Astronomy Unit 8

Ranking Task: The Size of Planets, Stars, and Stellar Remnants Part A: Listed following are several astronomical objects. Rank these objects based on their diameter, from largest to smallest. (Note that the neutron star and black hole in this example have the same mass to make your comparison easier, but we generally expect black holes to have greater masses than neutron stars.)

Ranking Task: The Size of Planets, Stars, and Stellar Remnants Part B: Listed following are several astronomical objects. Rank these objects based on their mass, from largest to smallest. (Be sure to notice that the main-sequence star here has a different spectral type from the one in Part A.)

Ranking Task: The Size of Planets, Stars, and Stellar Remnants Part C: Listed following are several astronomical objects. Rank these objects based on their density, from highest to lowest.

Sorting Task: The Bizarre Stellar Graveyard Listed following are distinguishing characteristics of different end states of stars. Match these to the appropriate consequence of stellar death.

Ranking Task: Length Contraction Part A: Each figure below shows a spaceship moving past your spaceship ("YOU") at the indicated speed. Assume that all the spaceships have equal length when at rest and that you watch the other spaceship as its clock ticks off one second. Rank the figures based on the length that you would measure for the other spaceship (in its direction of motion), from shortest to longest.

Ranking Task: Length Contraction Part B: The four figures below are the same as those in Part A. This time, rank the figures based on your length as measured by the passenger in the other spaceship, from shortest to longest.

Ranking Task: Length Contraction Part C: We can summarize the results of Parts A and B as follows: When another spaceship is moving by you (at constant velocity), you will measure the spaceship to be shorter than its rest length, while passengers on that ship will measure your length to be shorter. Imagine that you and the passengers on the other ship are arguing (by radio) about who really is the one that has become shorter. To settle the argument, you agree to meet up on Mars and put the two spaceships next to each other to see which one is really shorter. What will you find when you meet up on Mars?

Ranking Task: Time Dilation Part A: Each figure below shows a spaceship moving past your spaceship ("YOU") at the indicated speed. Imagine that you watch the other spaceship as its clock ticks off one second. Rank the figures according to how much time you would say passes (on your own ship) while the other ship's clock ticks off one second, from the shortest to the longest amount of time.

Ranking Task: Time Dilation Part B: The four figures below are the same as those in Part A. This time, imagine that the passengers on the other spaceship are watching your clock as its ticks off one second. Rank the figures according to how much time the passengers (on the other ship) would say passes (on their ship) while they watch your clock tick off one second, from the shortest to the longest amount of time.

Ranking Task: Time Dilation Part C: Consider again the spaceships from Parts A and B. Suppose that, at rest, both you and a passenger on the other spaceship have the same heart rate of 60 beats per minute. How will you and the passenger on the other spaceship observe each other's heart rates as you pass by in your spaceships?

Ranking Task: Understanding Curved Spacetime Part A: The figures below show several different astronomical objects. Rank the objects based on the strength of the gravitational force that would be felt by a spacecraft traveling at a distance of 10 AU from the center of each of the objects, from weakest to strongest. If the gravitational force is equal for two (or more) cases, show this equality by dragging one figure on top of the other(s).

Ranking Task: Understanding Curved Spacetime Part B: The figures below show several different astronomical objects. Rank the objects based on the amount that spacetime is curved (relative to flat spacetime) at a distance of 10 AU from the center of each of the objects, from least to greatest. If two (or more) cases are equal, show this equality by dragging one figure on top of the other(s).

Ranking Task: Understanding Curved Spacetime Part C: The figures below show several different astronomical objects. Rank the objects based on the amount that spacetime is curved (relative to flat spacetime) very near the surface (or event horizon) of the objects, from least to greatest.

Ranking Task: Understanding Curved Spacetime Part D: The figures below show several different astronomical objects. Rank the objects based on the acceleration a spaceship would have as it passed very near the surface (or event horizon) of each object, from smallest to largest.

Sorting Task: Effects of Relativity Imagine that you are located on Earth while a spaceship travels from Earth to the star Vega at constant velocity of 0.8c. The following items describe quantities that, according to Einstein's special theory of relativity, would be either larger (or longer), smaller (or shorter), or the same as their rest values. (Note that by "rest value," we mean the value you would find if both you and the spaceship were at rest on Earth.) Match each item to the correct category.

Ranking Task: The Size of the Milky Way Galaxy Part A: Listed following are several locations in the Milky Way Galaxy. Rank these locations based on their distance from the center of the Milky Way Galaxy, from farthest to closest.

Ranking Task: The Size of the Milky Way Galaxy Part B: Imagine a photon of light traveling the different paths in the Milky Way described in the following list. Rank the paths based on how much time the photon takes to complete each journey, from longest to shortest.

Ranking Task: Understanding Gravitational Lensing Part A: The figures below show several different astronomical objects. Rank the objects based on the amount that spacetime is curved (relative to flat spacetime) very near the surface (or event horizon) of each of the objects, from least to greatest.

Ranking Task: Understanding Gravitational Lensing Part B: The figures below show the same astronomical objects as shown in Part A. Rank the objects based on the amount that each would deflect the path of a photon of light from a very distant galaxy (as viewed from Earth), assuming the photon passes very near the surface (or event horizon) of each object, from smallest to largest.