1. The Nature of Science Chapter 1: What is Science?
Chapter 2: Science in Action
Chapter 3: Models in Science
Chapter 4: Evaluating Scientific
Explanation

2. What is Science Science – a way of learning about the natural world
Scientists ask questions about the natural world, but questions about art, politics, personal preferences, or morality can’t be answered by science.
Answers are uncertain because new knowledge and discoveries are continually being made

3. What is Science?
Scientific theory: An attempted explanation for repeatedly observed patterns in the natural world
A rule that describes a pattern in nature is a scientific law (doesn’t explain the “why”)

4. Systems in Science
Scientists study systems – collections of structures, cycles, and processes that relate to and interact with each other
All systems are made up of other systems
THREE branches of Science
Life Science – studies living things and how they interact….examples???
Earth and space systems are studied in Earth Science
Physical science studies matter and energy
The practical use of science is called technology

5. Discussion Question
What is the difference between a scientific theory and a scientific law?
A scientific theory explains, and a scientific law describes.

6. Science in Action
The scientific method includes observing, questioning, and researching; forming an hypothesis; predicting an outcome; investigating; analyzing; forming conclusions, communicating findings; and repeating the process
Scientists infer conclusions based on observations.

7. Controlled Experiment
One type of scientific investigation
Factors that can be changed in an experiment are called variables
Constants are variables that remain unchanged
Safety is important or both laboratory and field scientists

8. Scientific Processes and Methods
1. Observations/Questioning
2. Measuring, Organizing Data, and Classifying
3. Hypothesizing -- a testable explanation based on experience, reading, and/or previous experiments. (NOT A GUESS)
4. Predicting -- stating in advance the result that will be obtained from testing

9. Scientific Method, cont.
5. Experimenting -- A controlled procedure for testing a hypothesis
Control Group -- all conditions remain constant
Experimental Group -- same as control, except for ONE factor
Variable
Independent Variable - condition that changes
Dependent Variable - response to changed condition
Data
Qualitative ~ descriptive
Quantitative ~ numbers

10. Scientific Method, cont.
6. Analyzing Data
7. Inferring Conclusions (concluding from evidence collected during experimentation)
8. Modeling and Communicating
9. Test and Re-test ~ law or theory formed

11. Scientific Method, cont.
LAW -- general statement that describes a wide variety of phenomena
If a hypothesis describes HOW things happen and continues to be supported by evidence, it becomes a law.
THEORY -- most probable explanation for a set of data based on best available evidence
If a hypothesis describes WHY things happen and continues to be supported by evidence, it becomes a theory.

12. Scientific Method -- Example
Observations:
Fish populations in Twin Lakes are declining.
The pH (acidity) of the water in the lakes is dropping to 4.2.
One hundred miles west of Twin Lakes is a power plant that is burning tons of coal every year, releasing sulfur dioxide into the air.

13. Problem Twin Lakes -- Acid Rain Problem East Branch West Branch
100 miles
East Branch
West Branch
Power Plant

14. Questioning/Hypothesizing
Question: Is there a link between the power plant, the pH of the lake, and the fish decline?
Hypothesis: If acid rain falling on Twin Lakes is related to fish reproduction, then increasing acid rain amounts will cause the fish to have poor reproduction.

15. Experiment Experiment
Twin Lakes is a lake in the mountains that can be divided by a barrier.
A complete inventory will gather baseline data.
One arm of the lake, on the east side of the barrier, will be treated with sulfuric acid to reduce the pH to 4.0.
The west arm of the lake will be left alone, other than monitoring.

16. Experiment Twin Lakes -- Acid Rain Problem East Branch West Branch
100 miles
East Branch
West Branch
Barrier
Power Plant
Acid Rain Added
No Acid Added

17. Results East Branch: West Branch: Fish stop reproducing.
No change in fish reproduction.

18. Conclusion
The power plant emits sulfur dioxide into the air which combines with rain to produce acid rain. The addition of this acidic rain to the lakes lowers the pH and causes the fish to stop reproducing. This results in declining fish populations and jeopardizes the survival of the fish.

19. Models in Science
Model – representation of an object or event used as a tool for understanding the natural world.
Models come in THREE basic types:
Physical models can be seen and touched.
Computer models can be seen on a computer screen but not touched.
Idea models are concepts that describe how someone thinks about something in the natural world.

20. Physical Model

21. Computer Model

22. Idea Model
E = mc2
By Leonardo da Vinci

23. Model Uses Models communicate observations and ideas
Models can test Predictions
Models can save time, money, and lives
Can you think of any of these??
Models change over time as new observations and discoveries are made.

24. Evaluating Scientific Explanation
Critical thinking- using what is known to decide if new facts should be agreed with or believed
Evaluating the Data
Data should be specific and exact
Observations should be carefully, accurately, and completely noted ~science journal
Data must be repeatable to be reliable

25. Evaluating the Conclusions
Conclusions should make sense
Other explanations should be considered before a single conclusion is reached
Advertising claims should be carefully analyzed since they are designed to sell products rather than to promote scientific evidence impartially!!!