EARTH SPACE SCIENCE Chapter 1 Introduction to Earth

EARTH & SPACE SCIENCE Chapter 1 Introduction to Earth Science 1. 2 Science as a Process

1. 2 Science as a Process Objectives • Explain how science is different from other forms of human endeavor. • Identify the steps that make up scientific methods. • Analyze how scientific thought changes as new information is collected. • Explain how science affects society.

Introduction • It is the main goal of science that separates it from other human endeavors such as philosophy, art, and architecture. • Any human endeavor may include science as a component, such as exercising scientific method to determine which design is best for constructing an arch in a building. • The main goal of science is to explain natural phenomena.

Behavior of Natural Systems • It is assumed in science that phenomena are both natural and understandable. • It is also expected that similar forces in a similar situation will cause similar results. • Efforts are made to link cause and effect even when many variables are part of the system being studied. • With enough understanding, it is possible to make predictions of natural phenomena.

Behavior of Natural Systems • For example, if a person is bitten by a tse-tse fly that carries Trypanosoma, then that person is likely to develop the symptoms of African sleeping sickness. • Trypanosoma (cause) is the agent and African sleeping sickness is the disease (effect).

Scientific Methods • Scientific methods are not a rigid step-bystep system found on a checklist. • Scientific methods are guidelines to scientific problem solving that have been developed over time by the scientific community. • A scientific method may be thought of as an organized, logical approach to solving a research problem.

Scientific Methods

Scientific Methods • Scientific investigations usually begin with observation. • Observation is the process of obtaining information by using the senses. • Observations lead one to ask questions or state problems. • Most questions/problems can be answered/solved by researching the topic and looking at the work of other scientists. • Sometimes, however, a question/problem remains unanswered/unsolved.

Scientific Methods • The next step is to form a hypothesis. • A hypothesis is a testable educated guess that attempts to answer the question or solve the problem. • Hypotheses are often based on known facts about similar events and derived through careful observation and analysis. • Once formulated, a hypothesis must be tested.

Scientific Methods • An experiment is a carefully planned procedure that tests a hypothesis. • A variable is any factor that can be changed in an experiment. • Independent variables are factors that can be changed by the person conducting the experiment. • Dependent variables are variables that change as a result of a change in independent variables.

Scientific Methods • Only one independent variable can be changed or tested at a time. • A control group is the standard of comparison and it may be though of as the components of an experiment that do not change. • As the experiment is conducted, it is essential that accurate and consistent records be maintained. • At the conclusion of the experiment, the data are then put into a usable form and analyzed.

Scientific Methods • The analysis of the data will allow the investigating scientist to draw a conclusion that supports or refutes the hypothesis. • Both expected and unexpected results can lead to further study and broaden the investigating scientist’s knowledge of the natural world. • Once a conclusion is reached, the work can be shared with the scientific community through professional journals, books, conferences, etc.

Scientific Measurements and Analysis • Measurement is the most important method of gathering information that a scientist can use. • The International System of Units (SI) is the standard of measurements used by scientists around the world to allow them to communicate in a common set of units. • All SI units are based on an interval of 10.

Scientific Measurements and Analysis • When recording measurements, both accuracy and precision are important. • Accuracy refers to how close a measurement is to the true value of the thing being measured. • Precision is the exactness of the measurement. • For example, a distance measured in millimeters is more precise than a distance measured in centimeters, though both may be very accurate.

Scientific Measurements and Analysis • How accurate a measurement is depends primarily on who is taking the measurement. • The precision of a measurement is determined primarily by the device used to measure the quantity.

Scientific Measurements and Analysis • Error is an expression of the amount of imprecision and variation in a set of measurements. • Confidence interval or percentage deviation is usually used to express error such as in political polls. • When a controlled experiment is impossible, a scientists may make many observations and gather additional evidence to compare how the hypothesis fits with the additional data.

Scientific Measurements and Analysis • A model is a description, imitation, or representation of an object in the natural world. • Models are often used to simulate conditions in the natural world. • Models may be classified into different categories. – – Physical (globe) Conceptual (endosymbiont hypothesis) Mathematical (E=mc 2) Computer (weather maps on the evening news)

Which One is a Scientific Model?

Acceptance of Scientific Ideas • Scientific journals and professional meetings are the most common way to communicate scientific information. • Professional journals often have a specified format for submission of peerreviewed articles. • Many professional journals are now online to allow for quicker and more environmentfriendly distribution.

Acceptance of Scientific Ideas • Peer review is the process in which experts in a given field examine the results and conclusions of a scientist’s study before that study is accepted for publication. • The peer review process acts like a filter to ensure that only well-supported ideas are published. • After original publication, an idea may be the focus of many more experiments and publication. • The original idea may become disproved, modified, or accepted.

Acceptance of Scientific Ideas • A theory is the explanation for some phenomenon that is based on observation, experimentation, and reasoning. • A theory must be supported by a large quantity of evidence and must not conflict with any existing experimental results or observations. • A theory may be thought of as an explanation that is consistent with all existing tests and observations. • A scientific law is a general statement that explains how the natural world behaves under certain conditions, but does not explain how.

Acceptance of Scientific Ideas • Cooperation between many scientific disciplines is necessary to solve problems in the natural world. • For example, the impact hypothesis proposed to explain the Cretaceous. Tertiary extinction event draws on information from paleontology, geology, physics, chemistry, astronomy, and climatology.

Science and Society • Scientific knowledge helps us to understand our world. • Science is used to develop new technology and processes. • Science has an obligation to consider both positive and negative consequences of new developments.

References • Trypanosoma http: //faculty. plattsburgh. edu/jose. deondarza/Bio 103/Handouts/notes_13. htm • Scientific Method (left) http: //is. asu. edu/plb 108/course/scimeth/page 4. ht ml • Scientific Method (right) http: //biotech. biology. arizona. edu/Scientific_Met hod/scientific_method. html • Callipers http: //www. toolsnextday. ltd. uk/vernierclp/verniercaliper. htm

References • Ruler http: //www. unitmath. com/um/p/FAQ/Precis ion. html • Einstein Model http: //maniera. wbp. zabrze. pl/foto/humor/ka rykatury/page_02. htm • Fashion Model http: //www. viewimages. com/partneryahoo/source/images. aspx? id=51627412