1. Ch. 1 Introduction to Science Section 2: Science as a Process

2. Goal of Science The goal of science is to explain natural phenomena.
Scientists ask questions about natural events and then work to answer those questions through experiments and examination.

3. Behavior of Natural Systems
(1) assume science is understandable and similar forces in similar situations cause similar results
Not always true- example: changes in temperature and humidity may cause rain in one city but fog in another city.

4. Behavior of Natural Systems
(2) expects nature to be predictable- future behavior of natural forces can be anticipated
Understanding the forces and materials involved in a process can help them predict how the process will evolve.
Example: Ice Core in Antarctica can show past environmental conditions of a region up to thousands of years ago- scientists can use this data as a model to predict future conditions

5. Scientific Methods (1) Ask a Question:
Observation = the process of using the senses of sight, touch, taste, hearing, and smell to gather information about the world.
These observations lead to questions!
Example:
Observation = You see thunderclouds forming outside of your window.
Possible questions = What causes a tornado to form? What is the difference between a tornado and a hurricane? How can you tell the distance away a thunderstorm is away from you?

6. Ask a Question
Observation: You see a car driving down your street with black smoke coming out of the exhaust pipe.
COME UP WITH 3 QUESTIONS you have about this observation!
You have 2 minutes!- Go!

7. Scientific Methods (2) Form a Hypothesis:
Once a question has been asked and basic information has been gathered, a scientist may propose a tentative answer AKA a hypothesis.
Hypothesis = a possible explanation or solution to a problem.
Can be developed through careful observation and are based on known facts about similar events.

8. Hypothesis
Remember- Observation: You see a car driving down your street with black smoke coming out of the exhaust pipe.
Pick your BEST question and come up with a HYPOTHESIS for that question!
You have 2 minutes- GO!

9. Scientific Methods (3) Test the Hypothesis:
After a hypothesis is proposed, it is often tested by performing experiments.
Experiment = procedure that is carried out according to certain guidelines.
Factors that can change in an experiment are variables:
Independent Variables = factors that are changed by the person performing the experiment
Dependent Variables = variables that change as a result of a change in independent variables
In most experiments- only 1 independent variable is tested at a time

10. Test the Hypothesis
Remember- Observation: You see a car driving down your street with black smoke coming out of the exhaust pipe.
Now, get with a partner – choose one hypothesis.
Write down at least 5 steps in an experiment that you would perform to test your hypothesis.
You have 5 minutes!- GO!

11. Scientific Methods (4) Draw Conclusions:
After many experiments and observations, a scientist may reach conclusions about his or her hypothesis.
If the hypothesis fits the known facts, it may be accepted as true.
If the experimental results differ from what was expected, the hypothesis may be changed or discarded.
Results of scientific inquiry may also lead to new knowledge and new methods of inquiry that further scientific aims.

12. Draw Conclusions
Remember- Observation: You see a car driving down your street with black smoke coming out of the exhaust pipe.
With your partner- imagine that you performed the experiment you came up with- based on your experiment- predict your conclusion:
(A) Did your results support your hypothesis (yes or no)?
(B) Would you change anything about your experiment to be able to make better predictions?

13. HW:
Complete Questions at the bottom of your notes #1-5

14. Section 2 Continued!
Scientific Measurement and Analysis

15. Scientific Measurement and Analysis
During an experiment, scientists gather information.
Gathering information is done in many different ways but one of the most important ways is measurement.
Measurement = comparison of some aspect of an object or event to a standard unit.
Scientists around the world use a system called the International System of Units, or SI.

16. Some SI Units Quantity Unit Name Symbol Length Meter m Mass Kilogramkg
Time
Second s
Temperature
Kelvin or Celsius
K or C

17. Some SI Prefixes Prefix Symbol Exponential Factor Mega- M 106 Kilo- k
103
Deci- d
10-1
Centi- c
10-2
Milli- m
10-3
Micro- u
10-6

18. SI Measurement Lab
Next week we will practice SI measurement with a LAB! 

19. Accuracy and Precision
Accuracy = how close a measurement is to the true value of the thing being measured.
Precision = the exactness of the measurement.
Example:
distance that is measured in millimeters is more precise that a distance measured in centimeters.

20. Error
Error = an expression of the amount of imprecision or variation in a set of measurements.
Commonly expressed as percent error
Percent error = {(accepted value - experimental value) /accepted value} * 100

21. Observations and Models
Scientists use models to simulate conditions in the natural world.
Model = description, representation, or imitation of an object, system, process, or concept.
4 types:
(1) Physical Models = 3 D model that can be touched
Examples: Maps and Charts
(2) Conceptual Models = verbal or graphical models that represent how a system works or is organized.
(3) Mathematical Models = mathematical equations that represent the way a system or process works
(4) Computer Models = use math to create and display an image.

22. Acceptance of Scientific Ideas
When scientists reach a conclusion, they introduce their findings to the scientific community.
New scientific ideas undergo review and testing by other scientists before they are accepted.

23. Publication of Results and Conclusions
Scientists commonly present their results of their work in scientific journals or at professional meetings.

24. Peer Review
Scientists in any one research group tend to view scientific ideas similarly.
Therefore, they may be biased to accept their own findings so all scientific ideas undergo peer review.
Peer Review = process in which several experts on a given topic review another expert’s work on that topic before the work gets published.

25. Formulating a Theory
After results are published, they usually lead to more experiments, which are designed to test and expand the original idea.
This process may continue for years!
When an idea has undergone much testing and reaches general acceptance, that idea may help form a theory.
Theory = an explanation that is consistent with all existing tests and observations; based on scientific laws.
Scientific Law = general statement that describes how the natural world behaves under certain conditions and for which no exceptions have been found. (Example: gravity)

26. Importance of Interdisciplinary Science
Scientists from many disciplines commonly contribute the information necessary to support an idea.
Example: Impact Hypothesis on the extinction of dinosaurs- studied by Paleontology, Geology, Astronomy, and Climatology

27. Science and Society
Scientific knowledge helps us understand our world.
Science is part of society, and advances in science can have important and long-lasting effects on both science and society.

28. Quick Demonstration! CARDS! Analyze your results:
(1) Lay out 10 cards- record the number of red cards.
(2) reshuffle- repeat step 1 four more times.
(3) Which trials showed the highest number of reds? Calculate the total range of red cards by finding the difference between the highest number and lowest number.
(4) Determine the mean number of red cards per trial by adding the number of red cards in the five trails and divide by 5.
Analyze your results:
(1) A deck of cards has 50% red cards- How close are you to this average?
(2) What about the entire class? (Average all answers to #1)
(3) How does changing the sample size affect the accuracy?

29. HW: Complete Section 2 Review Questions #1-3 at the end of your notes-
(1) Describe the conditions under which scientific laws and theories can be changed.
(2) Summarize how scientific methods contribute to the development of modern science.
(3) Explain how technology can affect scientific research.