1. What is science?

2. If this bug landed on you, what would you do? Why?

3. What Science is and is not
1) Goal of Science: - investigate and understand the natural world - explain events in the natural world - use explanations to make useful predictions 2) Science is… an organized way of using evidence to learn about the natural world

4. Thinking like a scientist…
3) Observation = information or facts detected by the senses collected in an orderly way used to find patterns or relationships 4) Information collected from observation = ______
Data

5. 5) 2 Types of Data Quantitative Qualitative Uses numbers
Uses measurement and units
Examples:
Length (meters)
Time (seconds)
Mass (grams)
Temperature (C)
Uses descriptions that are not measured
No numbers
Examples:
Color
Texture

6. Thinking Like a scientist
6) Inferences = - a logical interpretation based on prior knowledge - an assumption based on observations - could become a hypothesis

7. Hypothesis
= a proposed scientific explanation for a set of observations Must be testable Must be worded in a testable way (If…then…) Hypothesis are tested by gathering more data or using and experiment Hypotheses can be supported or ruled out

8. What do we know about Redi?
For centuries, people believed in “spontaneous generation”
The idea that new life forms sprang up from non-living sources
Example: maggots “spring up” from dead meat
In 1668, Francesco Redi performs an experiment to test the hypothesis

9. Francesco was the Man!!!!
I was the Man!!!!
Mi è stato l'uomo!!!

10. The experiment… 1) Set out two sets of jars both containing raw meat
2) One set is covered with gauze on top, the other set is left open to the air
3) Come back after several days and observe
Data = The jars without gauze have maggots, the jars with gauze do not

11. Redi’s experiment

12. What did Needham do?
Gravy

13. Needham’s Challenge
Boiled gravy to kill all organisms in it then let it sit for several days
Observed a few days later, the gravy was swarming with micro-organisms
Needham claimed that this proved that the micro-organisms had to come from the gravy

14. Gravy is delicious!

15. Spallanzani to the rescue

16. Spallanzani
Spallanzani conducted Needham’s experiment except using two containers of gravy
Boil them both to kill organisms
Seal up one container but allow the other access to the air
After a few days, the sealed jar contained no life while the unsealed jar swarmed with life again
Spallanzani concludes that the micro-organisms came from the air, not the gravy.

17. Pasteur confirms it
Louis Pasteur conducted a similar experiment with a flask of broth
The flask had a long curvy neck
Boil the broth then allow it to sit
The curvy neck allows air to enter the flask easily but not dust or microbes
After days, no microbes
Break the neck off and microbes appear a few days later
Boiling liquids to kill microbes and sealing off the no clean liquid is a process we now call Pasteurization (milk)

19. Pasteur

20. What is the process of Science?
Scientific Method
Step 1) Problem / Question (based on limited previous observations)
Step 2) Hypothesis – proposed explanation of the problem question
- educated guess
- must be testable
- if…then…statement

21. The process of Science continued
Step 3) Design and conduct an experiment
- 2 variables:
Manipulated = What you control
(Independent, Controlled)
Responding = what you observe for changes
(Dependent, Experimental)
Control = a group or trial used for comparison with your experiment (no variables are changed)

22. Collecting Data Quantitative = a number value or measurement
Qualitative = a description (no numbers)
Be accurate – as close to the actual value as possible
Be precise – same level of performance in all measurements, every time

23. Accuracy and Precision

24. What do I do with all the data?
Step 4) Analysis of data
Look for patterns or relationships
Graph the data:
Independent variable on x-axis
Dependent variable on y-axis
Label all graphs and axes in detail -

25. Variables Manipulated = What you control (Independent, Controlled)
Responding = what you observe for changes
(Dependent, Experimental)
Control = a group or trial used for comparison with your experiment (no variables are changed)

26. Final Step… Step 5) Conclusion
A good conclusion always answers two questions:
Did your experiment support the hypothesis or not?
Do you need to retest or experiment differently?

27. How many drops of water will fit on a penny?
You will need: White boards Marker Penny Pipet Cup of water Set up a good experiment Write down everything that you do Record all observations Be accurate and precise

28. Hypothesis vs. Theory
Hypothesis = a proposed scientific explanation for a set of observations (educated guess) Theory = a well-tested explanation covers a wide range of observations