WHAT IS THE NATURE OF SCIENCE?

WHAT IS THE NATURE OF SCIENCE?


• An attempt to interconnect and validate ideas about the physical, biological, psychological, and social worlds.

• Scientific ideas enable successive generations to achieve an increasingly comprehensive and reliable understanding of these “worlds” and the universe.


• Scientific ideas are developed by particular ways of observing, thinking, experimenting, and validating.

• These ways represent a fundamental aspect of the nature of science and reflect how science tends to differ from other modes of knowing.

WHAT IS THE SCIENTIFIC WORLD VIEW?

1. The World, the Universe, Is Understandable

• Scientists believe that things and events in the universe occur in consistent patterns that are comprehensible through careful, systematic study.

• Scientists believe that through rational thought, and aided by instruments that extend the senses, people can discover these patterns in nature.


2. Science assumes that the universe is a vast single system in which the basic rules are the same everywhere.

• Knowledge gained from studying one part of the universe is applicable to other parts.

• The same principles of motion and gravitation that explain the motion of falling objects on the earth’s surface also explain the motion of the moon and the planets.

• The same principles of heredity based on DNA explain genetic processes in all living organisms.


3. Scientific Ideas Are Subject To Change• Science is a process for producing knowledge.• The process depends both on making careful

observations of phenomena and on inventing hypotheses to make sense out of those observations.

• Change in knowledge is inevitable because new observations may challenge prevailing theories.

• No matter how well one theory explains a set of observations, it is possible that another theory may fit just as well or better, or may fit a still wider range of observations.


3. Scientific Ideas Are Subject To Change

• In science, the testing and improving and occasional discarding theories, whether new or old, goes on all the time.

Scientists assume that even if there is no way to

secure complete and absolute truth, increasingly accurate approximations can be made to understand the universe and how it works.


4. Scientific Knowledge Is Durable

• Although scientists reject the idea of attaining absolute truth and accept some uncertainty as a part of nature.

• Modifying ideas, rather than rejecting them

outright, is the norm in science.

• Powerful concepts tend to survive, grow more precise, and become widely accepted.


4. Scientific Knowledge Is Durable• For example, in formulating the theory of relativity,

Albert Einstein did not discard Newton’s laws of motion but rather showed them to be only a limited application within a more general concept.

• The increasing ability of scientists to make accurate predictions about natural phenomena provides convincing evidence that humanity really is gaining in understanding how the universe works.


4. Scientific Knowledge Is Durable

• Continuity and stability are as characteristic of science as change is, and confidence is as prevalent as tentativeness.

• Our confidence level tends to increase over time.


5. Science Cannot Provide Complete Answers to All Questions

• There are many matters that cannot usefully be examined scientifically.

• There are, for instance, beliefs that—by their very nature—cannot be proved or disproved (such as the existence of supernatural powers and beings, or the true purposes of life).



• In other cases, a valid scientific concept might be rejected as irrelevant by people who hold certain beliefs (such as, in miracles, fortune-telling, astrology, or superstition).



• Scientists do not have the means to settle questions concerning good and evil, although they can sometimes contribute to the discussion of such questions by identifying the likely consequences of particular actions, which may be helpful in weighing alternatives.

THIS IS THETHIS IS THESCIENTIFIC WORLD VIEWSCIENTIFIC WORLD VIEW

1.1. The Universe Is Understandable.The Universe Is Understandable.2.2. The Universe Is a Vast Single System In The Universe Is a Vast Single System In

Which the Basic Rules Are Everywhere Which the Basic Rules Are Everywhere the Same. the Same.

3.3. Scientific Ideas Are Subject To Change.Scientific Ideas Are Subject To Change.4.4. Scientific Knowledge Is Durable.Scientific Knowledge Is Durable.5.5. Science Cannot Provide Complete Science Cannot Provide Complete

Answers to All Questions.Answers to All Questions.

WHAT IS THE NATURE OFSCIENTIFIC INQUIRY?

Different Scientific Disciplines share Fundamental Principles:

• make observations and use evidence

• use hypothesis testing to formulate relationships, laws and theories

• use logic, mathematics and statistics


The different scientific disciplines differ in:

• what phenomena they investigate

• in how they go about their work

• in the reliance they place on historical data or on experimental findings


The different scientific disciplines differ in:• in their use of qualitative or quantitative

methods

• in their building from fundamental principles

• in their use of the findings of other sciences


• The exchange of information, concepts, and techniques among scientists goes on all the time

• Scientists have common understandings about what constitutes a scientifically valid investigation


• It is not easy to describe scientific inquiry outside the context of particular experiments or investigations

• There is no one fixed set of steps that scientists always follow, no one path that leads them accurately to scientific knowledge


• There are, however, certain features of science that make it distinctive as a means of understanding the world/universe

• Those features are especially

characteristic of the work of professional scientists, but anyone can use them to think scientifically about many aspects of everyday life

Science Demands Evidence

• The validity of scientific claims is settled by referring to observations of phenomena

• Therefore, scientists concentrate on getting accurate data


• Scientific evidence is obtained by observations and measurements of matter or energy or behavior taken in situations that range from natural settings (ocean, continent, atmosphere, outer space) to completely artificial ones (laboratory, computer simulation)


• To make observations, scientists use their own senses (e.g., eyes), instruments that enhance those senses (e.g., microscopes) , and instruments that investigate characteristics unavailable to humans senses ( e.g., magnetic fields, nerve impulses).


• Scientists observe the universe passively (e.g., earthquakes, bird migrations, human interactions),

• make and describe collections of components

of the world (rocks, shells, molecules),

• and interact with the world (e.g., by boring into the earth's crust or administering experimental medicines).


• Sometimes scientists can control or alter conditions deliberately and precisely to obtain evidence.

• Conditions which can be controlled include: temperature, concentration of chemicals, which organisms mate with which others, etc.

• This use of controlled conditions is what is often thought of as “The Scientific Method.”

• That is an oversimplification.

THE SCIENTIFIC METHOD1. Observe and describe a phenomenon or group of

phenomena. 2. Formulate hypotheses to explain the phenomena;

hypotheses often take the form of a proposed causal mechanism or mathematical relationship.

3. Use the hypotheses to predict the existence or actions of other phenomena, or to predict quantitatively the results of new observations.

4. Perform additional data collection or repeat experimental tests of the predictions by several independent experimenters using properly performed techniques or experiments.

THE SCIENTIFIC METHOD

• Observations/Data Hypotheses Hypothesis ➔ ➔Testing Models Laws Theories➔ ➔ ➔

• At some point in time, each stage must be reported to the larger scientific community by presentations or publications.


• The scientific method does not allow any hypothesis to be proven true.

• Hypotheses can be disproven in which case that hypothesis is rejected as false.

• A hypothesis which withstands a test designed to falsify establishes a level of probability that the hypothesis accurately explains data and can be used for further predictions, subject to further tests.


• hypothesis testing:

SCIENTIFIC LAWS AND THEORIES

• A Scientific Theory is an explanation of a set or system of related observations or events based upon proven hypotheses and verified multiple times by detached groups of unbiased researchers. (One scientist cannot create a theory; s/he can only create a hypothesis.)

• As a result of our confidence in the Scientific method, both a scientific law and a scientific theory are accepted to be true by the scientific community as a whole. Both are used to make predictions of events. Both are used to advance technology.


• The biggest difference between a law and a theory is that a theory is much more complex and dynamic.

• A law governs a single action or situation, whereas a theory explains an entire group of related phenomena. (Mendel’s Laws versus Darwin’s Theory of Evolution by Natural Selection)

• [Note: Evolution is a Fact; Darwin’s Theory is the scientifically accepted explanation for the fact of evolution.]


• Genuine scientific theories must be falsifiable by means of additional application of the scientific method (data collection and hypothesis testing).

• If one cannot imagine means of specific investigation, based on predictions from the theory, leading to results which can further verify or refute the predictions, then the theory, as an explanation, is not scientific.


• By the time the scientific community accepts a Law or Theory, it represents the best understanding of the explanations for the elements and behaviors of a given system at that point in time.

• A Scientific Theory represents our best understanding of the “truth” about some aspect of the universe, even though it is not proven as absolute and is still understood to be subject to future revision, even to rejection.

COMMON MISTAKES IN APPLYING THE SCIENTIFIC METHOD

• Failure to collect appropriate data or perform appropriate experiments

• Personal, institutional or cultural bias – interpreting or manipulating data to produce a desired outcome or ignoring or dismissing evidence which disagrees with a preferred hypothesis

• Failure to recognize or account for errors in description, measurement or analysis

• Failure to review relevant prior scientific evidence• Failure to communicate the results of research

honestly or completely

THE EXPERIMENTAL METHOD• The Experimental Method is usually taken to be

the most scientific of all methods, the “method of choice.”

• The main problem with all the non-experimental methods is lack of control over the situation.

• The experimental method is a means of trying

to overcome this problem.

THE EXPERIMENTAL METHOD• An experiment is a study of cause and effect. • It differs from non-experimental methods in that

it involves the deliberate manipulation of one variable, while trying to keep all other variables constant.

• Experiments must be properly designed and include controls.

THE EXPERIMENTAL METHOD

• By varying just one condition at a time, scientists hope to identify its exclusive effects on what happens, uncomplicated by changes in other conditions.

• Often, however, control of conditions may be impractical (as in studying stars), or unethical (as in studying people), or likely to distort the natural phenomena (as in studying wild animals in captivity).

THE EXPERIMENTAL METHOD• When experimental control is difficult or

impossible, observations have to be made over a sufficiently wide range of naturally occurring conditions to infer what the influence of various factors might be.

• Because of the reliance on evidence, great value is placed on the development of better instruments and techniques of observation, and the findings of any one investigator or group are usually checked by others investigators.

SCIENCE IS A BLEND OFLOGIC AND IMAGINATION

• Although all sorts of imagination and thought may be used in coming up with hypotheses and theories, sooner or later scientific arguments must conform to the principles of logical reasoning—that is, to testing the validity of arguments by applying certain criteria of inference, demonstration, and common sense.

SCIENCE REQUIRES LOGICAL REASONING

• Scientists may often disagree about the value of a particular piece of evidence, or about the appropriateness of particular assumptions that are made—and therefore disagree about what conclusions are justified.

• But they tend to agree about the principles of logical reasoning that connect evidence and assumptions with conclusions.

• Scientists do not work only with data and well-developed theories.

HYPOTHESIS GENERATION IS AN EXERCISE IN LOGIC

• Often scientists have only tentative hypotheses about the way things may be.

• Such hypotheses are widely used in science for choosing what data to pay attention to and what additional data to seek, and for guiding the interpretation of data.

• In fact, the process of formulating and testing hypotheses is one of the core activities of scientists.

HYPOTHESIS GENERATION

• To be useful, a hypothesis should suggest what evidence would support it and what evidence would refute it.

• A hypothesis that cannot in principle be put to the test of evidence (data collection and analysis) may be interesting, but it is not likely to be scientifically useful.

HYPOTHESIS GENERATION

• The use of logic and the close examination of evidence are necessary but not usually sufficient for the advancement of science.

• Scientific concepts do not emerge automatically from data or from any amount of analysis alone.

• Inventing hypotheses or theories to imagine how the world works and then figuring out how they can be put to the test of reality is a creative thought process.

SCIENTIFIC PROGRESS CAN BE UNPREDICTABLE

• Sometimes discoveries in science are made unexpectedly, even by accident.

• But knowledge and creative insight are usually required to recognize the meaning of the unexpected observation or result.

• Aspects of data that have been ignored by one scientist may lead to new discoveries by another.

SCIENCE EXPLAINS AND PREDICTS

• Scientists strive to make sense of observations of phenomena by constructing explanations for them that use, or are consistent with, currently accepted scientific principles.

• Such explanations—theories—may be either sweeping or restricted, but they must be logically sound and incorporate a significant body of scientifically valid observations.

• The credibility of scientific theories often comes from their ability to show relationships among phenomena that previously seemed unrelated.


• The theory of moving continents, Plate Tectonics, for example, has grown in credibility as it has shown relationships among such diverse phenomena as earthquakes, volcanoes, the match between types of fossils on different continents, the shapes of continents, and the contours of the ocean floors.


• The essence of science is validation by observation.

• But it is not enough for scientific theories to fit only the observations that are already known.

• Theories should also fit additional observations that were not used in formulating the theories in the first place; that is, theories should have predictive power.


• Demonstrating the predictive power of a theory does not necessarily require the prediction of events in the future.

• The predictions may be about evidence from the past that has not yet been found or studied.


• A theory about the origins of human beings, for example, can be tested by new discoveries of human-like fossil remains.

• This approach is clearly necessary for reconstructing the events in the history of the earth or of the life forms on it.

• It is also necessary for the study of processes that usually occur very slowly, such as the building of mountains or the aging of stars or the evolution of life.

SCIENTISTS TRY TOIDENTIFY AND AVOID BIAS

• When faced with a claim that something is true, scientists respond by asking what evidence supports it.

• But scientific evidence can be biased in how the data are interpreted, in the recording or reporting of the data, or even in the choice of what data to consider in the first place.

• Scientists' nationality, sex, ethnic origin, age, political convictions, and so on, may incline them to look for or emphasize one or another kind of evidence or interpretation.


• For example, for many years the study of primates—by male scientists—focused on the competitive social behavior of males.

• Not until female scientists entered the field was the importance of female primates' community-building behavior recognized.


• Bias within the investigator, the sample, the method, or the instrument may not be completely avoidable in every instance, but scientists want to know the possible sources of bias and how bias is likely to influence evidence.

• Scientists want, and are expected, to be as alert to possible bias in their own work as in that of other scientists, although such objectivity does not always occur.

• One safeguard against undetected bias in an area of study is to have many different investigators or groups of investigators working in it.

SCIENCE IS NOT AUTHORITARIAN

• It is appropriate in science, as elsewhere, to turn to knowledgeable sources of information and opinion, usually people who specialize in relevant disciplines.

• But esteemed authorities

have been wrong many times in the history of science.

Aristotle

SCIENCE IS NOT AUTHORITARIAN

• In the long run, no scientist, however famous or highly placed, is empowered to decide for other scientists what is true, for no scientist is believed by other scientists to have special access to the truth.

• There are no pre-established conclusions that scientists must reach on the basis of their investigations.

SCIENCE IS SELF CORRECTING AND PROGRESSIVE

• In the short run, new ideas that do not mesh well with mainstream ideas may encounter vigorous criticism, and scientists investigating such ideas may have difficulty obtaining support for their research.

• Challenges to new ideas are the legitimate business of science in building valid knowledge.


• Even the most prestigious scientists have occasionally refused to accept new theories despite there being enough accumulated evidence to convince others.

• In the long run, however, theories are judged by their results:

• When someone comes up with a new or improved version that explains more phenomena or answers more important questions than the previous version, the new theory eventually takes its place.


• SF Author Sir Arthur C. Clarke’s First Law: “When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.”

THE SCIENTIFIC ENTERPRISE• Science as an enterprise has

individual, social, and institutional dimensions.

• Scientific activity is one of the main features of the contemporary world and, perhaps more than any other, distinguishes our times from earlier centuries.

SCIENCE IS A COMPLEX SOCIAL ACTIVITYSCIENCE IS A COMPLEX SOCIAL ACTIVITY

• Scientific work involves many individuals doing many different kinds of work and goes on to some degree in all nations of the world.

• Men and women of all ethnic and national backgrounds participate in science and its applications.


• These people—scientists and engineers, These people—scientists and engineers, mathematicians, physicians, technicians, mathematicians, physicians, technicians, computer programmers, librarians, and computer programmers, librarians, and others—may focus on scientific knowledge others—may focus on scientific knowledge either for its own sake or for a particular either for its own sake or for a particular practical purpose, and they may be practical purpose, and they may be concerned with data gathering, theory concerned with data gathering, theory building, instrument building, or building, instrument building, or communicating.communicating.


• As a social activity, science inevitably reflects social values and viewpoints.

• The history of economic theory, for example, has paralleled the development of ideas of social justice—at one time, economists considered the optimum wage for workers to be no more than what would just barely allow the workers to survive.

• A view similar to “Social Darwinism” about which we will talk later.


• Before the twentieth century, and well into it, women and people of color were essentially excluded from most of science by restrictions on their education and employment opportunities; the remarkable few who overcame those obstacles were even then likely to have their work belittled by the science establishment.

George Washington Carver (1864-1943)

SCIENCE IS A COMPLEX SOCIAL ACTIVITY

• During the late nineteenth and early twentieth centuries, the eugenics movement advocated discouraging the birth rate or even sterilizing individuals thought to be genetically inferior.

• The Nazis used this scientific perspective,

later proven to be wrong, to help justify genocide.

SCIENCE IS INFLUENCED BY CULTURE AND SOCIETY

• The direction of scientific research is affected by informal influences within the culture of science itself, such as prevailing opinion on what questions are most interesting or what methods of investigation are most likely to be fruitful.

• Elaborate processes involving scientists themselves have been developed to decide which research proposals receive funding, and committees of scientists regularly review progress in various disciplines to recommend general priorities for funding.

SCIENCE IS ORGANIZED INTO CONTENT DISCIPLINES

• Organizationally, science can be thought of as the collection of all of the different scientific fields, or content disciplines.

• From anthropology through zoology, there are dozens of such disciplines.

• Scientific disciplines do not have fixed borders. • New scientific disciplines (astrophysics and

sociobiology, for instance) are continually being formed at the boundaries of others.

• Some disciplines grow and break into subdisciplines, which then become disciplines in their own right.

SCIENCE AS A WAY OF KNOWING1. The Universe Is Understandable.2. The Universe Is a Vast Single System In Which the Basic

Rules Are Everywhere the Same. 3. Scientific Ideas Are Subject To Change.4. Scientific Knowledge Is Durable.5. Science Cannot Provide Complete Answers to All Questions.

Scientific ideas are developed by particular ways of observing, thinking, experimenting, and validating.

Observations/Data Hypotheses Hypothesis ➔ ➔Testing Models Laws Theories➔ ➔ ➔

Evaluating the Theory of Evolution

Here are some questions to consider during this course:

1. What types of evidence support the Theory of Evolution?

2. Which independent lines of evidence support the Theory of Evolution?


3. What previously unconnected areas of biological knowledge were united by the Theory of Evolution?

4. Does the Theory of Evolution make important predictions about the living world? If so, give examples.


5. How clear are the causal mechanisms which support the Theory of Evolution?

6. Does the Theory of Evolution adequately explain the ultimate origin of the systems it describes, i.e., all life on earth?

7. Is the Theory of Evolution scientifically controversial?


8. Is the Theory of Evolution socially or politically controversial? Why or why not?

9. Does the Theory of Evolution provide practical and economical benefits outside the realm of academic biological science?


10. Is the Theory of Evolution widely understood and accepted by the general public? Why or why not?

11. How does the Theory of Evolution compare with the other major scientific theories (quantum mechanics and relativity in physics, plate tectonics in geology, atomic theory, quantum mechanics and valence bond theory in chemistry, expanding universe in astronomy) with regard to the same ten questions?


12. How does the Theory of Evolution compare with the fundamental theories of the other scientific disciplines (physics, geology, chemistry, and astronomy) as the central theory of its discipline?

13. Is the Theory of Evolution bad, good or even great science?

Principles and Processesof Evolution

• For the rest of the semester, we will be looking at the fact of Evolution and the evidence that supports Darwin’s Theory of Evolution.

• By the end of the semester, you should be able to support your answer to the question: Is the Theory of Evolution bad, good or even great science?

Be Prepared to DiscussSome of these Questions

on your Final Exam!


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WHAT IS THE NATURE OF SCIENCE?