams, or the sense of resentment, anger or joy, is all carried out in different forms. You could not even begin to imagine the greatness of the memory storage! I have two types of memory, one short and one-long term. In my short term memory, I can store up to between seven and nine different things at any one time. Nothing remains in my short-term memory for more than a few minutes. Everything that you remember after this is stored in my long-term memory. In my long-term memory things can remain for days, months or even years. Everything you know and learn is stored in your long-term memory. By the time you are eight years old, the information in your memory is enough to fill one million pages. However, this is a mere drop in the ocean; the long-term memory is so vast that it can never become full. Even when you reach a hundred, I will have the capacity to store new information, so never assume that you are overloading a child’s mind and never deprive them of education…Some presumptuous people say; “Never force a child to memorize at a young age, it will affect the brain.” Do not believe them! The learning of foreign languages, the Qur’an and religious education is recorded in my memory by electric pulses and this is so much easier and healthier in the early stages of life. In fact, such activities at a young age can even strengthen the memory. The event called ‘recollection’ is the repeat of the electric pulse codes that are recorded at the actual time of an event. Occasionally you try to remember a person’s name, and although the name is on the tip of your tongue, you just cannot remember. You struggle and eventually give up. Then suddenly, two days later the name comes to your mind. You are quite puzzled and of course pleased that you have remembered, but have you ever wondered how this happens? As you try to remember, you control each of my nerve cells individually, because you are not sure where you placed the files that bear this information. But you are unable to find which section of the millions of cells bears the information. As you have not used this information often, or because you did not consider it to be important, you did not register it in a particular place. But you would never forget your father’s name, as it is important to you and use it often, so the file is in front of you constantly. Well, you get frustrated at not being able to remember and stop searching; however, what you call the subconscious is in fact a much more mysterious mechanism. It begins to search without you being aware of it. Then to your surprise it produces the file two days later. The subconscious is a very mysterious place, it affects everything about you. Only the most sincere feelings are recorded in the subconscious; no veil, no hypocrisy, only actual thoughts are recorded. And also events that deeply affect you, the sad or bad memories you experience, and of course sins…The subconscious is what causes the sense of guilt or an inferiority complex; this is reflected in much of your behavior. But problems like guilt or an inferiority complex are something we can change; it all depends on you. If you are a person who has self-control, you perform good, favorable deeds, and are continuously patient; thus you can eventually renew the contaminated sections of your subconscious so that it will not upset you anymore. Indeed, this is the reason why, of all the creatures on earth, only humans were blessed with the sense of remorse and faith. If you suppress feelings of guilt and sin in the subconscious, the autonomic system affects the organs without you even realizing it; the thalamus, hypothalamus, or the pituitary gland (hypophsis), which are small in size, but bear a great responsibility; eventually this disturbs the balance of the whole body and you become ill. Although this may not be an organic complaint at first, due to psychosomatic symptoms which are caused by suppressing your subconscious, over time this will affect the functions of one of your organs and you become ill. Of course the exact opposite is also possible, with inspiration, pleasant thoughts and good actions the positive signals transmitted to the affected organ may possibly be the means to recovery.

Dear Peter! I have so many more facts and mysterious functions to describe to you, but unfortunately the pages here are not enough. Well, I suppose I must stop somewhere. I really wanted to talk to you about a number of different things, like dreams, mental illnesses such as Parkinson’s, Alzheimer’s, strokes, sleep, hypnosis, and the damage caused by drugs. However, each of these subjects is so vast, and many of them have already been explained in previous issues, so for now I will leave it to others to describe these subjects to you, and say my last words…

Dear Peter!… While your hand is writing and reading these words, or explaining what you have read to your friends, or learning all this information and passing it through the filter of thought, you are constantly using my nerves and my systems. There is not a single moment where I am not informed of events that occur in your body. Who knows just how much of the mysteries in me you will use in order to rise to the peak of accomplishment with the blessings that have been bestowed upon you by the Creator. Even the greatest computers made by human beings are mere toys compared to me. Nevertheless, the knowledge of engineers and craftsmen which design, plan, and place every piece into these computers with total accuracy is only possible because of me. Presumably you are not denying those who designed, constructed, and made the computer operate, are you? In which case you should thank God, the One who created me, an organ whose capacity exceeds that of thousands of computers, with His eternal power and wisdom; always remember to use me in good, blessed, and honest actions!…May God protect you!…

Irfan Yilmaz is a professor of biology at Dokuz Eylul University, Izmir. 

He has granted you from all that you ask Him. Were you to attempt to count God’s blessings, you could not compute them. But for sure, humankind is much prone to wrongdoing (sins and errors of judgment) and to ingratitude. (Ibrahim 14:34)

Today a large part of modern science focuses on understanding the human body. Researchers working on life sciences hope that one day the secrets of every single detail that make us human will be revealed. Every year billions of dollars are spent by scientific institutions on learning more about us. Actually this fact by itself is enough to suggest how little control we have over things happening in our bodies, and we know even less about the mechanisms of moving, touching, speaking, seeing, or hearing, and so on.

As a scientist, I really cannot guess whether life scientists will ever be able to learn enough to solve the puzzles of the human body, but I feel a lack of satisfaction when the knowledge we have gained from scientific discoveries is compared with what is unknown. In my opinion this is why one of the most intelligent physicists in history, the Nobel laureate Richard Feynman, once said, “I was born not knowing, and have only had a little time to change that here and there” [1]. My understanding is that such a conclusion must be inevitable if the primitive knowledge given to us by modern sciences is not interpreted in the light of a far superior logic that is meant to explain the whole creation. In that sense, I believe that we have to consider every single detail in creation as a vital part of the whole in order not to feel lost before the grand picture of this masterpiece.

Last year, in a seminar at Osaka University Graduate School for Frontier BioSciences, I was thrilled to hear Professor Keichi Namba say, “Japan’s fastest supercomputer dissipates more than billion times the power dissipated by a fly’s brain, yet it is not able to simulate the brain of such a tiny animal.” This worked as a wakening call or a reminder for me to think again about the magnificent arts of the Creator. In particular, I wanted to revise my research on a hearing-related protein from a new perspective, rather than using the mechanical attitude that is followed most of the time.

This article is an attempt to explain an amazing mechanism in our ears that enables us to hear the faintest whispers. A mechanism that is switched off at loud cries to protect us from disturbing noises, yet amplified to make the softest sounds audible. Before starting to explain the basic anatomy of the human ear, I should mention that today the ear’s active amplification mechanism is still being investigated in research centers by biologists and physicists together.

How do we hear? What is happening in the inner ear?

Findings from the last century have shown that our ears are not just simple receivers as we had imagined. In 1979, David Kemp of University College, London discovered that mammalian ears can also emit sound vibrations. By placing a very sensitive microphone close to the eardrum he could detect whistles, implying that there is a source of vibration within the ear [2]. However, before trying to explain the cause of vibrations in the ears, we have to go over the mechanism of hearing briefly: The delicate design of the outer ear, the tympanic membrane (eardrum), and the tiny bones (malleus, incus and stapes) enables to collect sound waves traveling in the medium and transfer them to the inner ear (Figure 1a). In the inner ear the sound waves are sorted according to their frequency and amplitudes and then converted into electrical signals which can be transported to the brain via nerves. At the onset of this process the sound waves are transformed into standing waves on the basilar membrane which is laid along the organ resembling a snail, the cochlea (Figure 1b). The frequency of the incoming sound wave determines the positions of the distortions along the cochlea: High pitches create vibrations at the basal end of the cochlea (i.e. adjacent to the middle ear) whereas low frequencies vibrate closer to the apical end (Figure 1c) where the cochlea gets narrower. This geometry helps our ears to act as a frequency analyzer.

The efferent and afferent nerves that connect the ear to the central nervous system are attached to the organ of Corti, which is situated right next to the basilar membrane, extending over the cochlea. In other words, Corti is the sense organ of hearing, converting the motion of the basilar membrane into electrical signals that are conducted to the brain via neuronal cells [3]. The organ of Corti is also lined with multiple rows of sensory hair cells.

The hair cells of the organ of Corti

Corti is decorated with two different sets of sensory cells: single row of inner hair cells (IHCs) accompanied with 3–4 rows of outer hair cells (OHCs), both spanning the whole cochlear tube (Figure 2a). They are called “hair cells” because both IHCs and OHCs have typical bundles of stereocilia that contain mechanosensitive ion channels (Figure 2b).

The major function of IHCs is to detect the sound waves and then convert them into equivalent electrical signals that are to be interpreted by the brain. When the basilar membrane is perturbed by the incoming sound waves, the IHCs found in that region sense this activity by the movement of their hair bundles (bundles of stereocilia). The hair bundles of IHCs deflect and re-align as the basilar membrane moves up and down (Figure 3). We should note that this is an amazingly sensitive process such that deflections of the stereocilia on the order of a few nanometers (one millionth of a millimeter) can be detected and converted into nerve signals by the IHCs [4].

However, this by itself is not sufficient for hearing; no matter how effective IHCs work, the fluid that fills the cochlear tube is a threat to the sound waves traveling in the inner ear. In 1948, a young astrophysicist named Thomas Gold was the first person who has pointed out that the fluidic nature of the cochlea would dampen the sound vibrations and make them too weak to be detected by IHCs. He has concluded that an inherent vibration amplification mechanism is necessary in order to overcome such a problem [5]. Unfortunately, Gold’s statements were overlooked by the physiologists of his time who had performed their hearing related experiments on dead cochleas.

Gold’s predictions were justified around ten years later by William Rhode, a physiologist from University of Wisconsin, who has shown that the vibrations of the basilar membrane in live tissue samples are stronger than anticipated [6]. In the present day the existence of an amplification mechanism within a live cochlea is a well accepted fact. The only disagreement among scientists is about how the mechanism of the amplification works. Several scientific laboratories have reported different experiments performed on the organ of Corti and they have proposed different models. At the center of one of these models is prestin, a membrane protein which is not found in any cell but OHCs in the human body.

Electro-motile outer hair cells and prestin

In 1985, the distinctive properties of OHCs were first discovered by William Brownell, a University of Geneva neuroscientist, who has shown that these cells can convert electrical signals into motion: A phenomenon called electromotility. Electromotile OHCs can elongate or shrink in response to electrical charge density changes in their membranes. About a decade ago Peter Dallos and co-workers from Northwestern University in Chicago discovered a membrane protein, unique to OHCs, that can respond to electrical signals [3]. The Dallos group coined the name “prestin” for this protein in an analogy with the musical term “presto” (quickly) due to its rapid response to electrical signals. Various kinds of mammalian cells genetically engineered to produce prestin at their membranes displayed the electromotile responses that are very similar to OHCs.

According to Peter Dallos prestin protein works as a tiny machine which is a crucial element for cochlear amplification [7]. His theory is verified by recent studies which show that cochlear sensitivity in mice decreases hundredfold when prestin activity is disrupted by genetic means [8]. As the sound waves reach the inner ear, prestin-driven electromotility enables the OHCs to move like pistons. The piston movement in phase with the basilar membrane motion amplifies the vibrations and makes them stronger for IHC detection (Figure 4a,b). The prestin-driven vibrations were what Thomas Gold proposed and David Kemp had detected so many years ago. However, scientists are still searching and learning new things about this nanometer scale machine. One of the discoveries showed that prestin can adjust itself according to the amplitude of the incoming sound waves: Basically, the amplification is stronger when the sound waves are hard to hear but gets weaker as the volume increases.

Up to this point, we have briefly explained how the amplification mechanism of hearing in mammals works. Unfortunately, even though it took decades of research for scientists to discover and define the active nature of the mammalian ear, this explanation highlights only a minuscule part of the whole picture. That is why we are still incapable of curing most hearing problems. For example, hearing loss due to slightly disturbed hair cells with damaged stereocilia turns out to be chronic (Figure 5). The medical treatments we have to hand are too primitive to mend such delicate structures. Moreover, hearing aids made by today’s technology are not nearly as effective and functional as needed.

On the other hand, the delicacy of the hair cells and the limited control scientists have over them are not the only lessons we have learned from research on the inner ear. We cannot overlook the other messages attached to the research on the grounds that the time given to us is just too short to comprehend. It is an undeniable fact that the sense of hearing is designed in the best way to serve human beings. The different characteristics of hearing amplification at different sound levels make life much easier for us: Prestin-driven hearing is most effective when the sound waves are weak and harder to hear. This way the incoming sound waves are amplified enabling us to hear the faintest whispers. However, as the sound strength increases, the prestin-driven amplification gradually gets weaker and finally diminishes after a point to make sure that loud noises are less disturbing and hazardous for us. In my opinion, this amazing quality of a tiny protein found in our ears is one of the pieces of evidence that remind us of the necessity of pondering the favors of our Creator. Qur’anic verses such as Ibrahim 34 at the beginning of this article give us clues about how to interpret scientific findings that reveal the amazing qualities of our bodily organs. May the Creator of our ears allow us to reflect more on His favors and live accordingly.

Hamdi Sener is a biophysicist living in Boston. He can be contacted at hamdisener@gmail.com.

References

1. Gleick, J., Genius: The Life and Science of Richard Feynman. Reprint ed. 1993: Vintage. 560.
2. Kemp, D.T., The evoked cochlear mechanical response and the auditory microstructure- evidence for a new element in cochlear mechanics. Scand Audiol Suppl., 1979. 9: p. 35–47.
3. Zheng, J., et al., Prestin is the motor protein of cochlear outer hair cells. Nature, 2000. 405(6783): p. 149–55.
4. Robles, L. and M.A. Ruggero, Mechanics of the mammalian cochlea. Physiol Rev., 2001. 81(3): p. 1305–52.
5. Gold, T., Hearing II. The physical basis of the action of the cochlea. Proc. Roy. Soc. B., 1948. 135: p. 492–498.
6. Rhode, W.S., Observations of the vibration of the basilar membrane in squirrel monkeys using the Mossbauer technique. J. Acoust. Soc. Am. , 1971. 49: p. 1218–1231.
7. Cho, A., What’s Shakin’ in the ear? Science, 2000. 288: p. 1954-1955.
8. Liberman, M.C., et al., Prestin is required for electromotility of the outer hair cell and for the cochlear amplifier. Nature, 2003. 419: p. 300-304.
9. Fettiplace, R. and C.M. Hackney, The sensory and motor roles of auditory hair cells. Nat Rev Neurosci., 2006. 7(1): p. 19-29.
10. Dallos, P. and B. Fakler, Prestin, a new type of motor protein. Nat Rev Mol Cell Biol, 2002. 3(2): p. 104-11.

The human ear and hearing

The human ear can be divided into several functional sections: the outer ear, the middle ear, the inner ear, and the auditory nerve. Sound goes through a series of changes as it travels through these sections until reaching the brain. The outer ear picks up sound pressure waves, amplifies them and then converts them into mechanical vibrations on the ear drum, which is connected to a series of small bones in the middle ear. These small bones further amplify or diminish the mechanical vibrations in the ear drum and transfer them to the cochlea, a snail-shaped cavity filled with fluid which is located in the inner ear. Change in fluid pressure caused by vibrations within the cochlea lead to changes in the flexible membrane, called the basilar membrane. These changes contain information about the frequency and strength of the sound that has entered the ear. Attached to the basilar membrane are mechanical receptor cells, called hair cells, which are bent according to the deflections of the basilar membrane.The hair cells have hair-like structures. The bending of these hairs assists the release of an electrochemical substance that causes neurons to send electrical signals to the brainstem through the auditory nerve. These signals are in the form of a message (or a code) that the brain understands.

Cochlear Implant (CI) devices

If there is a broken link in any part of the auditory pathway, the brain does not receive any coded signals, and hearing impairment occurs. If a large number of hair cells or auditory neurons in the cochlea have been damaged, then the person is diagnosed as profoundly deaf. The hair cells can be damaged by certain diseases (e.g., meningitis, Meniere’s disease), by congenital disorders, by certain drug treatments, or by other causes. One negative outcome of damaged hair cells is that they can subsequently lead to the degeneration of adjacent auditory neurons. Research has indicated that the most common cause of deafness is the loss of hair cells (>95%) rather than the loss of auditory neurons. This has encouraged scientists to try implanting a device inside the iner ear or cochlea, bypassing the normal hearing mechanism of the ear, to stimulate the remaining auditory neurons directly through electrical signals. These are called Cochlear Implant (CI) devices, which can restore partial hearing in profoundly deaf people . A standard CI system, shown in Figure 1, composes of and performs the following functions: a microphone picks up sound pressure waves and converts these into electrical signals. The signals are sent to the speech processor that is worn by the patient. The speech processor analyzes and encodes these sound signals, sending them back to the external pick-up coil . After passing through a wireless radio link that lies between the external and implanted coils and an implanted electronic devise, coded signals are sent to the implanted array of electrodes in the cochlea to electrically stimulate the remaining auditory neurons , and the brain receives what it interprets to be sound.

Electrical stimulation of the ear, or CI research, can be traced back to the 1800s. The Italian scientist Alessandro Volta used a battery as a research instrument to demonstrate that electric stimulation could result in a number of human sensations . After connecting a 50- volt battery to his ears, he noted that “…at the moment when the circuit was completed, I received a shock in the head, and some moments after I began to hear a sound, or rather noise in the ears, which I cannot well define: it was a kind of crackling with shocks, as if some paste or tenacious matter had been boiling…”. That electric stimulation of the auditory nerve provides hearing sensation in deaf people was reported more than 100 years after Volta . Electric stimulation in two deaf patients resulting in hearing was reported in 1957. These successes resulted in intensive research into helping deaf people hear in the 1960s and 1970s. One of the early successful single-channel CI devices was developed in the early 1970’s (3MCorp/House) and became the first commercially available CI device approved in the United States in 1984. The University of Utah developed a six electrode implant called the Ineraid or the Symbion device in the early 1990s. It was followed by other devices in Europe, the United States, and Australia.

The present status of Cochlear Implants

Today, around 10% of the population in developed countries suffers from hearing impairment. At present, the number of CI users has reached more than 100,000 worldwide, and is still growing rapidly. Functionally, CI has evolved from the single-electrode device that was used as an aid for lip-reading and

sound awareness to a modern, multielectrode device that can allow an average user to talk on the telephone. Even though significant technological progress has been achieved in the last 50 years, there are still many mysteries about the human hearing process and the parts of the ear. Here, we will compare some aspects of the healthy human ear and CI devices, looking to the future. The human ear operates over a range of sound pressures (its dynamic range) which is greater than one million to one (120dB), with as many as 200 discrete steps in the range. In contrast, today’s CI devices typically provide a dynamic range of three to one (10dB) to ten to one (20dB) with 20 discrete steps. This major difference is mainly due to the fact that the human ear is very adaptive in noisy environments, and is able to suppress noisy background, while picking up and processing appropriate sound signals for better perception. CIs do not differentiate between sounds, but amplify all sounds, which results in poor sound perception. Today, a typical multi-channel CI system uses 16 to 24 electrodes implanted in the cochlea with 8 to 22 signal processing channels. A potential shortcoming of having so many electrodes and channels in current CI technology is the electrical interference of electrodes during simultaneous electrode stimulation. These electrical interactions can disrupt the stimulus waveform prior to neural activity and degrade sound perception. The normal ear contains roughly 3,500 inner hair cells in the cochlea that are tuned to different frequencies from 20 to 20,000 Hz. They are connected to about 35,000 auditory nerves. Hair cells work as signal processing channels, yet each of the inner hair cells has also been wired in a sophisticated and little-understood fashion to 10-20 auditory nerve fibers that carry information to the central nervous system. Since they work in the chemical domain, they do not have the gross interference issues of CI electrodes. While good speech understanding has been achieved by users of modern multi-electrode CIs operating in quiet environments with 70–80% sentence recognition, allowing users to talk on the telephone, the CI devices do not discriminate between noise and the meaningful signals, only achieving speech understanding at between 70% and 80%, which falls to 10% or lower in noisy environments. It is a great challenge for CI users to appreciate music. Some CI listeners reported that they can enjoy music and are able to recognize melodies, but most described musicas sounding unpleasant and noisy, and performance could not be increased with current CI technology. CI users have difficulty in identifying differences in frequencies. Typically, they cannot discriminate any frequency difference for frequencies higher than 500 Hz, while the normal ear can hear up to 20,000 Hz with frequency discrimination between 2 to 3Hz at best. This gross difference is related to the issues surrounding signal processing strategies and electrodes of current CI systems. Predicting post-surgical performance based on presurgical conditions and tests of a CI candidate is still a problem for the physician. The cost of surgery is still high; in the United States, for example, a typical cost is between $40,000 and $75,000. Beyond these issues, the moral, cultural and ethical issues related to CIs are very complex. They are still debated, and are an important part of CI development in the world today. The hair cells in the human ear naturally deteriorate and die as we grow older. This process is typically sped up with exposure to loud noise. In common with all mammals, new hair cell generation in human ears stops right after the birth. However, in fish and amphibians, very similar cells are present and reproduce throughout life. Recently, it was found that hair cells of birds are repaired after being damaged by exposure to noise or ototoxic agents. It was also discovered that hair cells in the mammalian vestibular (balance) organ, very similar to those in the hearing system, can regenerate. These findings, along with other advancements in medical fields, lead to long-term research into different aids for hearing- impaired people. Despite the fact that hearing loss is usually permanent, scientists are optimistic that it may eventually be possible to reverse the damage in the ear by repairing or regenerating the sensory hair cells through gene therapy, stem cell transplantation, or ultimately by replacing the human cochlea with an artificial one. Today, Auditory Brainstem Implants are also being tried on humans for direct brainstem stimulation, bypassing the ears and the auditory nerves. Human beings and most animals on earth are born and equipped with a pair of ears for a good reason: having two ears enhances hearing and sound localization. Scientists are examining whether this is also true for deaf children who receive not one, but two CIs.

Conclusion

The sense of hearing is a gift for human beings which they hold dear and are grateful for, as much as for any of the other senses with which they have been equipped. It is important to strive to find cures for all kind of diseases, yet, more important than the cure is prevention of harm to our body and its amazing senses. Here, we have tried to open a small window onto human hearing, to examine how related impairments are being dealt with through cochlear implant (CI) devices, as well as looking at the issues related to these devices and the future directions of research for restoring hearing to deaf people. It is obvious that we have learned much about human hearing and ear in the past century; yet, this may well be just the tip of the iceberg.

References

1. S.U. Ay, F.-G. Zeng, B.J. Sheu, “ Hearing with bionic ear,” IEEE Circuits & Devices Magazine, Vol. 13, No. 3, pp.18-23, May 1997.

2. F.-G. Zeng, “Trends in cochlear implants,” Trends in Amplification, Vol. 8(1), pp.1-34, 2004.

3. A. Volta, “On the electricity excited by mere contact of conducting substances of different kinds,” Royal Soc. Philos.Trans., vol. 90, pp.403 431, 1800.

4. A.M. Andreev, G.V. Gersuni, A.A.Volokhov, “On the electrical excitability of the human ear: On the effect of alternating currents on the affected auditory apparatus,” Journal of Physiology USSR, Vol. 18, pp.250-265, 1935.

Modern medicine, which tries to understand the biological structure of human beings, has been carrying out research in recent years that reveals the manifestations of the above fact. For instance, in classical text books the heart is introduced as a mechanical system that pumps the blood, a center to which all the organs of the body are directed; but recent research shows that there is a nerve system in the heart, just as there is in the brain, and that the heart assumes responsibility, to the same degree as the brain, in the control of the body. It has been revealed that the harmonious functioning of all the other bodily systems is regulated by the heart to the same degree as done by the brain. In recent years, the heart has been depicted as the sage and master of the palace that is the body. Alongside the abstract, analytical, and logical intellect of the brain, the heart is equipped with emotional and communicational intellect. Emotions are first produced in the heart; the signals produced in the heart are then carried very rapidly over to the limbic system of the brain. It is then through the brain that the emotional response is carried over to the body and communicated to those around it. Research which has been carried out in the framework of studying the heart-brain relationship has revealed things that may change our attitude toward the heart, as well as affecting our presuppositions about humanity and how our health can be protected.

The two-way communication system that exists between our heart and brain is one of the most complex communication systems in the world. For a start, the heart is made up of 40,000 nerve cells which pertain to it alone. This number of nerve cells is close to the average found in various centers of the brain. It has a complex and mysterious nervous system unto itself and this nervous system is defined as the “brain in the heart.” There is clear and sound proof that the heart communicates with the brain along four different pathways. The first is via the nerves (the neurological pathway); the second through the hormones and neurotransmitters (the biochemical pathway); the third is made up of the pulse waves created by blood pressure (the biophysical pathway); with the fourth being the interaction of the electromagnetic fields (the energy pathway). The sympathetic nerves that envelope the heart like a web are one of the four important communication and regulation branches of the heart-circulation system. The heart operates in a system which produces one of the most powerful and broadest electromagnetic fields in the human body. The bioelectromagnetic fields that are produced can be measured by SQUID (Superconductor Quantum Interference Device) from 50-70 cm away. The electrical field in the heart measured by an electrocardiogram (ECG) is on average 60 times greater in amplitude than the electrocephalogram measurements taken from the brain; the magnetic component of the heart is 5,000 times stronger than the one in the brain. Consequently, these forces cannot be absorbed by the tissues and disappear; similarly the blood pressure that is produced by the rhythmic activity of the heart, the sound pressure, and the changes in the electromagnetic waves are not only carried over to each part of the body, but at the same time the scattering of that field of energy is felt by the people who are experiencing it. All these observations show that the heart has been given the role of a signal station, providing and regulating the synchronicity within the entire body. When people experience different emotions (fury, happiness, fear, and despair) the heart beat changes along with the rhythmic patterns produced by the pulse (Figure l and 2). 

The Emotional State of the Heart Affects the People around

The quality of the electrical signals that emanate from the heart affect all the cells of the body in a negative or positive way. It has been observed that the electromagnetic fields produced in the heart affect the emotions and thoughts of other people who are in physical contact or 50-70 cm away from a heart that is producing these emotions (Figure 3).

This shows that the emotional state of educators in preschool environments and mothers has a direct effect on the development (especially that of heart and mind) of the children. In particular, if the people who work in preschool environments are under stress, temperamental, unhappy, or depressed, this will not only affect the educator, but also the development of the children under their care. When those who are working with children have positive emotions, are affectionate, and smile, this has a positive effect on the development and learning curve of children.

The development of the brain and heart in children is dependent on their mothers and educators having a healthy heart. For these hearts to be healthy they have to possess positive emotions (such as affection, compassion, and love). In one study carried out at Harvard University, it was observed that adults who had not received sufficient amounts of love during their childhood or who received no affection became ill more frequently and also died sooner. It is now understood that the general heath of human beings is more dependent on our living with positive emotions and having a strong spiritual dimension than on living with logical and rational thoughts. From these we understand much better the importance of controlling the emotions that emanate from the heart through a sound education. The heart is one of the centers that regulates the general health of the individual. Behavior patterns (overworking, the performing of hasty actions, anxiety, or being temperamental) are risk factors that deteriorate the health of the heart and that can lead to heart attacks. Some research shows that an intense episode of negative emotions, like fury, anxiety, or despair over a long duration can lead to sudden death related to heart disease. The risk of stress that is related to poorly managed chronic negative emotions causing cancer and heart disease is six times greater than the risk involved in smoking, high cholesterol, and hypertension. Disliking or being unsatisfied with the work that one does is also considered to be a great risk factor when it comes to heart attacks.

The Heart Rate Variability

According to messages emanating from the sympathetic nerves in the autonomous nervous system, one of the four pathways used in the control and regulation of heart activity, the heart rate and secretion of adrenal hormones increase. The stimuli that come from the parasympathetic nerves, on the other hand, slow down the beating of the heart. The balance and harmony between the two is very important for the health of the heart. The changes that are observed in pulse patterns over time are a key measure of the balance between the brain and the heart. Heart rate variability (HRV) shows whether or not the electrical stimuli in the sinoatrial knot (the group of nerve cells that are responsible for the production of the electrical current in the heart) are being regulated as they should. Since the HRV parameter forms a window through which we can measure the ability of the heart to respond to the regulating signals that travel from the heart to the brain and from the brain to the heart; in recent years the determination of the percentage of heart rate variance has gained importance. The HRV measurements are carried out via tacograms; these measure and analyze the HRV for the duration of an hour. Normally, the HRV parameter is the capacity of the heart rate to respond to changing circumstances and to adapt to the required pace. The decrease and increase in this capacity in situations such as stress, temper, excessive joy, and panic disturbs the capability of the heart to adapt; it causes a decrease in this capability and can result in the collapse of the whole system. An HRV which has decreased, due to either material or emotional causes, could be a harbinger of arrhythmic cardiac arrest, myocardial infarction, the speeding up of atherosclerosis, or heart failure. Patients whose HRV decreases may die sooner than patients whose HRV is normal or high. If the HRV does not keep within the normal, balanced limits, it is highly probable that those patients may die due to a sudden heart attack.

In the biological working of the body, the brain obeys the heart. When the changes in the heart rate are harmonious, the waves (alfa or lower wavelengths) that are produced in the person’s brain are also in synch with the rhythm of the heart. In other words, there is a harmonious cooperation and an excellent unity in the compatibility of heart beats and the relationship between the heart and the brain. The research that has been done in this field shows that the activity of the brain has been programmed in synch with the activity of the heart. For instance, in embryonic development, the brain follows the heart. While the child is developing in the womb, the heart develops before the brain. The development of the brain is completed only after a child reaches one year of age. According to recent research, when a person’s emotions change, the quality of the signals that emanate from the heart to the brain change automatically as well. In other words, if the psycho-physiological state of the individual is balanced and positive, the HRV rhythms of the heart are accordingly harmonious and consequently the electrical activity in the brain is synchronized with this balance and harmony that is produced in the heart.

Research shows that humans live 80-90 percent of their lives automatically and mechanically; in their daily lives they make most of their decisions and do most of their activities unconsciously, according to habit and subconscious directives. Consciousness and will have a very weak hold on our emotions, whereas our strong emotions (for instance passion) have a greater capacity to control and direct our will and consciousness. The automatic way of life conducted through habit is dominant over the way of life led through conscious choices and will; emotions (especially passions) have, in that sense, a natural superiority over reason and logic. This natural condition and tendency of humanity makes it essential to find the answer to the question of how one may live a life that is governed by reason, logic, and will, yet maintain health at an optimal level. The key to finding the answer to this question is to take the education of the heart (or the education of “emotional reason”) seriously and giving it priority. Education which does not take emotion or passion into account, which overlooks them, has to be abandoned immediately. In its place, an education and life philosophy that gives due importance to the heart and the emotions, a philosophy where reason and logic help emotions and show them the way must be adopted.

References

• Gulen, M.F., Key Concepts in the Practice of Sufism, The Light, Inc., NJ: 2004.
• McCraty, R., M. Atkinson, D. Tomasino, Science of The Heart, Institute of HeartMath, California: 2001.
• http://www.futurehealth.org/Freezeframe.htm
• http://www.heartmath.org.

What is reality? What is illusion? Do we have free will, or is our life somehow preprogrammed? Such questions have vexed humanity from the beginning. Technology has added another wrinkle: virtual reality. Now that we can create reality, how do we know that what we consider reality is really real? Might we be in somebody elses virtual reality program?

External Reality

Nobody remembers being born. By learning about ourselves, we learn things from our surroundings and people, and how to experience events on our own. If our senses function normally, we begin to wonder about our sense-related experiences and seek meaningfulness: Who am I? How were I and the world created? Why am I here?

Each normal person is aware of himself or herself and the external world. We learn how to distinguish colors and shapes through sight and touch. But how would blindness or an impaired sense of touch alter our perception and understanding? Perhaps we would ask: Is the red that I see, the roundness that I see and touch, inside or outside of me?

No one can explain what red is. Yet we know what it is because people tell us that a ripe tomato is red, or that beaming the 620 to 740 nanometers wavelength into our eyes lets us experience redness. In both cases, someone else causes us to see red. Redness is also in the mind, for we can see it behind closed eyes. This is true for the other senses as well.

Recent brain studies reveal that neither light nor sound reaches our brain. Rather, it receives electrical stimuli produced by our senses and then processes them into meaningful sense impressions.(1) As the brain cannot distinguish between a real and an artificial electrical stimulus, we can make it see and respond to imaginary pictures as if they were real. When we see a red apple, what do we really see? What does its reality mean? Is it outside of us, are our senses tricking us, or is the world presented to us in another way?

What Is Virtual Reality?

Scientists and philosophers traditionally considered space and time absolute, as defined by Aristotle and formulized by Newton.(2) In other words, the space we inhabit existed before us and will exist after us, and time flows over and through it at a uniform rate. Modern science, particularly Einsteins theory of relativity, undermines this assumption.(3) Time and space are not absolute; they exist with us, partly because we invest them with reality and meaning. If we define real by what we feel, smell, taste, hear, and see, then real is simply electrical signals interpreted by our brain. The world may exist as part of a neural-interactive simulation, meaning that we might be living in a dream world.

Virtual reality is defined as a cartoon that we can enter; an interactive computer system so fast and intuitive that the computer disappears from our mind and leaves its generated environment as reality; and a computer-synthesized, 3-D environment in which more than one person can engage and manipulate simulated physical elements and interact with human representations or invented creatures.(4) Essentially, it is a hardware system that uses headgear, gloves, and other items to make us feel that we are in a computer program. Its core is a simulation system based on a programmed process that handles all interactions, scripted object actions, simulations of physical laws (real or imaginary), and determines the worlds status. This simulation is a discrete process that is iterated once for each time step or frame. Several systems can be coordinated to create a smooth virtual world.

Is Virtual Reality Possible?

As we are conscious beings, our senses gather data and transmit it to our brain for processing. But we cannot consider this data processing, which is a computers main task. We experience things; computers process data.

Virtual reality appears to go a step further because it creates a reality. Miniature screens in goggles, stereophonic sound in headphones, and a pressure-sensitive glove can create an illusory immersion in another 3-D space. But such informatic technologies still depend upon our sense organs to have any effect. Virtual-reality goggles display moving imagery to the retina, but that information must be transported along the optic nerve to the brains visual cortex. Only the brain can render this bio-information into conscious experience.

Theoretically, a computer can create a desired reality via an electrical stimulation of nerve fibers. The brain can be manipulated to see red by stimulating nerves in our retina, feel tension in our shoulders, and so on. Some say scientists can construct a virtual world that is just as real as the real world. Others disagree, citing two objections: the direct mind“body connection, and the necessity of simulating the entire universe.

The Direct Mind Body Connection: Pressing a finger causes a sensation in that fingera specific, visible location in 3-D spacenot in the brain or mind. But if we swing a numb leg, we feel a tingling sensation along it. This numbness and tingling is caused by a compressed nerve further up the leg, maybe in the knee, while the sensations paradoxically seem to be spread toward the foot. Apparently, the brain receives signals from a particular nerve fiber and imaginatively projects the resulting sensation back to the nerve ending. Since the brain receives only a bundle of nerve fibers bearing pulsed signals from the leg, and no information about where these signals originated, it assumes that they originated in the leg’s nerve endings and projects the sensation to that site. As the mind can be fooled, we can say that it creates a complete, subjective body image and then assigns all bodily sensations to specific locations. Do we press our physical or body-image finger? We press our body-image finger, for this is the finger recognized by the brain. Some people say that such feelings as love and toge-therness cannot be simulated. But they can, for the world we experience exists inside the mind and is projected onto the physical world. Seeing love in a spouse’s eyes is the result of light reflected from his or her eyes, focused onto our eyes’ retinas, and coded electrical signals transmitted from the eyeballs to the brain. Thus the only connection is one mediated by electrical (albeit biological) signals. Whether we have bionic or normal eyes is irrelevant, for what matters is the person behind the eyes, not the eyes’ mere visual apprehension. If a couple is immersed in virtual reality, they can still look into each others’ eyes in exactly the same manner. The same is true for togetherness and other feelings, as well as what our five senses experience. Simulating the Universe: This argument overlooks two points: First, we focus on certain things, relegating everything else to the background. Our optic nerve can be stimulated to ignore what we consider un-important. Second, as our sight and hearing are limited to a narrow spectrum of light and sound, the computer only has to focus on that particular spectrum.

An Interesting Experiment

A Ph.D. project in Manchester involves communicating with a robot located 40 miles from the lab.(6) Sensors in its hand read temperature, pressure, and humidity. When wired to a fast communication net, it sends collected data to a glove worn by an operator in the lab so that he or she can feel what the robot feels. This two-way communication system enables the operator to command the robot to move its hand and touch nearby objects by moving the glove. In one test, the hand touched a hot object and the operator’s hand felt the burn. The operator sees what the robot sees, thanks to two video cameras in the latter’s eyes.

What Would Happen If ? (7)

We can simulate a world. A normal brain stores at least 1018 bits and processes information at about 1015 bits per second.(8) Thus we can make an hour seem like a year. The subject will see changing seasons, solar and lunar movements, and lengthening and shrinking shadows. We know that our program causes these effects, but he believes cause and effect to be operative: Have you not seen how your Lord spread the shadowif He willed He could have made it still thus We have made the sun its guide (25:45). This verse indicates that the sun rises toward noon, and that shadows shrink and then begin to lengthen as the sun declines. The subject is limited by the program. For example, he appears to throw a stone, but only if the computer generates the necessary images and sensations. His action is virtual, as in: You killed them not, but God killed them. You threw them not when you threw, but God threw, that He might test the believers by a fair trial from Him (8:17). Let’s send in a virtual messenger to inform the subject of the programmer’s rules. If he does not obey, he will be punished. For example, we could easily rewrite the program to exclude sunlight. After terminating the program, the programmer could explain and demonstrate the truth of the virtual messenger’s words. The subject would have to accept the programmer’s control of, and his lack of influence upon, his life. This is a lesson for those who struggle with their perception of the physical world and the reality of the unseen spiritual world. Two Qur’anic verses show that such speculations are not so different from the subject’s virtual world: Say: Tell me, if God made night perpetual for you until the Day of Resurrection, who is a god beside God who could bring you light? Will you not then pay heed? (28:71), and: How can you reject faith in God? Seeing that you were without life and He gave you life; then He will cause you to die and will bring you again to life; and to Him you will return? (2:28)

Conclusion

For believers, such advances bring one question to mind: Are we living in a virtual world created by God? Most religions answer yes. Although their goals or understandings may differ, the main point is the same: Our life in this world is only a prelude of what is to come.

Footnotes

1. The Brain Tumor Foundation of Canada. Online at: www.oncolink.upenn.edu.
2. Online at: http://eserver.org/ philosophy and www-groups.dcs.st-and.ac.uk/history, respectively.
3. The Virtual Reality Store. Online at: www.thevrstore.com.
4. http://ksi.cpsc.ucalgary.ca.
5. Christianity, Judaism, and Islam consider this world a testing ground for the eternal life. Buddhism and Hinduism consider it an illusion that must be penetrated to achieve enlightenment.
6. Osman Kocak, Virtual Reality in Medicine (Ph.D. diss., Salford University [Manchester, UK], 1996).
7. Adapted from H. Baki, Virtual Reality (Ph.D. diss., Newcastle University [Newcastle, UK], 1997).
8. Ibid.

In recent years, we have realized that the world’s supplies of coal, gas and oil are limited. Nuclear power has been used as an alternative solution to fossil fuels. However, the use of nuclear power and fossil fuels incurred environmental problems so there is widespread public antipathy. As a result, the popularity of renewable energy has grown during the past twenty years. The World Energy Council estimated that renewable energy sources, such as solar, wind, hydro, wave and bio-mass, met 18% of the world’s energy needs in 1990 (World Energy Council, 1993). Their scenario is that the contribution from renewable energy could increase 30% by 2020.

One of the most promising of the renewable energy sources is the direct conversion of solar energy into electricity by photovoltaic generation. There are many reasons for growing popularity:

1. Photovoltaic generators do not pollute the air and do not leave waste products.

2. Photovoltaic generators are silent during operation.

3. They work effectively even in cloudy weather. They are more efficient at low temperatures.

4. As there are no moving parts, they work reliably for 20-30 years with little maintenance.

5. Solar energy is available everywhere so power can be generated anywhere it is needed. This makes photovoltaic generators attractive in the many places where there is no mains supply.

6. Photovoltaic generators can be planned and installed within a few months in contrast to conventional power stations which take at least five years to become operational.

7. Finally, photovoltaic generators can be located anywhere, such as in the roof or walls of an existing or already planned building, therefore they do no need to use up extra land.

The photovoltaic effect was first observed by Edmund Becquerel in 1839. Much later, in the 1930s, solid state researches developed the first photocells which were used in photographic exposure meters. In 1954, the Bell Telephone Laboratories made crystalline silicon solar cells with a conversion efficiency of 6% which was used in space programs. The market for photovoltaic modules has been growing steadily since; in 1991 it had reached about 50 MW per annum.

Solar Cell

The total radiant power from the sun falling on one square meter of a surface area can be as high as 1000W/m2 on a clear summer’s day and it can fall to 100W/m2 in cloudy conditions. In northern Europe, it seldom exceeds 850W/m2 (Treble F.C., 1993).

The inactive energy, solar energy, can be converted into electrical energy by solar cells. The absorption of light in semiconductors creates additional electrical charge carriers, both electrons and holes equally. If an electric field exists within the semiconductor, the negative electrons and positive holes move in opposite directions and this electrical charge separation results in the creation of a voltage. The movement of the electrical charges creates an electrical current and voltage so both current and voltage are generated simultaneously. This is the photovoltaic effect, the creation of a voltage by the action of light.

The basic way to establish an electric field in a semiconductor is to make a p-n junction. The electric field at the junction attracts electrons from the p-side and forces them to the n-side making it negatively charged. Similarly holes from the n-side are forced to the p-side, making this positively charged. Thus holes are creating a voltage. Figure 1 shows the basic features of a solar cell. The front contact grid is a thin metallic grid on the front surface and the back contact usually covers the whole of the back. This is called an n-on-p cell. Silicon is one of the popular semiconductor in the electronics industry so it is used for solar cells. Most commercial cells have a probable 20% efficiency which is the ratio of the maximum output power to the input power from the sun, but over 25% efficiency has been achieved in the laboratory. The theoretical limit for crystalline silicon cells is about 30% under 1000W/m2 irradiance and 25 °C operating temperature (Hill B., 1995). Solar cells which were made from gallium arsenate have achieved 34.2% efficiency.

Solar cells are fine objects which must be protected from any possible damage. The cells are usually connected in series, in parallel or a combination of both in order to produce necessary power and voltage. A photovoltaic module which is a collection of solar cells was bought about US$4/Wp (US$ per peak watt) in 1995. Modules must be capable of reliable operation for many years. The current target is a lifetimes of 30 years.

Photovoltaic applications

In 1994 the total world sales of photovoltaic modules reached 70 MWp per year. In recent years, photovoltaic modules have found many applications in various sectors. The main applications are given below:

1. Space applications: solar cells were first used to produce electricity for satellites in 1958. Since then, photovoltaic power generation has become an essential energy source in space. Solar cells can operate near or far from sun.

2. Telecommunication: transmitters and repeater stations are often located in distant places such us mountains, islands or deserts. Solar power has proved the cheapest and most reliable power for transmitters and repeater stations.

3. Electricity in villages: the majority of the population of the developing countries, approximately two billion people, live in small villages without electricity. As almost developing countries will find extending the mains grid to a few customers far removed from the mains supply lines too expensive, photovoltaic systems are the obvious, cheaper alternative. A small photovoltaic module with a battery can provide enough power for basic lighting, TV and a small refrigerator for a house. By 1993 more than 10,000 home systems had been installed in Indonesia. In addition, solar home systems had been installed in the Philippines, the Dominican Republic, Columbia, India, Kenya, Mexico, Morocco, Sri Lanka and Zimbabwe by 1993. The average price of a 50 Wp solar home system was about US$500 in 1993. Assume that a 50 Wp solar house system in future will cost about US$250, then 400 million solar home systems will be

installed in the world. The other applications of solar modules in villages are water pumping, irrigation, water purification, street lighting and TV receivers (Lysen E.H., 1994).

4. Grid connected buildings: the solar modules can be fixed on roofs or walls so no additional land is required. The most sensible use of photovoltaic cladding would be on commercial buildings because they need energy during working hours rather than at night. Photovoltaic cladding presently costs about 800m-2 in comparison with marble cladding cost around 1000m-2, granite cladding 800m-2. Photovoltaic cladding gives high-tech images for office blocks at lower cost than marble.

5. Central power stations: photovoltaic power stations have, so far, only been installed for purposes of research. Today, Austria, Germany, Italy, Spain and USA have small stations of this type.

The other applications of photovoltaic systems are pocket calculators, watches, clocks, torches, garden lights, portable radios, battery chargers for boats, caravans, electric cars, toys, railway signals, traffic warning lights, alarm systems, automatic weather stations, military equipment and so on.

Conclusion

The photovoltaic system cannot at present compete with mains electricity. However, early in the next century, when economies of scale are expected to bring about a reduction in manufacturing costs, solar power will be an important energy source.

References

• World Energy Council (1993) Energy for Tomorrow’s World, Kogan Page /St. Martin’s Press.
• Treble F. C. (1993) Solar Energy, The Solar Energy Society, Birmingham.
• Hill B. (1995) ‘Solar Power’, IEE Power Engineering Journal, (August 1995), pp. 175-80. Lysen E.H. (1994) ‘Photovolts for villages’, IEEE Spectrum, 31, (10), pp.34-9.