1 Chapter 1, Section 3 BELLWORK (write answers only!) When you were a child, you probably had many questions about how the world worked. Over the years, you have probably answered many of those questions. 1) What is an example of something you wondered about? (it can be something simple) 2) How did you figure it out?

2 Chapter 1, Section 3 Science and Inquiry  The word science is derived from Latin and means “ knowledge ”.  Science is all about having questions and then finding a way to answer them. We answer questions by collecting data. Data: Recorded observations

3 Chapter 1, Section 3 Types of Data   Data fall into 2 categories: 1.____________ : measurements, which are sometimes organized into tables and graphs. »Examples? 2.____________ : non-numerical descriptions; not measurements. »Examples?

4 Chapter 1, Section 3 Hypothesis-Based Science  Observations can also lead us to ask questions and propose explanations called hypothesis. –These are NOT “ guesses ”. A hypothesis is a possible explanation for the cause of the observation.

5 Chapter 1, Section 3 The Role of Hypotheses in Inquiry experimentation  A scientific hypothesis can be tested by experimentation.  Ex: Observation: Your flashlight doesn’t work  Question: Why doesn’t your flashlight work?  Hypothesis 1: The batteries are dead.  Hypothesis 2: The bulb is burnt out.

6 Chapter 1, Section 3 A Closer Look at Hypotheses in Scientific Inquiry  A hypothesis must be: 1.testable 1.testable : there must be a way to check its validity 2.falsifiable 2.falsifiable : there must be a way to reveal if a hypothesis is not true.  A hypothesis gains support by surviving various tests that could falsify it.  And falsifying alternative hypotheses.

7 Chapter 1, Section 3 More on Hypotheses false  Falsifying a hypothesis proves it false.  But failure to falsify a hypothesis does not prove it true.  Ex: You replace your flashlight bulb, and it now works.  This falsifies Hypothesis 1 (dead batteries).  This supports Hypothesis 2 (bulb burnt out), but does not prove it – perhaps the first bulb was inserted incorrectly.

8 Chapter 1, Section 3 More on Hypotheses PROVE  Nothing can PROVE a hypothesis true. wrong is probably right  It’s either wrong or, at best, is probably right.

9 Chapter 1, Section 3Variables Independent variable - what you change or control directly Dependent Variable - what changes as a result. No direct control. Control - Something that remains constant throughout the experiment.

10 Chapter 1, Section 3  The hypothesis can become stronger with more testing.  Until it becomes a theory. Scientific theory - explains WHY things behave a certain way.

11 Chapter 1, Section 3  Can theories be proven right or wrong? ____  Just like hypotheses.  It is only the best explanation.  Useful because they can be used to make predictions.  Help us form mental pictures of processes called models.

12 Chapter 1, Section 3  Another outcome when certain behavior repeats many times is a scientific law. Scientific law - only tells us WHAT happens.  Often expressed as an equation  TPS: –Can a theory become a law? ______ –Can laws change? ______

13 Chapter 1, Section 3 Laws vs. Theories  Laws tell ______  And theories tell ______

14 Chapter 1, Section 3 Example  You have a suspicion that stretching before a track meet actually makes you run slower. To test this, you stretch for 30 minutes before each race for a week. The following week you stretch for 15 minutes, and then the next week you don’t stretch at all.  Question: –What is the independent variable? –What is the dependent variable? –State a hypothesis for this experiment. –How would you control this experiment?

15 Chapter 1, Section 3 Penny Drop Lab  Objectives: Conduct an experiment to determine if a penny can hold more drops of regular water or soapy water.  Each person will turn in a lab sheet at the end of class to be graded.  We will have a lab quiz once everyone is finished.