Q Topic: Our Weird Universe Purpose This activity assesses students' ability to apply learning objective #2: Analyze the expansion of the Universe Only a student's first post can be counted because everyone else's posts are visible after you post the first time. I will grade and discuss your answers after the discussion period has closed. Directions Part 1: Due Thursday at 9pm. Answer the questions below. Lookback Time and Cosmic Light Horizon: Above is a representation of our cosmic light horizon. The black circles represent galaxies (not to scale!). a) What is located at the center of the Observable Universe, marked X? b) Can we see galaxy C? Why or why not? c) Remember the Lookback Time. If galaxy B is 9 billion ly (9 Gly) away, how long does it take light to travel from galaxy B to us? d) Which looks younger, galaxy A or galaxy B? Why? e) Which galaxy has the bigger cosmological redshift, A or B? f) What is outside the Observable Universe? Answer only one: nothing more galaxies Big Bang only photons a different universe g) So we are in a Universe with no center and no edge, but it is expanding... and it might be infinite. And it is all space and time and mass and energy, but was born out of nothingness. What do you think about this? Does it seem sensible and natural or do you find it odd and confusing? Can you think of any better explanation for what we see? I would like your answer to be at least five (5) sentences long. Part 2: Due Sunday at 9pm. Read your peer review student's answer to question g above. What is interesting or confusing about their reply? Answer in at least four thoughtful sentences. Remember, the rubric mentioned below is for you to see how to be successful on an assignment and for me assess your work; students cannot and should not use it to grade anyone. Peer reviews are not for giving grades to the students. Once your student for peer review is assigned, the notification you receive allows you to access them to leave your comments in the comments sidebar. I am looking for gentle, guiding advice, questions, praise and other scientifically relevant comments. I am hoping that looking at each other's work will help you improve yours! You can view peer review notifications in Canvas in the Recent Activity Stream, the To Do list, and from the individual discussion page. Once peer reviews are assigned, you can also be notified according to your Canvas notification preferences. Click on "Review Now." To complete the peer review you must review the student's discussion reply and add a comment in the comment sidebar. Don't use the Rubric mentioned below for peer reviews; that is just for you to see how I will grade each discussion. Canvas looks like it will force you to use the Rubric BUT you will receive no points for peer review if you write in the Rubric! The peer review must be written only in the comments sidebar. Rubric To view grading criteria, click on the three dots in the upper right and select Show Rubric. (This is not for use with the peer reviews!) After I have graded your Discussion, visit your Grades page and click on the Rubric icon at the right side for this Discussion to see my personal comments to you. ________________________________________ Netiquette • Be kind and respectful to others • Use scientific terminology, not jargon or slang • Use language that supports others