1. 3.1 Inquiry and the Scientific Method
Scientists believe the universe follows a set of rules called natural laws.
The primary goal of science is to discover these natural laws and what they mean.

2. 3.1 Inquiry and the Scientific Method
Learning about science by asking questions is called inquiry.
An inquiry is like a crime investigation with a mystery to solve.

3. 3.1 Inquiry and the Scientific Method
Because evidence is so important in science, there are careful rules defining what counts as scientific evidence.
The evidence must accurately describe what happens in the real world.

4. 3.1 Scientific Evidence Scientific evidence must be objective.
“Objective” means the evidence should describe only what actually happened as exactly as possible.
It is reported without bias or opinion.

5. 3.1 Scientific Evidence Scientific evidence must repeatable.
“Repeatable” means that others who look the same way at the same thing will observe the same results.
Galileo’s drawings of the moon.
More evidence of lunar cycles.

6. 3.1 Scientific theories
One of two things can happen when new evidence is found:
The current theory correctly explains the new evidence. Or,
The current theory does not explain the new evidence so a new (or improved) theory is waiting to be discovered.

7. 3.1 Scientific theories
The word theory in science means a single explanation is supported by lots of evidence collected over a long period of time.
Theories in science start out as hypotheses.

8. 3.1 Scientific hypotheses
A scientific hypothesis must be testable.
We collect evidence that supports or refutes the hypothesis.

9. 3.1 The Scientific Method
Scientists observe nature, then develop or revise hypotheses about how things work.
The hypotheses are tested against evidence collected from observations and experiments.
Any hypothesis that correctly accounts for all of the evidence from the observations and experiments is a potentially correct theory.
A theory is continually tested by collecting new and different evidence. Even one piece of evidence that does not agree with a theory forces scientists to return to step one.

10. 3.2 Experiments and variables
An experiment is a situation specifically set up to investigate something.
The goal of any experiment is to understand the relationship between variables.
In a simple ideal experiment only one variable is changed at a time.

11. 3.2 Experiments and variables
The variable you change in an experiment is called the experimental variable.
The variables you keep the same are called control variables.
Each time you run the experiment is called a trial.
See if you can identify each component in this experiment…

12. Experimental variable
Trials
Control variable
Control variable
Control variable

13. 3.2 Experimental techniques
Your experimental technique is how you actually do the experiment.
The procedure is a collection of all the techniques you use to do an experiment.

14. 3.2 Experiments then and now
Michael Faraday, a British scientist, made some important discoveries while experimenting with electricity and magnets.
Faraday’s original question was “How are electricity and magnetism related?”
Electric current is created when a coil rotates in a magnetic field.

15. 3.2 Experiments then and now
Earth is like a giant magnet.
In 1996, NASA conducted a modern version of Faraday’s electromagnetism experiments using a tethered satellite.