The Nature of Science and Scientific Theories

Science teachers teach about science concepts in their classrooms, but rarely do they take time to help students understand what science is and what it is not. One of the greatest problems in science education centers on this lack of understanding by teachers, school administrators, and the general public. 

The following information should be of help to teachers, parents, and students.  The business of science is to develop theories based on natural explanations about how the natural world works.

• Position Statement on Science Education
• Comparison of the Ways of Knowing
• What teachers should know about the Nature of Science
• A Simple Explanation of How Scientists Conduct Their Work
• Well Known Scientific Theories 
• What teachers should know about The Theory of Evolution 
• History of Creation Science in Arkansas Courts
• Intelligent Design

Position Statement on Science Education
Arkansas Science Teachers Association 2006

Arkansas Science Teachers Association (ASTA) members hold various personal views concerning the origin of the universe and of life. As a professional organization, ASTA is opposed to any religious view, such, as creationism or intelligent design, being taught in the public schools as science.

ASTA finds science and religion to be complementary rather than contradictory. Science strives to explain the nature of the cosmos while religion seeks to give the cosmos and the life within it a purpose. Human existence is enriched by a knowledge and understanding of both science and religion.

Religious explanations of the origin of the universe and of life are based on faith. Because these explanations vary among different religions, the views are best taught in the home or within the context of religious institutions.

Scientific explanations regarding the origin of the universe and of life are based on experimentation and may change, as new evidence is uncovered. The goal of science is to discover and investigate universally accepted natural explanations. This process of discovery and description of natural phenomena should be taught in public schools. Therefore, both curriculum and selection of instructional materials for public schools must reflect established scientific evidence.  back to top

People have several ways that they know about their world.  The chart below lists some of the ways of knowing.  One way of knowing is no more valid that another to most people.  However, as you read the chart please note that science is a way of knowing that requires the use of certain rules and methods that differs from the other means of knowing.  Scientific knowledge limited to the natural world. Scientific knowledge and religious knowledge do not have to be contradictory.  It is important to know these differences, so that they can be complementary.

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Teachers should know the following about the Nature of Science

Grades 4 & 5

Teachers should know and be able to teach:

Grades 6, 7, & 8

Teachers should know and be able to teach:

• Science deals with inquiry about the natural world. Supernatural explanations are not a part of scientific studies (see ways of knowing).
• Scientists look for cause and effect in nature. Case and effect are real in the natural world.
• Laws of nature do not change in space or time (thus the carbon clock is the same now as it always has been)
• The simplest natural explanation is the accepted one (the Law of Parsimony)
• Scientists have a series of checks and balances to validate new data and evidence.
• Define hypothesis, law, and theory and distinguish between these terms.
• The word theory in science is not used, as people often use the word theory, to mean a hunch or a guess. A theory is held with a high degree of confidence and is supported by enough evidence to make its abandonment unlikely.

Grades 9-12

Teachers should know and be able to teach:

• Science is the method of explaining the natural world. Science presumes that the objects and events in the universe occur in consistent patterns that are comprehensible through careful, systematic study.
• Science assumes that anything in the natural world can be observed or measured is amenable to scientific investigation.
• Science also assumes that the universe operates according to regularities that can be discovered and understood through scientific investigations. The testing of various explanations of natural phenomena for their consistency with empirical data is an essential part of the methodology of science.
• Science is limited to explaining natural phenomena through the use of empirical evidence; therefore it cannot provide answers to personal or religious beliefs, superstitions, myths or ultimate explanations (see ways of knowing).
• The primary goal of science is the formation of theories (explanations) and laws, which are terms with very specific meanings.
• Scientists test hypotheses (A testable statement or prediction about the natural which can be supported by experiment or observation) by conducting observations or experiments from which they collect data, analyze the data and write up their results for publication.
• Scientists must publish their results and evidence in scientific journals for peer review and acceptance to become a part of scientific knowledge.
• Peer review leads to attempts to replicate and verify the results. If the results are verified this may lead to further observations and experiments.
• Some scientists may review these findings and work of other scientists to further develop or refine theories and in infrequent cases development new theories.
• Laws are generalizations of universal relationships related to the way that some aspect of the natural world behaves under certain conditions is often stated in a form of a mathematical equation.
• Theories are well-substantiated explanation of some aspect of the natural world that explains facts, laws, inferences, and tested hypotheses. Theories do not become laws even with additional evidence; they explain laws. However, not all scientific laws have accompanying explanatory theories.
• Well-established laws and theories must be internally consistent and compatible with the best available evidence, must be successfully tested against a wide range of applicable phenomena and evidence, must possess appropriately broad and demonstrable effectiveness in further research, and must have the potential to lead to new knowledge and have predictive power.
• Scientific explanations are called "theories." In ordinary speech, "theory" is often used to mean "guess" or "hunch," whereas in scientific terminology, a theory is a set of universal statements that explain some aspect of the natural world. A scientific theory is held with a high degree of confidence and is supported by enough physical evidence to make its abandonment unlikely.
• The body of scientific knowledge changes as new observations and discoveries are made. Theories and other explanations change. New theories emerge, and other theories are modified or discarded. Throughout this process, theories are formulated and tested on the basis of evidence, internal consistency, and their explanatory power.
• Scientific knowledge is simultaneously reliable and tentative. Having confidence in scientific knowledge is reasonable while realizing that such knowledge may be abandoned or modified in light of new evidence or re-conceptualization of prior evidence and knowledge.
• Although no single universal step-by-step scientific method captures the complexity of doing science, a number of shared values and perspectives characterize a scientific approach to understanding nature. Among these are a demand for naturalistic explanations supported by empirical evidence that are, at least in principle, testable against the natural world. Other shared elements include observations, rational argument, inference, skepticism, peer review and replicability of work.  back to top 

A Simple Explanation of How Scientists Conduct Their Work:

Teachers should know and be able to teach:

• Scientists ask questions about the natural world based on observations. To do this they must first research all the previous scientific results on a particular question.
• Scientists develop hypotheses: possible explanations for the phenomena they observe in the natural world (possible answers to questions) that can be tested based on observations and/or experiments and that are consistent with what is already known about these phenomena.
• Scientists develop predictions, observations, and/or experimental results that we expect to see if the hypothesis is true.
• If the predictions are not confirmed, scientists conclude that the hypothesis is not supported, since if it had been supported by observations, what was predicted would have been observed.
• If the predictions are confirmed, scientists conclude that the hypothesis is supported, but they do not conclude that it is true, because there might be another hypothesis that would predict the same outcome or other evidence that is contradictory, which has yet to be discovered.
• Hypotheses do not become theories. Hypotheses are predictions of specific instances, whereas theories are explanations of phenomena in a general sense.  back to top 

Teachers’ should know and be able to teach scientific theories. All of these are strongly supported by scientific evidence. One undisputed fact by all scientists around the world is that scientific knowledge is in a constant state of change.  As more sophisticated methods of investigation are developed, the knowledge base of science will continue to expand.  There are multiple examples of this of which teachers should be aware:

1.   Modern Atomic Theory

2.      Kinetic Molecular Theory

3.      The Big Bang Theory 

4.    The Theory of Gravity

5.      The Theory of Evolution

6.      Cell Theory 

7.      Germ Theory of Disease 

8.      The Theories of Relativity

9.      Plate Tectonic Theory

10. Quantum Mechanical Theory

11. String Theory

12. Unified Field Theory 

Modern Atomic Theory: Since the earliest consideration that matter existed as solid particles more than 2500 years ago, the description of the atom has been modified extensively. It was only in 1917 that the entire scientific community finally abandoned the argument of the existence of a continuous form of matter and agreed that matter existed only in particulate form. Over the past century, as fundamental observations exploring for a deeper understanding of matter and energy were occurring, a more in depth understanding of the nature of the atom was emerging and has been recognized as today’s Modern Atomic Theory.  As more information is uncovered through additional scientific research, the theory will continue to be modified to explain all of the existing evidence.

In simplest terms, the atom is composed of a central nucleus composed of two particles, the neutron and proton, surrounded by a cloud of extremely small particles called electrons.   The identity of the atom depends upon the number and type of particles contained in its nucleus.  Neutrons and protons are composed of smaller particles called quarks. The atom is best described through high-order mathematical relationships in a field of science called Quantum Mechanics.

Some fundamental concepts of atomic structure can be illustrated using simple visual methods (drawings, 3D models, etc.); however, it is important to emphasize that the method utilized is only a visualization technique of something no one has really seen.  The challenge of describing an atom in simplistic terms on the macroscopic level is made more difficult because the physical laws that determine the actual “appearance” of an atom exist only in the ultramicroscopic level described in quantum mechanics.  The physical laws as taught at the macroscopic level are no longer valid and have no meaning at the quantum level.  Therefore, any macroscopic description is inherently flawed because the scientific laws and principles used to explain the atom are actually untrue at the atomic level.  Teachers should only go into as much detail about the structure of the atom as is necessary to teach the information required under the Arkansas Science Frameworks while constantly reminding the students that the picture presented is only the best depiction possible at the macroscopic level. back to theories     back to top 

Kinetic-Molecular Theory: The Kinetic-Molecular Theory (KMT) states that matter is composed of tiny particles in constant motion.  Through KMT, the processes of osmosis, diffusion and the concept of temperature can be explained.  KMT is the basis of our knowledge of the movement of matter on a macroscopic level.  The theory allows scientists to explain the behavior of matter in the different physical states that matter can exist. The theory also provides a thorough means of understanding the process of energy transfer between particles of matter.  back to theories     back to top 

Big Bang Theory: Big bang theory assumes that the universe began from a singular state of infinite density and expanding from an explosive moment of creation. Fred Hoyle coined the term Big Bang.   The Big Bang Theory is the dominant scientific theory about the origin of the universe.  According to the Big Bang, the universe was created sometime between 10 billion and 20 billion years ago from a cosmic explosion that hurled matter and in all directions.  back to theories     back to top 

Gravitational Theory: According to legend, Isaac Newton developed a Theory of Gravity which describes an attractive force which will always exist between two bodies of matter after he saw an apple falling (whether the apple hit him on the head is open to discussion). Modern gravitational theory has taken on new avenues of thought as theoretical work by Einstein and others have opened up entirely new line of thought. Considering the four fundamental type of forces in nature (strong nuclear; weak nuclear; electromagnetic; and, gravitational), gravity has several characteristics that distinguish it from the other three forces: (1). It is universal, (2). It is always attractive, (3). It is a long-range interaction (long range meaning gravity can affect objects millions of miles distant from each other).  back to theories   back to top 

The Theory of Evolution: Evolution theory says that all living things are related to one another through common ancestry from earlier forms that differed from the present forms. Exactly how evolution occurs is still a matter of debate, but that it occurs is a scientific fact. Biologists agree that all living things arose through a long history of changes shaped by physical and chemical processes that are still taking place.  According to the theory, variability among individuals in a population of sexually reproducing organisms is produced by mutation and genetic recombination. The resulting genetic variability is subject to natural selection in the environment.  See a detailed explanation below.  back to theories     back to top

Cell Theory: The cell theory of life states: (1). All living material is made up of cells (2). All cells are derived from previously existing cells; most cells arise by cell division, but in sexual organisms they may be formed by the fusion of sperm and egg (3). A cell is the most elementary unit of life (4). Every cell is bounded by a plasma membrane, an extremely thin skin separating it from the environment and from other cells (5). All cells have strong biochemical similarities and (6). Most cells are small, about 0.001 cm (0.0004 in) in length; for example, the smallest cells of the microorganism mycoplasma are 0.3 micrometers in size, whereas some giant algae cells may be several centimeters long.  back to theories     back to top

The Germ Theory of Disease: French bacteriologist Louis Pasteur is considered the founder of microbiology. Pasteur argued that germs caused infectious diseases.  The germ theory has affected our views on infectious disease, surgery, hospital management, agriculture, and industry.  back to theories     back to top

Relativity Theories: Albert Einstein’s theory of special relativity, published in 1905, revealed that energy and matter are different manifestations of the same phenomenon and can be transformed into each other in terms of the relationship E = mc⁽²⁾ .  Einstein’s theory of general relativity, published in 1917, provided a powerful new way to view gravity as a warping of the four-dimensional space-time continuum by the presence of matter. If space-time is imagined as a rubber sheet, then massive objects such as stars and galaxies create deformations in space-time, just as a bowling ball sitting on a mattress creates a dent into which nearby smaller objects fall. Thus the shape of space-time determines the behavior of matter/energy. At the same time, the presence of matter/energy determines the shape of space-time.  back to theories     back to top

Plate Tectonics Theory:  Plate tectonics is an all-embracing theory that the Earth is divided into a number of rigid plates floating on a viscous under-layer in the mantle.  Alfred L. Wegener was the first to propose in 1912 that the continents were at one time connected and had drifted apart. In 1960 when H. H. Hess suggested that new ocean floor was created at the mid-oceanic ridges and that the ocean evolved by seafloor spreading.  back to theories     back to top 

Quantum Theory: This theory says that energy exist in tiny discrete units called quanta. Just as earlier theory showed how light, generally seen as a wave motion, could also in some ways be seen as composed of discrete particles (photons), quantum theory shows how atomic particles such as electrons may also be seen as having wavelike properties. Quantum theory is the basis of particle physics, modern theoretical chemistry, and the solid-state physics that describes the behavior of the silicon chips used in computers. Quantum theory and the theory of relativity together form the theoretical basis of modern physics.  Later work by scientists elaborated the theory into what is called quantum mechanics (or wave mechanics).  back to theories     back to top 

String Theory: This theory is that all matter is composed of strings. The strings themselves are the smallest possible particles, with a length of 10^-33 cm, and no width or height. Strings can be open or closed. Closed strings have the shape of a circle or oval, and open strings have ends. A string occupies one single point in space-time at any one time.  back to theories   back to top

Unified Field Theory: Einstein proposed that there must be a “simpler” explanation in nature for the interactions between matter than the concept of the four fundamental interactions (or forces) because he believed that all of the laws of nature were very basic and should only exist in simplest terms.  To Einstein, having four fundamental forces was not simplest.  Having a single concept that manifests itself in four different ways was much more elegant and therefore simpler.  Einstein worked for the last 20 years of his life without discovering the elegant answer he was sure that existed. Since his death in 1955, continued scientific investigation has unified three of the four forces and some evidence has been made public that the fourth force (gravity) has also been unified.  If this is true then Einstein’s dream would have come true.  Only time and additional study will confirm or refute this claim .  Back to theories     back to top 

Teachers should know the following about The Theory of Evolution

Lack of understanding of the nature of science can cause a conflict between the theory of evolution and religion with some people.   Science and religous knowledge come from two different domains.  Scientific knowledge does not have anything to say about religion since it is a belief system that is based on the supernatural.  Many scientists are very religious people.   ASTA's position above is very power in that it states that science and religion to be complementary rather than contradictory.

Grades 4-5^th

Teachers should know and be able to teach:

• All life on Earth is related.
• That reproduction leads to a variety of individuals in each generation, individuals who differ from each other.
• The organisms that are most successful at capturing energy and escaping predators are the parents of the next generation.
• Offspring tend to resemble their parents, so species gradually over long periods of time becomes better and better fitted to the environment that it lives in.
• Many different life forms have existed in the past that different in appearance from today life forms. The past life forms have died out (become extinct).
• Identify some of the life forms that no longer exist, give their names and why they no longer exist.
• The Earth is 4.5 billion years old. Teachers should be able to site the scientific evidence that supports the age of the Earth.

Grades 6^th - 7^th (Life Science)

Teachers should know and be able to teach:

• Evolution is the change in behavior, structure, genetics or function of species over time.
• Variation exists within the genes of all species that are the results of mutations.
• How some individuals of a species are better suited for survival and leave more offspring in a particular environment and that this is called natural selection.
• How over time, changes within species, leads to the replacement of old species by new species as less successful species become extinct and that this is call evolution.
• How Earth's present-day complex species developed from earlier, distinctly different simpler species.
• There is only one theory of evolution. It has changed over time as new evidence is found. 

High School Grades

Teachers should know and be able to teach:

• Lamarck's explanation of evolution and Darwin's theory of evolution and compare these with what we presently know about evolution.
• Explain what makes a scientific theory, and why there is only one scientific theory for evolution.
• Evolution is a change in allele frequencies across successive generations in a population of organisms.
• The DNA of an organism will occasionally change, or mutate.
• A mutation changes the DNA of an organism in a way that affects its offspring, either immediately or several generations down the line.
• The change brought about by a mutation can be beneficial, harmful or neutral (If the change is harmful, then it is unlikely that the offspring will survive to reproduce, so the mutation dies out and goes nowhere. If the change is beneficial, then it is likely that the offspring will do better than other offspring and so will reproduce more. Through reproduction, the beneficial mutation spreads).
• The process of culling bad mutations and spreading good mutations is called natural selection. It is a driving force in what life forms exist in a give time and environment.
• Natural selection acts on the phenotype rather than the genotype of an organism.
• Alleles that are lethal in a homozygous individual may be carried in a heterozygote and thus maintained in a gene pool.
• New mutations are constantly being generated in a gene pool.
• Variation within a species increases the likelihood that at least some members of a species will survive under changed environmental conditions.
• Solve the Hardy-Weinberg equation to predict the frequency of genotypes in a population, given the frequency of phenotypes.
• Evolution is the result of genetic changes that occur in constantly changing environments.
• Natural selection determines the differential survival of groups of organisms.
• A great diversity of species increases the chance that at least some organisms survive major changes in the environment.
• Explain the effects of genetic drift on the diversity of organisms in a population.
• Reproductive or geographic isolation affects speciation.
  Analyze fossil evidence with regard to biological diversity, episodic speciation, and mass extinction.
• Use comparative embryology, DNA or protein sequence comparisons, and other independent sources of data to create a branching diagram (cladogram) that shows probable evolutionary relationships. Scientists use cladistics (phylogenetic systematics) to analyze relationships in living things and then group organisms according to shared features.
• Know how several independent molecular clocks, calibrated against each other and combined with evidence from the fossil record, can help to estimate how long ago various groups of organisms diverged evolutionarily from one another.
• Relate how gradualism and punctuated equilibrium describe the rate of evolution.
• Describe the importance of fossils as evidence of evolution and give examples.
• Explain how relative and radioactive dating is used to date fossils.
• Be able to give examples of five types of evidence (DNA and protein, fossil, morphology, embryology and geographic distribution of related species) for evolution.
• Be able to discuss antibiotic resistance in bacteria, pesticide resistance in insects, herbicide resistance in weeds, and drug resistance in viruses as examples of evolution.
• Define extinction and give examples and cause of the extinction in the past.
• Evolution is important not only in biology courses (where evolution is the central concept of the entire field), but also in physics, astronomy, geology, chemistry, and physical science.  These other science help students understand the age and origin of the Earth, radioactive dating, how fossils tell us about the past, astrobiology, the search for extraterrestrial intelligence, the "chemical evolution" on Earth, and how organic molecules and compounds can change (mutate) over time.  back to top 

History of Creation Science in Arkansas Courts

• Creation science focused on defending a literal reading of the Genesis account, usually including the sudden creation of the earth by the Biblical God a few thousand years ago, special creation for species without change, no recognition of natural selection, and separate ancestry for apes and man.
• In 1968, in Epperson v. Arkansas, the United States Supreme Court invalidated an Arkansas statute that prohibited the teaching of evolution. The Court held the statute unconstitutional on the grounds that the First Amendment to the U.S. Constitution does not permit a state to require that teaching and learning must be tailored to the principles or prohibitions of any particular religious sect or doctrine.
• ACT 590 of 1981,An ACT to require balance treatment of creation-science and evolution. The requirement for balanced treatment meant that public schools within this State shall give balanced treatment to creation-science and to evolution-science. Balanced treatment to these two models shall be given in classroom lectures taken as a whole for each course, in textbook materials taken as a whole for each course, in library materials taken as a whole for the sciences and taken as a whole for the humanities, and in other educational programs in public schools, to the extent that such lectures, textbooks, library materials, or educational programs deal in any way with the subject of the origin of man, life, the earth, or the universe;
• Creation-science means the scientific evidences for creation and inferences from those scientific evidences. Creation-science includes the scientific evidences and related inferences that indicate: (1) Sudden creation of the universe, energy, and life from nothing; (2) The insufficiency of mutation and natural selection in bringing about development of all living kinds from a single organism; (3) Changes only within fixed limits of originally created kinds of plants and animals; (4) Separate ancestry for man and apes; (5) Explanation of the earth's geology by catastrophism, including the occurrence of a worldwide flood; and (6) A relatively recent inception of the earth and living kinds.
• Evolution-science means the scientific evidences for evolution and inferences from those scientific evidences. Evolution-science includes the scientific evidences and related inferences that indicate: (1) Emergence by naturalistic processes of the universe from disordered matter and emergence of life from nonlife; (2) The sufficiency of mutation and natural selection in bringing about development of present living kinds from simple earlier kinds; (3) Emergency [sic] by mutation and natural selection of present living kinds from simple earlier kinds; (4) Emergence of man from a common ancestor with apes; (3) Explanation of the earth's geology and the evolutionary sequence by uniformitarianism; and (6) An inception several billion years ago of the earth and somewhat later of life.
• In his 1982 decision on ACT 590 in the case of McLean v. Arkansas Board of Education, U.S. District Court Judge William R. Overton wrote that creation science is based on foundational beliefs derived from the Hebrew Scriptures (Old Testament) and the court found the statute did not have a secular purpose, noting that the statute used language peculiar to creationist literature in emphasizing origins of life as an aspect of the theory of evolution. While the subject of life's origins is within the province of biology, the scientific community does not consider the subject as part of evolutionary theory, which assumes the existence of life and is directed to an explanation of how life evolved after it originated. The theory of evolution does not presuppose either the absence or the presence of a creator.
• These court cases and others make it illegal to teach creation science as science in the public classroom.  back to top 

Intelligent Design (ID is a religious viewpoint and not science)

• Intelligent design (ID) is an attempt to legislate science. The ID holds that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection.
• ID advocates present an argument of "irreducibly complex systems," systems that could not function if they were missing just one of their many parts. These systems cannot evolve in a Darwinian fashion, because natural selection works on small mutations in just one component at a time. ID concludes that intelligent design must be responsible for these irreducibly complex systems. It is an argument against natural selection.
• ID does not meet the requirements to be a scientific theory because it does not provide conclusive evidence that can be subjected to the test of observation, experimentation, reasoning and peer review. It does not have the ability to explain what has been observed in nature, or to predict what has not yet been observed, or be able to submit to experimentation and to be modified as required by the acquisition of new data.
• There is debate about ID and evolution -- but not in the scientific community. Among scientists, ID has not only been ignored, but it has also been forcefully rejected on the basis of 1) clear lack of testable hypotheses, 2) misrepresentation of scientific evidence pertinent to both evolution and arguments used in favor of ID, and 3) misrepresentation of motive. There is only one theory of evolution in science.
• The first question that must be answered about ID is who or what is the designer. Only a supernatural force would guide natural selection and mutations. If it is God, this violates separation of church and state and does not have a secular purpose, plus it moves the question out of realm of science. Science only seeks answers about the natural world using natural explanations (see the chart above).
• Recent court cases have shown ID to be a type of creation science and thus illegal to teach it as science in a public school classroom.  back to top 

Misconceptions about Evolution

http://www.talkorigins.org/faqs/faq-misconceptions.html#proof

Creationism Arguments and Rebuttal

http://www.talkorigins.org/indexcc/list.html