Science

1. Science • A way of learning about the natural world

2. Types of Science • http://www.youtube.com/watch?v=E-5sWfqa6wM

3. Science Lab Rules • http://www.nsta.org/pdfs/SafetyInTheScienceClassroom.pdf • http://www.youtube.com/watch?v=yclOrqEv7kw

4. Scientific terminology • Scientific inquiry

5. Common Science Terms • Observation is using one or more of your senses to gather information and collect data • Inference is an interpretation of an observation typically drawn from some data

6. Hypothesis is an educated guess. • Theoryis a well tested concept that explains a wide range of observations

7. Scientific Method • Posing a question • Gather information, observe, and make inferences • Form hypothesis • Test hypothesis by doing an experiment and collect data (multiple trials) • Analyze and interpret data • Draw conclusions • Retest (usually by other scientists)

8. Variable • Question: What's a variable? • Answer: A variable is an object, event, idea, feeling, time period, or any other type of category you are trying to measure. There are two types of variables-independent and dependent.

9. Independent variable • Independent Variable • An independent variable is a variable that you can control. • It is the variable that the child can change during the experiment. • For example, in an experiment on the effect of light on plant growth, the child can control how much light a plant receives. He can put one plant near a window and another plant in a dark closet.

10. Dependent variable • Dependent Variable • A dependent variable is the variable that you observe and measure. • You have no control over the dependent variable; you want to observe what happens to the dependent variable when you change the independent variable. • For example, if the child is testing the effects of light on plant growth, how much the plant grows after some period of time would be the dependent variable. The child can measure how much the plant in the closet grows relative to how much the plant near the window grows.

11. Controlled Variable • Controlled Variables • Besides independent and dependent variables, every good experiment needs to control certain variables so that they do not influence the outcome of the experiment systematically. • A controlled variable is one that you keep the same for all the conditions of your experiment. A good scientist needs to think through all the variables that might need to be controlled so that they do not interfere with the experiment. • For example, to get reliable results for the plant experiment, both the plant near the window and the plant in the closet need to receive the same amount of water so that testers would know that it was the differences in light and not the differences in water that made one plant grow more than the other.

12. The reliability and validity can affect science experiments

13. Variables in scientific investigation • Independent variable (manipulated variable) is the variable that is changed to test a hypothesis • Dependent variable (responding variable) is the factor changes • Controlled variable (constant) are all the other factors in experiment that must remain the same.

14. Video on Independent, Control, and Dependent Variables • http://www.youtube.com/watch?v=x2606GQmDqY

15. Scientific Laws • Law is specific to certain conditions • Supported by a large amount of data • Widely accepted by a vast majority of scientists

16. Difference between Laws & Theories and Hypothesis • Laws are statements based on observation alone which always appears to be true. • Hypotheses and theories, on the other hand, are an attempt to explain what has been observed. Often scientists form theories to explain laws.

17. Law Examples • Laws: • 1. The Law of Gravity. This law tells us the size of the gravitational force, but it does not explain why gravity exists or even why it is as strong as it is. • 2. The First and Second Laws of Thermodynamics. The first law of thermodynamics tells us that every experiment ever done leads to the conclusion that energy is always conserved. It is a fact, but it is not an explanation.

18. Theories • Theories – very broad but able to be explained • 1. Theory of evolution • http://www.youtube.com/watch?v=Wl7ldMr_m5k • 2. Big Bag Theory • http://www.youtube.com/watch?v=zDQzKTedGNEhttp://www.youtube.com/watch?v=zDQzKTedGNE

19. Scientific Laws and theories • Law of Gravity • Newton’s three laws of motion • Law of Inertia - object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force • Acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object). • For every action there is an equal and opposite re-action.

20. Scientific Laws and theories • Big Bang Theory • Evolution and natural selection

21. Law, theory or hypothesis? • a. In every case, male birds are either similar or more colorful than their female counterparts . • b. Zinc in the diet will lower the rate and intensity of viral outbreaks. • c. There is a strong connection between nutrition and a variety of cancers.

22. Answers: • a. is a law. It is a statement of something which appears to always be true, but it is not an explanation of anything. • b. is a hypothesis. It is a very specific prediction about the connection between one thing and one other thing. • c. is a theory. It is a broad statement that nutrition in general can have an impact on a range of very different kinds of cancer.