The teeth of a tiny mollusk (Patella vulgata), which is a species of sea snails, have been found to be some of the strongest biomaterials in the world. Also known as limpets, these mollusks are a very small crustacean, often around 0.05-2 cm in size with a large cone shell and possess an incredibly complex system of teeth that dazzles the mind.

Research has revealed that the tensile strength of the sea snail’s teeth is higher than that of spider silk and is comparable to only the strongest commercial carbon fibers. It was found that the teeth of sea snails scraping algae off of rocks showed a tensile strength between 3 and 6.5 GPa (gigapascals). Spider silk roughly reaches a tensile strength of about only 1.3 Gpa. Scientists say that the snail’s teeth can even withstand the pressure that turns carbon into diamonds. Studies have determined that, to our current knowledge, there is no other material of this size (roughly 100 μm micrometers) with as much strength and durability.

This exceptional durability has led scientists to do research on the structure and functioning of these teeth, and the studies showed fascinating results.

The role of teeth in nutrition

Sea snails have a special tongue, called a radula, which they use to scrape off food from rocks. The most important feature of the radula is that it contains more than 100 rows of iron-mineral teeth. However, those used for food intake consist of only 10 rows on the outermost part of the teeth. During eating, a tremendous mechanism operates: the teeth are constantly repositioned according to their conditions of maturation and wear. Worn teeth are replaced by newly matured teeth over the course of 12 to 48 hours to ensure that fresh, sharp teeth are used instead of dulled ones.

This wonderful displacement system operates in a similar way to the movement mechanism on a conveyor belt where the teeth begin to grow primarily in the posterior part of the radula. Meanwhile, they are strengthened and matured by iron mineralization. When this mineralization is complete, they are moved towards the front of the radula. In this way, completely matured teeth are permanently retained at the far-front scraping area. During the scraping process, the matured teeth wear out at a rate equal to the growth rate. In the meantime, a new set of teeth begins to grow. By means of this magnificent cycle, new teeth are constantly created and matured so that there are no disruptions in nutrition.

Biomineralization

The structure of the sea snail’s teeth is also a masterpiece of material science. The dazzling durability of its structure provides optimum strength when scraping food off of rock surfaces.

Although the exact process of biomineralization of the teeth is not known, it is believed that it involves reactions of dissolution and re-precipitation. When the non-mineralized matrix is examined, well-arranged and densely packed chitin fibers are observed that are only a few nanometers apart. The matrix is a structure which keeps the reinforcing material together in layers that are composed of different materials. This organic matrix serves as a framework for crystallization in the structure of the teeth. In the mineralization system, the basic macromolecule α-chitin component is created first. The first mineral that then precipitates is the “goethite,” i.e. the aqueous iron-oxide mineral, which crystallizes parallel to the chitin fibers. These crystals are nucleated on the chitin fibers and formed between them by pushing and pulling the fibers. This way, crystals placed in order cause biomineralization of the structure.

It was found that 80% of the overall volume of the structure is composed of these crystals. The gap between the crystals and the chitin matrix is filled with amorphous silica (SiO₂). The iron contained in the aqueous iron-oxide mineral is the metal that constitutes the largest proportion of the composition. Other metals such as sodium, potassium, calcium, and copper are present in different proportions depending on the sea snail’s exact geographic location.

Critical factors in durability

The most important reason that the sea snail’s teeth have such high durability is because the fibers of the aqueous iron-oxide minerals in the teeth are nano-scale. This is due to the fact that materials of this size are not affected by the conditions that reduce strength.

Another critical durability factor is the small length of critical fibers. Critical fiber length is a parameter that defines the length of a material required to transfer strain from the matrix to the fibers at the time of external pressure. To achieve maximum strain, the length must be greater than the critical length. Materials with a large critical fiber length can hardly reinforce the matrix because most of the strain is not transferred to the fibers and remains on the matrix. On the contrary, materials with smaller critical lengths can transfer the strain on the matrix to the fibers. Therefore, they serve as an effective reinforcement for the matrix.

Fibers of aqueous iron-oxide minerals are of a critical length of 420 to 800 nanometers. This is much smaller than the length of the fibers in the teeth of about 3.1 µm (micrometers). This shows that nanofibers are an effective reinforcer for the matrix and contribute greatly to the ability of the teeth to bear loads.

Besides the structure and composition of the snail’s teeth, its morphological shape is also important in providing strength. It ensures that the strain is evenly distributed all over the tooth.

Modeling of biomaterials

All these studies indicate the presence of high-strength composites, which is when a material obtained by combining two or more materials with different physical characteristics, in nature.

Sea snail teeth, which have been created as a highly resistant and strong biomaterial, act as an inspiration for engineering and material science. Their characteristics, such as content and design, are expected to be modeled in areas that require durability and rigidity.

These marvelous systems found in the natural world, sometimes in creatures as tiny as a snail or mollusk, serve as a reminder that nature is filled with wonders for us to explore.

References

· Barber, Asa H., Dun Lu ve Nicola M. Pugno, Extreme Strength Observed in Limpet Teeth,  Journal of The Royal Society Interface, April 2015, DOI: 10.1098/rsif.2014.1326, PubMed.

· World’s Strongest Natural Material Discovered, How It Works, Imagine Publishing, No. 71, p. 11.

· en.wikipedia.org/wiki/Limpet
www.iflscience.com/plants-and-animals/worlds-strongest-natural-material-limpet-teeth/

· www.newworldencyclopedia.org/entry/Limpet

· Barber Asa H., Lu Dun and Pugno Nicola M. “Extreme strength observed in limpet teeth.” 12. J.R. Soc. Interface. http://doi.org/10.1098/rsif.2014.1326

Educators have identified some skills that are necessary for students to succeed in their lives – these are called 21st century skills (Partnership for 21st Century Skills, 2008). In the age of innovation and information, certain skills such as critical thinking, problem solving, communication, innovation, and technological proficiency are vital for succeeding in the new workforce, yet many countries have not yet utilized their resources to teach and assess these skills. It is believed that if countries fully understood the link between students developing these skills and the future of their economies, these countries would invest and develop ways to foster the aforementioned skills in their students.

Due to this, educational researchers have proposed that it is an economic and social imperative for everybody to work towards ensuring the next generation will be eQuipped with 21st century skills (Triling – Fadel, 2009; National Research Council, 2010). In this article, I will discuss some of the 21st century skills, their importance, and whether these skills are enough for today’s students to succeed in the workforce and be happy in their social lives.

21st century skills

Due to increased globalization and access to technology, new skills are needed to succeed in the workforce. Educators, government officials, and business people were asked about what these 21st century skills” entailed. I’m going to address some of their most common answers.

Jerald (2009) justified and explained what skills our students need in this age – and why they need them. He believes we need a generation with newer skills due to changes in automation, globalization, workplace, demographics, and personal risk and responsibility. Computer technology in manufacturing has led to the automation of many jobs that humans once performed better, faster, and cheaper than machines. Technological and political changes as well as competitive forces have caused economies to be globalized. Together, these factors have changed how businesses operate. There is less hierarchy and supervision, and greater autonomy and personal responsibility for workers. Also, the global economy and ever-changing technology create a mobile population; thus, the population demographics of many countries are changing. As a result, individual risk and responsibility have increased. The skills defined as imperative for the 21st century have some commonalities, and they include reading literacy, mathematical literacy, scientific literacy, communication and collaboration, critical thinking and problem solving, and creativity (Jerald, 2009; Pacific Policy Research Center, 2010). I want to look at each of these skills in detail.

Reading literacy: Reading literacy is more about reading to learn rather than learning to read (Jerald, 2009). It is expected that employees are able to decipher many kinds of documents to carry out all kinds of tasks. This task may change from getting a driver’s license to voting in an election to learning how to run new eQuipment. There are a number of national and international assessments that examine teenage and adult literacy. For example, the PISA reading literacy assessment measures students with reading charts, graphs, tables, maps, diagrams, forms, information sheets, advertisements, political flyers, vouchers, and myriad different certificates. Research supports the importance of strong literacy. Adults with stronger literacy skills are more likely to be employed, paid higher, and to have better jobs. Therefore, both individual and organizational success is highly dependent upon a high level of literacy.

Mathematical literacy: Mathematical literacy is sometimes called Quantitative literacy or numeracy.” This implies something other than what students do in a classroom, like answering a multiple-choice Question or solving a test Question. Jerald (2009) says it’s possible that even highly educated people cannot be successful in understanding real life Quantitative information, such as understanding credit card offers or comparing the cost per ounce of food.

Lynn Steen, a professor of mathematics at St Olaf Collage, points out that the roles played by numbers and data in contemporary society are virtually endless” (in Jerald, 2009, p.39). Professor Steen summarizes why mathematics literacy is so important by saying:

Virtually every major public issue-from health care to social security, from international economics to welfare reform-depends on data, projections, inferences, and the kind of systematic thinking that is at the heart of Quantitative literacy (In Jerald, 2009, p.39).

Scientific literacy: Science is known as one of the least favorite or most difficult subjects for most students, but experts say that all adults need to understand and apply science in daily life. There are several types of knowledge necessary for scientific literacy. The first is to be familiar with important scientific topics. OECD’s PISA science literacy assessment measures 15 year old students’ knowledge of physical systems, living systems, earth and space, and technology. The second necessary knowledge is how science works and how to apply scientific methods such as observation and testing. The third piece of necessary knowledge is an understanding of how science and technology impact our society and physical world, for good or ill. Therefore, scientific literacy is one of the critical skills that people have to possess in the 21st century.

Financial literacy: This skill is particularly important for each and every citizen to make healthy economic decisions. Educational research points out that there are considerable weaknesses in financial literacy among students and adults in the United States. For instance, the Jump$tart Coalition’s 2002 biennial financial literacy test results showed that American high school seniors answered only 50 percent of the Questions correctly. Likewise, the Institute of Certified Financial Planners conducted a survey and found that making individual financial decisions is one of the major problems for participants.

Communication and collaboration: Learning is a social activity that happens either in a formal school setting or other environments. Communication and collaboration skills entail students’ ability to communicate clearly by using oral, written, and non-verbal means, and to collaborate effectively and responsibly with the people around them (Pacific Policy Research Center, 2010). The world is shrinking and becoming like a small village thanks to the Internet and new technologies. This creates new communication challenges. Although education has reQuired good communication skills, including speech, writing, and reading, the increasing diversity of the global economy demands a much more complicated and advanced set of skills for communication and collaboration (Trilling – Fadel, 2009). For example, it is expected that students and workers are able to listen effectively to superiors to decipher deeper meanings within the speaker’s speech and attitudes. An effective communicator shouldn’t just be able to listen well, but should be able to speak with diverse groups about different topics – and oftentimes in different languages. For collaboration skills, each individual has to demonstrate the ability to work productively and respectfully with diverse groups. Being flexible and helpful, and making necessary compromises are essential components of effective collaboration skills. Researchers suggest that using active learning methods, including project-based learning, problem-based learning, and game-based learning may help students develop the aforementioned skills.

Critical thinking and problem solving: Employers value critical thinking and problem solving skills the most (Jerald, 2009) because research indicates that workplace tasks demand employees doing things without having to be told or directed to do so (Levy – Mrunane, 2007). For instance, almost 60 percent of companies rate critical thinking and problem solving as very important skills which they expect high school graduates to possess. Unfortunately, 70 percent of employers report that students are mostly lacking in these areas. Mark Maddox, of Unilever Foods North America, explains why critical thinking and problem solving skills are so important and necessary in the workplace, saying, For our production and crafts staff, the hourly workers, we need self-directed people who either have problem-solving skills or can easily be trained to think on their feet and find creative solutions to some very tough, challenging problems” (In Jerald, 2009, p. 51). His company has such high expectations because they no longer employ supervisors who take control or explain things. Students or employees with such skills are good not only for the workplace, but also for their participation in solving local, national, and global problems that pose threats to everybody.

Creativity and innovation: The new Skills Commission (2007) did extensive research on the workforce and global economic indicators; they concluded that in addition to all the important above-mentioned skills, the U.S. needs a crucial new skill that will maintain its competitiveness in the global economy – a skill called creativity and innovation. Creativity is an essential skill that incorporates communication, problem solving, risk taking, curiosity, tolerance of ambiguity, and Questioning (Conference Board, 2008). The type of creativity adults need in today’s workplace is the one that enables workers to solve problems not encountered before. It also helps them cope with ill-structured tasks or problems that have no single right solution – or even any good solution.

Global awareness: This theme emphasizes the importance of working collaboratively with diverse people from different cultures, lifestyles, religions, ideologies, and backgrounds; this work must be done with an attitude of mutual respect. Also, promoting the study of other languages is very meaningful and necessary for understanding different nations and cultures. Doing this will enable students to feel closer to global issues and diverse learning communities; thus, they will create a new world where everybody respects each other, accepts others in their positions, and seeks ways to solve problems rather than fighting and killing innocent people and destroying valuable land.

Conclusion

I believe that these are all important skills for an individual’s success in life and countries’ success in the global economy. But today, it is not only the economy that reQuires a different set of skills. Rapidly changing technology and the internet have changed both personal and international affairs, from relationships to trade. The only meaningful way to make each and every country’s future bright and promising is to develop a generation of citizens who are aware of their responsibilities to preserve and strengthen diversity and democracy. This will ensure our world is a better place. Thus, we want our schools, regardless of culture and location, to prepare students eQuipped with the aforementioned skills to face a changing world.

Sahin, PhD, is a Research Scientist at Aggie STEM.

References

• Jerald, C. D. (2009). Defining a 21st century education. Retrieved from http://www.cfsd16.org/public/_century/pdf/Defininga21stCenturyEducation_Jerald_2009.pdf
• Levy, F. – Murnane, R. J. (2007). How computerized work and globalization shape human skill demands. In Suarez-Orozco, M. M. (Ed.), Learning in the global era: International perspectives on globalization and education (pp. 158-176). Berkeley, CA: University of California Press.
• Nelson, C. (2005). Fethullah Gulen: A vision of transcendent education. Retrieved from http://fethullahgulenconference.org/houston/read.php?p=fethullah-gulen-vision-transcendent-education
• National Center on Education and the Economy. (2007). Tough choices or tough times: The report of the New Commission on the Skills of the American workforce. San Francisco, CA: Jossey-Bass. (p. 19)
• National Research Council. (2010). Exploring the intersection of science education and 21st century skills: A workshop summary. Margaret Hilton, Rapporteur. Board on Science Education, Center for Education, Division of Behavioral and Social Sciences and Education. Washington, DC: The National Academies Press.
• NCREL – Metiri Group. (2003). enGauge 21st century skills: literacy in the digital age.Partnership for 21st Century Skills. (2008). 21st century skills, education – competitiveness: A resource and policy guide. Retrieved from http://www.pkwy.k12.mo.us/projectParkway/File/21st_century_skills_education_and_competitiveness_guide.pdf
• Pacific Policy Research Center. (2010). 21st century skills for students and teachers. Retrieved from http://www.ksbe.edu/spi/PDFS/21%20century%20skills%20full.pdf
• Trilling, B. – Fadel, C. (2009). Q – A on 21st century skills. Retrieved from http://21stcenturyskillsbook.com/blog/Q-a/

Will there be wars over elements like there have been over petroleum and water? What element have we been using in color televisions? What substance is used to make energy saving, environmental light bulbs?

Each of the elements found in the periodic table have their own characteristics. After they have been cooked in the pot of the universe, these substances that are offered to our service can be radioactive (like uranium), metallic (like magnesium) and even gaseous (like helium). Seventeen of the elements not easily found among the layers underground have unique properties. These elements are called rare-earth elements, because it is hard to discover and mine them.

Rare-earth elements are in many of our everyday devices. The data projected on a computer screen is transmitted via optic cables containing erbium. The light of a tablet device is generated by the phosphorescent element europium. We actually touch indium covered surfaces when we scroll our fingers on touch screen monitors. When listening through headphones, we are using neodymium magnets that are ten times stronger than iron magnets.

From space technologies to defense industries, from cell phones to LED lighting, many such rare-earth elements are used in every stage of our lives. These elements – many of which we cannot live without, even though we’ve never heard of them – were recorded into the Critical Materials Strategy Document published by the U.S. Department of Energy in 2010. In a public announcement, the department declared fourteen of the elements as specially significant regarding clean energy, listed six of them as critical, and the other four as near critical. Fifteen elements, beginning with lanthanum and ending with lutetium, numbered between 57 and 71, comprise lanthanides. Combined with scandium and yttrium, these make up the seventeen rare-earth elements.

The elements that we touch on screens

Indium (atomic number 49) gains the properties of electrical conductivity and optic transparency when combined with tin, which, at number 50, is indiums’s neighbor on the periodic table. Optical transparency is a desired property for plasma screen and television technologies. Indium is also an important material for mobile phone touchscreens. Interestingly, when indium combines with cadmium, also as a neighbor at number 48, it loses the optical transparency. Instead, it is able to absorb light. Light harvesting is a very critical feature in the production of solar cells.

The relationship of indium with its two neighbors opens new horizons for scientists. In the near future, it is hoped that many unknown and interesting features will be unearthed by investigating the known elements of the periodic table. It is amazing that these elements have been around for thousands of years in the universe only to be discovered by technological advancements.

The need for rare-elements in the world is around fifty thousand tons. The current recorded reserve for rare-earth elements is 110 Million tons. Currently, 95% of the demand for rare-earth elements is supplied by China, yet the country only has 35% of the world’s reserves. Therefore scientists are constantly searching for rare-earth element mines to eliminate the Chinese monopoly and to boost the production of these rare materials. In recent years, China has gotten into political debates with Japan and the United States by curbing rare-earth element exports. Economic journals covering these debates wondered if “element wars” were near. In 2010, a massive reserve of elements, enough to sustain worldwide demand, was discovered in the Pacific Ocean. Developed countries are now planning to recycle rare-earth elements from used devices due to low reserves.

Yttrium, europium, and terbium (atomic numbers 39, 63 and 65) have been known for a long time. Terbium and yttrium are named after the Swedish town of Ytterby. Yttrium is the first rare-earth element discovered, at the end of 18th century. Plastics containing europium are used to make laser products; it’s also used as an element to provide the red color on television screens. Yttrium has a supplementary role that enhances europium’s red color production. And terbium oxide activates the green phosphorescence of television tubes with its yellow-green phosphorescent property.

Terbium also enables an 80% reduction of energy consumption in light bulbs. This makes it one of the most wanted elements in the $2 billion rare-earth element market. Today, when we purchase class A type light bulbs, we are actually buying rare elements like terbium.

Neodymium (number 60), which emits a green light via laser pointers, is also used in the magnets of electric motors. When neodymium combines with boron and iron, it makes a magnet twelve times stronger than simple iron magnets. Because it is significantly less dense than iron, it makes electric motors and laptop computers much lighter. Another interesting feature of neodymium is that it enhances the data storage capacity of hard drives. Furthermore, neodymium is wanted for electrical devices and wind turbines.

The union of elements

Dysprosium was discovered in 1886 and can never be found in a free form in nature. This is because it exists in a compound form with other minerals, like gadolinite. Dysprosium is also known for its magnetic property, and when mixed with terbium and iron, it forms a substance called Terfenol-D. In a magnetic field, Terfenol-D has unique transformational abilities. Dysprosium is utilized in laser production together with vanadium, and it emits infrared radiation when used with cadmium.

The magnetic alloys of iron, boron, and neodymium lose their magnetic features beyond 300 degrees Celsius. However when this alloy is combined with dysprosium at a 5% ratio, that problem disappears. Therefore, these magnets are used for electric turbines and hard disc motors. Dysprosium also makes magnets in electric motors 95% lighter. And dysprosium and nickel mixed fillings are used as cooling rods in nuclear reactors.

The human mind becomes fascinated after seeing all the wisdom and properties involved in these lifeless elements. Either we conclude that these elements have doctorate degrees in physics and chemistry from Harvard University, or we may express our weakness and fascination in front of The Grand Creator who created and presented these elements for our benefit.

Is the yellow color in glasses from the planet Ceres?

Since Dell recalled four million laptop computers in 2006, because of a possible explosion caused by overheating battery, scientists’ eyes have been focused on lanthanum and cerium. These two elements are considered to be safer than other alternatives. Lanthanum and cerium are used in electrical equipment and energy saving light bulbs, and are classified as critical elements in these processes, along with tellurium. Cerium, named after the planet Ceres, is responsible for the yellow coloration in glasses. Cerium is also used in polishes, ceramics, and petrol refineries. Tellurium is produced indirectly, unlike most other elements. The production of cadmium takes place during zinc production, and tellurium during copper refining. Tellurium is a cheaper element that has been used in combination with cadmium on solar cells since 2009; before then, most solar cells used expensive silicon panels.

Elements in our lives, from space rockets to ultrasound imaging

Hafnium, tantalum, erbium, and technetium are important elements, even though they are not listed critical. Even though hafnium and technetium are not rare-earth elements, they were still added to the critical material strategy document produced by the US Department of Energy. Hafnium is employed in space rockets for its resistance against extreme temperatures and wearing. Hafnium oxide is a valuable material for electronic transistors since it is a very effective electric insulator. It is 20% faster than the silicon oxide that is commonly used in transistors. A transistors length is around 65 nanometers when silicon oxide is used, but it is only 32 nanometers with transistors made of hafnium oxide. This 50% decrease enables smaller devices.

Touchscreens containing indium, laptop computers powered by lithium ion batteries, and cell phones with hafnium transistors are some of today’s technological wonders. Would these inventions still be possible without these elements? Could we reach the high capacities in hard discs without the tantalum? Would we be able to protect ourselves from electric leakage in computers without high quality electric insulators such as tantalum oxide?

Radioactive technetium, which was discovered in 1937, is the first artificially produced element. The technetium 99 isotope is used in nuclear medicine. Technetium produced from uranium has a half life of 211,000 years, as opposed to the 6 hour half life of the technetium 99 isotope. The number of technetium based nuclear medicinal tests, like ultrasounds and x-ray imaging, is estimated to be above thirty million annually.

We take advantage of these elements in every stage of our lives, from medicine to technology. Could we become dependent upon elements the way we are upon petroleum? Only time will tell. Either these elements will be replaced by other materials, or other technologies will outdate the current technologies. It is also possible new elements will be discovered.

A majority of our modern technologies would not exist without these elements that were dispersed among the earth billions of years ago. These elements were placed here for our benefit, and so we could utilize them, and produce institutes of scientific research and education to study them.

Kadir Can and Mehmet Ramazanoglu are science teachers in Ankara, Turkey.

What are complex systems?

If there are multiple elements (variables/factors) interacting with each other in the creation of an event or a being, this structure is called a “Complex System.” For example, in the air system, air and water molecules are a factor. Plants and animals in an ecosystem can also be considered as a factor. These are interconnected to one another in a way hard to imagine and have impacts on each other. Systems with these specifications display complex situations throughout time. For example in the medical field, a disease is described multi-factorial if many factors (causes) take part in its development. However in the past, these laws, specifications, and progress-dependent patterns of the multifactor diseases had to be overlooked due to the lack of a suitable paradigm to study with. But today, with the complex system paradigm, we have a greater access to the inner dynamics of these multi-factor diseases.

Multi-factor systems in terms of structure and function exhibit complex features during the process. Thus, complicated features of a complex system have been found to be dependent on the “Force Law” when investigated with the complex system paradigm. They also establish the basis for principles and laws that are occurring coincidentally. According to the Force Law, in all complex systems, small scale changes occur in greater numbers, and larger scale changes happen less often. This state corresponds to the same direct line, when plotted on the x-y plane logarithmically with scale of changes versus chances of events being created. This indeed results in the stability of the system in the macroscale and yet reveals the variability and instability of the microscale. In other words, the state of the macrosystem is put forth momentarily by selection among many micro incidents, which, for believers, is an indication of an ultimate Divine will in possession of infinite power. The information level, energy and interaction strength of such events or beings plays a great role in the possible selection of micro incidents in the grand scheme of causes.

Complex systems that become visible via space-time river also enters a dynamic cycle which is composed of sub-critical, critical, and super critical states. In this way, events and existence become subjected to newer manifestations or degrees of glory, as for believers, life and existence are artworks of God and His Divine attributes in the visible universe, which resembles a drawing board. Living things display an adaptive and dynamic character along with being a complex system. Healthy processes in the human body display adaptive dynamic complex system properties yet exhibit complex behaviors that bring system down like cancer as well. The medical world in recent years have been referring to cancer more so than before because of undetermined factors in its development, hardships encountered during diagnosis and treatment; as cancer is a multi-factored disease, it is necessary to look at cancer with the complexity lens.

The science of complex systems which studies multidimensional and multifactor relations states that in each complex system there are common features, and that these features can also be observed in cancer just like in all other scientific fields and in all scales. The following will focus on the subject since cancer makes a good metaphor in understanding complex systems of behavior.

In complex systems, a whole system means more than the total value of its factors. This principle emphasizes that properties of events and beings that are the sum of many separate factors do not exist in separate units or tend to disappearas each part is handled more individually. The deduction-reduction examples of a peacock coming out of an egg, a tree growing from a seed, and water that consists of various elements are used as metaphors to explain matters that pertain to belief and bear complex system properties. There are many genetic, epigenetic, metabolic, internal and external factors in ontogeny of cancer, however it only develops with the interaction of these elements and differentiates from regular cells. According to widely accepted views, in order for a cell to become cancerous, it is not enough for it to undergo many genetic mutations on its own. The few mutations that take place in a specific order alongside other epigenetic factors could lead to a tumor and cause a “system death” which means much more than the total value of components. That is why death occurs systematically in humans-cell death, tissue death, organ death, system death (excretion and transport) and death of organism.

All complex systems not only have a specific perimeter but they also remain a part of this boundary. This feature brings attention to the fact that there is even a relation between the Sun and and eye of a mosquito. Cancer starts out with a single cell made up of specific inner parameters, in a particular placement within a tissue. It is not possible for a cancerous cell to proliferate for a long time and cause the death of an individual all by itself. It can cause death as a result of communication with surrounding cells, conversion of these into cancerous types, and dispersion through blood vessels into other organs.

Inhibition or the delay of these stages makes up the most significant strategic approaches of the therapy. Because of this, while a cancerous cell is programmed to change its surrounding it also begins utilizing the nutrient sources of surrounding live cells for itself, as if trying to resolve an optimization problem, and causes disruption in the system by displacing other cells with an uncontrolled proliferation potential. This incident points out that there is no such thing as a “minor” in complex systems.

In complex systems, the more diversity exists within a system, the more powerful the system becomes. This principle brings attention to maintenance contingency and sustainability of the system and the conditions that pertain to it, for the lifespan of complex systems correlates directly with the abundance and diversity encompassed in it. This viewpoint could be observed in the case of a normal cell turning malignant. A mature tumor is a group of differentiated cell types that can provide interaction with neighboring cells through intra- and inter-cellular structures (matrix). That is why one of the characteristics of cancer is progress-dependent heterogenity at a cellular level. Because of this reason, although there is only one cancerous cell at the beginning, it can divide into different populations in time. Each population can be considered as an independent (sub-population) population since each has a specific genetic composition. This diversity is one of the major sources of problems in cancer treatment.

A continued relationship of factors with each other in a complex system has critical importance regarding system survival. Metastasis of a tumor not only depends on relations with surrounding cells but at the same time relies on the stimulation of blood vessel synthesis factors (angiogenesis). Two events are required for the dispersal of cancer cells freely; the first is the reduced interaction with other cancer cells. This can be possible with regulation of cell-to-cell connection molecules (adhesion). Second is the formation of new blood vessels via stimulation to connect with the bloodstream from the vicinity of the tumor. Finally, cancer cells that have reached their target of joining the blood stream should be able to leave the circulation, penetrate the new tissue, and manage to grow again. Metastasis is a situation for cancer cells to regulate limiting factors according to their new conditions to survive.

Behaviors in complex systems which display more features (emergent situation) that are not present in the units or even in the total value of constituents are plentiful and complicated, yet principles as causes behind these rich motifs are simple and determine the function of the system. Cancer disease arises from the execution of three simple basic principles of interaction, proliferation, and dispersion in cancerous cells. Interaction, proliferation, and dispersion do result in a healthy cell if it happens properly in the correct place, time, and dosage; otherwise it results in a cancerous cell. These three principles can cause cancer as a complex system disease or a healthy life which also displays characters of a complex system. Critical factors that control the management of these principles are location, position, timing, and dosage.

In complex systems, minor scale changes in initial conditions can lead to major effects after a certain amount of time, like a small snowball getting bigger as it rolls. Metaphorically, this situation is called the “butterfly effect” which assumes the possibility of a hurricane in one part of the world resulting from a complex chain of events starting with the strokes of a butterfly in another far corner of the world. Most of the adaptive complex systems are called “self-organized systems” in the scientific jargon, however these may exhibit such behaviors that are hard to overlook and believers would attribute to Divine guidance rather than to their so-called self-organization capacity. These systems organized with Divine guidance reach a “critical state” at the end. One of the models that were developed to explain this critical state is called the “sand pile model.” The system is named sub-critical when sand particles start to pile up on a surface, since at this stage the system is not affected from the fall of the next sand particle. As sand particles pile up, they reach a critical state in which every new particle added to the pile can lead to one of the following: 1. Nothing will happen; this is called the super-critical state. Particle can stay on top or roll down to the bottom of the pile. 2. Particles that hit the top of the pile affect other particles and can cause a small avalanche. 3. Sand pieces hit the top and cause some displacement of other particles. These displaced particles successively can cause a bigger avalanche.

This bigger avalanche again restores the system back into a sub-critical level. All complex systems arrive at these stations of sub-critical, critical, super-critical and again sub-critical successively in the flow of time. At each station they are dressed with a form of existence corresponding to a different macroscopic situation. So the outcome of the next situation is contingent on the mean average of microstates and thus points to a manipulator, who wills it to be that way. As a result, a minor event can lead to a “point of no return,” a stage called catastrophe, a super-critical state. These stages result in the continuum of the universe as it transforms and renews itself. A cancer cell also stops by the above mentioned stations and step by step, like a snowball turning into an avalanche, it can impact the whole body after reaching the super-critical stage, and lead to death. That is why early diagnosis (made during sub-critical or critical level) increases the chances of treatment, yet late diagnosis (at super-critical level) decreases therapy outcomes.

There is no hierarchical chain of command or control of causes on each other in complex systems. In other words, not only is there not a single factor in control of the system, but also a great number of factors function in a nonlinear mode of interaction. The development and progression of cancer as a complex system is controlled through interaction of internal and external factors, genetic, epigenetic, physical and metaphysical, tangible and intangible elements. Initial conditions that prepare the basis for cancer progress does exist in human genome, for genes that play a role whether in development, suppression, or regulation of cancer are built in the human genomic library from the beginning. Embryonic development is maintained with proper activation of these regulatory genes in the correct time and place during pregnancy. However, same genes may initiate cancer if not properly expressed in the right time, place, and level after birth. Moreover, all the factors that the zygote is left exposed to during its interaction with the surroundings leave a mark (memory) on the system. This is called “system exposition.”

Exposition forms microstates that will lead to positive/negative development of the organism through interaction with genetic and epigenetic memory of the system. That is why programmed cell death is put in place to eliminate damaged and dysfunctional cells that form in the system.

Cancer, as a consequence of progress-dependent corresponding interaction of genome and system exposition, is a system that can display chaotic behavior. Because of this, spiritual factors as well as physical ones may cause a “butterfly effect” in development of cancer and there is no single center of command that is designed to control each of these in the causation chain. This being the case, one cannot help but wonder how causes can comply with the force law of all complex systems and that they share common features without a hierarchical command on each other.

Each complex system is composed of holographic sub-systems. The human body is an ecosystem of various systems placed within each other. The well-being of the ecosystem depends on proper interaction and health of these sub-systems. A tumor can be considered as a local ecosystem (sub-system) where various species and clones exist in a human ecosystem. While each tumor grows, there are living and dead clone populations in it. One billion elements exist in a tumor as small as 1 cm3 (1 gr). If we omit cell death, this corresponds to the 35th generation of an abnormal cell. Ten more generations later this reaches one trillion cells. This way, a population that started out with a single cell exceeds the total number of humans ever lived throughout history. So, human death with cancer starts with the disruption of one single cell. Once reached a super critical stage, system death occurs when the cancer branches out via blood circulation and disperses into various organs, leading to disconnection between them.

Cancerous cell reminds us that there are no minor events in the universe and points out that the health of our social and spiritual world takes shape according to the rules of complex systems. As a side thought, we may easily infer from cancer that underestimating any seemingly minor misbehavior or a sin and failure of immediate action to make up for it may lead to undesired consequences in our social and spiritual lives. It is also significant to be aware that we do not have an absolute control over our future and we cannot determine whether we will attain healing or not; however we can and we should try with science to elucidate some of the tangible causes of the disease and can point out some possible ways of treatment.

First, we should emphasize that Prof. Zewail’s statements resonate very well with what famous scholar Ibn-al Haytham said 10 centuries ago:

“The seeker after truth is not one who studies the writings of the ancients and, following his natural disposition, puts his trust in them, but rather the one who suspects his faith in them and questions what he gathers from them, the one who submits to argument and demonstration, and not the sayings of a human being whose nature is fraught with all kinds of imperfection and deficiency. Thus the job of the man who investigates the writings of scientists, if learning the truth is his goal, is to make himself an enemy of all that he reads, and applying his mind to the core and margins of its content, attack it from every side. He should also suspect himself as he performs his critical examination of it, so that he may avoid falling into either prejudice or leniency.”

Every human being is given the ability to think. That is what makes all the progress of humanity possible. When we think we process the information we receive based on what we already know and we usually make judgments. Nobody can deny that all humans go through this process many times every day. But we can question the outcome of our thinking process, that is, our judgments. Many times, we can be wrong in our judgments, and this is where “critical” thinking might help.

Today, most people learn how to think systematically at schools, particularly during university education. In fact, according to Derek Bok, the former president of Harvard University, faculty members in the US almost unanimously agree that “teaching critical thinking” is the principal aim for undergraduate education. Although many have great conviction that critical thinking is very important, there is no universal definition for it. The American Philosophical Association gives the following definition:

“Purposeful, self-regulatory judgment which results in interpretation, analysis, evaluation and inference as well as explanation of the evidential, conceptual and methodological considerations on which a judgment is based.”

Based on this definition and what we quoted from Ibn-al Haytham, we can identify the following points about critical thinking:

1) When you read or hear a statement, do not accept it without question.

2) Try to find other information that can support or disprove the statement, try to come up with ways to demonstrate validity or falsehood of the statement, and test the statement.

3) As you perform your critical examination, be aware of your own deficiencies as a human. Consider your own biases, numerous possibilities of making mistakes in your judgments, or prejudices you can assume without knowing.

4) Be aware of the method you use for evaluating a claim, and think about both its strengths and weaknesses.

Critical thinking, if we develop the habit of performing it, can help us every day. Consider how you receive information in the twenty-first century. Typically, you read a newspaper or watch news on TV. If you just accept what you hear and see, then you can sometimes be manipulated or fooled. In an ideal world we can assume that objective presentation of news is possible. In the real world, however, those who transfer news bits to the population are also humans who are prone to similar biases. Many times a newspaper or a TV station represents certain values, ideologies, or supports some political positions. Besides, news reporting is so much commercialized that news editors and reporters also think about how to attract readers, and might use catchy words deliberately. Therefore, everyone should ask questions, clarify certain interpretations, and need to fight their own biases before reaching conclusions whenever they encounter a media report. An increased number of critical thinkers will help create a healthy debate about controversial issues.

We can expand this critical approach with respect to news media to our formal education experiences. At schools, our teachers deliver new information every day. We also read our textbooks. Typical student tendency might be to just accept what they hear and what they read, though this may depend on the student’s intellectual development and the culture of the society. If we perform critical thinking in the classroom and while reading textbooks, we can grow intellectually much more than otherwise. We can retain what we learn more easily. In addition, the purpose of schools and universities is to prepare us for life. We all know that in real life problems are never well defined, and most of the time you cannot readily find an authoritative figure or a manual to consult. Therefore, it is imperative that we teach students to question what they hear and what they read. In order to encourage students to perform more critical thinking in the classroom, however, we might need to find alternative modes of teaching and move away from conventional method of active teacher – passive students.

Although we must strive to teach critical thinking, we should also recognize the fact that there are roughly three distinct phases in our lives with respect to thinking, and not everyone is in the same phase at a given time. When we are young we usually think that every question has a certain answer, and it is just a matter of finding the authority who can give that answer. As we grow up, however, we realize that sometimes many authoritative figures may disagree. This observation may make one a relativist; that is, we might start thinking that depending on who you ask the answer varies, and it is all relative. As we further grow in our intellectual development, we usually notice that although people disagree on certain topics, we should always make some decisions, and some points of view have more support than others. By performing critical thinking we can filter out less reliable information, and come to better conclusions. In some complex cases, however, we might realize that there is no single correct judgment, and circumstances might lead us down different paths.

In the context of these three different phases, we can safely claim that on the average you expect the ability to think critically improve, as we get older. Elementary school children are most likely to think that there is a correct answer to every question. In middle and high school, many students will realize that there may be different answers to the same question depending on whom you ask. By the time of their graduation we expect university students to learn how to critically evaluate information. This final outcome, though very significant for a healthy society, highly depends on our teaching strategies. That is, if rote memorization is more valued than critical evaluation, then university graduates might stay as naive relativists or even worse.

Critical thinking is extremely crucial to separate the truth from myth. A well known example is about our brains. In many societies, it is said that people typically use about 10% of their brain, and geniuses like Einstein are able to use more of their brains. Some questions to ask are as follows:

1) What does it mean to use 10% of the brain?

2) Who provides this information? Is s/he a neuroscientist?

3) How do people measure brain usage?

4) Einstein lived long time ago. Did they measure his brain activity the same way as the control group to conclude that he used more of his brain?

When we search for answers to these questions, we typically find that there is no basis for this claim. It does not mean much. Maybe the statement originally meant that many do not use their brain’s full potential, which might be true. But, when the statement is compared to what we know about brain science, then it becomes a myth.

While everyone and every profession benefits from critical thinking, some jobs require critical thinking more than others. Scientists, for example, have an obligation to be extremely critical of others’ work. Let us remember that Ahmad Zewail and Ibn-al Haytham are both scientists. In science, there is a process called “peer review,” which is extremely useful. Any research carried out becomes scientific knowledge after it is submitted to the critical reviews of other scientists in the field. Any contribution submitted to a scientific journal is tested for correctness and originality. At the end of the critical review, the reviewers submit a report to the editors of the journal, who then make a decision. Many times the authors of the article are asked questions or are asked to make modifications, to which they may respond. In short, we can safely state that a scientist must be a critical thinker, or otherwise s/he cannot perform his or her research duties, and s/he is prone to become a repeater of someone else’s ideas, and may go awry at times.

From what we explained so far, it is probably obvious that we need some background knowledge about a subject in order to become a real critical thinker. It is clear that if someone knows nothing about urban planning, for example, it is very hard for him to critically examine any work on urban planning. This straightforward observation suggests that most people cannot be critical thinkers even if they want to be. Fortunately, this conclusion is only partially true because critical thinking is not a single discrete outcome but rather a continuum. Although knowledge of a topic makes us better thinkers in a field, there are always some minimal questions one can ask. For example, there is a controversial topic and someone makes some crucial statements about it. Even if you don’t know about the topic, you can ask whether the speaker is an expert on the topic or not. Or you can ask about what kind of evidence he is using. Does the evidence presented come from a reliable source? Why may this person take this side of the argument, but not other alternatives? Are there any other alternative approaches to the same issue? That is, at minimum, the answers to these questions can help us develop sound judgment.

A great case in which many feel lost is the global warming debate. By doing a simple web search on global warming you can find articles both supporting and denying human-caused global warming. But which point of view should you believe? Although there is consensus that global warming is happening, there is disagreement about whether it is caused by our technological conveniences, or whether it is just a result of natural temperature fluctuations in geological time scales (hundreds of thousands of years).

Indeed, the question “which point of view should you believe?” may not be the correct question. Instead, perhaps we should ask why people feverishly debate about this issue. Why do people care a lot about various aspects of global warming and atmospheric science research? A little investigation shows that there is a lot at stake. Accepting that excessive use of energy by humans, which leads to increase in carbon dioxide levels in the atmosphere, causes global warming has many economic, political, and social consequences. If you agree that man-made global warming can trigger many other events which can eventually make the climate on the Earth fall off-balance, then it follows that many people in the world must change their lifestyles, and this may also mean that some big companies must make changes which may hurt their profits, or that some governments might not use certain political leverage in international relations.

Obviously, it will not be easy to accept such findings, even if they come from some prominent scientists. There are, in fact, scientists on both sides of the aisle. This is because atmospheric science is extremely complex, and even with our best computers modeling the changes in the atmosphere it remains a very hard task. Further investigation also shows that there are different types of evidence people use. Some point to reports prepared with sponsorship from some governments or companies. Some expand on disagreements among scientists, and conclude that no action is needed until all the claims are proven. As we mention above, there are also scientific articles published in “peer-reviewed” journals. The Intergovernmental Panel on Climate Change (IPCC) puts out consensus statements. In short, it is a complex issue, and the credibility of evidence varies. We leave further investigation on climate change to practice critical thinking to the interested reader.

Critical thinking requires effort, sometimes a lot of effort. Lazy personalities and those who do not like to engage their mental abilities are less likely to perform critical thinking. In this regard, critical thinking is also very different from rote criticism. Rote criticism does not require much effort; typically the statements of the person performing the critique do not have a sound basis. While critical thinking is necessary for a healthy society to clarify especially certain controversial topics, mere criticism of one another can be a means to create unnecessary enmity among individuals.

Critical thinking does not mean that we need to become a skeptic and reject everything. In fact, descriptions of critical thinking involve paying special attention to certain criteria and standards. In practice, if one does not have any reference it becomes very hard to move forward in thought. What needs to be emphasized is that the world is not black and white. It displays a vast variety of colors. We can give more weight to certain colors than to others. What we cannot claim is that there is a single color, and all others are false. We can certainly have certain beliefs, paradigms, and values. These may become the basis for some of the criteria and standards against which we evaluate new information. At times, great events and findings might force us to evaluate certain paradigms we take for granted, too. However, such sharp turns do not happen frequently in the life of an individual or society.

In conclusion, critical thinking skills are essential for everybody. We should be aware of our own shortcomings, biases, prejudgments, as well as the sources, agendas, worldviews, paradigms and the information channels we use when we process new information. Critical thinking cannot be done instantly; it requires effort and courage to come face-to-face with one’s own errors. Teaching critical thinking is not instant, either. Formal and informal education institutions must strive to develop critical thinking skills in students, and such an endeavor might require modification of our approach to teaching. In the final evaluation, it is extremely crucial that we take the necessary steps to increase the number of critical thinkers in the world for the benefit of all humankind.

Dr. Ertan Salik is an Assistant Prof. of Physics at California State Polytechnic Univ, Pomona. As well as teaching and conducting physics research Dr. Salik is currently involved in many education programs.

Notes

1. The Fountain magazine, interview with Ahmad Zewail by Nuh Gedik, Jan-Feb 2009, issue 67.
2. Steffens, Bradley. Ibn-al Haytham: First Scientist, Morgan Reynolds Publishing. Also see Book Review in The Fountain Magazine, issue 63, May-June 2008.
3. Bok, Derek. Our Underachieving Colleges, Princeton Univ Press, 2006.
4. Critical Thinking: A Statement of Expert Consensus for Purposes of Educational Assessment and Instruction, American Philosophical Association Report, 1990.
5. IPCC consensus statements can be downloaded from http://www.ipcc.ch/.