Today is Thursday,May 7th, 2015

Pre-Class:Today we are reviewing.

Have your questions ready!

Today’s Agenda

• Review• Review• Bling?• Review

Review Game Rules

• I will ask a question to the class.• Each participant (that’s you) writes down the

answer silently.– Not each group…each individual.

• After a few moments, I will say, “Compare answers.”

• Each of you will look at what the other wrote.

Review Game Rules

• Did you each get the right answer?– 2 points.

• Did one of you get the right answer?– 1 point.

• Neither of you?– For shame. 0 points.– And eternal guilt.

Review Game Rules

• The List of Do Nots:– Do not talk to each other, make noises, gesture,

give answers (my discretion here) between when the question has been read and when I say, “Compare answers.”• Doing so will result in a disqualification for that round.

Don’t believe me? Try it.

– Do not fall asleep when I’m getting scores.• If you’re not paying attention, I’m not giving you points.

Review Question 1

• During a lunar eclipse, one might say that the Moon and Sun are in what kind of alignment?– Opposition.

Review Question 2

• During a solar eclipse, one might say that the Moon and Sun are in what kind of alignment? BE SPECIFIC.– Inferior conjunction.

Review Question 3

• What units must “a” be in for the equation for Kepler’s third law? (P2 = a3)– Astronomical units (au).

Review Question 4

• What units must “P” be in for the equation for Kepler’s third law? (P2 = a3)– Years, or specifically Earth-years.

Review Question 5

• What does Kepler’s first law state?– That orbiting bodies moving around the Sun take

an elliptical path.

Review Question 6

• What is the distinguishing feature of the Tychonian model of the solar system?– Some planets orbiting around the Sun, which

orbits around the Earth, while other planets simply orbit the Earth without orbiting the Sun.

Review Question 7

• BONUS NON-ASTRONOMY QUESTION• You may wager any/all of your points.• Category: Geography

• In which state is the United States’ highest mountain peak (from sea level) located?– Alaska (Mount McKinley; elevation 20,321 ft).

Review Question 8

• If some celestial object somewhere in the universe has a prograde rotation, is it rotating clockwise or counterclockwise?– Neither. Prograde simply means the planet is

rotating in the same direction as a related body, most likely the Sun, but outside the solar system that may not be counterclockwise.

Review Question 9

• English comedy group Monty Python is famous in part for The Galaxy Song (from The Meaning of Life), in which they attempt to put things in perspective by highlighting how fast the Earth is moving through space.– Here’s a clip.

• If the velocities they cited were averages, at what point in Earth’s orbit would the planet be moving at the highest velocity above average?– Perihelion, which for Earth is in January.

Review Question 10

• Who was that guy that suggested the heliocentric solar system model before Ptolemy proposed the geocentric model?– Aristarchus (of Samos).

Review Question 11

• Who was that Greek guy that measured the circumference of the Earth?– Eratosthenes.

Review Question 12

• BONUS NON-ASTRONOMY QUESTION• You may wager any/all of your points.• Category: Geography

• What US state features a publicly-open state park in which visitors can (and do) dig for diamonds?– Arkansas.

Review Question 13

• Ptolemy tried to explain the weird, westward motion (relative to stars) of the planets by saying that they went in weird little circles as they moved around the Sun. What were the weird little circles known as?– Epicycles.

Review Question 14

• Ptolemy tried to explain the weird, westward motion (relative to stars) of the planets by saying that they went in weird little circles as they moved around the Sun. What was the larger arc around the Sun known as, instead of the term “orbit?”– The deferent.

Review Question 15

• In what country would you find the pre-telescope “observatory” known as Bighorn Medicine Wheel?– The United States (Wyoming).

Review Question 16

• Where within a planet’s orbit is the Sun located? BE SPECIFIC.– At one of the two foci.

Review Question 17

• What’s the eccentricity of a straight line?• 1.

Review Question 18

• Gravity is a function of what two parameters of an object?– Mass of the object.– Distance to the object (from another object).

Review Question 19

• Where would you have more mass, Jupiter or Saturn?– Neither. Mass does not change.

Review Question 20

• Suppose the Sun were to disappear. According to physics, within ten minutes the Earth would be expected to do what?– Continue off its orbit into a straight line.

Review Question 21

• Which of Newton’s laws tells us that the Earth would do that?– Newton’s First Law of Motion: An object in motion

tends to stay in motion; an object at rest tends to stay at rest, unless acted on by a force.

Review Question 22

• BONUS NON-ASTRONOMY QUESTION• You may wager any/all of your points.• Category: Torture Devices

• What old-fashioned torture device puts the criminal’s head and hands through holes between two hinged wooden boards, causing more shame than pain?– The pillory. The stocks were the same thing, but

for legs/feet.

Review Question 23

• Given the equation P2 = a3, how long does it take Mercury to get around the Sun once if its major axis is 0.76 au? INCLUDE UNITS.– Approximately 0.234 Earth-years (or just “years”).– If you got the wrong answer, it could be because I

gave you the major axis (not “a”) instead of the semi-major axis (“a”).• Cause I’m a shifty bastard.

Review Question 24

• Which planet is the appropriate focus of study for the Cassini-Huygens probe?– Saturn, because that’s the planet Christiaan

Huygens and Giovanni Cassini primarily studied.

Review Question 25

• Why don’t rockets go straight up into space when launched? Why do they turn?– Rockets perform a gravity turn to make for a more

efficient launch at a lower velocity to compensate for a relatively high escape velocity necessary to leave Earth by simply accelerating upward.