WHAT IS SCIENCE? How we know what we know The Nature of Science 1. Science is a path to gaining knowledge about the natural world 2. Science does not rely on faith or opinions 3. Science is in the realm of facts and observations 4. Science does not make moral judgments 5. Scientific ideas can change if we gather more data or learn more Scientific Method 1. A series of steps that help investigate a question 2. All things can be explained through natural processes 3. Based on data and observations 4. Free from religious/cultural interference Question Conclusion Research Data Hypothesis Experiment Question 1. Begin with a testable question then try to answer the question with evidence and logic a) Example: i. Why are there more earthquakes in California than in North Carolina? ii. Why is the sky blue? 2. Some questions are impossible to test a) Example: i. Is there life after death? ii. Do ghosts exist? Research 1. Someone has probably asked this question before. 2. Scientists keep good records, read a lot, work together, and share information. a) Books, magazines, Internet, experts 3. Determine what is already known. Hypothesis 1. Testable prediction based on research 2. Must be something you can measure and document a) Not supernatural things 3. You are usually proving only a tiny part of the problem Experiment 1.Design a way to test your hypothesis 2.Have as few variables as possible a)Independent Variables b)Dependent Variables c) All else should be constant Variables 1. Independent Variable: The factor that the experimenter will change or manipulate a) Under the direct control of the experimenter b) “manipulated variable” 2. Dependent Variable: The factor that changes based on the independent variable a) May or may not be different among the trials b) NOT under the control of the experimenter c) “measured variable” Variables 1. The effects of independent variable on dependent variable 2. Does the amount of sleep a student gets affect his/her grades? 3. The effects of sleep on grades. Constant 1. Constant: Anything that is not a variable a) Why is it important to keep everything else constant? Control 1. The standard for comparison that will show the independent variable was the cause of the results 2. Control group vs. Experimental Group a) Example: Drug trials placebos Data 1. Data: the information gathered during the experiment a) Displayed in the form of graphs, charts, or tables b) May be quantitative or qualitative c) There must be enough data points to prove your claims d) Everything must be measured properly e) Notes and observations may also be important Conclusion 1. Was your hypothesis supported? 2. What experiments need to be done in the future? 3. Share data – Publish your results 4. Different people may have different conclusions from the same data Scientific Community 1. Scientific discovery works best with collaboration 2. A hypothesis needs to be confirmed by many different scientists before it can become a theory 3. Scientists may publish their findings after several scientists review the paper – this is called “peer review” Theory 1. If a hypothesis explains all the data and none of the data contradicts the hypothesis, the hypothesis becomes a theory 2. A theory is the simplest explanation that explains observable facts a) Examples: Germ theory of Disease, Theory of Gravitation, Theory of Evolution, Atomic theory of matter, Quantum Theory 3. Theories can be constantly tested and revised Scientific Models 1. Scientists often cannot directly touch or see what they are studying 2. Models are simpler representations of complex real world phenomena 3. Models are useful for testing hypotheses and making predictions about real world events 3 Types of Models 1. Physical Model: physical representation of subject being studied a) Example: Globe or Map 2. Conceptual Model: ties together lots of ideas to create an explanation a) Example: Giant Impact Hypothesis 3. Mathematical Model: complex equations that take many variables into account a) Example: predicting the path of a hurricane Earth Science 1. Main divisions of the earth 2. Geosphere: solid earth Geology Oceanography 1. Hydrosphere: water on earth Oceanography Meteorology 1. Atmosphere: gases around earth Meteorology Biology 1. Biosphere: living things on earth Biology Environmental Science 1. Environmental Science: studies the effects people have on their environment and living things Astronomy 1. Astronomy: study of outer space Matter 1. Matter is anything that has mass and volume a) Volume: the amount of space an object takes up Atoms 1. The smallest unit of matter is the atom Molecules 1. Atoms can be bonded together to form molecules The delicate inner structure of a pentacene molecule has been imaged with an atomic force microscope Element 1. There are over 100 different kinds of atoms a) Each type of atom has a different structure of protons, neutrons, and electrons 2. An element is a substance in which all the atoms have the same structure States of Matter 1. Matter on Earth exists in one of three states: a) Solid: atoms are moving very slowly (less energy) Solid (Definite Shape; Definite Volume) Liquid a) Liquid: atoms are moving at intermediate speed (intermediate energy) Liquid (Indefinite Shape; Definite Volume) Gas Gas: atoms are moving very rapidly (more energy) Gas (Indefinite Shape; Indefinite Volume) Energy 1. All matter has energy a) E=MC2 Add Energy Solid Add Energy Liquid Gas Continents 1. Mostly granite a) Less dense than ocean basins 2. Edges are often under water 3. Very old a) Billions of years old 4. Subject to erosion and mountain building Ocean Basins 1. Mostly basaltic rock a) Denser than granite 2. Covered with water 3. Young a) Millions of years old 4. Constantly expanding and changing Changing Earth 1. Earth’s surface is constantly changing over short and long periods of time 2. Constructive forces – formation of new landforms and seafloor a) Volcanic activity or uplift of the crust 3. Destructive forces – modification of existing landforms a) Erosion and weathering Constructive Forces Destructive Forces Direction 1. North and South Poles: where the axis of rotation intersects with the planet 2. In space there is no up or down, so this system only works on Earth 3. Magnetic and Geographic Poles are different North on the Earth Latitude and Longitude 1. Latitude a) Equator: halfway between the poles0˚ b) North Pole: 90˚N; South Pole: 90˚ S 2. Longitude a) Prime Meridian: not natural 0˚ b) International Date Line: 180˚ c) Everything else is given as number of degrees East or West 79˚ W Latitude and Longitude 1.Parallels = Latitude a)All lines are parallel 2.Meridians = Longitude a)All lines intersect at the Poles Latitude and Longitude 1. LatitudeLadder a) Evenly spaced steps b) Each step takes you higher or lower 2. LongitudeLong a) Longitude lines are longer than most latitude lines b) Every longitude line is equally long Latitude and Longitude