Theory Of Phlogiston example essay topic

Phlogiston TheoryAccording to the phlogiston theory, propounded in the 17th century, every combustible substance consisted of a hypothetical principle of fire known as phlogiston,which was liberated through burning, and a residue. The word phlogiston was first used early in the 18th century by the German chemist Georg Ernst Stahl. Stahldeclared that the rusting of iron was also a form of burning in which phlogiston was freed and the metal reduced to an ash or calx. The theory was supersededbetween 1770 and 1790 when the French chemist Antoine Lavoisier showed that burning and rusting both involved oxygen and concluded that both ash and rustwere compounds of oxygen.

Lavoisier's oxidization theory has been accepted by scientists from about 1800 to the present day. The theory of phlogiston was predominantly German in origin, with much early work done in Mainz, though it was widely believed through much of the eighteenthcentury -- two of the most prominent followers of the theory, Johann Joachim Becher and Georg Ernst Stahl (who first used the name phlogiston in 1700), wereSwedish. Phlogiston was not only widespread but deep-seated, and gave way to the atomic theory only slowly. Phlogiston theorists identified three essences which comprise all matter: sulfur or terra pinguis, the essence of inflammability; mercury or terra mercurialis, theessence of fluidity; and salt or terra lapida, the essence of fixity and inertness.

In this respect phlogiston theory is similar to the ancient alchemical notions of earth,air, fire, and water. The terra pinguis was renamed phlogiston. In this view, metals were made of a 'calx' (or residue) combined with phlogiston, the fiery principle,which was liberated during combustion, leaving only the calx. Air, according to the theory, was merely the receptacle for phlogiston; all combustible or calcinablesubstances, in fact, were not elements but compounds containing phlogiston.

Rusting iron, for instance, was believed to be losing its phlogiston and thereby returningto its elemental state. Phlogiston theory was widely supported throughout the eighteenth century, although it came under increasing attack as empirical research pointed up its difficulties. When it was determined that some metals actually gained mass when burnt, partisans explained it by giving phlogiston a negative mass. Even Priestley believed in thetheory until his death, convinced that his discovery of oxygen was 'dephlogisticated air. ' It was up to Lavoisier to realize the significance of his discovery. Lavoisier made a symbolic break with phlogiston theory by burning all textbooks that supported the theory, just as Paracelsus had destroyed his copies of the worksof the medieval medical authorities.

His theory of oxidation soon replaced phlogiston theory, and remains a part of modern chemistry. Although he exaggerated its importance, Lavoisier was the first to understand the significance ofPriestley's work on oxygen, and is considered by some to have discovered the element. Hedisproved phlogiston theory by demonstrating that oxygen is required for combustion, rusting, andrespiration. He combined his chemical abilities with an interest in zoology to produce pioneeringwork on anatomy and physiology. phlogiston theory, hypothesis regarding combustion. The theory,advanced by J.J. Becher late in the 17th cent. and extended andpopularized by G.E. Stahl, postulates that in all flammable materials there ispresent phlogiston, a substance without color, odor, taste, or weight that isgiven off in burning. APhlogisticated@ substances are those that containphlogiston and, on being burned, are Adephlogisticated.@ The ash of theburned material is held to be the true material.

The theory received strongand wide support throughout a large part of the 18th cent. until it wasrefuted by the work of A.L. Lavoisier, who revealed the true nature ofcombustion. Joseph Priestley, however, defended the theory throughout hislifetime. Henry Cavendish remained doubtful, but most other chemists of theperiod, including C.L. Berthollet, rejected it. Phlogiston TheoryThe failure to understand combustion was an insurmountable obstacle to real progress inchemistry.

Any theory of chemical change must be able to explain combustion and phlogistonwas the first real attempt to do so. The fact that wood turns to ashes and metals become soft powders when heated and can bechanged back into metals in the presence of charcoal is hard to reconcile without imagining theaddition or subtraction of some substance. Phlogiston was that substance. The theory was simple, and although having serious contradictions, was better than no theory atall. Besides, despite the quantitative work of Galileo and Newton, the importance of quantitativemeasurements had not yet been impressed upon the chemists. The phlogiston theory was really quite simple.

Metals and combustible substances contained an imponderable substance known as phlogistonwhich was released into the air along with caloric. Air had a limited capacity to absorbphlogiston. Since phlogiston was an imponderable substance, it~Os properties were incapable of beingdetected by senses and could be contradictory. Sometimes it had weight, sometimes it had negative weight, and sometimes it had no weight atall. Phlogiston theory explained many facts about combustion1. combustibles lose weight when burning because they lose phlogiston 2. a flame goes out in an enclosed space because air becomes saturated with phlogiston 3. charcoal leaves little residue upon burning because it is nearly pure phlogiston 4. a mouse dies in an airtight space because the air becomes saturated with phlogiston 5. some metal calxes turn to metals when heated with charcoal because phlogiston fromcharcoal is restored to the calx A serious problem was that the calx formed when a metal such as magnesium burns weighs morethan the metal from which it formed, just as a rusty nail weighs more than the nail.

The supporters of the phlogiston theory answered this by postulating that metallic phlogiston hasnegative weight while other combustibles contain phlogiston with positive weight. Adding a special postulate such as this signaled a theory in trouble and led to the ultimatedemise of the theory. phlogiston theoryphlogiston theoryPronounced As: flojiston, hypothesis regardingcombustion. 'Phlogisticated substances are those that containphlogiston and, on being burned, are'dephlogisticated. The ash of the burned material isheld to be the true material. Hippocrates of Cos (460-ca. 370 BC) Greek physician who founded a medical school on Cos.

This school produced more than 50books, as well a system of medical methodology and ethics which is still practiced today. Uponbeing granted their M.D. degrees, new doctors still swear a so-called Hippocratic oath. In OnAncient Medicine, Hippocrates stated that medicine is not philosophy, and therefore must bepracticed on a case-by-case basis rather than from first principles. In The Sacred Disease, hestated that epilepsy (and disease in general) do not have divine causes. He advocated clinicalobservations, diagnosis, and prognosis, and argued that specific diseases come from specificcauses. Hippocrates's methodology relied on physical examination of the patient and proceeded inwhat was, for the most part, a highly rational deductive framework of understanding throughobservation.

(An exception was the belief that disease was caused by 'isonomia', an imbalance inthe four humors originally suggested by Empedocles and consisting of yellow bile, blood, phlegm,and black bile.) The Hippocratic corpus of knowledge was widely distributed, highly influential,and marked the rise of rationality in both medicine and the physical sciences. Galen of Pergamum (ca. 130-ca. 200) Greek physician considered second only to Hippocrates of Cos in his importance to thedevelopment of medicine, Galen performed extensive dissections and vivisections on animals.

Although human dissections had fallen into disrepute, he also performed and stressed to hisstudents the importance of human dissections. He recommended that students practice dissectionas often as possible. He studied the muscles, spinal cord, heart, urinary system, and proved thatthe arteries are full of blood. He believed that blood originated in the liver, and sloshed back andforth through the body, passing through the heart, where it was mixed with air, by pores in theseptum. Galen also introduced the spirit system, consisting of natural spirit or 'pneuma' (air hethought was found in the veins), vital spirit (blood mixed with air he believed to found in thearteries), and animal spirit (which he believed to be found in the nervous system). In On theNatural Facilities, Galen minutely described his experimentation on a living dog to investigate thebladder and flow of urine.

It was Galen who first introduced the notion of experimentation tomedicine. Galen believed everything in nature has a purpose, and that nature uses a single object for morethan one purpose whenever possible. He maintained that 'the best doctor is also a philosopher,' and so advocated that medical students be well-versed in philosophy, logic, physics, and ethics. Galen and his work On the Natural Faculties remained the authorityon medicine until Vesalius in the sixteenth century, even though many of his views about human anatomy were false since he had performed his dissections on pigs, Barbary apes, and dogs.

Galen mistakenly maintained, for instance, that humans have a five-lobed liver (which dogs do) and that the heart had only two chambers (it has four). Erasistratus of Chios (ca. 304-ca. 250 BC) Greek anatomist who continued the systematic investigation of anatomy begun by Herophilus in Alexandria. He described the cerebrumand cerebellum, studied nerves (which he believed to be hollow) and the valves of the heart.

He distinguished between veins and arteries, believing the latter to be full of air. He proposed mechanical explanations for many bodily processes, such as digestion. He believed in a tripartite system of humors consisting of nervous spirit (carried by nerves), animal spirit (carried by the arteries), and blood (carried by the veins). After the work of Erasistratus, the use of dissection and study of anatomy declined.

Vesalius (1514-1564) Flemish anatomist who founded the sixteenth century heritage of careful observation characterizedby 'refinement of observation. ' Vesalius changed the organization of the medical schoolclassroom, bringing the students close to the operating table. He demonstrated that, in manyinstances, Galen and Mondino de' Luzzi were incorrect (the heart, for instance, has fourchambers). He conducted his own dissections, and worked from the outside in so as not todamage the cadaver while cutting into it.

Vesalius also wrote the first anatomically accuratemedical textbook, De Humani Corporis Fabrica (1543), which was complete with preciseillustrations. Vesalius's careful observation, emphasis on the active participation of medicalstudents in dissection lectures, and anatomically accurate textbooks revolutionized the practice ofmedicine. Through Vesalius's efforts, medicine was now on the road to its modernimplementation, although major modifications and leaps of understanding were, of course,necessary to make its practice actually safe for the patient. Harvey, William (1578-1657) English physician who, by observing the action of the heart in small animals and fishes, proved thatheart receives and expels blood during each cycle.

Experimentally, he also found valves in theveins, and correctly identified them as restricting the flow of blood in one direction. He developedthe first complete theory of the circulation of blood, believing that it was pushed throughout thebody by the heart's contractions. He published his observations and interpretations in ExercitatioAnatomica de Motu Cordis et Sanguinis in Animalibus (1628), often abbreviated De MotuCordis. Harvey also noted, as earlier anatomists, that fetal circulation short circuits the lungs. Hedemonstrated that this is because the lungs were collapsed and inactive. Harvey could not explain,however, how blood passed from the arterial to the venous system.

The discovery of theconnective capillaries would have to await the development of the microscope and the work of Malpighi. He was heavily influenced bythe mechanical philosophy in his investigations of the flow of blood through the body. In fact, he used a mechanical analogy withhydraulics. He could not, however, explain why the heart beats. Furthermore, Harvey used quantitative methods to measure thecapacity of the ventricles. Harvey was the first doctor to use quantitative and observation methods simultaneously in his medical investigations.

In Exercitationesde Generatione Animalium (On the Generation of Animals, 1651), he was extremely skeptical of spontaneous generation and proposed that all animals originally came from an egg. His experiments with chick embryos were the first to suggest the theory ofepigenesis, which views organic development as the production in a cumulative manner of increasingly complex structures from aninitially homogeneous material. Lavoisier, Antoine (1743-1794) French chemist who, through a conscious revolution, became the father of modern chemistry. Asa student, he stated 'I am young and avid for glory. ' He was educated in a radical tradition, afriend of Condillac and read Maquois's dictionary. He won a prize on lighting the streets of Paris,and designed a new method for preparing saltpeter.

He also married a young, beautiful13-year-old girl named Marie-Anne, who translated from English for him and illustrated hisbooks. Lavoisier demonstrated with careful measurements that transmutation of water to earthwas not possible, but that the sediment observed from boiling water came from the container. Heburnt phosphorus and sulfur in air, and proved that the products weighed more than he original. Nevertheless, the weight gained was lost from the air.

Thus he established the Law ofConservation of Mass. Repeating the experiments of Priestley, he demonstrated that air is composed of two parts, one ofwhich combines with metals to form calxes. However, he tried to take credit for Priestley'sdiscovery. This tendency to use the results of others without acknowledgment then drawconclusions was characteristic of Lavoisier. In Consid'erations G'en'erales sur la Nature desAcides (1778), he demonstrated that the 'air' responsible for combustion was also the source ofacidity. The next year, he named this portion oxygen (Greek for acid-former), and the other azote (Greek for no life).

He alsodiscovered that the inflammable air of Cavendish which he termed hydrogen (Greek for water-former), combined with oxygen toproduce a dew, as Priestley had reported, which appeared to be water. In Reflexions sur le Phlogistique (1783), Lavoisier showed the phlogiston theory to be inconsistent. In Methods of ChemicalNomenclature (1787), he invented the system of chemical nomenclature still largely in use today, including names such as sulfuric acid,sulfates, and sulfites. His Trait'e 'El'ementaire de Chimie (Elementary Treatise of Chemistry, 1789) was the first modern chemicaltextbook, and presented a unified view of new theories of chemistry, contained a clear statement of the Law of Conservation of Mass,and denied the existence of phlogiston. In addition, it contained a list of elements, or substances that could not be broken down further,which included oxygen, nitrogen, hydrogen, phosphorus, mercury, zinc, and sulfur. His list, however, also included light, and caloric, which he believed to be material substances.

In the work, Lavoisier underscored the observational basis of his chemistry, stating 'Ihave tried... to arrive at the truth by linking up facts; to suppress as much as possible the use of reasoning, which is often an unreliableinstrument which deceives us, in order to follow as much as possible the torch of observation and of experiment. ' Nevertheless, hebelieved that the real existence of atoms was philosophically impossible. Lavoisier demonstrated that organisms disassemble andreconstitute atmospheric air in the same manner as a burning body. With Laplace, he used a calorimeter to estimate the heat evolved per unit of carbon dioxide produced. They found the same ratio for aflame and animals, indicating that animals produced energy by a type of combustion. Lavoisier believed in the radical theory, believingthat radicals, which function as a single group in a chemical reaction, would combine with oxygen in reactions.

He believed all acidscontained oxygen. He also discovered that diamond is a crystalline form of carbon. Lavoisier made many fundamental contributions tothe science of chemistry. The revolution in chemistry which he brought about was a result of a conscious effort to fit all experiments intothe framework of a single theory. He established the consistent use of chemical balance, used oxygen to overthrow the phlogistontheory, and developed a new system of chemical nomenclature. He was beheaded during the French revolution. avoisier, Antoine LaurentPronounced As: "aNtw"an lor"aN l"avw"azya, 1743-94,French chemist and physicist, a founder of modernchemistry.

He studied under eminent men of his day,won early recognition, and was admitted to theAcademy of Sciences in 1768. Much of his work wasthe result of extending and coordinating the research ofothers; his concepts were largely evolved through hissuperior ability to organize and interpret and weresubstantiated by his own experiments. He was one ofthe first to introduce effective quantitative methods inthe study of chemical reactions. He explainedcombustion and thereby discredited the phlogistontheory. He also described clearly the role of oxygen inthe respiration of both animals and plants. Hisclassification of substances is the basis of the moderndistinction between chemical elements andcompounds and of the system of chemicalnomenclature.

He also conducted experiments toestablish the composition of water and of manyorganic compounds. Lavoisier worked as well toimprove economic and social conditions in France,holding various government posts. He was appointeddirector of the gunpowder commission (1775),member of the committee on agriculture (1785),director of the Academy of Sciences (1785), member ofthe commission on weights and measures (1790),and commissioner of the treasury (1791). As one of thefarmers general, however, charged with the collectionof taxes, he was guillotined during the Reign of Terror. His works include Trait'e 'el'ementaire de chimie (1789) and the posthumously published M'emoires de chimie (1805). Lavoisier, Antoine Laurent, 1743B94, French chemist and physicist, afounder of modern chemistry.

Introduction to the Scientific MethodThe scientific method is the process by which scientists, collectively and over time, endeavor to construct an accurate (that is,reliable, consistent and non-arbitrary) representation of the world. Recognizing that personal and cultural beliefs influence both our perceptions and our interpretations of natural phenomena, we aimthrough the use of standard procedures and criteria to minimize those influences when developing a theory. As a famous scientistonce said, 'Smart people (like smart lawyers) can come up with very good explanations for mistaken points of view. ' In summary,the scientific method attempts to minimize the influence of bias or prejudice in the experimenter when testing an hypothesis or atheory. I. The scientific method has four steps1. Observation and description of a phenomenon or group of phenomena.

2. Formulation of an hypothesis to explain the phenomena. In physics, the hypothesis often takes the form of a causal mechanism ora mathematical relation. 3. Use of the hypothesis to predict the existence of other phenomena, or to predict quantitatively the results of new observations. 4.

Performance of experimental tests of the predictions by several independent experimenters and properly performed experiments. If the experiments bear out the hypothesis it may come to be regarded as a theory or law of nature (more on the concepts ofhypothesis, model, theory and law below). If the experiments do not bear out the hypothesis, it must be rejected or modified. Whatis key in the description of the scientific method just given is the predictive power (the ability to get more out of the theory than youput in; see Barrow, 1991) of the hypothesis or theory, as tested by experiment. It is often said in science that theories can never beproved, only disproved. There is always the possibility that a new observation or a new experiment will conflict with a long-standingtheory.

II. Testing hypothesesAs just stated, experimental tests may lead either to the confirmation of the hypothesis, or to the ruling out of the hypothesis. Thescientific method requires that an hypothesis be ruled out or modified if its predictions are clearly and repeatedly incompatible withexperimental tests. Further, no matter how elegant a theory is, its predictions must agree with experimental results if we are tobelieve that it is a valid description of nature. In physics, as in every experimental science, 'experiment is supreme' and experimentalverification of hypothetical predictions is absolutely necessary.

Experiments may test the theory directly (for example, theobservation of a new particle) or may test for consequences derived from the theory using mathematics and logic (the rate of aradioactive decay process requiring the existence of the new particle). Note that the necessity of experiment also implies that atheory must be testable. Theories which cannot be tested, because, for instance, they have no observable ramifications (such as, aparticle whose characteristics make it unobservable), do not qualify as scientific theories. If the predictions of a long-standing theory are found to be in disagreement with new experimental results, the theory may bediscarded as a description of reality, but it may continue to be applicable within a limited range of measurable parameters. Forexample, the laws of classical mechanics (Newton's Laws) are valid only when the velocities of interest are much smaller than thespeed of light (that is, in algebraic form, when vs. / c << 1). Since this is the domain of a large portion of human experience, the laws ofclassical mechanics are widely, usefully and correctly applied in a large range of technological and scientific problems.

Yet in naturewe observe a domain in which vs. / c is not small. The motions of objects in this domain, as well as motion in the 'classical' domain, areaccurately described through the equations of Einstein's theory of relativity. We believe, due to experimental tests, that relativistictheory provides a more general, and therefore more accurate, description of the principles governing our universe, than the earlier'classical' theory. Further, we find that the relativistic equations reduce to the classical equations in the limit vs. / c << 1. Similarly,classical physics is valid only at distances much larger than atomic scales (x >> 10-8 m). A description which is valid at all lengthscales is given by the equations of quantum mechanics.

We are all familiar with theories which had to be discarded in the face of experimental evidence. In the field of astronomy, theearth-centered description of the planetary orbits was overthrown by the Copernican system, in which the sun was placed at thecenter of a series of concentric, circular planetary orbits. Later, this theory was modified, as measurements of the planets motionswere found to be compatible with elliptical, not circular, orbits, and still later planetary motion was found to be derivable fromNewton's laws. Error in experiments have several sources. First, there is error intrinsic to instruments of measurement. Because this type of error hasequal probability of producing a measurement higher or lower numerically than the 'true' value, it is called random error.

Second,there is non-random or systematic error, due to factors which bias the result in one direction. No measurement, and therefore noexperiment, can be perfectly precise. At the same time, in science we have standard ways of estimating and in some cases reducingerrors. Thus it is important to determine the accuracy of a particular measurement and, when stating quantitative results, to quote themeasurement error. A measurement without a quoted error is meaningless. The comparison between experiment and theory is madewithin the context of experimental errors.

Scientists ask, how many standard deviations are the results from the theoreticalprediction? Have all sources of systematic and random errors been properly estimated? This is discussed in more detail in theappendix on Error Analysis and in Statistics Lab 1.. Common Mistakes in Applying the Scientific MethodAs stated earlier, the scientific method attempts to minimize the influence of the scientist's bias on the outcome of an experiment. That is, when testing an hypothesis or a theory, the scientist may have a preference for one outcome or another, and it is importantthat this preference not bias the results or their interpretation. The most fundamental error is to mistake the hypothesis for anexplanation of a phenomenon, without performing experimental tests.

Sometimes 'common sense' and 'logic' tempt us into believingthat no test is needed. There are numerous examples of this, dating from the Greek philosophers to the present day. Another common mistake is to ignore or rule out data which do not support the hypothesis. Ideally, the experimenter is open to thepossibility that the hypothesis is correct or incorrect. Sometimes, however, a scientist may have a strong belief that the hypothesis istrue (or false), or feels internal or external pressure to get a specific result. In that case, there may be a psychological tendency tofind 'something wrong', such as systematic effects, with data which do not support the scientist's expectations, while data which doagree with those expectations may not be checked as carefully.

The lesson is that all data must be handled in the same way. Another common mistake arises from the failure to estimate quantitatively systematic errors (and all errors). There are manyexamples of discoveries which were missed by experimenters whose data contained a new phenomenon, but who explained it awayas a systematic background. Conversely, there are many examples of alleged 'new discoveries' which later proved to be due tosystematic errors not accounted for by the 'discoverers. 'In a field where there is active experimentation and open communication among members of the scientific community, the biases ofindividuals or groups may cancel out, because experimental tests are repeated by different scientists who may have different biases. In addition, different types of experimental setups have different sources of systematic errors.

Over a period spanning a variety ofexperimental tests (usually at least several years), a consensus develops in the community as to which experimental results havestood the test of time. IV. Hypotheses, Models, Theories and LawsIn physics and other science disciplines, the words 'hypothesis,' 'model,' 'theory' and 'law' have different connotations in relationto the stage of acceptance or knowledge about a group of phenomena. An hypothesis is a limited statement regarding cause and effect in specific situations; it also refers to our state of knowledge beforeexperimental work has been performed and perhaps even before new phenomena have been predicted. To take an example fromdaily life, suppose you discover that your car will not start. You may say, 'My car does not start because the battery is low.

' This isyour first hypothesis. You may then check whether the lights were left on, or if the engine makes a particular sound when you turnthe ignition key. You might actually check the voltage across the terminals of the battery. If you discover that the battery is not low,you might attempt another hypothesis ('The starter is broken'; 'This is really not my car. ') The word model is reserved for situations when it is known that the hypothesis has at least limited validity. A often-cited example ofthis is the Bohr model of the atom, in which, in an analogy to the solar system, the electrons are described has moving in circularorbits around the nucleus.

This is not an accurate depiction of what an atom 'looks like,' but the model succeeds in mathematicallyrepresenting the energies (but not the correct angular momenta) of the quantum states of the electron in the simplest case, thehydrogen atom. Another example is Hook's Law (which should be called Hook's principle, or Hook's model), which states that theforce exerted by a mass attached to a spring is proportional to the amount the spring is stretched. We know that this principle is onlyvalid for small amounts of stretching. The 'law' fails when the spring is stretched beyond its elastic limit (it can break). This principle,however, leads to the prediction of simple harmonic motion, and, as a model of the behavior of a spring, has been versatile in anextremely broad range of applications.

A scientific theory or law represents an hypothesis, or a group of related hypotheses, which has been confirmed through repeatedexperimental tests. Theories in physics are often formulated in terms of a few concepts and equations, which are identified with 'lawsof nature,' suggesting their universal applicability. Accepted scientific theories and laws become part of our understanding of theuniverse and the basis for exploring less well-understood areas of knowledge. Theories are not easily discarded; new discoveriesare first assumed to fit into the existing theoretical framework. It is only when, after repeated experimental tests, the newphenomenon cannot be accommodated that scientists seriously question the theory and attempt to modify it. The validity that weattach to scientific theories as representing realities of the physical world is to be contrasted with the facile invalidation implied by theexpression, 'It's only a theory.

' For example, it is unlikely that a person will step off a tall building on the assumption that they willnot fall, because 'Gravity is only a theory. 'Changes in scientific thought and theories occur, of course, sometimes revolutionizing our view of the world (Kuhn, 1962). Again,the key force for change is the scientific method, and its emphasis on experiment. V. Are there circumstances in which the Scientific Method is not applicable?While the scientific method is necessary in developing scientific knowledge, it is also useful in everyday problem-solving. What doyou do when your telephone doesn't work? Is the problem in the hand set, the cabling inside your house, the hookup outside, or inthe workings of the phone company? The process you might go through to solve this problem could involve scientific thinking, andthe results might contradict your initial expectations.

Like any good scientist, you may question the range of situations (outside of science) in which the scientific method may be applied. From what has been stated above, we determine that the scientific method works best in situations where one can isolate thephenomenon of interest, by eliminating or accounting for extraneous factors, and where one can repeatedly test the system understudy after making limited, controlled changes in it. There are, of course, circumstances when one cannot isolate the phenomena or when one cannot repeat the measurement over andover again. In such cases the results may depend in part on the history of a situation.

This often occurs in social interactions betweenpeople. For example, when a lawyer makes arguments in front of a jury in court, she or he cannot try other approaches by repeatingthe trial over and over again in front of the same jury. In a new trial, the jury composition will be different. Even the same juryhearing a new set of arguments cannot be expected to forget what they heard before. VI. ConclusionThe scientific method is intricately associated with science, the process of human inquiry that pervades the modern era on manylevels.

While the method appears simple and logical in description, there is perhaps no more complex question than that of knowinghow we come to know things. In this introduction, we have emphasized that the scientific method distinguishes science from otherforms of explanation because of its requirement of systematic experimentation. We have also tried to point out some of the criteriaand practices developed by scientists to reduce the influence of individual or social bias on scientific findings. Further investigationsof the scientific method and other aspects of scientific practice may be found in the references listed below.