1. Hypotheses,
Theories,
and Laws

2. Many hypotheses are written as “If…then” statements:
If ______(independent variable)_________
then____(dependent variable) ____.

3. If I feed my cat a lot of food then she will get fat.
Example:
Independent variable:
I feed my cat a lot of food
Dependent variable: She will get fat
If I feed my cat a lot of food then she will get fat.

4. ****To make the hypothesis more specific, use INCREASE and DECREASE****
If I increase the amount of food I give my cat, then she will increase her weight.

5. Hypothesis practice:
1. Chocolate causes pimples.
___________________________________
2. Sunlight may cause skin cancer.
If I increase the amount of chocolate I eat then I will increase the number of pimples I get.
If I increase in the amount of time I spend in sunlight then I will increase my chance of gettingskin cancer

6. What is the IV and the DV in these hypotheses:
3. If dogs are given an Advantage flea collar, then the dogs will have a decrease in the number of fleas on their bodies.
IV=________________________________
DV=_______________________________
Advantage flea collar
Number of fleas

7. Laws Theories Law vs Theory ___________ tell us what happens.
_____________ examine what happens and tell us how and why it happens.
Laws
Theories

8. In the language of science, the word "law" describes an analytic statement. It gives us a formula that tells us what things will do.
For example, Newton's Law of Universal Gravitation tells us that "Every point mass attracts every single point mass by a force pointing along the line intersecting both points. The force is directly proportional to the product of the two masses and inversely proportional to the square of the distance between the point masses."
That formula will let us calculate the gravitational pull between the Earth and the object you dropped, between the Sun and Mars, or between me and a bowl of ice cream.

9. While the law lets us calculate quite a bit about what happens, notice that it does not tell us anything about why it happens. That is what theories are for.
In the language of science, the word "theory" is used to describe an explanation of why and how things happen. For gravity, we use Einstein's Theory of General Relativity to explain why things fall.
A theory starts as one or more hypotheses, untested ideas about why something happens. To become a scientific theory, an idea must be thoroughly tested, and must be an accurate and predictive description of the natural world.

10. .
****While _______rarely change, ________ change frequently as new evidence is discovered.*****
Laws
Theories

11. ****Instead of being discarded due to new evidence, theories are often revised to include the new evidence in their explanation. The Theory of General Relativity has adapted as new technologies and new evidence have expanded our view of the universe.
So when we are scientifically discussing gravity, we can talk about the law that describes the attraction between two objects, and we can also talk about the theory that describes why the objects attract each other.

12. Theories do not eventually “become “ laws; these are separate and describe different roles in science!!

13. Examples of Laws:
Law of Gravity
Laws of Thermodynamics
Newton’s Laws of Motion
Kepler’s Laws
Ohm’s Law
Examples of Theories:
Theory of Relativity
Big Bang Theory
Cell Theory
Atomic Theory
Theory of Evolution