Online reading assignment: cosmology (NC campus)

Astronomy 210, spring semester 2013
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on evidence for the big bang, and models of the early big bang.

Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.
"The tale about the crocodile and the elephant's trunk was cool to read about, even though there is no evidence that it ever happened."

"I found Olbers' paradox very interesting because it would make sense that the night sky should be bright like daytime because of the astonishing amount of stars in our universe, one would think that the night sky would be so covered that it would be blinding."

"The video, it helped me understand why it is dark at night."

"I thought it was interesting that the universe doesn't have an edge. There really is no center to the universe or at least that is what the introductory chapter said. That is pretty cool to think about. The universe is so big, it is formless almost and doesn't really have boundaries."

"I think it's interesting how much we know and don't know about the big bang theory because we are so young as a planet and we're learning new things every day!"

"I find the big bang particularly interesting because it is how everything started. It is so mind blowing to me that everything started from nothing."

"The cosmic microwave background proving the big bang theory by detecting photons is interesting to me due to my faith in creationism."

"I found it interesting that because of finite speed of light, looking at objects further away from us allows us to see those objects farther in the past."

"If a proton and its antiproton 'evil twin' meet up with each other, they will be destroyed and converted back into energy which is the process of annihilation."

"Everything. Especially learning about how some protons were able to survive. This interests me for two reasons. First because it is mysterious. Why did they survive? Second because those surviving particles were the seeds to everything we know."

"How the edge of the universe is time instead of space."
Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"I don't understand how they find an edge in time/space, and how scientists know they have run out of galaxies to see."

"Probably a lot of it."

"Time zero confuses me because I don't understand what was there, or here, before that. Do we know what it could have been?"

"The statement that says the universe in not infinite, but finite (in time)confuses me because I don't understand what it means."

"Distant galaxies appear to be younger, since I thought they would appear to be older."

"Hubble's law! I feel like I almost get it but am having a hard time wrapping my mind around the raisin bread model. Is it just that two galaxies that are close together move away less from one another during expansion? I get it when I think about distance but when I can't understand how the distance increases the rate of motion of galaxies moving away from each other."

"I'm still trying to understand the big bang. I always it started from a certain point, but now I read it really started from a state of high density and high temperature with no space between galaxies. I'm having a hard time understanding that."

"How the edge of the universe is time instead of space."

"Nothing at all."
Briefly explain how it is possible for you to see a star in tonight's sky that may have already died a long time ago.
"It is possible because of the finite speed of light, it takes a very long time for stars' light to travel to us."
Describe what will happen when a matter particle and an antimatter particle meet each other.
"Both particle and antiparticle disappear, leaving behind the energy they were made of. This is called 'annihilation.'"
Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"How certain are you that they are right about the big bang?" (I am very certain that the science of the big bang is correct...so far.)

"There's a song called 'The Big Bang' by Rock Mafia but I'm not sure if it's related to astronomy." (Whether it is about the big bang or not, the video does feature Miley Cyrus...)

It's my observation that many of the flashcard questions do not actually have the answer in the text, but allude to the answers." (Yes, since they require more sophisticated thinking than reading comprehension--which is what you get to practice in many of the in-class activities.)

"Why is the universe expanding and cooling? Don't things normally expand with heat? Does expansion just mean more matter being created?" (Yes, if you add heat to a gas to increase its temperature, the gas will expand. But if you allow a gas to expand (without adding heat to it), the gas will cool off and drop in temperature. The expansion of the universe doesn't mean more matter is being created, but more space is being created, so the distances between galaxies are getting bigger.)

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