Online reading assignment question: advice to future students

Astronomy 210, fall semester 2019
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. The following question was asked after the last lecture, but prior to the final exam.

Tell a student who is about to take this course next semester what he/she needs to know or to do in order to succeed in this course. (Graded for completion.)

"Do the reading assignments on time. It's easy to forget, and the lost points add up."

"Tackle the material covered with general curiosity. In a sense 'trip out' and invest your time into genuinely and you will do great!"

"in order to succeed in astronomy, you need to do be in class every day. Skipping any class day will cause you to lose points for the in-class activities. You also need to do the online reading assignments as missing them will hurt your grade. Finally, study for the exams and the final, they are the most important to do and getting a good grade on them will boost your grade significantly."

"You need to:
•Study for the quizzes.
•Come to class so you learn the material but also don't miss out on in-class-assignments.
•Don't forget to do the online reading assignments."

"I would say definitely show up, pay attention, actually listen and ask for help or ask questions if you don't get it and most importantly talk to the instructor! Super-chill, understanding and extremely helpful. (Thanks for the help btw and putting in effort as well.)"

"Do your homework and pay attention to the presentation slides posted on the blog. If you don't understand something, Google it. But come to class prepared enough to teach the subject to another student and you'll be fine."

"Do the online reading assignments. Show up to every lecture. Be genuinely interested."

"Turn off your phone during class."

"Prepare by doing the reading assignments to provide a rough assessment of your understanding, and questions to bring for the lecture."

"Come to every class--most important thing."

"Keep up with the blogs, not just the reading."

"Do the quiz question packets! Those will help you in preparing for the quizzes and tests which make up the majority of your grade. Helps you get a good grasp of the material. And of course showing up to class!"

"Something I had to learn during this course is to try and open my mind to the universe and using lots of visuals to understand how everything is connected. Specifically for this class I would say showing up for class and participating in lecture is super-important."

"Simply review your quizzes because they will be re-written on the exams."

"Go to office hours with the practice quizzes, get help answering them, study up those sheets and you'll never worry about failing a quiz. "

Online reading assignment question: advice to self for next semester

Physics 205A, fall semester 2019
Cuesta College, San Luis Obispo, CA

Students have a bi-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. The following question was asked after the last lecture, but prior to the final exam.

Give a piece of advice to yourself at the start of next semester on what you should do (the same, or differently) in order to succeed in Physics 205A/B (or similar science courses). (Graded for completion.)

"Just stay on top of your assignments, it's easy points. Also try to focus on things that aren't very clear to you the most because if you have a grasp on other concepts then it's pretty straight forward, considering physics is somewhat logic based. Also for the midterms just study what you messed up on the quizzes and grind those concepts into your skull. Other than that, easy cash. I should not procrastinate to study when an exam is coming up."

"Keep up, don't procrastinate. Get very familiar with free-body diagrams vs. tail-to-tail diagrams as early as possible. These are essential to understanding the problems and especially Newton's laws! Study super-hard and read the textbook. It's going to help you understand the material. Don't be dumb and procrastinate."

"A piece of advice I would give myself is to get help from a tutor immediately because you can't teach yourself how to do it."

"Keep up with the homework and reading."

"Keep up on the homework assignments and readings."

"Stay on top of the assignments and don't forget them."

"Spend more time going back through notes/examples from class."

"Look at the more conceptual side of topics. If I look at the more confusing stuff before the basics, it won't do much good."

"Chose the best teachers as always."

"Prepare enough sooner and get use to the format of the class in the beginning so its easy to stay on top of the workload."

"Go to the physics tutor in the Cuesta learning labs."

"Study early on and don't cram/procrastinate."

"I should continue to keep up with the classwork such as labs, homework, practice problems, but I need to stop procrastinating be being very last minute in when studying for exams in Physics 205B/my other course."

"Although it's stupid to procrastinate, getting it done later is better than never getting if done."

"I would tell myself that if you never miss a lab or lecture there's a very good chance that you'll get an 'A' in this class. I would also tell myself to spend a good amount of time trying to understand the reading assignments on waiferx.blogspot.com because they're super-informative and helpful with understanding the material. And P-dog will go over any part of the reading assignment that you don't understand in class the following day!"

"I would advise myself to do all the homework assignments to maximize my points in those categories and give myself a chance of skipping the final altogether."

"Define equation variables before exams."

"Don't give up and keep moving forward! Read the book from the start of the semester!"

"I would tell myself to prepare to have a roller coaster ride through concepts but stay in your seat the whole time and get through it because it will be over before you know it."

"Make sure to do all the online homework and reading assignments because those points rack up."

Astronomy current events question: giant exoplanet orbit computer simulation

Astronomy 210L, fall semester 2019
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Tim Stephens, "Simulations Explain Giant Exoplanets with Eccentric, Close-in Orbits" (October 30, 2019)
news.ucsc.edu/2019/10/giant-planets.html

The close-in, eccentric orbits of gas giant exoplanets may be due to planetary collisions and ejections, based on:
(A) look-back time.
(B) far-infrared imaging.
(C) computer simulations.
(D) gravity wave detectors.
(E) lack of solar flare activity.

Correct answer: (C)

Student responses
Sections 70178, 70186
(A) : 4 students
(B) : 5 students
(C) : 24 students
(D) : 1 student
(E) : 0 students

Astronomy current events question: multiple Sunburst Arc galaxy images

Astronomy 210L, fall semester 2019
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

Martina d'Angelo, "Astronomers Observe a Sunburst from the Early Universe--in 12 Copies" (November 8, 2019)
titan.uio.no/node/3518

Multiple zoomed-in images of early star formation in the Sunburst Arc galaxy were produced by:
(A) antimatter fields.
(B) neutrino emissions.
(C) gravitational lensing.
(D) radio interferometry.
(E) scanning old photographic plates.

Correct answer: (C)

Student responses
Sections 70178, 70186
(A) : 1 student
(B) : 9 students
(C) : 16 students
(D) : 4 students
(E) : 3 students

Astronomy current events question: high velocity star S5-HVS1

Astronomy 210L, fall semester 2019
Cuesta College, San Luis Obispo, CA

Students are assigned to read online articles on current astronomy events, and take a short current events quiz during the first 10 minutes of lab. (This motivates students to show up promptly to lab, as the time cut-off for the quiz is strictly enforced!)

News release, "Runaway Star Was Ejected From The 'Heart Of Darkness'" (November 12, 2019)
carnegiescience.edu/news/runaway-star-was-ejected-heart-darkness

Astronomers determined that the high velocity star S5-HVS1 will eventually leave the Milky Way, after being ejected by:
(A) dark matter.
(B) globular clusters.
(C) a type II supernova.
(D) colliding neutron stars.
(E) the central supermassive black hole.

Correct answer: (E)

Student responses
Sections 70178, 70186
(A) : 3 students
(B) : 2 students
(C) : 4 students
(D) : 6 students
(E) : 20 students

Astronomy quiz archive: Milky Way, nucleosynthesis, cosmology

Astronomy 210 Quiz 7, fall semester 2019
Cuesta College, San Luis Obispo, CA

Section 70158, version 1
Exam code: quiz07sNt4


Section 70158

0- 8.0 :
8.5-16.0 :	***** [low = 11.5]
16.5-24.0 :	***
24.5-32.0 :	************ [mean = 27.7 +/- 8.3]
32.5-40.0 :	********** [high = 40.0]

Section 70160, version 1
Exam code: quiz07No37


Section 70160

0- 8.0 :	* [low = 8.0]
8.5-16.0 :	********
16.5-24.0 :	****** [mean = 18.5 +/- 8.5]
24.5-32.0 :	****
32.5-40.0 :	* [high = 36.5]]

FCI pre-test to post-test comparison

Students at Cuesta College (San Luis Obispo, CA) were administered the 30-question Force Concept Inventory (David Hestenes, et al.) during the last week of instruction.

The pre- to post-test gain for this semester is:

Physics 205A fall semester 2019 sections 70854, 70855 (matched-pairs only, N = 42)
<initial%>	= 26% ± 16%
<final%>	= 38% ± 15%
<g>	= 0.15 ± 0.17 (matched-pairs); 0.16 (class-wise)

The paired Student's t-test of the null hypothesis for Cuesta College FCI pre-test scores versus post-test scores results in p = 0.0001 (t = 5.5774, degrees of freedom = 41), thus there is a strongly statistically significant difference between Cuesta College FCI pre-test and post-test scores.

This Hake gain is notably larger than the previous two semesters' paired results for algebra-based introductory physics at Cuesta College (0.09 and 0.11). (Previous semesters before 2017 were analyzed using unpaired results.)

Notable about this Physics 205A class at Cuesta College since fall semester 2017 is the absence of an embedded tutor (student teaching assistant circulating in class along with the instructor during open discussion and problem-solving sessions); otherwise as taught from fall semester 2014 onwards is the requirement that students read and answer questions on the textbook and lecture slides before coming to lecture (in a "flipped classroom," but this label was not given to the students this semester, as was done up through fall semester 2018!), instructor discussion in-class based on answering student questions and concerns submitted online previous to lecture, in-class problem-solving sessions ("lecture-tutorials," including ranking tasks, and/or a brief written explanation of a selected question submitted by each student every lecture).

D. Hestenes, M. Wells, and G. Swackhamer, Arizona State University, "Force Concept Inventory," Phys. Teach. 30, 141-158 (1992).
Development of the FCI, a 30-question survey of basic Newtonian mechanics concepts.

Previous FCI results:

(Paired Student t-tests from 2017 onwards)

• Cuesta College, fall semester 2018 pre-test to post-test comparison.
  
• Cuesta College, fall semester 2017 pre-test to post-test comparison.
  
  (Note only unpaired Student t-tests were run prior to 2017)
  
• Cuesta College versus UC-Davis, fall semester 2016 pre-test to post-test comparison.
  
• Cuesta College versus UC-Davis, fall semester 2015 pre-tests, and post-tests.
  
• Cuesta College versus UC-Davis, fall semester 2014 pre-tests, and post-tests.
  
• Cuesta College versus UC-Davis, fall semester 2013 pre-tests, and post-tests.
  
• Cuesta College versus UC-Davis, fall semester 2012 pre-tests, and post-tests.
  
• Cuesta College versus UC-Davis, fall semester 2011 pre-tests and post-tests.
  
• Cuesta College versus UC-Davis, fall semester 2009 pre-tests and post-tests.
  
• Cuesta College versus UC-Davis, spring semester 2009 pre-tests and post-tests.
  
• Cuesta College versus UC-Davis, fall semester 2008 pre-tests and post-tests.
• Cuesta College versus UC-Davis, spring semester 2008 pre-tests and post-tests.
• Cuesta College versus UC-Davis, fall semester 2007 pre-tests and post-tests.

Physics quiz question: concrete beam contraction

Physics 205A Quiz 7, fall semester 2019
Cuesta College, San Luis Obispo, CA

A concrete beam (linear expansion coefficient 9.8×10^–6 K^–1) is 12.2 m long at room temperature (293 K). In order to contract by 0.0010 m, its temperature should be decreased by:
(A) 1.2×10^–5 K.
(B) 8.2×10^–5 K.
(C) 0.38 K.
(D) 8.4 K.

Correct answer: (D)

The relation between the change in length ∆L due to a temperature change ∆T is given by:

α·∆T = ∆L/L,

such that:

∆T = ∆L/(α·L) = (–0.0010 m)/((9.8×10^–6 K^–1)·(12.2 m)) = –8.36400133824 K,

or to two significant figures, the decrease in temperature is 8.4 K or 8.4° C.

(Response (A) is L·α; response (B) is ∆L/L; response (C) is ∆L/(α·T₀).)

Sections 70854, 70855
Exam code: quiz07VlnC
(A) : 3 students
(B) : 8 students
(C) : 3 students
(D) : 37 students

Success level: 73%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.49

Physics quiz question: concrete vs. glued laminated wood beam contraction

Physics 205A Quiz 7, fall semester 2019
Cuesta College, San Luis Obispo, CA

"Finger joints in glue-lam beams, Polkky mill, Kuusamo2"
Eli Sagor
https://flic.kr/p/9xRT62

A concrete beam (linear expansion coefficient 9.8×10^–6 K^–1) and glued laminated wood beam (linear expansion coefficient 3.6×10^–6 K^–1[*]) have the same length at room temperature (293 K). If they both decrease in temperature by the same amount, the length of the concrete beam will be __________ the length of the wood beam. (A) shorter than.
(B) equal to.
(C) longer than.
(D) (Not enough information is given.)

[*] awc.org/pdf/codes-standards/publications/archives/lrfd/AWC-LRFD1996-Glulam-0203.pdf.

Correct answer: (A)

The relation between the change in length ∆L due to a temperature change ∆T is given by:

α_concrete·∆T = ∆L_concrete/L,

and similarly for the glued laminated beam:

α_wood·∆T = ∆L_wood/L,

where the original length L and the temperature change ∆T is the same for both the concrete and glued laminated beam. Solving for this common factor for both beams:

L·∆T = ∆L_concrete/α_concrete,

L·∆T = ∆L_wood/α_wood,

we can then set this common factor for both beams equal to each other:

L·∆T = L·∆T,

∆L_concrete/α_concrete = ∆L_wood/α_wood.

From inspection, since α_concrete > α_wood, then for the equality to hold, ∆L_concrete > ∆L_wood, and so the concrete beam would contract more, and as a result be shorter than the glued laminated beam.

Sections 70854, 70855
Exam code: quiz07VlnC
(A) : 18 students
(B) : 7 students
(C) : 26 students
(D) : 0 students

Success level: 35%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.05

Physics quiz question: comparing specific heat capacity values

Physics 205A Quiz 7, fall semester 2019
Cuesta College, San Luis Obispo, CA

A 0.25 kg glass sample (400 K initial temperature) and a 0.75 kg graphite sample (300 K initial temperature) are brought in contact with each other to reach thermal equilibrium with a final temperature of 330 K. Ignore heat exchanged with the environment. The specific heat capacity values of these two substances are not known. The __________ sample has the larger specific heat capacity value.
(A) glass.
(B) graphite.
(C) (There is a tie.)
(D) (Not enough information is given.)

Correct answer (highlight to unhide): (A)

The transfer/balance energy conservation equation for this system is given by:

Q_ext = ∆E_glass + ∆E_graphite,

and since there is no heat exchanged with the environment, Q_ext = 0, such that:

0 = m_glass·c_glass·ΔT_glass + m_graphite·c_graphite·ΔT_graphite,

and:

–m_glass·c_glass·ΔT_glass = m_graphite·c_graphite·ΔT_graphite,

–(0.25 kg)·c_glass·(–70 K) = (0.75 kg)·c_graphite·(+30 K),

(17.6 kg·K)·c_glass = (22.5 kg·K)·c_graphite.

From inspection, for the equality to hold, c_glass > c_graphite, and thus glass must have a greater specific heat capacity value than graphite.

Sections 70854, 70855
Exam code: quiz07VlnC
(A) : 25 students
(B) : 17 students
(C) : 3 students
(D) : 6 students

Success level: 49%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.82

Physics quiz question: doubling sleeping pad thickness

Physics 205A Quiz 7, fall semester 2019
Cuesta College, San Luis Obispo, CA

"Klymit-Static-V-Luxe-side"
Rebecca J. Crawford
hikingmastery.com/gear/sleeping-pads/klymit-static-v2-sleeping-pad.html

A Klymit® Static V sleeping pad[*] (area of 1.07 m² and thickness of 0.0635 m) has a thermal resistance of 0.21 K/watts. If the pad were made twice as thick, its __________ would increase.
(A) thermal resistance.
(B) thermal conductivity.
(C) (Both of the above choices.)
(D) (Neither of the above choices.)

[*] klymit.com/static-v-camping-sleeping-pad.html.

Correct answer (highlight to unhide): (A)

The thermal resistance R of an object can be related to the thermal conductivity κ of its material:

R = d/(κ·A),

where d is the thickness of the object that heat must conduct through, and A is the cross-sectional area. As the thermal conductivity κ is an intensive property of the material, it would not change because of doubling the thickness of the pad, in contrast to the thermal resistance, which would increase as a result.

Sections 70854, 70855
Exam code: quiz07VlnC
(A) : 36 students
(B) : 6 students
(C) : 9 students
(D) : 0 students

Success level: 71%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.58

Physics quiz question: changing emissivity of a brick

Physics 205A Quiz 7, fall semester 2019
Cuesta College, San Luis Obispo, CA

"Red bricks"
Ramesh NG
flic.kr/p/8TmkRf

A red brick has an emissivity of 0.93[*], and has a surface temperature of 270 K. Ignore conduction and convection heat transfers to/from the environment. If the brick were coated with aluminum paint such that its emissivity was lowered to 0.45, the rate of heat per time the brick _________ would decrease.
(A) radiates to the environment.
(B) absorbs from the environment.
(C) (Both of the above choices.)
(D) (Neither of the above choices.)

[*] thermoworks.com/emissivity-table.

Correct answer (highlight to unhide): (C)

The net power (rate of heat per time) radiated is given by:

Power = –e·σ·A·((T_obj)⁴ + (T_env)⁴) = –e·σ·A·(T_obj)⁴ – e·σ·A·(T_env)⁴,

where the first (negative) term corresponds to the rate of heat being removed (radiated) from the object, while the second (positive) term corresponds to the rate of heat being put into (absorbed) by the object (in order to be consistent with the ±Q convention for removing heat from (–) or putting heat into (+) a thermodynamic system).

As it is a factor common to both the radiation and absorption terms, lowering the emissivity value from 0.93 to 0.45 would then decrease both the rate of heat per time radiated to the environment and the rate of heat per time absorbed from the environment.

Sections 70854, 70855
Exam code: quiz07VlnC
(A) : 10 students
(B) : 5 students
(C) : 35 students
(D) : 1 student

Success level: 69%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.52

Physics quiz archive: temperature, thermal equilibrium, heat transfers

Physics 205A Quiz 7, fall semester 2019
Cuesta College, San Luis Obispo, CA
Sections 70854, 70855
Exam code: quiz07VlnC



Sections 70854, 70855 results

0- 6 :	* [low = 3]
7-12 :	**********
13-18 :	**************
19-24 :	******************* [mean = 18.9 +/- 6.2]
25-30 :	******* [high = 30]

Online reading assignment: origin of life, are we alone? (SLO campus)

Astronomy 210, fall semester 2019
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 the origin of life, a "Here Is Today" timeline, LEGO® washing tips and the extraterrestrial hypothesis.

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.

"It's crazy how the timespan humans have existed is such a small amount in comparison to the life of the universe."

"How life was formed."

"The transition from chemical compounds in the atmosphere to life forms is fascinating."

"How long it takes to build life naturally, just to create a simple (yet not simple) organism."

"The Miller-Urey experiment."

"That we live in a very small moment in time, it's a very sobering perspective."

"How small our window of existence is in the whole cosmological timeline. It makes me feel so insignificant."

"How it would take massive amounts of energy, fuel, and time to even propel a spaceship to the nearest star because there is no way we can travel at the speed of light. I think this is a significant piece of evidence in disproving UFO's and aliens visiting Earth because it is pretty much impossible."

"That moons of other planets have water."

"All of it!!! I have always wanted to know more of the history of our Earth and evolution so that is why learning about it is interesting to me."

"The Drake equation is something I've never heard of and is an interesting way to explain or predict scientific situations like the Goldilocks zones."

"I like the chemistry turning into biology, as molecular chains begin to react to surroundings."

"The 'Here is Today' website was very interesting, as it was cool to see new we are in the timeline of Earth."

"Human life is barely shown by the thinnest red line ever on a timeline of life. crazy how we haven't caused a bigger dent."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"Nothing was confusing."

"The LEGO-washing presentation."

"The Drake equation (just a little bit)."

"The complex molecules going from being randomly assembled in their environment to them self replicating."

"I found the Drake equation pretty confusing, but naturally anything with numbers confuses me."

"The Drake equation."

"How is life could be so uncommon. granted there are way too many unknowns, but you'd think the great Random Number Generator Gods might throw in a couple of winning civilizations."

"I felt the Chilbolton radio message that we sent out is so anthropocentric. Why on Earth did the people sending it ever think aliens (if there were any) would ever understand it, and if they did, would care to answer to us--a bunch of talking apes?"

"How we can expect other technological civilizations to exist and be able to actually communicate with us via radio. How can we expect them to know or even have the means of understanding to send a different anti-coded message back to us? I just find it hard to believe."

"That water on the moon would boil away into the atmosphere. It's confusing because I thought the moon is cold."

"When it starts to get a bit like chemistry I got confused trying to understand the different atoms and molecules."

"I don't understand the part about the crop circles and sending coded messages. How are pixelated messages sent through radio frequencies?"

"I think crop circles are kind of dumb, but also whoever is making them is putting a lot of effort into making them look good."

"The Drake equation, because of the many factors that are can't be discovered."

"I understand the definition for the Drake equation but the actual equation and the variables are a huge question mark."

Briefly describe a difference between life and non-living things.

"Life has the ability to regenerate, adapt, and overcome problems and difficulties that are presented in front of it in order to survive."

"Living things manipulate their environment and create a new generation which will also manipulate their environment."

"The difference is that life living things keep evolving, reproducing, and adapting for survival."

"Living things are composed of cells while non-living things do not have a specialized structure."

"Living things require a form of nutrients to keep surviving, while non-living things have no need of any."

"Voluntary movement."

"Living things basically grow, respire, need energy, move, reproduce, evolve, or maintain homeostasis. Anything that doesn't do this is 'non-living.' But ultimately, this definition is just a subjective yardstick we humans have created to classify the two."

"Living things are able to manipulate their environment and use energy to live. Non-living things simply exist and are made up of solids, liquids, and gases."

"Living things breath, non-living things don't."

"Living things maintain themselves."

"Non-living things do not attempt to alter their surroundings in order to grow. Living things manipulate their surroundings to reproduce and grow."

"Life is able to reproduce, and each generation adapts to the environment, which by its existence life is also causing to change. Non-living things just lay there as stuff (Laws of physics) happens to them without the components to react to their environment."

"Living things can reproduce on their own, move by themselves, can grow and are comprised of cells. Non-living things cannot do one of the following, depending on the organism. Viruses cannot reproduce on their own, they hijack a living cell and use that to reproduce, thus viruses are lot living things."

"Non-living things do not obtain abilities of living thing like: the ability to breath, evolve, age, grow, etc."

Rank the amounts of time it takes for each of the following to have occurred on Earth.
(Only correct responses shown.)

Time after the formation of Earth for single-cell life to arise: a medium amount of time (about 1 billion years) [41%]
Time for the first types of simple single-cell life to evolve into fishlike creatures: the longest amount of time (about 3 billion years) [55%]
Time for fishlike creatures to evolve into more complex land-based animals today: the shortest amount of time (about 0.5 billion years) [55%]

How important is it to you to know whether or not there may be life elsewhere other than on Earth?

Unimportant.	** [2]
Of little importance.	**** [4]
Somewhat important.	****** [6]
Important.	****** [6]
Very important.	**** [4]

Briefly explain your answer regarding the importance of knowing whether there may be life elsewhere other than on Earth.

"I think knowing there is life elsewhere would give the people of earth new way of looking at things and inspire a generation."

"Although it likely will not really affect me or my way of life if I know the answer, knowing whether or not there is other life (specifically intelligent life) out there will answer a lot of philosophical and theological questions that we otherwise have no way of answering."

"It is not important because I believe there is only life on Earth."

"Because there has always been a mystery about life elsewhere outside our planet and I would like to know how truth that is."

"It is important for the development of the human race as we progress off of the planet and into space, but it does not effect our day-to-day lives."

"Knowing that other civilizations may be out there is extremely mind boggling to think about. To know that they have a completely different way of functioning would be astounding to learn about."

"Just not something I think we will find in my lifetime, so dwelling on it seems pointless."

"I am not actively searching for an answer to whether other life exists, but if someone came to me and told me that NASA found proof of extraterrestrials, I can assure you that it would rise to the top of my priority list."

"If so, and life is elsewhere than Erth, I think it would be extremely important. Especially if they have technology, if we communicated, our world could advance pretty significantly. I just think that would be a huge deal."

"If there is than they likely developed similar to the way we did. Essentially they probably wouldn't know that much more than us or be a threat to our way of life. They may just have slightly different developments in science and technology."

"To provide perspective. To understand how life evolves in foreign environments."

"There are only two options: Either we are alone in the universe, or we are not. Both prospects are equally terrifying. If there are others, they are either less intelligent than us (so dangerous but can't reach us). Or more intelligent than us (more civilized and therefore don't have any use of contacting us hairless apes). I am scared however that they could see us a guinea pigs for their experiments... "

"That the creation of life is either consistent or possible with alternative methods, but also that the greater amount of life indicated means that we are approaching towards the fermi paradox as something is preventing life is before us."

"I do not believe in alien life elsewhere other than Earth, but I do not deny that there are small, simple-celled terrestrial organisms on other planets (Mars being the biggest example). In my Christian faith, I believe that God created the heavens and Earth in seven days, and he specifically designed Earth for man to inhabit. I do not believe advanced, intelligent life forms were created on other planets at the beginning of mankind, so it is not important for me to know alien life forms are there because I do not think they exist."

"It would be very fascinating to learn of other life, however, I do not think it should be a top priority because there are lots of problems here on Earth that need to be addressed and worked on before worrying about other life."

"I assume there's life elsewhere. Or at least that it's very possible. It's kind of freaky, tho, so I don't concern myself with it."

"It would change things to know whether there may be life other places on Earth and increase our investigation of it perhaps leading to something greater"

"Knowing that there is other life in the universe would only be useful to me in the sense that it would blow my mind like most since does. However, if extraterrestrial life is found, the likelihood that it will have an impact on my life is so small that it is essentially pointless for me to care about."

"The wondering is okay, but I'm not obsessed with knowing. My opinion is that life of some sort (perhaps intelligent) is out there, but the distances are so vast it is likely that even if we exist at the same time, we won’t contact them; if they contact us, they will likely be dead; if we contact them, we will likely be gone before we get a response."

"It'd be super-cool to know about it!!! But I don't know if I'll be around to find out..."

"How can it not interest anyone if there is life outside of Earth? It's would be am extraordinary discovery, and a lot of new information would arise."

Which type of star would be least likely to have a planet that could support life?

Massive.	*************** [15]
Medium-mass.	*** [3]
Low-mass (red dwarf).	*** [3]
(Unsure/guessing/lost/help!)	* [1]

Briefly explain your answer to the previous question (type of star least likely to have a planet that could support life).

"It seems that a planet with neither extreme of conditions provides the highest chance of life."

"The lifetime of massive stars are too short for life to evolve."

"Low mass stars do not produce enough heat/light for life to comfortably take place."

"A medium-mass star is sun-like so we already know that given the correct circumstances, a medium-mass start can produce a planet with life. A red dwarf is not too big or hot, so I think it could possibly have a planet with life, but a massive star is far too big and hot."

"Massive stars have short lifespans and don't live for very long, and complex life organisms would need a lot of time to evolve and become complex."

"Since red dwarfs live so long, it would give the species enough evolution time to adapt to the cold, small environment."

Describe what the Drake equation is used for.

"Calculating how many intelligent species are in the Milky Way."

"It is used to estimate the total number of communicative civilizations in the Milky Way."

"It can determine the amount of life that is capable of communication."

In your opinion, how plausible is it that the Chilbolton message is a reply from extraterrestrials?

Implausible.	******* [7]
Not very plausible.	******** [8]
Somewhat plausible.	******* [7]
Very plausible.	[0]
(Unsure/guessing/lost/help!)	[0]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"Cool stuff."

"Do you think aliens look human-like, or somewhat like the 'little green men' in movies?"

"You should talk more about the Chilbolton crop circle."

"What exactly are the symbols/variables for the Drake equation?"

"How do you recommend us to prepare for the final?" (The study guide is already posted on this week's announcements page.)

"If I were to travel back in time, I'd bring a lunch with me to the Jurassic period to hang out with some dinosaurs! I'd be the Dino Whisperer."

"Extraterrestrial life is scary until you realize that we could be extraterrestrial life (to whatever life could be out there)."

"Little known fact: astronomy originated when groups of nerds were lured into star watching by the promise of limitless access to foreign celestial bodies."

"Have you heard this Joe Rogan vidcast with a US Navy pilot who says he has seen UFOs? If not, check it out. Definitely interesting to say the least."

"It seems like most of science relies on the idea of balance of forces, equal and opposite effects, and pairs of matter-antimatter particles. Doesn't this break down if one of these paired matter-antimatter particles gets sucked into a black hole, and then the blackhole suffers a Hawking 'evaporation?' If that evaporation happens, part of a pair is gone, and laws of physics start breaking down. Are we sticking to an idea of balance because we like the idea of balance, the same way that Aristotle liked circles? Or is it because our laws of physics aren't advanced enough yet to detect other forces and effects...?" (There's no imbalance here, because of the symmetry between mass (whether matter or antimatter) and energy--if one of the matter-antimatter particles falls into the black hole (while the other escapes), then the mass that is "removed" from the universe is expected to be made up by the resulting decrease (the "evaporation") in the mass of the black hole. That said, there have been no observations of this theoretical Hawking evaporation, yet.)

Online reading assignment: origin of life, are we alone? (NC campus)

Astronomy 210, fall semester 2019
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 the origin of life, a "Here Is Today" timeline, LEGO® washing tips and the extraterrestrial hypothesis.


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.

"I found the question on if we are alone as it is something I have always asked myself and something my friends and I always debate."

"The origin of life; how everything started."

"The most interesting thing to me was the Drake equation. To start off because the name I thought it was funny and to because I didn’t know there was an actual equation that could help us estimate the life span of an advanced civilization."

"How long we've really been around on Earth."

"The idea of not being alone."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"I am a bit confused on the Cambrian explosion. The book doesn't go into much detail as to how or why the Cambrian explosion happened."

"I found the Drake equation very confusing and can use a lot more clarification and in simpler terms to understand."

"The Drake equation."

Briefly describe a difference between life and non-living things.

"Non-living things do not reproduce, grow, eat, or have any sense that all living organisms can."

"To be classified as living is to be able to manipulate and adapt to your environment."

"Living things around us are human beings, animals, plants and microorganisms. Non-livings things do not exhibit any characteristics of life."

Rank the amounts of time it takes for each of the following to have occurred on Earth.
(Only correct responses shown.)

Time after the formation of Earth for single-cell life to arise: a medium amount of time (about 1 billion years) [30%]
Time for the first types of simple single-cell life to evolve into fishlike creatures: the longest amount of time (about 3 billion years) [70%]
Time for fishlike creatures to evolve into more complex land-based animals today: the shortest amount of time (about 0.5 billion years) [70%]

How important is it to you to know whether or not there may be life elsewhere other than on Earth?

Unimportant.	[0]
Of little importance.	* [1]
Somewhat important.	******* [7]
Important.	* [1]
Very important.	* [1]

Briefly explain your answer regarding the importance of knowing whether there may be life elsewhere other than on Earth.

"I'm just very curious to know if there is life out of our universe. It can't be that we are alone."

"I find the topic rather interesting, there's so much we don't know about our world that the slightest possibility of life elsewhere wouldn't surprise me."

"The odds of Earth being the only planet of life in an ever expanding universe is tiny. It’s almost selfish to believe life doesn't exist elsewhere."

"Well, if we ever find life outside of Earth is would be amazing to see what their species look like. If they end up being intelligent beings it would be really good for humans to develop and adapt to newer and better things to regarding resources."

"I find it important due to the environmental crisis that we are having on earth because if there is life on another planet we can possible be able to maybe explore and see if it is possible to travel to that other planet or maybe even see what methods they are doing to sustain life on their planet."

"It is important as it would fundamentally change everything that we know about life. If that life is similar to our own it would confirm many speculations about life and open up new ones as well. As this new life could be helpful to us one way or another."

"Even though we haven't found any yet I'm pretty sure it exists so I feel like I already know. I'd just want to learn more about them out of curiosity."

"Nothing more than just wanting to know."

"It is somewhat important because it would be cool to meet other life but then it wouldn't since we would know what it would be capable of."

Which type of star would be least likely to have a planet that could support life?

Massive.	********* [9]
Medium-mass.	[0]
Low-mass (red dwarf).	[0]
(Unsure/guessing/lost/help!)	* [1]

Briefly explain your answer to the previous question (type of star least likely to have a planet that could support life).

"Life on Earth took approximately 1 billion years to arise which is longer than the life of a massive star."

"Massive star lifetimes are too short for complex forms of life to develop as they would go supernova within a few million years."

"Massive stars form and die faster than life can evolve into complex organisms."

Describe what the Drake equation is used for.

"To try to guesstimate the number of possibilities of other life that could communicate with us."

"It is used to estimate the numbers of an advanced civilization in the Milky Way."

"According to Wikipedia: 'a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy.'"

"I didn't really understand this."

In your opinion, how plausible is it that the Chilbolton message is a reply from extraterrestrials?

Implausible.	[0]
Not very plausible.	**** [4]
Somewhat plausible.	***** [5]
Very plausible.	[0]
(Unsure/guessing/lost/help!)	* [1]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"Will any of this be on the final?" (Yes. But from the Ch. 15 question packet.)

"Why is the Drake equation even a thing if certain variables are impossible to determine and there might be even more unknown variables?" (At least it lets us know what we do know, even if that might not be that much.)

"Do you think there are aliens?" (Eh. I think so. I don't spend too much time thinking about that, though.)

Online reading assignment: standing waves

Physics 205A, fall semester 2019
Cuesta College, San Luis Obispo, CA

Students have a bi-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 a presentation on standing waves.


Selected/edited responses are given below.

Describe what you understand from the assigned textbook reading or presentation preview. Your description (2-3 sentences) should specifically demonstrate your level of understanding.

"Thick strings have lower fundamental frequencies than thinner strings when they are plucked."

"I understand that the fundamental frequency of a string depends on the wave speed v (which depends on its tension and thickness), and length L. The frequencies that this string will resonate at are then merely integer multiples of the fundamental frequency."

"What I understand is some of the standing waves stuff. I know the equation for getting the fundamental frequency of something. I also understand which things are independent and dependent parameters."

Describe what you found confusing from the assigned textbook reading or presentation preview. Your description (2-3 sentences) should specifically identify the concept(s) that you do not understand.

"I feel like this is more in depth of the previous waves section, this feels similar and not difficult, just more of it."

"Putting all the different parts together, and not mixing up the independent and dependent parameters."

"I'm having trouble understanding resonance and how nodes are created."

"The difference between node and antinode wasnt as clear to me. Will need some more clarification in class."

(Assuming that their tensions are approximately equal), the __________ strings have a slower wave speed.

thicker.	************************************** [38]
thinner.	*** [3]
(There is a tie.)	** [2]
(Unsure/lost/guessing/help!)	* [1]

After these same-length guitar strings are plucked (assuming that their tensions are approximately equal), the __________ strings vibrate at a lower fundamental frequency.

thicker.	************************************ [36]
thinner.	** [2]
(There is a tie.)	*** [3]
(Unsure/lost/guessing/help!)	*** [3]

After the bass string is plucked, sliding a finger down to decrease its length would __________ the speed of waves along the string.

decrease.	****************** [18]
not change.	******** [8]
increase.	***************** [17]
(Unsure/lost/guessing/help!)	* [1]

After the bass string is plucked, sliding a finger down to decrease its length would __________ the fundamental frequency of the string.

decrease.	*********** [11]
not change.	********* [9]
increase.	********************** [22]
(Unsure/lost/guessing/help!)	** [2]

For standing waves on a string, classify each of these parameters are being "independent" (able to be changed without affecting other independent parameters), or "dependent" (will be changed when independent values are changed).
(Only correct responses shown.)

Wave speed v: independent [59%]
String length L: independent. [43%]
Fundamental frequency f₁: dependent. [50%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"May we focus on the fundamental frequencies? I did not understand the equation."

"Go over deez."

"Is there a particular reason we left waves and then came back to them later?" (We lost a Monday due to Veteran's Day, so we'll pick it up here just before you do the standing waves lab later today. Also this stuff is not on Quiz 6 or on Quiz 7, but you'll see it on the Final Exam.)

"How was your Thanksgiving?" (Eh, it was okay. The day after Thanksgiving went much better.)

"I'm full from the turkey."