Nature of Science LS CH NOS

What is Science? The investigation and exploration of natural events. Science is not something you learn, it is something that you do! Learning Life Science means that you are learning ideas found through scientific investigations that relate to the living world. Scientists observe the natural world and form questions about what they see. “Why?” Scientists use reliable skills and methods in problem solving.

Branches of Science There are 3 main branches of science: Life, Earth, and Physical Each of these branches contain many, more specialized fields All branches overlap in certain ways. Life science, or biology, is the study of all living things. This is what we are studying in this class. Earth science is the study of Earth, including its landforms, rocks, soil, and forces that shape Earth’s surface. Useful in life science in many ways Physical science is the study of chemistry and physics. Physical scientists study the interactions of matter and energy. Chemistry and Physics each come up in life science.

How is Science Done? Scientific Inquiry Replaces “Scientific Method” Key point: There is no 1 right way to do science. For some things, no experiment can be done Other findings are accidents (Penicillin) Most scientific investigations do follow a somewhat similar path Not all have to though.

The Foundation of Inquiry: Asking Questions As scientists study the natural world, they ask questions about what they observe. Why do objects fall when dropped? How can Smallpox be stopped? Why do only certain mosquitoes carry the Zika virus? Why do kids look similar, but not identical to their parents? Etc.

Distribution of A. aegypti-Vector of Zika

Scientific Inquiry Scientists practice scientific inquiry-a process that uses a variety of skills and tools to answer questions. A scientist usually begins a scientific investigation by making an observation, which involves gathering information. Observations can come from any of our senses (sight, sound, taste, etc.) From these observations, you can make inferences. An inference is a logical explanation of an observation that is drawn from prior knowledge or experience.

Observations vs. Inferences

Inquiry Continued After making observations and inferences, scientists sometimes form a hypothesis that can be tested by scientific investigation. Hypotheses are testable statements about what will happen in an investigation. If it cannot be tested, it is not a valid hypothesis When a scientist forms a hypothesis, he or she usually makes a prediction, or a statement about what will happen next in a sequence of events. Testing a hypothesis often means testing predictions If the prediction is confirmed, it supports the hypothesis If the prediction is not confirmed, the hypothesis might need revision. Note: A rejected hypothesis is not a bad thing. It does not mean that you did something wrong. Rejected hypotheses still yield data that can be very useful.

Data Scientific Investigations require collecting data. The data can be qualitative (not including a number) or quantitative (including numbers) Three ways to organize data are to create graphs, classify information, and make models and calculations. Scientists must decide whether or not the data they have collected support their hypothesis

Types of Graphs (Last page of notes) Line graph Used to show trends Shows you a relationship between variables Bar graph Compares data Circle graph (pie chart) Shows percentages of a whole population

End Steps of Scientific Inquiry Once data has been gathered and organized, scientists can begin drawing conclusions Once conclusions are drawn, it is important to share the findings Communicating results is important because scientists use new information in their research. Findings must be shared, regardless or whether the hypothesis was confirmed. Again, even unsupported hypotheses can help others.

Results of Scientific Inquiry Scientific inquiry has many practical applications Outcomes of scientific inquiry may include technology, new materials, and possible explanations for phenomena. The practical use of scientific knowledge, especially for industrial or commercial use, is called technology. Scientific inquiry can also be used to confirm findings, refute ideas, or learn how discoveries were made. More what we’ll be doing in class.

Scientific Theories and Scientific Laws An explanation of observations or events based on knowledge gained from many observations and investigations is called a scientific theory. THEORIES IN SCIENCE ARE NOT GUESSES!!!!!!!!! It is different from how it is used in everyday language. A scientific law describes a pattern or an event in nature that is always true. Laws in science are usually mathematical (E=mc2) Laws tell you what will happen, and theories explain why it happens. Theories and laws do different things. Neither is better or worse than the other. Theories cannot become laws Examples of Laws we will study: Mendel’s Laws of inheritance. . . Examples of Theories we will study: The Germ Theory of Disease, The Cell Theory, The Theory of Natural Selection, The Theory of Homeostasis, The Gene Theory, and more

Get This Idea Out Of Your Head Right Now Hypothesis  Theory  Law

Skills Needed For Scientific Inquiry Scientists use certain skills, regardless of their area of study. These include skepticism and critical thinking It is important to be skeptical, or to question information about scientific issues presented in the media. Dr. Oz… Also, be skeptical in general, of all claims you hear, even if it is from your friends. Comparing what you already know with the new information you are given in order to decide whether you agree with it is called critical thinking

What Questions Can Science Answer? Science can only answer questions about phenomena in the natural universe. Science cannot answer questions about personal opinions, values, beliefs, or feelings

Safety and Ethics in Scientific Investigations Scientists follow safety procedures when they conduct investigations. Read all instructions before beginning a scientific investigation It is important to follow ethics when you work with living things or do research with people. We will not be using live animals, but make sure the lab remains safe for all of your classmates

Scientific Descriptions and Explanations A spoken or written summary of observations is called a description An observation that uses senses is called a qualitative observation The plant grew. An observation that uses numbers is called a quantitative observation The plant grew 5 cm. The interpretation of observations is called an explanation The plant began the week at 2 cm and ended the week at 7 cm, showing that it grew 5 cm during the week.

The International System of Units The internationally accepted system for measurement is the International System of Units (SI) SI comes from the French: Système International d'Unités Related to the metric system Used everywhere on Earth, except Liberia, Burma, and the United States… Unlike the English system, SI uses base units and prefixes. Some base units are the meter, gram, second, etc. We will primarily use the following Distance: meter Volume: Liter Mass: gram Time: Second Temperature: degrees C

Accuracy and Precision in Measurement A description of how close a measurement is to an accepted value is called accuracy. A description of how similar or close measurements are to each other is called precision. Tools used to measure quantities can limit the accuracy of a measurement The better the tool, the more accurate the measurement will be A thermometer with measurements divided into tenths is more accurate than a thermometer with measurements divided into whole numbers When you take any measurement, some digits you know for certain and some digits you estimate Significant digits are the number of digits in a measurement that are known with a certain degree of reliability.

Designing an Experiment A type of scientific investigation that tests how one variable affects another variable is called a controlled experiment. In a controlled experiment, the control group contains the same factors as the experimental group, but the independent variable does not change. Variables are any factor in an experiment that can have more than one value. Controlled variables are the variables that are done the same to all subjects. Independent variables (also called Manipulated variables) are the factors that are changed so the result can be observed. Dependent variables (also called Responding variables) are the changes caused by changing the independent variable. These are what you measure.