Animals such as butterflies, turtles, and birds are given the ability to perceive the Earth’s magnetic field and navigate themselves accordingly. Migratory species also benefit from the sun, stars, and even scents in nature as they from one place to another.

Magnetic fields and poles

Modern studies have focused on how animals perceive the Earth’s magnetic field and act accordingly. We need to look closer at the Earth’s “magnetic polar points” to understand how magnetic fields work exactly.

It is important not to confuse geographic and magnetic poles. There is a layer called the “inner core” in the center of our Earth where all substances are in a fluid state, similar to those seen in volcanic eruptions. Volatile and molten elements such as nickel and iron form a magnetic electric field above the Earth. This is also the force that is responsible for causing our compasses to point north. At the center, the Earth’s magnetic field changes due to these fluid substances. That is, our compass does not always show the “true north,” i.e. the exact geographical north.

As of the last decade, the Earth’s magnetic pole has kept moving at a rate of about 55 km per year. The magnetic north pole, found in Canada in 1831, has now shifted 2300 km and approached Siberia. Scientists say that about 780 thousand years ago, today’s southern and northern magnetic poles were exactly the opposite. Although the magnetic poles shift, the Earth’s magnetic field continues to function properly. This is imperative for protecting all life on Earth, as a balanced magnetic field protects our planet from the magnetic effects of solar flares and solar winds.

Effects of polar shift

A new magnetic map of our planet is released every five years due to the fact that our magnetic poles are constantly shifting. This does not affect most people on a daily basis, however it does present a challenge for people and vehicles that rely on a compass. Due to the shift, a difference called “magnetic declination angle” occurs between the magnetic north pole and the geographic north pole. This angle varies according to the location. For example, in Canada the magnetic deflection angle is 13 degrees whereas in Brazil it is 20 degrees. In order to determine their exact location, military and civilian aircraft and ships manually or automatically calculate their location based on the angle of deviation and navigate accordingly. Even if we are not aware, our mobile phones are automatically updated according to this calibration. In physics, the formula known as Lenz’s Law, or a tool called a gaussmeter, can be used to calculate the Earth’s magnetic field.

Cryptochromes

This complex and intricate system affects most animal life on Earth, including birds, insects, and fruit flies. So, if these magnetic poles keep changing how do animals find their way? Most creatures utilize cryptochromes, a type of flavoprotein that affects their body clock.

Cryptochrome (CRY) [1] is found to play a leading role in this regard. Cryptochrome-2, one of the two cryptochrome photoreceptors, has been proven to be instrumental in regulating the daily life rhythm of beings by fine-tuning their body clocks and assisting certain animals such as migratory birds, king butterflies, and fruit flies to navigate their migratory paths accurately.

Years of research conducted by Steven Reppert and his team at the University of Massachusett’s School of Medicine on fruit flies and butterflies revealed the function of cryptochrome-2.

According to the research published in Nature magazine in 2009 [2], Dr. Reppert and his team found that flies could not adjust themselves to a new magnetic field without any form of cryptochrome, but that they could regain their sensitivity to a magnetic field only after cryptochrome-2 production.

During the study, the genetic structure of fruit flies was examined and it was ensured that they produced cryptochrome-2.

Speaking to the BBC, Dr. Reppert emphasized that they developed a system to understand how the perception of the magnetic field works in fruit flies. They sought the answer to the question, if cryptochrome-2 was to be transferred from animals to flies, can these proteins act like magnetic sensors in other forms? They have found out that human beings were the most effective option among all vertebrates to yield cryptochrome for this purpose. Their experiment with butterflies yielded the same results. They observed that flies without cryptochromes did not show any signs of magnetic field detection only until their genetic structure was intervened to produce a human version of the molecule.

In another experiment carried out by scientists, a group of migratory birds had iron nuggets, some of which were magnetized to scramble the Earth’s magnetic field, attached to their feet. It was observed that the birds with magnetized nuggets lost their migration path and the birds with unmagnetized nuggets could navigate as easily as usual.

Of course, birds could not know these exact calculations that many people do not even know. Pathfinding skills are “programmed” into birds before they are born so that even if the magnetic field shifts this wonderful mechanism in animals always delivers them to the right location.

The loggerhead sea turtles

As soon as they hatch on the east coast of Florida, the loggerhead sea turtles, Caretta Carettas, swim into Sargasso Sea, migrate into the North Atlantic Circle, and then subsequently into the Atlantic Ocean. The turtles first swim to the northeast towards Europe, then to the south, and return to North America after spending 5-10 years in this hot and nutrient-rich migratory loop.

Dr. Kenneth Lohmann and his team at the University of North Carolina wanted to observe whether loggerhead sea turtles used regional magnetic fields to find their migration paths. They set up a mechanism in a large water tank that was installed with coils in order to form multiple magnetic fields. 79 newly hatched turtles were then clad in cloth vests with wires connected to a computerized monitoring system and left in the same tank. Juvenile turtles were subjected to magnetic fields equivalent to those that exist at critical points of the North Atlantic Cycle, such as in the north of Florida, off the coast of Portugal, and at the southern end of the cycle. As a result, it was observed that in every magnetic field simulated in the experiment, the turtles begin to swim in the opposite direction. For instance, when the magnetic field in the northeastern part of the loop was applied, the animals headed south. In a real ocean setting, this direction keeps them on the right track and prevents them from entering icy waters and dying of hypothermia.

How do animals do it?

There are several research works documenting that not only birds, but also bats, ants, foxes, deer, and even cows feel magnetic fields.

Animals generally migrate to find more suitable reproductive, feeding and living areas for themselves. It is amazing how they know which way to go as soon as they are born. How do they decide that a place they’ve never been to is most suitable for them? How did they learn those navigational skills?

It is amazing to observe this intricate and interlinked system between the Sun, the Earth, and all the living things in it: while the rays of the Sun are needed for life, the harmful ones among them need to be shielded away from the Earth with a magnetic field, a field which is detected by a protein in animals so they can travel to places to continue their lives.

Human cryptochrome

Cryptochrome proteins are also present in the human body [3]. Cryptochrome-2 is especially functional and is linked more to adjusting biological rhythm rather than perceiving the Earth’s magnetic field.

Dr. Aziz Sancar, Chemistry professor and Nobel Prize winner, observed in his experiments of circadian clocks [4] that the cryptochrome pigment located in the eye, skin, and part of the brain regulated the circadian rhythm of mammals.

Currently, many theories are proposed and experiments are conducted on discovering the extent that human beings can perceive the Earth’s magnetic field.

Meanwhile, the wisdom behind the constant shift in the Earth’s magnetic pole awaits to be revealed.

Notes

1. https://en.wikipedia.org/wiki/Cryptochrome
2. Buchen, Lizzie. “Butterflies’ Migrational Timekeeper Found.” Nature, September 24, 2009.
3. Discovered between 1996 and 1998 in humans by Aziz Sancar and his colleagues, cryptochrome is one of the four genes that set the circadian clock in mice. This protein is also a member of a family of proteins including photolyase, DNA’s repair enzyme, on which Prof. Aziz Sancar has worked throughout his scientific career.
4. Rhythmic behavior and physiological changes that have a 24-hour cycle and regulate the day and night cycles of living beings. 

Further reading

Attenborough, David. 1998. The Life of Birds, Princeton University Press Princeton, New Jersey.

Smart prosthetic hand combines both human and robot control

Zhuang et al. Shared human–robot proportional control of a dexterous myoelectric prosthesis. Nature Machine Intelligence, September 2019.

Holding an object in your hand might seem easy, but it’s actually a very complicated and challenging task; if, for instance, an object starts to slip, you typically have a couple of milliseconds to react. Scientists have been trying new approaches for improved control of robotic hands, particularly for use by amputees. A recent technology was able to combine individual finger control and automation for improved grasping and manipulation by successfully merging the fields of neuroengineering and robotics. This interdisciplinary approach was tested on three amputees and seven non-amputee subjects. The neuroengineers achieved the intended finger movement from muscular activity on the amputee’s stump, allowing for individual finger control of a prosthetic hand, which had never been done before. The robotics team enabled the robotic hand to take hold of objects and maintain contact with them for robust grasping. The amputee first performed a series of hand movements in order to train the algorithm through a machine learning paradigm. This taught the algorithm to decode user intention and translate it into finger movements of the prosthetic hand. Concurrently, sensors placed on the amputee’s stump detected muscular activity, which trained the algorithm to learn which hand movements corresponded to which patterns of muscular activity. Once the user’s intended finger movements were acquired, this information could then be used to control individual fingers on the prosthetic hand. When the user tried to grasp an object, the robotic automation initiated. The algorithm told the prosthetic hand to close its fingers when an object was in contact with sensors on the hand’s surface. This automatic grasping was designed to infer the shape of objects and grasp them based on tactile information alone, without any help of visual signals. The robotic hand has the ability to react within 400 milliseconds, and it is equipped with pressure sensors all along the fingers: it can react and stabilize the object before the brain can actually perceive that the object is slipping. While this promising technology can be used in in several neuro-prosthetic applications such as bionic hand prostheses and brain-to-machine interfaces, there are still many challenges remaining to implement this technology in a commercially available prosthetic hand for amputees. It is currently being tested and improved.

Cats securely bond with people, too

Vitale et al. Attachment bonds between domestic cats and humans. Current Biology, September 2019.

Dogs have long been regarded as man’s best friend. They’re sociable, faithful, and obedient. Cats, on the other hand, are often described as more aloof, mysterious, and independent. But a new study suggests that cats actually bond with their owners in similar ways to how humans and dogs bond with companions. The most established way to study human attachment behavior is to observe an infant’s response to a reunion with their caregiver following a brief absence in a novel environment. When a caregiver returns, secure infants quickly return to relaxed exploration while insecure individuals engage in excessive clinging or avoidance behavior. These tests had been previously run with humans, primates, and dogs; researchers decided to run the same test with cats. 79 kittens and 38 adult cats and their caregivers were recruited. During the test, an adult cat or kitten spent two minutes in a novel room with their caregiver followed by two minutes alone. Then, they had a two-minute reunion. The cats’ responses to seeing their owners again were classified into attachment styles. The results show that cats bond in a way that’s surprisingly similar to infants. In humans, 65% of infants are securely attached to their caregiver and domestic cats and kittens mirrored this, as about 65% of them securely bonded to their people. After the first round of tests, the researchers enrolled half the kittens used in the study in a training and socialization course. The other half served as a control group. Researchers then found the same results, suggesting the training did not have an effect on kittens’ attachment behavior toward their owners. This indicates that once a cat forms a bond, it seems to remain stable over time. This social flexibility may have helped facilitate the success of the species in human homes. It is still not clear what the factors are that shape the caretaker relationship, but it’s likely a miraculous complex mix of genetics, personality, and experience.

An efficient and green way to convert heat into electricity

Zheng et al. Paramagnon drag in high thermoelectric figure of merit Li-doped MnTe. Science Advances, September 2019.

A recent discovery could help scientists to develop more efficient ways to generate electricity from heat that would have been otherwise wasted, such as heat coming from car exhaust, industrial processes, and interplanetary space probes. In principle, magnetic fields can be used to generate electricity. If we move a magnet through a coil or wire, the magnet pushes and pulls electrons that create an electrical current. Magnets themselves don’t have energy, but they can control energy currents through the created magnetic field. The main problem with magnets is that when a magnet is heated up, it loses most of its magnetic properties and becomes a so-called paramagnet. Until this discovery, scientists believed that paramagnets couldn’t be used for generating electricity. In the new study, researchers found a way of designing thermoelectric semiconductors that can convert heat to electricity. The tiny particles in paramagnets, so called paramagnons, ended up producing enough spin to push an electron, for only a billionth of a millionth of a second – apparently long enough to make paramagnets viable energy-harvesters. This breakthrough in the conventional understanding of magnetic properties could lead to more research into how magnets and energy interact to potentially facilitate electricity production from heat that is otherwise wasted and oftentimes harmful to the environment.

Meinecke et al. Turbulent amplification of magnetic fields in laboratory laser-produced shock waves, June 2014, Nature Physics.

A supernova is the explosion of a massive star which releases a burst of radiation that can be as bright as 10 billion suns. Such a massive amount of radiation can shine throughout the entire universe for several light-years. Supernovas are triggered either when the fuel within a star ignites or when a star’s core collapses under extreme gravitational forces. Supernovas have already taught us very important lessons about the history of the universe. For example, these explosions have provided solid evidence that the universe is expanding. Supernovas can also tell us a lot about how old stars die and how new stars are born. When a star goes through a supernova explosion, it leaves behind a skeleton made of expanding dust and gas that scientists call a remnant. These star-remnants spread around space. They might end up on earth or other planets, or they could form the energy source of a new star. Since the best way to understand supernovas is to actually explode a star, researchers recently developed a technique to simulate small-scale supernovas in a lab environment. To do this, scientists used lasers that are 60,000 billion times more powerful than a laser pointer. They focused the laser beams on a thin carbon rod inside a gas-filled chamber. The lasers heated the chamber to over 1 million degrees Celsius, which caused the carbon rod to explode and expand out through the low density gas – just like how exploding stars speed through space. The experiment revealed that as the blast passes through the grid, it becomes irregular and turbulent. They also noticed that the magnetic field was dramatically higher within the grid than without, suggesting that the magnetic field was amplified by the generated turbulence. The supernova system developed in this study holds the possibility of helping us better understand how the universe was formed and evolved, and could provide some insight into how magnetic fields were first created.

Young blood: The fountain of youth?

Villeda SA et al. Young blood reverses age-related impairments in cognitive function and synaptic plasticity in mice. June 2014, Nature Medicine.
Sinha M. et al. Restoring systemic GDF11 levels reverses age-related dysfunction in mouse skeletal muscle. June 2014, Science.

Two recent studies of lab mice showed that transfusions of blood from younger individuals reverse the effects of aging in their elders. One research group showed that neural damage of mice with age-related cognitive impairments could be reversed by such transfusions. Alternatively, injecting the younger plasma into the brain was also very effective at repairing neural damage. Another research group showed that blood from younger mice repaired age-related heart defects in older mice. Researchers further discovered that high levels of the protein GDF11, present in the blood of younger mice, were the key for rejuvenation. Researchers proposed that blood from younger mice contains molecules with anti-aging properties that awaken the stem cells of the brain and heart muscles and thus initiate the rejuvenation. These studies are incredibly encouraging for combating Alzheimer’s disease, heart disease, and many other age-related diseases; however, a comprehensive set of clinical tests needs to be conducted before testing the effects in humans.

“Chameleon” plant discovered

Gianoli E. and Carrasco-Urra F. Leaf mimicry in a climbing plant Protects against herbivory. May 2014, Current Biology.

Scientists thought for many years that camouflage and mimicry were only observed in the animal kingdom. A newly discovered wood vine in Chile, Boquila trifoliolata, has been found to transform its leaves to mimic a variety of host trees. B. trifoliolata is the first plant ever shown to imitate multiple hosts. This is a rare trait called “mimetic polymorphism” and it was only previously observed in butterflies. As B. trifoliolata climbs onto a tree’s branches, it changes the color, size, shape, orientation, and even the vein patterns of its leaves to match the surrounding flora. When the same vine crosses over to a second tree, the size of its leaves can even increase 10 times  to match the second host plant. According to scientists, mimicry may protect the vine from plant-eating herbivores such as weevils and leaf beetles. It is perplexing how a plant can distinguish between individual trees and keep changing its physical characteristics. Odors, chemicals, or microbes that are released form host plants are potential candidate mechanisms for this intriguing plant behavior.

Nanoscience and nanotechnology started off in the early 1980s when scientists were able to detect materials on the nano-level through microscopic systems. This development enabled the synthesis of nano-level materials such as carbon nanotubes, nano crystals, and metal oxide nanoparticles. Nanotechnology is a type of technology, resulting from the research conducted on the atomic, molecular and macromolecular levels. A nanometer is one-billionth of a meter. Nano-level studies are conducted with materials whose sizes range between one to a hundred nanometers. Studies on the nano-level are conducted in the contemporary science fields such as chemistry, materials science, physics, biology, etc. One of the most compelling reasons that renders the research with nano-level materials so significant is that nanoparticles reflect a lot more different characteristics than when they do at the macro-level. Due to their small sizes, nanoparticles, especially those under 20 nm, have magnificent optical, magnetic, and chemical properties.[1] Nanoparticles include much more energy than the macro-level materials; this is because the ratio of the surface area of nanoparticles to their volume is much more bigger than the ratio in macro-level materials. A significant amount of energy is stored in nanoparticles as free surface energy. This energy revealed on the nano-level not only increases the reactivity of iron nanoparticles (the propensity to chemical reactivity), but also renders the magnetic qualities of materials quite differently than they would be at the macro-level.

Many types of nanoparticles are widely used in our daily lives. Iron, gold, silver and cadmium sulphide nanoparticles are some of the most commonly investigated nanoparticles. Yet iron nanoparticles receive special attention from scientists essentially in the field of biotechnology. Iron nanoparticles demonstrating different magnetic features have a wide range of use in fields, including but not limited to health care and electric/electronic industry. Owing to its magnetic feature, iron is also used in magnetic recording. The production of needle-shaped iron nanoparticles with high magnetic features has facilitated the manufacturing of mobile electronic devices with a high recording capacity. In this paper, we will focus on the use of iron nanoparticles’ contribution to the advances in the field of biotechnology, among numerous other contributions of iron nanoparticles in other fields.

Nanobiotechnology

Nanobiotechnology, among other fields of nanotechnology, is the field that focuses on biological systems. Nano-level devices designed to work with biosystems, nano-level cell biology, cell and nanoparticle interactions are some of the applications used in nanobiotechnology. Through those applications, biochemical processes and reactions in living beings can be scrutinized in great detail, which, in turn, enables scholars to come up with innovations in both diagnosis and treatment of various illnesses.

The following are the primary application areas of magnetic nanoparticles in the field of bionanotechnology: development of magnetic resonance imaging systems, and cancer research. Especially, iron oxides (magnetite, Fe3O4, maghemite, Fe2O3), owing to their cohesion with the chemical structure of biological systems, are prevalently used in biotechnology.

Magnetic Resonance Imaging (MRI)

MRI, mostly used in the medical field, is the method to monitor the internal structure of living mechanisms. Through the magnetic area and radio frequency waves, the image of a living tissue is formed. MRI is a complex system that produces images based on the intensity and movements of hydrogen atoms in the tissue. The MRI technique is used to diagnose almost all sorts of illnesses today. Yet it is most frequently used with illnesses pertaining to the central nervous system, brain and spinal cord. It has also been used to diagnose muscle-related and skeleton-related medical conditions, such as meniscus and herniated disc symptoms, as well as all types of neurological illnesses. MRI has not been found detrimental to any living organism thus far.

It is the paramagnetic ions such as gadolinium that are most frequently used as contrast enhancement agents in MRI applications. Although gadolinium has a high moment, this moment is too low compared to superparamagnetic materials. For this reason, superparamagnetic iron oxide nanoparticles are known to be more efficient MRI contrast enhancement agents. Known as such, those iron oxide nanoparticles are quite advantageous over gadolinium. Those nanoparticles can easily be functionalized to interact with biological samples. For example, superparamagnetic nanoparticles, which are not normally taken up by cells efficiently, can do so after being covered with another material (e.g. Dextran) that can ordinarily go into a cell. Thus, MR images of particular tissues could be obtained clearly, which enables us to make more accurate diagnoses and treatments.

Iron oxide nanoparticles are also deemed to be an efficient potential future method in cancer treatment. The results of several studies conducted to fulfill this goal are encouraging.

Iron oxide superparamagnetic nanoparticles are being tested as a method in hyperthermia treatment. Hyperthermia is defined as an abnormally high body temperature, and its treatment is carried out through the removal of certain tissues by increasing its temperature up to (42–46) 0C for 30 minutes. For instance, cancer infected liver tissues are exterminated through the hyperthermia method, which sends biologically activated iron oxide nanoparticles to those infected tissues. Moreover, none of the healthy tissues are damaged during this process. You may find more detailed information in references [1, 2, 4, 6] on how nanoparticles are aptly sent to the cancer infected tissues only while the surrounding healthy tissues remain unaffected by them. Hundreds of researchers carry out experiments and publish their findings on this topic everyday. Yet, further research needs to be done in order to reach solid conclusions.

Iron, which seems to carry greater potential significance than we previously thought, should receive much attention from scholars due to the fact that a chapter (surah) in the Holy Qur’an is entitled “Iron” (Hadeed). The question is, why was a 29-line chapter in the Qur’an is called (Iron) when the word “iron” was only mentioned once throughout the entire chapter.

The chapter “Iron” first begins by drawing the reader’s attention to the attributes and praised names of God. It invites people to believe in God and his messenger Muhammad (peace be upon him) by exalting God as the Almighty, Sovereign, Ruler, One whose existence is without a beginning and an end, Manifest and Hidden. Then, the chapter goes on to encourage believers to donate their wealth for the sake of God, for those who follow the word of God are rewarded with a place in Heaven. It also advises believers never to lose their ardor, while reminding them that even the earth will be resurrected after all has perished. And the wisdom behind the creation of iron is explained as such:

Assuredly We have sent Our Messengers with manifest truths (and clear proofs of their being Messengers), and We have sent down with them the Book and the Balance so that (relations among) humankind may live by equity. And We have sent down iron in [the essence] which is stern might and benefits for humankind, so that God may mark out those who help (the cause of) God and His Messengers, though they do not see Him. Surely God is All-Strong, All-Glorious with irresistible might. (57:25)

This particular verse includes several remarkable points. First, the very use of the phrase “sending down” for iron is so striking that it was also mentioned in [3, 5]. Another perplexing statement is, We sent down iron in [the essence] which is stern might and benefits for humankind, which might pave the way for thought-provoking venues regarding nanotechnology. The verse also indicates that which makes iron so special, its indiscernible or hidden qualities, rather than the outer surface of it. The specific reference to the “essence” of iron hints at this point. If the message of the verse had been related to the external qualities of iron, then the choice of the words would differ accordingly. Since the Qur’an is the word of God, there is wisdom behind the selection and sequencing of each word and letter. From this point of view, we can interpret that this verse informs us about the significance of the essence of iron on the nano level.

The significance of iron as stated in a single verse of the Qur’an has been briefly discussed. Numerous studies on the use of iron in nanotechnology seem to be on the horizon, which will only contribute to our admiration for the miracle of the Qur’an.

Kamil Ezgin is pursuing a PhD degree in chemistry in USA. For correspondence with the author kamilezgin@gmail.com.

References

1. Dale L. Huber. Synthesis, Properties, and Applications of Iron Nanoparticles, small, 2005, 1, No. 5, 482-501.
2. An-Hui Lu, E.L. Salabas, and Ferdi Schuth, Magnetic Nanoparticles: Synthesis, Protection, Functionalization, and Application, Angew. Chem. Int. Ed. 2007, 46, 1222-1244.
3. Edib Masûkî. “Enteresan Bir Tespit: Demirin Sakladiði Sir,” Sizinti, 1985, No. 73.
4. Peter Majewski and Benjamin Thierry. “Functionalized Magnetic Nanoparticles- Synthesis, Properties, and Bio-Applications,” Critical Reviews in Solid State and Materials Sciences, 2007, 32, 203-215.
5. http://www.mergeous.com/bullet.asp?tag=72
6. Volker Mailander and Katharina Landfester, “Interaction of Nanoparticles with Cells,” Biomacromolecules 2009, 10, 2379–2400.

In the early 1970s, a young graduate student, Richard Blakemore, observed an interesting group of bacteria in a mud sample collected from Eel Pond in Massachusetts. These bacteria were migrating through a certain edge of the microscope slide. Rotating the slide did not affect their motion; they were still moving through north. Repeating the experiment in the dark also showed that it was not light that affected the bacteria’s swimming direction. The experiments left one possible explanation to the directed motion of the bacteria and that was a crazy one-that they were sensing the magnetic field of the earth! It wasn’t hard for Blakemore to place a magnet next to the microscope slide and to prove that the crazy idea was indeed true. The bacteria were attracted by the south pole of the magnet and repelled by the north pole of it. This was the beginning of a new field of an interdisciplinary research, which attracted many scientists from very different fields such as, microbiology, physics, geophysics and paleogeology.

To understand how magnetotactic bacteria feel the magnetic field, it would be useful to check one’s transmission electron micrograph (Figure 1). The chain of magnetite (iron oxide) crystals forming a specialized organelle, called magnetesome, can be seen easily. The length of the whole chain is around one micron and each small crystal is around 50-60 nanometers. Each small crystal can be considered as a small magnet. These small magnets are aligned in a way that they support each other and the chain becomes a strong magnet. A lipid bilayer membrane surrounds this chain and holds them together. Forming chains on a straight line is not an expected behavior for small magnetite crystals. If they are produced synthetically, they accumulate together to form an aggregate. The pathways of chain formation in magnetesome are still an open question.

Magnetotactic properties are not limited to a certain species. There are many different bacteria that have magnetotactic properties. Therefore the magnetesomes may differ in size, length and even in chemistry. Some magnetotactic bacteria have greigite (iron sulfide) minerals instead of magnetite. Alsothere are magnetotactic bacteria that have more than one magnetesomes. (Figure –2)

Magnetesomes passively align bacteria parallel to the geomagnetic field but do not exert a force on bacteria to change their speed. Aligned with the magnetic field, the bacteria decide to either move towards south or north. Interestingly, almost all magnetotactic bacteria in northern hemisphere are north seeking, almost all magnetotactic bacteria in southern hemisphere are south seeking, and magnetotactic bacteria living around the geomagnetic equator consist of almost equal number of bacteria of each magnetic polarity. The bacteria in northern and southern hemispheres may have different polarities but they have one thing in common; they both move downwards. The geomagnetic field is not exactly parallel to the earth’s surface except around the geomagnetic equator. As it may seem in figure-3, the magnetic field lines are tilted up and down respectively in southern and northern hemispheres. Therefore the north seeking bacteria in northern hemisphere end up at the bottom of the water and so do the south seeking bacteria in southern hemisphere. Most of the magnetotactic bacteria cannot survive in atmospheric oxygen levels, so sensing vertical position and moving downwards, where oxygen concentration is low, is crucial for them.

Being north seeking or down seeking, i.e. polarity, is a genetic property for magnetotactic bacteria. Almost all progenies (descendants) of a north-seeking cell are also north-seeking cells. However this requires partition of magnetesomes to each daughter cell during the division. Occasionally, daughter cells may have no magnetesomes or they maybe too small to have a magnetic moment, so they develop their own magnetesomes. When these progenies develop their own magnetesomes they may have either polarity. Therefore any natural population of magnetotactic bacteria has less than 0.5% “wrong” polarity members. Wrong is written in quotation marks because without that “mistake” magnetotactic bacteria would live only in one hemisphere of the earth.

Magnetotactic bacteria are not the only creatures that can sense geomagnetic field. For example birds, also, can sense geomagnetic field and find their direction while they are migrating. However, birds use other factors such as sun and the horizon to find their direction and their body is much more complex. Also they do not sense magnetic field in a mechanical way like magnetotactic bacteria do, but probably they have some complex chemical ways of magnetic reception. That is another research field by itself and this article’s volume is not enough to go into it.

Everything, every entity that we see around us calls us to reflect upon their Creator. The ones that we see with electron microscopes or high-tech tools are not exceptions. Magnetotactic bacteria synthesizes magnetite crystals from scratch and then puts them in an order like beads hitched on a string. Could it be possible for them to manage this incredible task on their own accord and without acting in the name of God? To this day we cannot even understand the basic principles of that process to its complete degree in order to mimic it. In fact, the more we understand the more we esteem and at awe we become from the great craft of Supreme Artist.

Auroras (northern lights), with their beautiful colors, make long winter nights more bearable in Arctic Circle. They are emitted by charged particles, something very harmful for living creatures if ever reached to earth’s surface and trapped in earth’s geomagnetic field. (Figure-4) While thinking about magnetotactic bacteria I remember those beautiful scenes I had seen in pictures that had caught my awe and wonder and can’t help but express deep gratitude once more to the Creator and Sustainer of it all, of us all, who guides the tiny little cells to more livable environments with the very same geomagnetic field that He protects us from harmful solar winds. Extraordinary is the ordinaries we are surrounded by!

Ahmet Uysal is a PhD candidate in Physics at Northwestern University, Evanston, IL.

References

1. Richard P. Blakemore, 1982, “Magnetotactic bacteria”. Ann. Rev. Micrbiol. 36:217-238
2. Dirk Schüler, 2008, “Genetics and cell biology of magnetesome formation in magnetotactic bacteria”. FEMS Microbiol. Rev., 32:654-672
3. Arash Komeili, 2007, “Molecular mechanisms of magnetesome formation”. Annu. Rev. Biochem. 76:351-366
4. Thorsten Ritz, Salih Adem, and Klaus Schulten, 2000, “A model for photoreceptor-based magnetoreception in birds”. Biophysical Journal. 78:707-718
5. http://www.birdgeo.com/images/CTE1810.jpg
6. http://solar-center.stanford.edu/images/solar-wind-magfield_b.gif

More than 99% of the matter in the universe is in a state of plasma. The energy that the Sun distributes comes from the core, which is like a blast furnace; here matter is pure energy or is converted to energy. In the core hydrogen atoms are combined and helium is created through nuclear fusion, which occurs at very high temperatures. During nuclear fusion, enormous amounts of energy are emitted. The total capacity of the Sun’s outer layer that emits energy is around 3.86 x 1,026 watts. However, only 1,368 watt per m² comes into the orbit of the Earth. This energy results in the light that we see when we look at the Sun. The core of the Sun is 160 times denser than water on Earth. The temperature in the core is about 15 million °C. If the Sun had not been created at this density and high temperature, such a great amount of energy could not be produced. The energy produced in the core is conveyed to the radiation zone, so called as energy here is conveyed by radiation. The energy produced in the core heats everything while moving to upwards and when it comes close to the outer layer, it loses heat and energy. For instance, there is 1-2 million °C of heat that is dissipated before the end of the radiation zone. At the point where the radiation zone ends, the density of the matter is equal to the density of water on Earth. The energy is conveyed by radiation in the interior part of the Sun, while being conveyed by convection in the outer layer. The source of energy that maintains the light and heat of the Sun is the furnaces at the core. The heat decreases in proportion to the distance from the core. Curiously enough, when moving away from the photosphere (radiation zone) towards the corona, one might think that the temperature in the solar atmosphere should decrease, but in fact it increases. The interior of the corona is almost as hot as the core of the Sun, but the temperature decreases in the outer part of the corona. The cooling process that begins when moving away from the core stops at the corona and the temperature rises from 100,000 °C to 1-5 million °C. Scientists have not yet resolved why the corona has this very high temperature.

The outer layer of the Sun is very stormy. We can compare the events in the outer layer to water boiling in a kettle. This layer is known as the convection zone, which is kept in place by the magnetic field in the corona. The gas pressure in this zone is relatively higher than the magnetic field pressure. Therefore the magnetic field retreats inward and is twisted as a result of the turbulent movements of gas. These movements fulfill the role of enlarging the magnetic field lines of the corona. In the corona, the magnetic field pressure is higher than the gas pressure. It is possible that the extra energy conveyed to the magnetic field is transferred to the plasma in the corona. The energy, in the state of hydromagnetic waves, is squeezed and converted into energy. But we do not know exactly how the energy in the magnetic field is converted to heat in the corona.

The most interesting research topics at the moment are the transfer of energy to the corona and the storage mechanisms for this energy. Matter is heated in the convection zone and expands and rises to the surface. It cools as it rises to the outer layer, becoming denser and then, in a plasma state, sinks down again. This cyclic movement, consisting of a rise and fall, is what is meant by the term “convection.” This movement is conducive to the conveyance of energy from the base of the convection zone to the top. The matter approaching the top cools down and becomes denser here, distributing its energy to the environment. The rising and falling movements of matter in this convection zone are similar to the circular movement observed in water boiling in a kettle. These movements cause the formation of strong magnetic fields in the outer layer of the Sun.
The extremely hot gas in the corona moves away from the Sun. When this hot gas mass heads to the planets it is known as “solar wind.” Solar winds are the officers in charge of changes in the climates of planets. This activity in the solar atmosphere causes atmospheric air currents that bring about snow and rain. There are relatively few magnetic fields in the outer layer of the Sun, while there are a number of magnetic fields in the solar atmosphere. The interplanetary magnetic field is formed as a result of the Sun’s magnetic field. Coronal mass ejections expand away from the Sun at speeds that measure as much as 1,250 miles per second. These blasts carry up to ten billion tons of plasma away from the Sun. It may take a few days for the matter, which covers distance at a speed of 60-600 miles per second, to reach the Earth. Solar flares move at the speed of light and can reach the Earth in eight minutes. If coronal mass ejections reach the atmosphere of the Earth, they can create geomagnetic storms. Auroras (radiation that can be observed in Polar zones) are the atmospheric events related to the coronal mass ejections. Large geomagnetic storms can cause electrical power outages and damage communication satellites.

Astronomers record the xrays that emanate from the Sun in the same way that a doctor records the occurrences of pain in patients. It has been discovered that there is a strong correlation between the density of solar flares and the pains of those who suffer migraines. Even if this correlation is statistically meaningful, more controlled research needs to be carried out to understand if there is any biological significance. The storage of magnetic energy in the solar atmosphere and the ejection of the same, like a sudden explosion, cause solar flares. A solar flare occurs when magnetic energy that has built up in the solar atmosphere is suddenly released. During such an explosion, radiation is emitted across virtually the entire electromagnetic spectrum. The amount of energy released is the equivalent of millions of 100-megaton hydrogen bombs exploding at the same time. Considering how just one hydrogen bomb is enough to destroy the entire world, we must thank the All-Powerful God Who placed the Sun at an ideal distance, protecting us both from freezing and burning. The energy released during a flare is typically to the order of 1027 ergs per second. This energy is ten million times greater than the energy released by a volcanic explosion.

The system in which magnetic fields are produced in the Sun can be the cause of some changes on Earth. For example, between the years of 1600 and 1850s solar activities decreased and low temperatures (a minor ice age) were recorded on Earth, especially in much of Europe and North America. Therefore, solar activity carries out its duty on the order of God and works for the adjustment of climates on Earth. It was determined that the temperature differences measured at 6 miles above the North Pole (in the boundary of troposphere/stratosphere) were related to a eleven-year cycle of sunspot explosions. The stratosphere heat over the Polar zones is relatively less cold when the Sun is active, depending on the stratospheric winds. However, the physical mechanisms have not yet been determined.

How do the planets stay in orbit around the Sun?

There are two hypotheses on this matter: one of them says that the revolving of the planets around the Sun while they are in their or bit is dependent on the movement around the common mass instead of on the force of gravity. The other theory is that the magnetic field forces, which are created as cycles in the core of the Sun, play an important role in interplanetary gravity. The difference between the hypotheses stems from the structure of the orbits in terms of causes. Circular orbit is formed by the force of gravity, while elliptic orbits are the result of common mass movement. Therefore, it would be more sensible to say that while explaining the phenomenon of planets staying in their orbit around the Sun that a role is played by both common mass movement and matter cycles in the core, reminiscent of the oscillations in the core of the Sun, and the magnetic field that is produced. There are a number of verses in the Qur’an about the Sun and the sky. One of these is: “And the Sun runs the course appointed for it for a term to its resting-place for the stability of it(s system)” (Yasin 36:38). Bediüzzaman Said Nursi says, The Sun is a light-diffusing tree, and the planets are its moving fruits. But unlike trees, the Sun is shaken so that the fruits do not fall. If it were not shaken, they would fall and be scattered.¹

The period of the actual rotation of the Sun is approximately 27 days. The active zones of the sunspots can be observed on the side of the Sun that faces the Earth. The Sun’s movement forms an interesting orbit. Although it is not solid (being in a gas and plasma state), the outer layer of the Sun has different speeds of rotation at different latitudes. Scientists have lately started to use acoustic detectors to receive the signals that emanate from the Sun. The acoustic detectors are used to understand the rising and falling wave movements that this noise causes on the surface of the Sun. Scientists are trying to understand how the sound waves behave in an environment made up of other material, such as oil and vinegar, which form a layer in the water, and they then try to decipher the inner structure of the Sun by making analogies with the events that occur within the Sun. The sound waves that are related to events that occur at the center of the Sun vibrate like a spring. Measurements are made by special acoustic detectors and these reflect the cycles within the Sun. The sound that emanates from the interior parts of the Sun is converted into magnetic waves. These magnetic waves always move, in the form of oscillations that first rise above (to the solar atmosphere) then fall down (to the core of the Sun). The movements within the center of the Sun display rhythmic motions, like water in a pool that has been disturbed. Measuring the smallest sound waves that come from the very core of the Sun, Steven Tomczyk (1994) found that the core of the Sun rotates in a way that is similar to the rotation of the Earth. To put it another way, he found out that the rotation at the core of the Sun occurred independently of latitude and depth, unlike movement in the outer layer of the Sun. While explaining the meaning of the word “li mustaqar” (resting-place) in the Qur’an, Nursi refers to this rotation as follows:

Since the All-Wise Maker operates behind the veil of apparent causality, He has tied the planets to the Sun by His law of gravity and causes them to revolve with distinct but regular motions according to His universal wisdom. To produce gravity, He has made the Sun’s movement on its axis an apparent cause. Thus a resting place means that “the Sun moves in the place determined for it for the order and stability of its own (solar) system.” Like the Divine law, that motion produces heat, heat produces force, and force produces gravity.²

Some astronomers compare the Sun to a bell that is periodically struck. They also state that the cycles that occur within the Sun and at the outer layer of the Sun play a role in the formation of magnetic fields, gravity forces, and the common mass center of the Sun. As a result of the interconnectivity of all these factors, how the planets revolve around the Sun while staying firmly in their orbits (without being scattered in terms of causes) can be explained. The existence of this huge star and its continuity in a controlled way is a serious matter, which, even though we often take this miracle for granted, must be contemplated. The fact that the Sun is so vital for us, yet that we have no control over it shows us that this fire ball is in the service of humanity thanks to the order of the Divine Will.

References

• http://hesperia.gsfc.nasa.gov/sftheory/cme.htm
• http://www.ucar.edu/publications/lasers/sun/what-sun.html
• http://athena.wednet.edu/curric/space/sun/sunanat.html

Notes

1. Nursi, The Words, The Light, Inc., NJ: 2005, p. 413. 2. Ibid.

The theory is simple: Cosmic particles coming from outer space continuously collide with stable carbon-12 atoms in CO2 molecules, which are widespread in the atmosphere. Each carbon-12 atom takes up two neutrons and is converted into a radioactive carbon-14 atom. Radioactive carbon-14 atoms rapidly mix and become uniform throughout the atmosphere. Deep oceans, the biosphere, and carbonate rocks are giant reservoirs of carbon and with the addition of the atmosphere they constitute the carbon cycle of the Earth. Within this cycle, radioactive carbon-14 is continuously created and disintegrated. Both processes are in equilibrium. Since the total amount of carbon on the Earth is constant, a constant ratio is established between the amount of stable and radioactive carbon. This same ratio is valid in all the reservoirs of carbon in this giant cycle. In the biosphere, both carbon-14 and carbon-12 atoms are added to the food chain via assimilation; first by plants through photosynthesis and then by animals through consumption of the plants. For an animal or a plant, a carbon-14 atom is no different from a carbon-12 atom in assimilation. Living beings continuously take up both atoms, so the ratio of both atoms in their bodies remains constant throughout their life. When an organism dies, the uptake of exogenous carbon is terminated. After this point, although the amount of carbon-12 remains constant, carbon-14 continues to disintegrate and the ratio starts to decrease after the body dies. Because the ratio after death is related to the time that has passed since death, it is possible to determine the date of death by measuring the amount of radiocarbon present.

The half-life of radiocarbon is 5,730 years. This means that after 5,730 years half of the total amount of radiocarbon in a dead body disintegrates. The remaining half decays in the following 5,730 years and only a quarter of the first amount remains. This goes on until a very minuscule, undetectable amount remains. In bodies less than 50,000 years in age the amount of radiocarbon can be detected. For an older body, the amount of radiocarbon is so small that the instruments would be unable to measure the amount of radiocarbon present. In addition, such a test obviously works only on the remains of things that were once alive, such as bones or wooden parts of an old structure.

But how accurate is an age determined by this method? How dependable is this technique for enlightening us about the past? Although the theory seems quite consistent from a general outlook, one can see it is not the case when analyzed more rigorously.

Archeologists have tried different ways to test the accuracy of the method. The results have revealed long-term and short-term variations from the actual ages. Long-term variations show systematic deviations of the radiocarbon age from the real age; that is as the date of the sample gets older the deviation increases. On the other hand, short-term variations show irregular fluctuations in the radiocarbon age from the real age. These deviations apparently reveal that the assumptions made concerning the radiocarbon technique were not accurate. The results of these important abnormal conclusions in radiocarbon dating were summarized in the Introduction to Prehistoric Archaeology as follows: “for years, it was thought that possible errors could have minor effects, however, recent research shows that the natural concentration of carbon-14 deviates at some certain periods, significantly affecting the calculated ages.”

The method is based on two assumptions that should be examined carefully: Firstly, the method assumes that the ratio of carbon-14 to carbon-12 has remained constant in the atmosphere from the time the body died to the present. However, recent scientific research has proven that this ratio has not remained constant during geological time.

Secondly, the method also assumes that the carbon supply to the organism was made only by the global carbon cycle and no other source of carbon has affected the system.

Initial concerns about the possible sources of error were focused on the constant ratio assumption. So, why did the constant ratio assumption turn out to be incorrect? Actually, many reasons were found to refute the validity of this assumption. The most important ones are explained below:

Changes in the Earth’s magnetic field are believed to be responsible for long-term deviations in radiocarbon dating. By investigating the orientation of magnetic minerals in ancient rocks, geologists have proven that the magnetic field surrounding the Earth has not been constant throughout the time. Today, it is widely accepted that both the strength and direction of the Earth’s magnetic field has changed. Interestingly, these changes are appreciable even within a century. Changes in the geomagnetism affect the radiocarbon production in the upper atmosphere; cosmic rays are deflected according to the strength of the Earth’s magnetic field. If the magnetic field is high, more cosmic rays are deflected away from the Earth and the production of radiocarbon falls. If it is low, production rises. When the production rate changes, a new equilibrium concentration in the carbon cycle as a whole can only be established after a considerable amount of time has passed. The likely time scale for achieving the complete new equilibrium level is about 10,000 years. This is about the same as the age of the sample that is to be dated! The bottom line is that anything that affects the density of cosmic rays reaching the atmosphere will affect the rate of radiocarbon production, thus affecting the ratio.

Short-term changes might be the results of different factors. One of these is the variation in sunspot activity. Sunspots appear as dark places on the surface of the Sun for a short period of time and generate strong geomagnetic storms. Sunspot activity increases the Earth’s magnetic field and leads to a decrease in the radiocarbon production rate. Therefore, again, anything that causes a change in the Earth’s magnetic field will affect this ratio.

Other effects for short-term variations are the changes in the Earth’s climate. It is widely accepted that the amount of carbon in the atmosphere during geological time is strongly related to temperature changes on the Earth. This fact is also key in understanding the global greenhouse effect, which occurs with the release of high amounts of carbon dioxide to the atmosphere by hydrocarbon combustion. The global sea level has also been affected by these climatic changes. During low temperature seasons (ice ages or glacial periods), large ice sheets covered most of the continents and as a result of this, the sea level dropped appreciably. During these periods, a high amount of carbon (as carbon-dioxide) was kept inside glaciers and they became C-14 depleted (dead carbon). By the end of the Ice Age, large amounts of dead carbon had been released into the system and they had decreased the global ratio of radiocarbon.

Actually, three more resources of dead carbon make a negative contribution to the ratio. One of them is the dead carbon that comes up from deep Earth through volcanic eruptions. Radiocarbon dating of an organism that lived in the vicinity of a volcano gives inaccurate results. Because of the expulsion of dead carbon, samples found close to volcanoes have less radiocarbon in their body than others. Consequently, the age determination of these samples gives significantly incorrect results.

As is obvious from the previous examples, the main problem arises in the lack of knowledge about the history of the sample being dated by this method. Another example is when the sample being tested is wood from the inner part of a tree; the radiocarbon method gives an incorrect result in this case. The reason for this is that the innermost part of a tree finishes the carbon cycle before the tree dies. If a sample was made from this part of the tree (it is impossible to know which part of a tree is being used) then the date produced would be greater than its real age.

Even human activity is an important resource for dead carbon. Although only effective since the last century, a high amount of dead carbon in the carbon dioxide has been released into the atmosphere by the burning of fuel. So the ratio of radiocarbon has decreased. Actually, compared to the factors above, this effect has a more profound influence on the application of radiocarbon dating: No recent organic material can be used as a modern standard. Because of this, the zero point of the timescale chosen is to be 1950 AD, as determined by the US National Bureau of Standards for quoting radiocarbon results.

Consequently, the ages determined by the radiocarbon method are not taken seriously by archeologists because of the problems in the basic assumptions upon which the method was established. Occasionally, the radiocarbon method is used to roughly determine whether an object is modern or of considerable antiquity; in essence, it is used as an authenticity test. Even then the answer may not be clear-cut; for example, an old piece of timber could have been carved to produce an authentic looking sculpture!

Radiocarbon dating is an example of how scientific tools should be used carefully to unfold the reality around us. Scientific theories are only poor models of what is happening in reality. The history of science is full of such examples, which sometimes may be misleading if not handled carefully.

Reference

Radiocarbon Dating, Sheridan Bowman, University of California Press, 1990

At first, air seems to be quite simple” gaseous mixture of atoms, ions, and molecules; 78.1 percent nitrogen, 20.8 percent oxygen, and some trace amounts of carbon dioxide, hydrogen, argon, neon, and krypton, just like spice and salt for a meal. So far, nobody has disliked this meal,’ whose mysteries and secrets are revealed upon investigation.

Air as a Light Source

Air is a mirror that illuminates our surroundings. We cannot read a book or a magazine in outer space, for there is no illumination there. Outer space is a vacuum. Since it contains no molecules or atoms off which the sun’s light and heat can reflect, its darkness cannot be pierced. Since the moon has no atmosphere or layer of gaseous matter to scatter the sun’s light beams, its surface is bright but the space just above it is dark. The Creator of the sun and the eye also created the atoms and molecules in the air and put them at our disposal so that we could see.

Now let’s analyze air, since we depend upon it for our very lives. We inhale oxygen with every breath, and once in our body it burns our food and thereby provides the energy for all bodily functions and maintains bodily heat. It exits through the throat, mouth, and teeth in the form of words.

Nitrogen, the largest component of air, dilutes the concentration of oxygen and makes the air we respire more pleasant. Without it, oxygen would be hazardous and irritating to our lungs. Nitrogen also is a natural fertilizer absorbed by soil and passed onto various micro-organisms in the soil and then to plants. As a result, one of our basic nutrition source components is produced: proteins. This flow of nutrition from plants to animals to people is a fascinating example of mutual benefit and co-operation.

Carbon dioxide, another gas, has only a trace (0.03 percent) presence in air. And yet every year, with the help of plants, it is used to synthesize billions of tons of sugar in a process known as photosynthesis. Plant leaves absorb carbon dioxide, the roots absorb water, and when sunlight is added the final product is glucose, the vital food for every living organism.

Oxygen is another by-product. The resulting energy produced by burning glucose enables all bodily cells to function. Photosynthesis stores the energy from the sun as bond energy between carbon atoms in the sugar. Thus the sun is our food source, as the Qur’an points out: And if you ask them who sends down rain from the sky and gives life therewith to Earth after its death, they will reply, Allah!’ Say: Praise be to Allah!’ But most of them do not understand (29:63).

Let’s travel in the atmosphere to learn more about this Divine source of resources. Now we are 10 kms above Earth’s surface. We cannot breathe here, and so must use our oxygen tanks. At 13 kms, we start to feel a great pressure that almost causes our eyes and blood vessels to burst.

The Unfelt Load

The gases forming the air apply a pressure of 1 kg per cm2 on our skin. The resulting air pressure plays the biggest role in the meteorological events, for strong storms and hurricanes occur when there is a 1 percent change in it. All living things live comfortably and unconsciously with this pressure.

As we go higher into the atmosphere, the density of gases and atmospheric pressure decrease. Also, the pressure of our bodily fluids rises (our bodies are 75 percent water) so much so that we might wonder if they will vaporize or rush out of our bodies. The air has a great weight, although we think the opposite. Most of us do not know that air applies a pressure equal to 1 kg on a fingertip-sized part of our bodies. We do not feel such pressure”calculated to equal 15 tons of air”because its Creator balances it with an inner pressure that is equally intense. Any disturbance in this balance threatens human life. This is why people cannot live at high altitudes, why mountaineers experience severe headaches and nosebleeds, and why astronauts have to wear pressurized space suits.

Layers of Atmosphere

Scientists divide the atmosphere into several layers, each of, which is unique in terms of its heat, pressure, humidity, and the events taking place within it. The first layer is the troposphere, which extends as high as 16 kms above sea level. This layer, which features the perfect circulation of air and matter, is the home for such events as rain, snow, and wind. At its upper edge, its temperature can reach -56’C.1

But the Owner of the universe, following His own rules, makes the atmosphere work as a giant water distribution center. Light breezes circulate thousands of tons of water (as clouds) and guide the water to the soil that needs it. Air’s circulation is moderated so perfectly that no area is ever always wet or dry, and even deserts and rainforests receive what they need to survive.

As Earth’s axis has a slant of about 23′, northern countries receive less energy than southern countries. The result of this seeming disparity in energy levels is the efficient flow of hot air to colder areas so that each area has its energy needs met. Hot air forms low pressure systems as it rises, while cold air forms high pressure systems as it sinks. Wind patterns blow cold air to the south and hot air to the north, forming an ideal system that spreads water vapor, as well as heat, energy, and even pollen, throughout the globe according to need. All of this allows the storage of heat at the equator in the form of energy to spread air and wind around the planet”a sort of global heat machine programmed by its Creator to serve life.

Air temperature drops by 0.61’C for every 100 meters increase in altitude.2 When the ascending air goes into troposphere (the kitchen of the atmosphere), its steam condenses into small droplets. Then clouds, a sign of God’s Mercy, start to form. The thin droplets in these clouds transform into separate ice crystals whenever the temperature drops below 0’C, just like a large army, and fall to Earth as snow.

While doing all of this, the air in our lungs and veins helps to weave colorful motifs on each plant’s leaves and blossoms. While bringing rain with clouds, it conveys pollen from one flower to another. On its weak shoulders it carries tons of water as well as airplanes, spreads light and transports heat, and brings sounds of all frequencies to our ears and many different smells to our noses. No mistake is ever made.

In warm weather, air’s lightness and gentle blowing bring subtle and deep meanings to our heart’s ear. Sometimes it assumes the form of a storm, a blizzard, or a tornado that rips apart everything in its path to warn those who do not understand its acts and do not thank God for the blessings it conveys. Through such events, people understand their weakness and turn to their Creator. Those who read and ponder the Book of Universe carefully, especially the page for air, observe such events as Divine indications of truth or warnings that should be heeded.

An Amazing Filter

The troposphere, the atmosphere’s first layer, is 8 kms thick at the poles and 17 kms thick at the equator. Its highest point is around 22 kms. After this comes the stratosphere, which is about 50 kms thick and has a higher temperature. This layer prevents the sun’s high energy radiations from reaching Earth. The ozone layer, which is vital for life on Earth, is located in the stratosphere. Ozone, which filters the sun’s hazardous rays, is a compound made of three oxygen atoms. The ultraviolet rays convert oxygen molecules into ozone by combining with oxygen.

Some human-made chemical products harm the ozone layer and thus enable ultraviolet rays to reach Earth’s surface. One result has been an anomalous increase in cancer rates, as high-energy ultraviolet rays have very short wavelengths and thus can potentially break the bonds of DNA molecules. These waves, if they reach Earth, also heat up Earth’s atmosphere. An increase of 10 C is enough to cause blood and sap to boil.

Thus we can understand the ozone layer’s role in maintaining this very sensitive balance. Those who claim that such perfection is casual are unable to read the signs God sends to His creatures.

A Comparison

To appreciate these blessings, consider the moon: Its diurnal temperature reaches 120’C, while its nocturnal temperature plunges to -150’C. It is a desolate, silent, and dead place constantly afflicted by meteor showers and ultraviolet rays. This does not happen on Earth, because the carbon dioxide and water molecules in its atmosphere absorb the sun’s excess radiation. This limits the temperature rise during the day and preserves heat for the night. The atmosphere screens hazardous radiation from the sun during the day and preserves the temperature at night. This roof’ gives our planet a moderate climate, while other planets suffer from extreme temperatures.

The water in oceans and seas, which cover approximately 75 percent of Earth’s surface, regulates Earth’s climate. It protects the land from the freezing polar climate and from the scorching temperature of the tropics. Land easily radiates the energy absorbed from the sun’s radiation and thereby ensures a moderate climate.

Although the oceans and seas face higher radiation rates, it is hard to raise their temperatures. Millions of solar calories from the sun are needed to raise the water’s temperature by only a couple of degrees Celsius. Also, this water does not cool easily. This resistance to temperature change enables it to regulate the climate and provide water to the land via evaporation. If the land-sea/ocean ratio were lower, Earth would be full of deserts. Given this, how can we not see the plan of the Artist who created the universe with infinite wisdom?

Meteors

The next level, the mesosphere, extends for the next 80 kms.3 It protects Earth from the meteors that used to scare the Vikings. This is vital, for many meteors fall to Earth every day, as Earth’s gravitational pull attracts them. Also known as shooting stars, they disappear when they enter the atmosphere, for the combination of great speed and atmospheric air reduces them to dust. Without this shield, we would face the meteors every day, just as the astronauts who visited the moon discovered. This dust then goes on to form clouds by joining with water particles until a certain density is reached and the resulting mercy of rain falls to Earth according to a physical and mathematical plan.

A Mirror for Radio Waves

Now we come to the ionosphere, which extends for the next 400 kms. Here, all particles have either a negative or a positive electrical charge.

People were astonished when the wireless radio was invented. However, scientists saw a huge problem: Since radio waves must travel on a straight path, and Earth is a sphere, they could travel only 100 kms. But in 1901, England and Canada were able to communicate via wireless radio across the Atlantic ocean because particles in the ionosphere have an electric charge that makes them reflect radio waves coming from Earth back to Earth. The ionosphere was seen to be like a large echo chamber in space.

Thus we see that God took the needs of all centuries into consideration when creating Earth. As our knowledge increases, we discover what He placed there at the time of creation to benefit us at a later date.

Magnetic Shield

Next comes the exosphere, which extends another 2,000 to 3,000 kms. Here, there is almost no air and friction. Molecular collisions gradually decay, and the relative meaning of temperature no longer applies. Thus most satellites are placed in orbit at this layer.

A compass always points north on Earth because of the magnetic field lines. If we follow this direction, we reach the North Pole. Such knowledge enables us to navigate on land, sea, and air quite easily.

The poles are situated at opposite ends of a hypothetical axis passing from the middle of a hypothetical circle forming the equator. But they are only geographical”not magnetic”poles. The magnetic North Pole is located at the edge of the Ellef Ringes islands in northwestern Canada, 1,290 kms south of the geographical North Pole. The magnetic South Pole is located at Adelie Land in Antarctica. There are various explanations, but no solutions, about what causes these magnetic fields. One theory claims that magnetic field lines (Van Allen Belts) surround the Earth because of the hot liquid iron and nickel at its center.

This layer, the seventh, largest, and final layer, functions as a magnetic shield. The magnetosphere consists of belts formed by magnetic densities. The closest belt to Earth is 4,000 kms distant. The second belt is 16,000 kms distant and can effect things up to 30,000 kms distant. These invisible belts catch and prevent dangerous cosmic rays and charged particles from entering the lower levels by changing their direction. Thus these cosmic rays (having the force of atomic bombs) and solar winds (high-energy electron-carrying atoms) do not reach Earth. Before any of the atmosphere’s properties were discovered, the Owner of Earth and the sky told us about the atmosphere’s shielding: And We have made the sky a roof withheld (from them). Yet they turn away from its portents (21:32).

The Balance in the Atmosphere

Atmospheric gases, because of their nature, seek to scatter into space while gravity works to pull them down and keep them. However, a perfect balance ensures that neither development will happen. Using Earth’s mass, radius and gravity, and several other factors, the precise calculations and adjustments that maintain this balance are beyond even the imagination of humanity.

If Earth were closer to the sun, its air would be hotter and these hot gases would rise and leave the atmosphere. If Earth were further away from the sun, they would be pulled down onto Earth’s surface. If gravity were a little more or less than its current value, the same situation would occur. In addition, the incoming heat must be held for some time. This is done by carbon dioxide.

And yet our planet is a warm and lighted home moving rapidly in cold, dark space. In this home, we have everything we need. To appreciate what we have, all we have to do is compare it with the moon. Do those who seek the source of these actions in blind nature or unconscious and unintelligent reason know that they must assume that all lifeless and unconscious particles must have the knowledge of how to create the universe; how to meet every need and action of all parts of existence (especially of humanity), and also have absolute power to make these processes function with complete perfection for all of eternity?

Footnotes

1. www.geog.ouc.bc.ca/physgeog/contents/7b.html.
2. Ibid.
3. www.onlineastronomy.com/astr161/lect/earth/atmosphere.html.

The Process of Discovery

Kamerlingh Omnes, a Dutch physicist dedicated to achieving ultracold refrigeration, opened this field in 1908 by liquefying helium at -452 F (4 K or -269 C).(1) This achievement enabled scientists to cool materials to very low temperatures and study their properties.

Scientists knew that a metal’s resistance fell as the temperature was lowered, but did not know what the limiting value would be when 0 K (the absolute minimum temperature) was approached. In 1911, Omnes began investigating the electrical properties of metals at very low temperatures. Many contemporaries, including Lord Kelvin, believed that resistance eventually would level off to a nonzero value. While passing a current through a very pure mercury wire whose temperature was being steadily lowered, Omnes noticed that its resistance vanished at 4.2K. He remarked: “Mercury passed into a new state, which on account of its extraordinary electrical properties may be called the superconducting state.” This marks the birth of superconductivity.

Scientific and commercial potentials were obvious. A resistance-free metal wire could carry current for a long time without any loss. Omnes tried to determine the amount of such a loss. After letting a superconducting loop run for a year, he determined that there was no significant current loss. He was awarded the Nobel Prize in 1913 for his discovery.

In 1933, Walter Meissner and Robert Ochsenfeld discovered that superconductors are both perfect conductors and perfect diamagnets, for magnetic fields cannot penetrate a superconductor’s interior. When a material is superconducting and a field is applied, the current flowing on the superconductor’s surface generates a magnetic field that cancels the applied field inside the superconductor (the Meissner effect). Since the magnetic field generated inside the superconductor opposes the applied field, superconductors are diamagnetic. This shielding of an applied magnetic field occurs only if the applied field is not very large. Superconductivity is destroyed at a certain point.

Theoretical Progress and Surprises

Theoretical progress was much slower, however, almost as if superconductivity had been discovered too early. The scientific community’s incomplete understanding of quantum mechanics made it impossible to understand the mechanism behind superconductivity. Some phenomenological theories were developed during the 1930s and 1940s, but a clearer picture only began to emerge in 1957.

Three American physicists, John Bardeen, Leon Cooper, and Robert Schriffer, used quantum field theory and many-body physics to develop the BCS theory, which explains superconductivity for elements and some alloys.(2) In essence, the theory states that a superconductor’s electrons condense into a quantum ground state and move together coherently. Pairs of electrons (Cooper pairs)-not single electrons-achieve current transfer. These physicists received the Noble Prize in 1972.

Another milestone came in 1962. Brian Josephson, a Cambridge University graduate student, predicted that an electrical current could flow between two superconductors separated by thin insulating barrier. He made a suitable device (the Josephson Junction) by inserting an insulating material between two superconductors. Sending current through one superconductor, he saw it pass through to the other one. Known as the Josephson effect, it is one of the most important components in superconducting electronics. Josephson was awarded a share of the Nobel Prize in 1973.

In 1986, Alex Miiller and Georg Bednorz of IBM Research Lab (Switzerland) synthesized a ceramic compound that superconducted at 30K (-243C), the highest superconductor temperature ever reached. This compound contained lanthanum, barium, copper, and oxygen. Scientists do not know why it super-conducts, for it insulates at high temperatures and conducts electricity very poorly before it superconducts. Bednorz and Miiller received the Noble Prize in 1987.

This discovery inspired many researchers to combine elements to achieve superconductivity at higher temperatures. In January 1987, researchers at the University of Alabama replaced the lanthanum in the Bednorz-Miiller compound with yttrium and reached a transition temperature (Tc) of 92K. As a result, the much cheaper liquid nitrogen could replace liquid helium as a coolant. By trial-and-error experimentation, a Tc of 138K was reached in a compound consisting of mercury, thallium, barium, calcium, copper, and oxygen.

These new materials all contain layered copper and oxygen planes with other elements in between the crystal structure. Superconductivity occurs on the planes, and the rest of the crystal serves as a charge reservoir. The magnetic field gradually penetrates these new materials (called High Tc superconductors), causing a mixed state between the normal state and the superconducting state.

In 1997, existing theories were shattered when an alloy of gold and indium was used as a superconductor and a magnet. This is expected to have an important effect on magnetic data storage.

The most recent surprise came in November 2000. About 10 years ago, scientists learned that carbon-60 could superconduct at near absolute zero. By expanding the lattice structure, a Tc of 52K was reached. About a month later, the same group reached a Tc of 90K. Many believe that this temperature could reach well over 100K. Carbon-60 is the only material that has reached such high Tcs without having copper and oxygen planes in its structure.

Applications

Superconductors do more than just conduct electricity. Other important functions are as follows:

• The Korean-developed SQUID (Superconducting QUantum Interference Device) can detect magnetic field changes that are 100 billion times smaller than Earth’s minute magnetic field, and uses the most fundamental properties of superconductors and quantum mechanics. Medical researchers use SQUIDs to study the human brain. Systems in which hundreds of SQUIDs are arranged in a helmet-like configuration containing liquid helium are commercially available. These systems detect the magnetic field produced by thousands of neurons. Although neurons produce huge fields when compared to the SQUID’s sensitivity, a magnetically shielded room is required to filter out fields produced by TVs, computers, cars, and so on. In these rooms, external stimulation applied to the patient’s brain enables specialists to locate tumors or other ill-functioning areas by mapping the brain’s functions. The human brain has two types of responses: stimulated and self-generated (spontaneous). By using the SQUID’s fast temporal response, one can locate non-invasively the epileptic loci, which causes some diseases. Alzheimer’s and Parkinson’s research also use SQUIDs at the detection level.

• Magnetic levitation became possible after scientists built superconducting magnets. Since superconductors have no resistance, a small voltage can generate huge currents and, therefore, magnetic fields large enough to float vehicles on these superconducting magnets with almost no friction. In 1999, a train in Japan reached a speed of 343 miles per hour. Japanese researchers are studying the possibility of a mag-lev linear motor car.

• Superconducting magnets have been used extensively in particle accelerators since 1987. Particle physics requires the acceleration of subatomic particles to speeds very close to the speed of light. This necessitates high magnetic fields that, in turn, need high currents-something for which superconductors are ideal. One event that made superconducting better known is probably the American Congress’ cancellation of the multi-billion Superconducting Super Collider (SSC) project in 1993. A European consortium is now pursuing this research field.

•Superconducting wires improve an electric generator’s efficiency by more than 99 percent. In addition, such generators are about half the size of conventional ones. General Electric estimates that there is a potential $20-30 billion global market for superconducting generators. Unfortunately, the high costs of cooling systems rules out using this technology to supply cities with electricity. But the moment sufficiently high Tcs are reached, superconductivity’s impact in this area will be immeasurable.

•Other applications are high-performance and high-capacity electronic filters (currently used in some cellular phone systems); a petaflop-computer (1,000 trillion floating point operations per second-1,000 times faster than today’s computers); mine and submarine detection (the U.S. Navy); and storing energy to enhance power stability (American Superconductor Corp.); satellites; telescopes and other light detection instruments; and Internet routers.

Footnotes

1. F (Fahrenheit): A temperature scale registering water’s freezing point as 32F and boiling point as 212 F at one atmosphere of pressure. K (Kelvin): A unit of absolute temperature equal to 1/273.16 of the absolute temperature of the water’s triple point; equal to one Celsius degree. C (Celsius): A temperature scale registering water’s freezing point as 0 C and boiling point as 100 C under normal atmospheric pressure.
2. Quantum field theory: A body of physical principles that accounts for subatomic phenomena. Quantum many-body physics: The branch of theoretical physics that studies the new collective phenomena or “elementary” constituents of a many-particle system and the underlying quantum mechanics that determines their behavior.

References 

• Clarke, J. “Superconductivity: A Macroscopic Quantum Phenomenon.” Beam Line 30, no. 2 (summer/fall 2000): 41-48.
• Dull, R. W. and H. R. Kerchner. “Applications of Superconductors.” A Teacher’s Guide to Superconductivity for High School Students (1994). Online at:
• www.ornl.gov/reports/m/ornlm3063r1/pt4.html.
• Gunnarsson, O. “C60: The Hole Story.” Nature 1408 (30 Nov. 2000): 528-29.
• http ://superconductors .org
• Tinkham, M. Introduction to Superconductivity. 2d ed. McGraw-Hill Higher Education: 1995.

Birds, class Aves, are the only animals that have feathers. Aves is a large, highly diverse class with 8,600 species of water birds, songbirds, and birds of prey, including huge flightless runners, deep divers, and migratory species that travel thousands of miles each year. Although most birds have similar body structures, taxonomists, those who classify and name things such as animals and plants in groups, use variations in bone structure, muscles, and internal organs to distinguish one order from another. Variations in the shape and structure of the bills, wings, tails, and feet are also useful for classification and identification. Birds inhabit a wide variety of habitats and can be found on all the continents, most islands, and even on the open sea. They also have a wide range of size. The largest birds are the ostriches of Africa, up to 2m tall and weighing 136kg, and the great condors of the Americas, with wingspreads of up to 3m. The smallest known bird is Helena’s humming bird of Cuba, less than 6cm long and weighing less than 4g.

The skeleton system of birds is highly adapted for flight. In spite of its low weight, a bird’s skeleton is extremely strong. Hollow and fused bones are the two main bone types. Most bones` being hollow lessens overall body weight making flight more efficient. The skeleton of a bird is much lighter than any other kind of warm-blooded animal. However, this is achieved at a cost, and the skull of a bird is thin and susceptible to fracturing. Further lightening of the bird`s head has also been made possible by the absence of teeth. The other noticeable feature of a bird’s skull is the size of the eye sockets, to house the large eyes. This is probably because vision is a bird’s most crucial sense. The skeletal structure of the wing is relatively constant among the different species, but the actual shape of the feathers can be quite variable, depending on the flying capabilities of the species concerned. To provide effective thrust, the bones in the wing move together. As the bird’s wing beats downwards, special bones prevent its chest from being crushed. The thrust of the wing articulates with the scapula on each side of the body. The corocaid and the wishbone also provide reinforcement. The chest cavity is reinforced by the unusual structure of the ribs. The ribs have projections, known as incinerate process, which are directed backwards, overlapping each other. These help to provide support, especially in diving birds. In cross section, the wings are honeycombed. During flight, this lightens the load on the pectoral muscles which, attached to the keel of the sternum, may account for half of the birds body weight.

Flight is one of the most outstanding characteristics of birds. A bird’s body is adapted to meet the two major requirements for flight, which are low weight and high power. Unlike other vertebrates a bird has a skeleton that is very light in relation to body size, e.g. a pigeon’s skeleton accounts for only 4.4 per cent of its body weight. Birds have a compact, streamlined body, and the fusion of many of the bones gives the body the rigidity needed for flying. A birds wing bone is thin and hollow, with criss-cross reinforcements on the inside which provide support while adding little weight. Besides the unusual structure of bones, it is the presence of feathers that distinguishes birds from all other creatures that have conquered flight. Feathers are made of dead cells, and become dehydrated and are exceedingly light. Thus, they can be large and form the flight surface of the wings and tail without weighing much and without being susceptible to water or heat loss. Along with keeping a birds body warm, feathers function for flight. The long overlapping contour feathers streamline the body. These feathers form the wings and much of the tail. Wings made of contour feathers have much surface area and little weight. They are well adapted for fanning the air and for gliding on air currents.

The flight of birds is one of the most beautiful and wonderful things in nature. The make and arrangement of their feathers and bones, and their stream-lined shapes, from beak to tail, are instances of purposive adaptation. They soar with outstretched wings; they dart with folded wings. Their upward and downward mobility, as well as their stability in the air, and when they rest on their feet, have given many ideas to man in the science and art of aeronautics, But who taught or gave to birds this wonderful adaptation? None but God, Whose infinite Mercy provides for every creature just those conditions which are best adapted for its life. This is stated in a verse in the Qur’an (Mulk, 67.19):

Do they not observe the birds above them, spreading their wings and folding them in? None can uphold them except (God) Most Gracious: truly it is He that watches over all things. 

Flying techniques depend on the principles of aerodynamics. Reducing air pressure and friction against the body requires perfect aerodynamic structure. Up to recent times, a rain drop was accepted as the most perfect aerodynamic shape. However, the shape of a bird’s body is now accepted as the most perfect, and aircraft are designed according to the aerodynamic structure of birds. Compared with birds, the latest aircraft are still clumsier and have less agility than birds. Moreover, hypoxia, which is a deficiency of oxygen and results in drowsiness, mental fugitive, headache, and sometimes euphoria, affects pilots severely and can cause them to lose their consciousness on flying upward. But this is not a hindrance for birds because the air between their feathers, their bodies and wings is absorbing and reducing air pressure, Along with this ability, there are some movements which birds can do easily, such as turning sharply, doing somersaults, steep ascents and descents, whereas manmade flying machines face some serious risks in attempting the same movements. Birds can also glide for long periods without beating their wings while aeroplanes cannot sustain flight with stopped engines. Vertical take off and landing is something many flying animals such as bees and birds have been able to do for millions of years. The structure of birds has inspired engineers to design specific modifications in recent models of aircraft, such as the F-14, F-18, and M1G-25, It is true that producing an aircraft requires complex skills and knowledge, improved steadily over a long time. But is it not marvellous that birds have been demonstrating perfect flight for millions of years?

Birds have become adapted to a variety of environments, and various species have very different types of beaks, feet, wings, tails, and behavioural patterns. Although all birds must eat frequently (because they do not store much and yet must maintain a very high metabolic rate), their choice of food varies widely among species-seeds, fruits, worms, molluscs, rodents, rabbits, fish, snakes, lizards, even dead animals. The shape of the bills reflects the birds feeding habits. For example, nectar-feeders have narrow, pointed bills; finches, which consume large quantities of seed, have short, stout bills; and birds that eat insects and berries have a non-specific bill shape and so on.

Birds also lack teeth and this probably reduces body weight for flight. Instead of teeth, their mouths are modified into bills. In addition to this modification, birds have another adaptation for digesting food. A bird swallows small bits of gravel, which act as teeth in the gizzard, mechanically breaking down food. An interesting feature of the bird’s digestive system is the crop, an expanded, sack-like portion of the digestive tract below the oesophagus, in which food is temporarily stored, and where food such as hard seeds is softened with mucus. As a storage organ, the crop allows the bird to feed rapidly and to store large amounts of food. The bird also produces a white secretion, sometimes called crop milk’, which is rich in proteins and fats, and birds use this secretion to feed their young. Birds (except for the ostrich) do not possess a bladder, and so the uric acid passes directly, through the uretors, to the cloaca. After reabsorbing water back into the bird’s body, uric acid is excreted in the form of a semi-solid, whitish concentrate.

Birds often build up high concentrations in their bodies because they consume salty foods or sea water and lose water through evaporation in the urine and feces. To rid themselves of this excess salt, these animals have salt glands, special secretary organs near the eye or in the tongue that remove excess salt from the blood and secrete it in a solution of tear-like drops. Sensors in the wall of a bird’s heart apparently monitor the osmotic pressure of the blood and send nerve signals to the brain that trigger activation of the salt glands. Thus, the animal can drink sea water and yet, by excreting some of the water and all the salts, achieve a net water gain. This is an adaptive mechanism that helps to maintain a light body weight.

Birds have a well-developed nervous system with a brain. They rely heavily on vision; their eyes are proportionately larger than those of other vertebrates. Hearing is also well developed, in striking contrast to most animals, birds have developed the voice. The spoken word in human speech is different from the means of communication which birds have between each other. But no man can doubt that they have means of communication with each other, if he only observes the orderly flight of migratory birds which live in communities. This is also stated in the sacred book, Qur’an (al-Naml. 27.16):

And Solomon was David’s heir. He said: ‘O ye people! We have been taught the speech of Birds, and on us has been bestowed (a little) of all things.’ this is indeed Grace manifest (from God.)

Most birds have short simple calls that signal danger, or that influence feeding, flocking, or interaction between parent and young. Songs are usually more complex than calls and are performed mainly by males; they are related to reproduction, attracting and keeping a mate, claiming and defending territory.

Birds have a special system of air sacs that make fresh air almost continuously available to the sites of gas exchange. This provides the animal with the large quantities of oxygen needed for long distance, high- altitude flights — even a flight over Mt. Everest. A bird’s many air sacs also lower the body weight relative to its size. Air sacs lying between certain flight muscles are squeezed and relaxed on each stroke of the wing and this helps increase the amount of air during inhalation and exhalation. The faster the bird flies, the more rapid is the circulation of air through the lungs.

The paired lungs are relatively small and nine or more hollow air sacs are attached to the lungs and fill much of the body cavity. They are like balloons that lighten the body and serve as reservoirs for air that will later be needed. Experiments show that air flows continuously during both inhalation and exhalation, in one direction through the lungs, and the air is renewed during each inspiration. Therefore, oxygen and carbon dioxide exchange occurs in the lungs’ air capillaries during both inhalation and exhalation. The direction of blood flow in the lungs is opposite to the that of air flow through the parabrocni, tiny, thin-walled ducts in the lungs. This counter current flow increases the amount of oxygen that enters the blood.

This system enables birds to do the intense work of flying, even at high altitudes, and still maintain a high body temperature. Interestingly enough, rapid breathing also contributes to such a high performance; a Venezuela hummingbird, the sparkling violet ear, breathes 330 times per minute at sea level and 380 times per minute at high altitudes. This is a very high heart beat such as no other warm-blooded animal can accomplish.

The very effective respiratory and circulatory systems provide enough oxygen to the cells to permit a high metabolic rate. This is another important adaptation of birds: the maintenance of a high and constant body temperature in spite of changes in the external environment. High metabolic rate is necessary for the tremendous muscular activity required for flying. Some of the heat generated by metabolic activities is used to maintain a constant body temperature (between 35 and 42 degrees C) which permits birds to remain active in cold climates. Birds are among very few animals able to maintain a constant body temperature. Though birds are sometimes called warm-blooded, the preferred term is homeothermic.

One of the most interesting types of behaviour in birds is migration. Migration is the instinctive movement of animals, usually between their wintering grounds and their breeding grounds. Migration provides birds a better chance of surviving. By instinct, migrating birds make their long journeys each year to reach more favourable habitats. Some birds, such as the golden plover and arctic tern, fly from Alaska to Patagonia, South America, and back each year, flying 25,000km en route.

Migration is probably set in by several external stimuli, such as temperature and length of daylight. It is also triggered by the secretion of hormones. For many species the direction of migration is probably based on such factors as the bird’s observation of the sun and stars and even by the earth’s magnetic field. Few modern biological discoveries have been more surprising than the finding, in the 1970s, that bird’s, bacteria, and perhaps many other types of organisms orient their bodies to the earth’s magnetic field, How such animals can have acquired this magnificent ability is a question yet to be answered. How can living things perceive a force as elusive as magnetism?

Many birds and at least one mammal-the porpoise-have a small number of tiny crystals of magnetite (a form of iron oxide) in tissues near the brain. Likewise, magnetobacteria, have magnetite crystals in their cytoplasm and swim toward or away from the poles of an applied magnetic field. How some higher organisms use magnetic particles to sense the direction of the lines of magnetic force generated by the earth’s core remains a subject of research. One hypothesis suggests that the crystals in, for example, a pigeons head, function like tiny compass needless, and mechanoreceptors might detect their relative movement. Other work indicates that in the rat, changes in magnetic yield can alter enzyme activity and levels of melatonin in the pineal gland. Still other work suggests that regularly arrayed layers (also present in pineal glands) undergo certain changes as the head and eyes move relative to the earth’s magnetic field. They could allow the animal to sense magnetic fields, but not by a mechanoreceptor mechanism. Whatever the mechanisms, homing, migration and many other directional animal behaviours depend on detecting magnetic fields.

Birds with their perfect features are wonders in nature to be marvelled at as such. All creation, both animate and inanimate, celebrates Gods praise and bears witness to His power, wisdom and goodness. We can aspire to true knowledge of God through observing the wonders in nature. However, this is possible only if people do not insist on their positivistic viewpoint and see the direct manifestations of God’s Names in His creation:

The seven heavens and the earth, and all beings therein, declare His glory: There is not a thing but celebrates His praise. And yet you understand not how they declare His glory! Truly, He is Off-Forbearing,’ Most Forgiving! (Bani Israll. 17.44)