THE NATURE OF SCIENCE THE METHODS OF SCIENCE -1.1 What is science? Define SCIENCE: It is a method for studying the natural world. Or is a process based on inquiry that helps develop explanations about events in nature. Major categories of science What are the three main categories of science? Life science deals with living things. Earth science investigates Earth and Space. Physical science studies matter and energy. Science changes (explanation of the atom) Thomsons Atom : Electrons embedded in a ball of positive charge. Rutherfords Atom: The atom consisted of a nucleus with electrons orbiting it like the planets orbit the Sun. Present-Day or Modern Atom: A nucleus made of protons and neutrons surrounded by an electron cloud. Investigations Modeling Scientific Methods Define SCIENTIFIC METHOD: Pattern of investigation procedures that can include stating a problem, forming a hypothesis, researching and gathering information, testing a hypothesis, analyzing data, and drawing conclusions. State the problem first step Research and gather information Form a hypothesis Define HYPOTHESIS: Possible explanation for a problem using what is known and what is observed. Test a hypothesis Define EXPERIMENT: Organized procedure for testing a hypothesis; tests the effect of one thing on another under controlled conditions. Variables Define VARIABLE: Quantity that can have more than a single value, can cause a change in the results of an experiment. Independent and dependent variables Define DEPENDENT VARIABLE: Factor that changes as a result of changes in the other variables. Define INDEPENDENT VARIABLE: Factor that, as it changes, affects the measure of another variable. Constants Define CONSTANT: In an experiment, a variable that does not change. Define CONTROL: Standard used for comparison of test results in and experiment. Analyze the data One way to display data is by: Recording observations and organizing the test data into easy-to-read tables and graphs. Draw conclusions (a) Does your analysis of the data support your hypothesis? (b) If yes, then your hypothesis is elevated to a Law. (c) If no, then your hypothesis must be revised. Peer review Being objective Define BIAS: Occurs when a scientists expectations change how the results of an experiment are viewed. Visualizing with Models Define MODEL: Can be used to represent an idea, object, or event that is too big, too small, too complex, or too dangerous to observe or test directly. Models in history High-tech models What does computer simulation do? Uses the computer to test a process or procedure and to collect data. Science Theories and Laws Define THEORY: Explanation of things or events based on knowledge gained from many observations and investigations. Define SCIENTIFIC LAW: Statement about what happens in nature that seems to be true all the time; does not explain why or how something happens. The Limitations of Science STANDARDS OF MEASUREMENTS Units and Standards Define STANDARD: Exact, agreed-upon quantity used for comparison. Measurement Systems International Systems of Units What is SI? International System of Units-the improved, universally accepted version of the metric system that is based on multiples of ten and includes the meter (m), liter (L), and kilogram (kg). SI prefixes (Table will be given to you in class) Converting between SI units Measuring Length 1. What is the SI base unit of length? Meter 2. Choosing a unit of length Measuring Volume 1. Define VOLUME: Amount of space occupied by an object. Small solids = cm3 Large solids = m3 Convert solids to liquid volumes = 1cm3 to 1mL Measuring Mass and Density Define MATTER: Anything that takes up space and has mass. Define MASS: Amount of matter in an object. Define DENSITY: Mass per unit volume of a material. Define DERIVED UNITS: A unit obtained by combining different SI units. Examples of Derived units (1) Speed ______________ m/s (2) Velocity _____________m/s (3) Acceleration ________m/s 2 (4) Force _______________m kg s -2 (N = newton) (5) Momentum _________kg m/s (6) Work ________________kg m 2 s -2 (J = joule) (7) Energy ______________ kg m 2 s -2 (J = joule) (8) Power _______________J/s (W = watt) (9) Density ______________d=m/v Examples of Derived units: Measuring Time and Temperature Celsius (Centigrade) Define CELSIUS: The freezing point of water is 0C and the boiling point of water is 100C. Between these points, the scale is divided into 100 equal divisions. Each one represents 1C. Kevin and Fahrenheit Define KELVIN: The SI unit of temperature is the Kelvin (K). Zero on the Kelvin scale (0 K) is the coldest possible temperature, also known as absolute zero. Absolute zero is roughly equal to -273oC, which is 273oC below the freezing point of water. Define FAHRENHEIT: On the Fahrenheit scale, the freezing point of water is 32oF and the boiling point is 212oF. A temperature difference of 1o on the Fahrenheit scale is 5/9o on the Celsius scale. COMMUNICATING WITH GRAPHS A Visual Display 1. Define GRAPH: Visual display of information or data. Line Graphs 1. What do Line Graphs show? Line graphs often show how a relationship between variables changes over time. 2. Displaying data on line graphs Constructing line graphs a. HIAM (x axis) H = Horizontal axis I = Independent Variable A = Abscissa the (x -coordinate, the distance from a point to the vertical or y -axis measured parallel to the horizontal or x axis) M = Manipulated Variable b. DROV (y axis) D = Dependent Variable R = Responding Variable O = Ordinate (the y -coordinate, representing the distance from a point to the horizontal or x - axis measured parallel to the vertical or y axis) V = Vertical axis C. Bar Graphs 1.What do Bar Graphs show? A bar graph is useful for comparing information or displaying data that do not change continuously. D. Circle Graphs 1.What do Circle Graphs show? A circle graph, sometimes called a pie chart, is used to show how some fixed quantity is broken into parts. The circular pie represents the total. The slices represent the parts and usually are represented as percentages of the total. SCIENCE AND TECHNOLOGY 1.4 What is technology? Define TECHNOLOGY: Application of science to benefit people. Technological objects Technological methods or techniques Technological knowledge or skills Technological systems Global Technological Needs Developing countries Meeting basic needs Meeting basic needs as: Food, shelter, clothing, safe drinking water, and health care. Transportation (bus, bicycle) Industrialized countries Contrasting needs Social Forces that Shape Technology Define SOCIETY: Group of people that share similar values and beliefs. Personal values Economic Forces that Shape Technology Federal government Private foundations Private industries Moral and Ethical Issues Biotechnology Define BIOTECHNOLOGY: Any technological application using living things or living systems. Give some examples of Biotechnology: Breeding animals for certain traits. Using fermentation to obtain cheese or wine and baking bread with yeast. Using Human stem cells to prevent or treat disease. Using genetically-engineered crops to increase crop yield, tolerate heat and drought, and prevent crop diseases. CHAPTER 1 REVIEW 1.5 Check Concepts Please do Questions 32, 33, 34, 35, 36, 37, and 38. Apply Math Please do Problems 48, 49, and 50. Standardized Test Practice Please do Questions 1, 2, 3, 4, 5, 6, 7, 8, 11, 12, and 13.