1. YouTube Videos: Astronauts in Training April 8 & 9

2. DO NOW – B DAY Turn in your HW 1.BOTH papers for big bang notes You have 10 minutes to review the following with your peers (make CORRECTIONS! You will see this stuff on next class’ test!) – Team Quiz (take an answer key from my desk to keep!) – Ch 9 Quest – Post Lab – Black Hole Movie Notes – Big Bang Movie Notes – Your HW (once you get it back) TONIGHT’S HW: Prep for next class’ CLOSED NOTE test on CH 9 & 12!!!

3. DO NOW – A DAY Turn in your HW – 3 items!!! 1.Big Bang Movie Notes / Stars Web Quest (stapled packet) 2.Black Hole Notes: MYTH/ FACT & Movie Notes (single page) 3.Black Hole Notes: Web Quest (single page) You have 10 minutes to review the following with your peers (make CORRECTIONS! You will see this stuff on next class’ test!) Ch 9 Quest Post Lab Team Quiz Your HW (once you get it back) TONIGHT’S HW: Prep for next class’ CLOSED NOTE test on CH 9 & 12!!! (HW Pass = Thurs @ 7 - It Gets Better, but Why Wait?)

4. Stars Web Quest – A Day Obviously, there is a lot of info on there… I don’t expect you to memorize all of the stuff on here. However, you SHOULD know the common sense items. So, I have narrowed it down to the following questions: #1 – 12 (ALL Movie notes except #9) # 15 & 17 #18: a, c, d #20 – 22 #30 – 32

5. You Tube Videos…answer the ?s Watch “Life Inside the Space Station” http://www.youtube.com/watch?v=nGefSuwGylg http://www.youtube.com/watch?v=nGefSuwGylg – #1-3 Watch “NASA Zero-G Fun with the Vomit Comet KC-135 Reduced Gravity” http://www.youtube.com/watch?v=MMV_a7Olf2c https://www.youtube.com/watch?v=2V9h42yspbo http://www.youtube.com/watch?v=MMV_a7Olf2chttps://www.youtube.com/watch?v=2V9h42yspbo – #4 – 6 (25 seconds -1:05 for the explanation video) Watch “Space Toilet” http://www.youtube.com/watch?v=HUe2HcFUPSo&feature=related http://www.youtube.com/watch?v=HUe2HcFUPSo&feature=related – #7 Watch “Hilarious G-Force training” http://www.youtube.com/watch?v=Yjg6mRFzZzE http://www.youtube.com/watch?v=Yjg6mRFzZzE – #8 – 9 Watch “Astronauts on the moon” http://www.youtube.com/watch?v=FAqjys-cxoU http://www.youtube.com/watch?v=FAqjys-cxoU – #10 Watch “What Happens if Your Body is Exposed to the Vacuum of Space?” https://www.youtube.com/watch?v=pm6df_SExVw https://www.youtube.com/watch?v=pm6df_SExVw – #11

6. The rest of your notes (#12 – 19) These will NOT be on your test However, they MAY appear as extra credit questions So, you can finish clicking through this PowerPoint on your own to fill out #12-19, and use what you learned for potential extra points next class! From now until the bell to prep for the test however you see fit!

7. WEIGHT is a measurement of the force of gravity between you and the planet on which you are standing… BUT…how do you interpret it? Pressure against Earth is the sensation we interpret as weight. Weight and Weightlessness

8. The force of gravity, like any force, causes acceleration. Objects under the influence of gravity are pulled toward each other and accelerate. We are almost always in contact with Earth, so we think of gravity as something that presses us against Earth rather than as something that accelerates us…because we are always in contact with Earth…we are used to it! Weight and Weightlessness

9.  Stand on a bathroom scale that is supported on a stationary floor. The gravitational force between you and Earth pulls you against the supporting floor and scale.  By Newton’s third law, the floor and scale in turn push upward on you. Weight and Weightlessness

10. The sensation of weight is equal to the force that you exert against the supporting floor. -If you stand on the scale, your weight is “normal” -When the elevator accelerates upward, the bathroom scale and floor push harder against your feet. The scale would show an increase in your weight. Weight and Weightlessness

11. When the elevator accelerates downward, the support force of the floor is less. The scale would show a decrease in your weight. If the elevator fell freely, the scale reading would register zero. According to the scale, you would be weightless. You would feel weightless, for your insides would no longer be supported by your legs. **Remember – the sensation we interpret as weightlessness is really a LACK of SUPPORT FORCE Weight and Weightlessness

12. Rather than define your weight as the force of gravity that acts on you, it is more practical to define weight as the force you exert against a supporting floor; OR support force! According to this definition, you are as heavy as you feel. The condition of weightlessness is not the absence of gravity ( because gravity never goes away! ), but the absence of a support force. Weight and Weightlessness

13. Look at the picture: Both people are without a support force and therefore experience weightlessness. **Astronauts still have GRAVITY acting on them…they just lack a SUPPORT FORCE** Weight and Weightlessness

14. What sensation do we interpret as weight? Weight and Weightlessness

15. From within a rotating frame of reference, there seems to be an outwardly directed centrifugal force, which can simulate gravity. *It does NOT create gravity…it just FEELS like it* The centrifugal force experienced in a rotating reference frame is not a real force. Real forces include: gravitational, nuclear, & electromagnetic. 9.5 & 9.6 – Centrifugal Force & Simulated Gravity, pgs 129-132

16. Need for Simulated Gravity Today we live on the outer surface of our spherical planet, held here by gravity. What happens if we can no longer inhabit Earth? In the future, people may live in huge, slowly rotating space stations where simulated gravity allows them to function normally. 9.5 & 9.6 – Centrifugal Force & Simulated Gravity, pgs 129-132

17. Support Force Occupants in today’s space vehicles feel weightless because they lack a support force. Future space travelers need not be subject to these feelings of weightlessness. Their space habitats could spin, effectively supplying a support force and simulating gravity. 9.5 & 9.6 – Centrifugal Force & Simulated Gravity, pgs 129-132

18. The man inside this rotating space habitat experiences simulated gravity. As seen from the outside, the only force exerted on the man is by the floor The floor presses against the man (action) and the man presses back on the floor (reaction). The only force exerted on the man is by the floor. It is directed toward the center and is a centripetal force. 9.5 & 9.6 – Centrifugal Force & Simulated Gravity, pgs 129-132

19. As seen from inside the rotating system: In addition to the man-floor interaction, the man FEELS a centrifugal force pressing him on the wall. It seems as real as gravity. Yet, unlike gravity, it has no reaction counterpart. Centrifugal force is not part of an interaction, but results from rotation. It is therefore called a fictitious force. Centrifugal force is actually the acceleration you feel from rotation Floor pushes guy, Guy pushes floor… But NOTHING is pushing the GUY towards the floor! (his feet are just in contact w/ floor!) 9.5 & 9.6 – Centrifugal Force & Simulated Gravity, pgs 129-132

20. Challenges of Simulated Gravity The comfortable 1 g we experience at Earth’s surface is due to gravity. Inside a HYPOTHETICAL rotating spaceship the acceleration experienced is the centripetal acceleration due to rotation. 9.5 & 9.6 – Centrifugal Force & Simulated Gravity, pgs 129-132

21. Small-diameter structures would have to rotate at high speeds to provide a simulated gravitational acceleration of 1 g. Sensitive and delicate organs in our inner ears sense rotation. Although there appears to be no difficulty at 1 RPM, many people have difficulty adjusting to rotational rates greater than 2 or 3 RPM. *** Remember the ‘Vomit Comet’ video?** To simulate normal Earth gravity at 1 RPM requires a large structure—one almost 2 km in diameter. 9.5 & 9.6 – Centrifugal Force & Simulated Gravity, pgs 129-132

22. Artists’ depictions… Rotation will allow people inside the space station to experience a support force that simulates normal Earth gravity.

23. B DAY: The TWO-INCH Universe A powerful set of analogies to examine size and distance in astronomy Source: smithsonianeducation.org

24. Earth’s diameter = 8,000 miles QUESTION: If Earth is just two inches wide, how big would the Moon be at this scale? ObjectTo ScaleActual Earth2 inches8000 mi

25. Moon = ¼ inch! actual diameter = 2,000 miles QUESTION: At this scale, how far apart should they be? ObjectTo ScaleActual Earth2 inches8000 mi Moon¼ inch2000 mi

26. 5 feet! actual Earth-moon distance = 240,000 miles …1 light second! QUESTION: How big should the sun be in this analogy? ObjectTo ScaleActual Earth2 inches8000 mi Moon¼ inch2000 mi Earth – Moon 5 feet240000 mi

27. A minivan (16 feet across)! Actual Sun diameter = 875,000 miles QUESTION: If the 2-inch Earth were placed in the middle of the classroom, where would the minivan need to be parked to represent the position of the sun at this scale? ObjectTo ScaleActual Earth2 inches8000 mi Moon¼ inch2000 mi Earth to Moon 5 feet240000 mi Sun16 feet875000 mi

28. 6 football fields away! Actual Earth-Sun distance = 93,000,000 miles or 8 light minutes ObjectTo ScaleActual Earth2 inches8000 mi Moon¼ inch2000 mi Earth to Moon 5 feet240000 mi Sun16 feet875000 mi Earth to sun 6 football fields 93,000,000 mi

29. NEW ANALOGY Scale down the minivan sun into a 2-inch sun QUESTION: At this scale, how big would Earth be?

30. A grain of salt! QUESTION: How big would the moon be?

31. A speck of dust! QUESTION: How far away would this “speck of dust” moon be from the “grain of salt Earth”?

32. ½ inch! QUESTION: How far away would the sun be from the “grain of salt” Earth?

33. 20 feet!

34. New Analogy: 2-inch Solar System Sun speck in center, planets would be invisible at this scale! Actual solar system size = 7,000,000,000 miles (10 light-hours)

35. Next nearest star at this scale (Proxima Centauri) would be 2 football fields away! – Actual distance = 25.8 trillion miles or 4.3 LY Sun is 1 of billions of stars in our galaxy QUESTION: At this scale, how big is the Milky Way?

36. About the size of North America Actual Milky Way size = 100,000 LY At this scale, if the tiny dot of light at the center of the solar system were a grain of salt, a teaspoon of the salt would represent about 100,000 of the Milky Way’s 200+billion stars!

37. New Analogy: The Realm of Galaxies Side note: Andromeda galaxy is a galaxy that is very near the Milky Way and is seen as a single smeary light to the naked eye Actual Andromeda size = 1.3 million trillion miles (220,000 LY) Shrink the “continent-size Milky Way” down to 2- inches QUESTION: If Milky Way is 2-inches big, what is the distance between these two galaxies?

38. ~ 5 feet! Actual Milky Way-Andromeda distance = 15 million trillion miles (2.5 million LY) At this scale, individual stars in these galaxies would not be visible even with a microscope At this scale, the deep space galaxies seen by Hubble would be 4 miles from this classroom! So…QUESTION: How big is the universe? Let’s watch: http://htwins.net/scale2/http://htwins.net/scale2/