Biological clock

We get used to waking up every morning so much that we do not really think about what happens in our bodies during the waking up process. However during that period a miraculous alarm clock system takes action and wakes us up.

That is because Allah created our body with a clock, that can detect the sense of time. A body clock that ensures regulating the body activities such as sleeping, feeding, blood pressure and body temperature on a daily basis. Scientists name this clock hidden deep inside our bodies as “biological clock.”

Our biological clock is set up perfectly and operates perfectly.

There is a striking resemblance between our wristwatch and our biological clock. They both complete their rhythms in 24 hours.

The level of energy we will need in the morning, at noon, in the evening and at night changes. Allah created that biological clock to ensure our body operates with an appropriate tempo for our duties.

Thus our organs sense the time and operate accordingly. For example, with the help of biological clock our body senses that it is the morning already and wakes us up and even if you forget the meal time the hunger feeling will wake you up inviting you to eat. (Harun Yahya, The Miracle of Human Creation)

The biological clock is like a best friend following you like a shadow and making the necessary adjustments according to your current environment. In reality this friend is a complex system made up of cells inside you and oversees you as a transfiguration of Allah’s name the Compassionate.

How does the Biological clock function?

The biological clock is captained by a main clock in the brain. Aside from this main clock there are various peripheral clocks in our organs that only influence the concerned organ. Managed by the main clock, those peripheral clocks exist in organs such as kidneys, lungs, liver and veins. These play an important role in maintaining the overall balance of the body. The biological clock coordinates the operating rhythms of organs to provide a harmonious functioning inside the body. Biological clock has three important functions. Each phase being a miracle, those functions are as follows:

1. Perception of outside stimulus

2. Formation of the 24 hour rhythm

3. Arrangement of all clocks according to this rhythm

1. Perception of outside stimulus

Imagine if you felt sleepy after the sunrise and you had to sleep during the day, how would your life change? You would have to carry out your duties during the night-time. Bestowing countless blessings to people, Allah created the day and night in the most appropriate way for mankind as well. In a Qur’anic verse, Allah ordered as follows:


It is He Who appointed the night for you, so that you could rest in it, and the day for seeing. There are certainly Signs in that for people who listen. (Surah Yunus, 67)

Without a doubt the most striking fact about the biological clock is that it provides our organs in pitch dark to perceive whether it is the day or night outside. The main clock in the brain constantly tracks the light intensity outside and informs the other organs about it. Like you checking your clock and seeing what the time is, your body is checking the main clock in your brain to perceive what the time is. In reality in your brain there exist neither hands nor pointers, nor do your organs have the eyes to see those if they did exist. The biological clock is a miraculous system that demonstrates Allah’s unmatched creation. The main clock in our brain is a miracle both in terms of structure and function. It is formed by two nuclei (nerve cell heaps). Nuclei that are positioned symmetrically on the right and left side of the brain are approximately one fourth of a millimeter. The positions of those nuclei are set specifically for the function they perform; they are positioned just about 3 centimeters at the back our eyes, the optic nerves from the right and left eyes cross each other in an intersection at that point. Nuclei are just above this intersection and are connected in a special well to the intersection.

The main clock gets instant information about light conditions outside with the help of this road and intersection network. Information reaching the main clock occurs as follows: the light particles that fall on retina are transformed into electrical signals by the light sensitive cells there. Later, those signals are transferred both to the visual center and the nuclei. Thus, the nuclei, the main clock can perceive the clock outside instantly, second by second. That is the main control center of the biological clock.

2. Formation of the 24 hour rhythm

The rhythm of the biological clock is set exactly according to a day or 24 hours. The systems in our body function with a rhythm repeated every 24 hours. Researches on the nerve cells which form the main clock inside the brain demonstrate that this rhythm is formed by two special molecules produced in those cells. Molecules named Per and Cry is produced in a certain amount and later disappears by breaking up. The timeframe of molecule production signifies the daytime and the breaking up signifies the nighttime. Namely, the main clock in our brain interprets the molecule production as a sign of daytime and breaking up as a sign of nighttime. During the production a fast tempo is produced and during the breakdown a slow working tempo is formed. When the breakdown of molecules one by one during the night is complete, it is considered a signal and the production is started again. And the cells start functioning with a fast tempo as if it perceives it is daytime already. In this way the day and night rhythms are formed in the main clock inside our brain.

3. Arrangement of all clocks according to this rhythm

Per and Cry molecules are just produced in the main clock inside the brain, so the main rhythm is set there. The main clock in our brain starts getting the light signals from the eyes with the sunrise early in the morning. Even if we are sleeping and our eyes are closed when the intensity of the light reaches to a certain point our retina is stimulated. The light particles that fall on nerve nodes on retina run across a protein there specially created by Allah. The protein named Melanopsin is a light sensitive protein and senses the light and maintains the formation of electrical signals.  Those signals are transmitted to nuclei in hypothalamus, namely the main clock. The cells in nuclei sense the light and come to learn that day time started. Once the main clock cells get that signal, they spread signals to whole body to inform the body about the day time beginning. By this, many of the body systems are stimulated . Cognitive system is stimulated, your attention sharpens slowly. The absence of mind when you wake up is caused by this transition period.

The endocrine system is stimulated; the synthesis of hormones that the body needs begins. The immune system is stimulated, and that is why the effectiveness of the drugs you take differs during the day. Heart and vein systems are stimulated: The balance of substances blood carries are regulated, inter cell enzymes are produced. All those adjustments suited for daily conditions continue.  Thats why in a dark and dusky environment you can feel sleepy during the day time. For 24 hours the light intensity outside is sensed by the main clock, like an orchestra chef the main clock manages other clocks to protect the harmony of the body.  Us being unaware of all those changes, wake up in the morning, get ready and leave the house..

No wonder, Allah the Almighty orders the cells which can’t be seen by the eye to function like a clock and perfectly coordinates our body again and again every morning. In a Qur’an verse it is ordered as follows:

Truly Allah, He is the Provider, the Possessor of Strength, the Sure. (Adh-Dhariyat, 58)

It is He Who made the night a cloak for you and sleep a rest, and He made the day a time for rising. ( Al-Furqan,47)


The most obvious indicator of how the biological clock sets up our body to the external environment is the “Jet lag” that occurs in people travelling by air. When a person living in İstanbul goes to the West America, he goes 10 hours back in a day.

For example if this person took off from İstanbul at 5 p.m, when he arrives in California it will be 5 a.m. However this persons’ body woke up in İstanbul, and passed the morning and the noon in the rhythm that he is always used to.   

However, when this person deplanes in America his eyes perceive a different light. In a flash a change occurs between his body clock and the clock of the city he is in. This leads to a 10 hours of extension in the day time In America. The body of the person orders to sleep according to the body clock. But his eyes continue to perceive light because of the light in the environment and sends “stay awake” message.

The disharmony between the body clock and the main clock requires staying in America several days.  Until the systems are in harmony again, the person will be sleepless and uncomfortable. The “Jet Lag” displays how a big blessing the biological clock is. If there were no biological clock in our body there would be no harmony between our body and our daily life.

Norman Ruby who carried out an important invention on biological clock research, evaluates this as “If there were no biological clock it would be impossible to have an uninterrupted sleep. And the time when our body will go into sleep or will become active and awake wouldn’t be certain beforehand.

In research published in December 2002, Norman Ruby has proved the relationship between the biological clock and the “melanopsin” molecule in the Retina. This discovery was shown as one of the most important discoveries of the year by the famous Science magazine.

Bruce O’Hara is another scientist who played a role in the research. He comments “If there would be no biological clock many behavioral and physiological disorders would ocur and even the preservation of the body’s heat would be impossible. (

Think about it, during the day all of a sudden you would feel cold, or suddenly you would fall asleep,  or your blood pressure can rise and you can experience many other illnesses and discomforts.  However, because of the biological clock created by Allah in our bodies we are carry on our daily works in a healthy way.

We should praise and thank Allah for this blessing and health. This is mentioned in a verse in the Quran:


It is He Who has created hearing, sight and hearts for you. What little thanks you show! (Surat al-Muminun, 78)

As seen, the biological clock is a rhythm regulated for 24 hours, and programmed specially. Scientists have demonstrated that the 24 hours of circle of sleep-wakefulness continues in people isolated from external stimulants also. Moreover it is understood that the main clock cells in the brain perpetuated in a dark environment in a laboratory also shows this 24 hours rhythm.

In a scientific resource it is explained “In the last 50 years time this fact has emerged that “The nature of life of 24 hours, is not only consisted of the compulsion of the changes in the physical environment because of the worlds movement in 24 hours, but it is the result of the inner time harmony system in the brain. (

Another fact that needs attention is that, this programming is mentioned to us in the Quran. Allah mentions in the Quran that He created man according to rest at night and to work at day time:

It is He Who made the night a cloak for you and sleep a rest, and He made the day a time for rising. ( Al-Furqan,47)

Despite the advanced technologies all over the world, and with all the scientists coming together, they cannot make a similar biological clock that the great Allah has created for us in our bodies.

2010-10-10 11:26:49

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