1. Gravity
What’s going on?

2. Write down your observations for what you saw and share with your neighbor.

3. What do you know about what you saw
What do you know about what you saw? Write down at least 3 things that you learned last semester about the observed phenomenon.

4. Now give an explanation of how the observed phenomenon occurred
Now give an explanation of how the observed phenomenon occurred. In other words, explain how gravity works.

5. Watch this clip from Brian Greene’s Elegant Universe. (stop at 1:52)

6. The equation that Brian Greene brings up is called the Law of Universal Gravitation which was developed by Sir Isaac Newton.
What do you think goes into this equation? In other words, what do you think affects the force due to gravity between two objects?
𝐹=𝐺 𝑚 1 𝑚 2 𝑑 2
G is called the gravitation constant and was experimentally determined 111 years after Isaac Newton’s death. It has a value of 6.674×10−11 N m2/kg2.

7. Math time!!! 𝐹=𝐺 𝑚 1 𝑚 2 𝑑 2 G = 6.674×10−11 N m2/kg2
𝐹=𝐺 𝑚 1 𝑚 2 𝑑 2
G = 6.674×10−11 N m2/kg2
Calculate the force of gravity acting between you and your neighbor. Meter sticks are on the front table. Remember, 1.0 kg = 2.2 lb.

8. Watch the rest of the clip from Elegant Universe.
What evidence did Einstein have that Newton’s theory was incorrect?

9. Watch a clip from Fermilab’s Brain Cox about modern research into gravity.
Why did the scientist say that gravitons are hypothetical rather than theoretical?

10. To think about… What is science? What is the purpose of science?
What is the worth of science? (Are all scientific pursuits worthwhile?)

11. Homework (due Monday):
Look up one recent scientific discovery, briefly summarize the experiment and results, and give your opinion on the worth of the study (1-2 paragraphs). A great resource is the “Science is Awesome” page on Facebook.
2) Calculate the force of gravity between the earth and the moon.