20141230

Online reading assignment question: advice to self for next semester

Physics 205A, fall semester 2014
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.

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 205B (or similar science courses). (Graded for completion.)
"Do the homework!!!!!!!"

"Be prepared. And come to every class."

"1. Stay on top of the homework assignments.
2. Don't procrastinate."

"Physics as all of my classes I'm taking very serious and I do as much as I can to succeed in the courses. Next semester I will approach physics a little bit stronger, meaning, I will do all of the assignments and I will read everything that is assigned. Thank you."

"Continuing to understand equations and concepts on an intuitive level in order to understand varying scenarios."

"Do all the online homework."

"Do the online line homework every time."

"Dear Self,
Please study very hard for the first test. Also, it may be nice if you studied for a few more quizzes, three 18/30 scores wasn't your best performance.

Sincerely,
Yourself from the Past"
"Study more and be able to attend the lectures!"

"Go to office hours."

"You're better off looking online for explanations of the material instead of in the book."

"Keep up with the homework, go to class, and ask questions if you don't understand something. You got this!"

"Read the online website information well and often!"

"Work less to study more."

"I have done my schedule so that I will not have to miss a reading or homework assignment due to a late lab. I will also not have to hopefully miss class due to work. I am going to do the lab reports the next day and not wait five days."

"start doing homework right at the start of the course."

"Make more time to study and go over everything that I don't understand in the book and spend more time reviewing it. Don't overwork yourself."

"Keep track and monitor my time wisely. Time is the greatest component to studying."

"My piece of advice to myself: don't stress out so much. Enjoy the semester and remember you are learning a lot in the process. Whether it be something like figuring out projectile motion on the moon (pretty fascinating!) or strengthening skills such as time management, each semester has a lot to offer. It is not just about the letter grade."

"Learn that procrastination makes your stress levels go up and try to avoid procrastinating it."

"Come prepared."

"Brush up on material each week outside of class."

"My advice to myself would be to stay on track with the reading assignments, its easy to go off track with other school stuff and harder to understand what is going on during lecture."

"Prioritization of classes, figure out the amount of work each class requires and the grade I want for each class and set my schedule accordingly."

"Keep studying hard, and at least one week before any exam."

"Find more time to study, use better time management skills, and ask more question relating to work done."

"Do similar practice problems on the practice quizzes to better prepare for them."

"Look up similar practice problems for the quizzes/tests to be able to better understand how to do the test problems."

"I would tell myself to not get behind on the reading right away like I did. I feel like ever since then I've been playing catch up. I would also tell myself to be more disciplined when it comes to my homework."

"I need to make sure that I have a much better understanding of the equations that are used in any science class."

"You should take advantage of many available sources such as the textbook and Khan Academy. Also study on a regular basis."

"I should only take one big science class per semester in order to have time to dedicate to studying and learning the material."

"Figure out early the teaching style of the course so as to keep on top of homework/study habits, etc."

"You can actually do it. You're smart enough, and work hard enough for your goals."

"Take it seriously perhaps? Hard to be motivated when you're not interested in the class because you have to take it, and did not choose it."

"Hey you! Do the work, learn the stuff, make it happen! You know what I mean."

"Don't be afraid to ask questions! If you're lost, you might not be the only one!"

"Be 'on top of it' for every topic before every lecture."

"I would tell myself to make have a separate binder for the class. That I should the syllabus close to me, and to go to office hours to talk to the professor and keep progress with them."

"I would keep the attendance and would like to work on problems a bit more."

"Don't try to learn physics on YouTube."

"I would tell myself to remember to do the homework and to show up to more labs. Besides that, I feel I have understood the concepts discussed in this class pretty well."

"I would like to tell myself: 'Relax, you can do it!'"

"Don't neglect homework assignments, work out problems at home, read and understand the topics, and always study for the quizzes."

Online reading assignment question: advice to future students

Astronomy 210, fall semester 2014
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.)
"Logic/math/physics may help but it was a really unique subject in my opinion."

"In order to succeed in this course you must be prepared to come to class with the readings done and have a basic understanding from the pre-lectures."

"You need to do the reading assignment before class it will help you do better on the in class activities which make you do better on the quizzes and tests. If you do the work, it isn't hard to get at least a 'B' in the class."

"Stay on top of your homework (reading assignments, reading the presentations), take a look at in-class activities ahead of time, and ask questions. Do all that and you will succeed."

"Read the textbook and show up to class."

"Go to every class session and do the in-class activities, they are helpful, take photos of the work so you can study, and of course do not miss the quizzes and exams."

"Take the group work seriously and ask P-dog questions when he walks around to help."

"You need to show up and be ready to learn. Study for quizzes and tests. Figure out what you need to work on and work on it."

"Read on time or ahead if possible and do assignments on time."

"P-dog isn't super demanding, just do the readings and the reading assignments and don't get lazy!"

"Just come to class every time. The teacher doesn't make it hard to pass, and is very nice and smart."

"Read the text, and study for the quizzes."

"Just do the work and don't forget about the quizzes and online readings."

"In order to succeed in this course it is important to do the online reading surveys and review the slides."

"I would tell them to go to every class for the in-class activities and keep up with the readings for the homework."

"Ask questions! If you need clarification, no one will judge you! They may be just as confused as you are and it will benefit them too!"

"Read the blog presentations and do the group activities!!!!! And be thorough about it too!"

"One thing I would like to tell a student who is going to take this course next year is study more then usual it is the only way to truly understand what is needed to know in this class."

"The most important thing to know from my experience and observation of the teaching method and student interaction, is that you need to do the reading and focus during lecture. Spending time on your phone, while possibly more interesting to you, will only result in a poor grade. The universe is astounding, and it deserves your attention."

"Attendance really helps!"

"Don't be afraid to take this class because its fun. All you really need to do is take practice quizzes seriously because they help you with quizzes and quizzes help you with exams. Taking each of those and studying them, well help you pass!"

"Take notes, focus during lectures, study a lot for quizzes, do reading assignments, and try to go to every class."

"READ THE BOOK. DO THE STUDY GUIDES! GO TO CLASS! MAKE A STUDY GROUP. DO THE READING ASSIGNMENTS ONLINE! EASY POINTS! SO JUST DO IT."

"Do the reading assignments and homework. Show up to class and participate in the in-class activities."

"I found it really helpful to take notes on all the lectures/blogs that are online before completing the reading assignments, this way you have it written down and can easily look back on it. Do all the reading assignments and take vigorous notes on them. Be prepared to to struggle with quizzes."

"Go to class."

"Go over the flashcard questions online!!! Would have helped me so much."

"Print out flashcard questions and bring to them class to get questions answered, then use it and previous quizzes to study for the quizzes."

"Study and do work. Don't follow my example.""

"Yes! Keep up and go to every class."

"Pay attention and go to class or else you will be very lost."

"Attend every class, complete the readings and online assignments, pay attention and ask questions in class, do all the extra credit provided, and go to office hours for extra explanations."

"Attend class and focus on in class activities. Stay on top of things."

"Do the reading and study flashcard questions."

"Read the chapters."

"Actually read the book, it works wonders for your grade."

"Go to lectures, it explains things so much better than reading the book can."

"Do all the online stuff it's easy and it will help you a lot through the course"

"Show up for class and do the homework and you'll be fine. And study for the quizzes and exams by going to the office hours for extra help."

"Do the online reading assignment!!!!"

"Take advantage of the course website. Go in depth and look at P-dog's 'boring but important' blog. It's everything the name says it to be but sometimes the class period doesn't touch on everything needed for tests/ quizzes and the blog will help."

"Don't forget the reading assignments!"

"Read the material, and ask questions if you're confused."

"Read each chapter, do all the online assignments, and going to each class is very important because of all the material you learn and all the points you receive for in class assignments."

"Study for every quiz and study hard with a group for the test! The study group I had was fun and we helped teach each other a lot. (Well one classmate in particular helped teach us a lot haha.) This class was really fun and you will love P-DOG!"

20141214

Education research: SPCI statistics (fall semester 2014)

Students at Cuesta College (San Luis Obispo, CA) were administered the Star Properties Concept Inventory (SPCI version 3.0, developed by Janelle Bailey, University of Nevada-Las Vegas) during the first and the last week of instruction. Astronomy 210 is a one-semester introductory general science course, with a separate optional adjunct laboratory (Astronomy 210L).

The pre- to post-test gain for this semester at Cuesta College (excluding students with negative informed consent forms (*.pdf), and missing pre- or post-tests) is:

Astronomy 210 fall semester 2014 sections 70158, 70160
N = 74 (matched-pairs)
<initial%>= 34% ± 15%
<final%>= 60% ± 16%
<g>= 0.39 ± 0.22 (matched-pairs); 0.39 (class-wise)

This semester's SPCI pre- and post-instruction scores are slightly higher than results from previous semesters at Cuesta College, and this semester's gain is much higher than those in previous semesters.

20141213

Astronomy midterm question: habitability of Mars forming closer to the sun

Astronomy 210 Midterm 2, fall semester 2014
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked:
Pd: If Mars had originally formed closer to the sun, would it be more habitable today?
qu: Mars closer to the sun would be warmer, but actually less habitable with less water and atmosphere.
Discuss how Mars forming closer to the sun would have less water and atmosphere today, and how you know this. Explain using the properties of planet mass, atmosphere, and geological activity.

[*] answers.yahoo.com/question/index?qid=20141101111207AAt4Wdm.

Solution and grading rubric:
  • p:
    Correct. Discusses why both statements are correct about Mars located closer to the sun and being warmer would result in:
    1. less water, due to warmer temperatures evaporating all available water (or ultraviolet light breaking apart water molecules);
    2. less atmosphere, as warmer temperatures would allow atmosphere molecules to move faster and more easily escape from Mars' weak gravity.
  • r:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. One of the two points (1)-(2) correct, other is problematic/incomplete.
  • t:
    Contains right ideas, but discussion is unclear/incomplete or contains major errors. Both points (1)-(2) problematic/incomplete, or one is correct while the other is garbled/missing.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least attempts to use relationships between planet location and mass with atmosphere temperature and retention.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion not clearly based on relationships between planet location and mass with atmosphere temperature and retention.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 70158
Exam code: midterm02s0vA
p: 10 students
r: 4 students
t: 18 students
v: 10 students
x: 3 students
y: 0 students
z: 0 students

Section 70160
Exam code: midterm02n4Rs
p: 7 students
r: 6 students
t: 15 students
v: 2 students
x: 3 students
y: 0 students
z: 0 students

A sample "p" response (from student 1123):

A sample "x" response (from student):

Astronomy midterm question: distance modulus comparison

Astronomy 210 Midterm 2, fall semester 2014
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked:
??: Two stars have these apparent magnitudes and absolute magnitudes. What can we say about their relative distances from Earth?
m
apparent
magnitude
M
absolute
magnitude
Star X +9 +2
Star Y +4 +6

ba: The relative distances of stars can be determined by subtracting the absolute magnitude from the apparent magnitude. The more positive the answer, the farther away the star. For your example, Star X has a magnitude difference of 9 – 2 = +7, while the difference for Star Y is 4 – 6 = –2.
Discuss whether the technique discussed in this answer is correct or incorrect, and how you know this. Explain using the relationships between apparent magnitude, absolute magnitude, and distance.

[*] answers.yahoo.com/question/index?qid=20090321011229AAwvrJw.

Solution and grading rubric:
  • p:
    Correct. Understands difference between apparent magnitude m (brightness as seen from Earth, when placed at their actual distance from Earth) and absolute magnitude (M (brightness as seen from Earth, when placed 10 parsecs away), and discusses:
    1. that for star X, the brightness it has at its location (m = +9) is dimmer than its brightness when placed 10 parsecs away (M = +2), so its distance is greater than 10 parsecs; while for star Y, the brightness it has at its location (m = +4) is brighter than its brightness when placed 10 parsecs away (M = +6), so its distance is closer than 10 parsecs;
    2. how this is consistent with the method proposed by "ba" (which follows directly from the "distance modulus" (mM) in the relation (mM) = 5·log(d) – 5), as star X has a distance modulus of +7 ("more positive the answer, the farther away the star") and star Y has a distance modulus of –2 (which would indicate that it is closer than star X).
  • r:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. One of the two points (1)-(2) correct, other is problematic/incomplete.
  • t:
    Contains right ideas, but discussion is unclear/incomplete or contains major errors. Only one of the two points (1)-(2) correct, other is missing, or both are problematic.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least attempts to use relationships between apparent magnitudes, absolute magnitudes, and distances.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion based on garbled definitions of, or not based on proper relationships between apparent magnitudes, absolute magnitudes, and distances.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 70158
Exam code: midterm02s0vA
p: 14 students
r: 9 students
t: 12 students
v: 6 students
x: 4 students
y: 0 students
z: 0 students

A sample "p" response (from student 0978):

A sample "t" response (from student 4743):

Astronomy midterm question: doubling star distances

Astronomy 210 Midterm 2, fall semester 2014
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked:
JK: A star has an apparent magnitude of +12.5 and an absolute magnitude of –2.0. If the star is moved twice as far away (distance is doubled), would its apparent magnitude then be –0.5? I don't know if I am correct.
Discuss why this reasoning is incorrect, and how you know this. Explain using the relationships between apparent magnitude, absolute magnitude, and distance.

[*] answers.yahoo.com/question/index?qid=20090216102612AAzRHWy.

Solution and grading rubric:
  • p:
    Correct. Understands difference between apparent magnitude m (brightness as seen from Earth, when placed at their actual distance from Earth) and absolute magnitude (M (brightness as seen from Earth, when placed 10 parsecs away), and discusses how placing a star farther away will affect its apparent magnitude, making it dimmer (a larger positive number than +12.5) instead of brighter (the incorrect value of –0.5).
  • r:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors.
  • t:
    Contains right ideas, but discussion is unclear/incomplete or contains major errors.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least attempts to use relationships between apparent magnitudes, absolute magnitudes, and distances.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion based on garbled definitions of, or not based on proper relationships between apparent magnitudes, absolute magnitudes, and distances.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 70160
Exam code: midterm02n4Rs
p: 7 students
r: 6 students
t: 15 students
v: 2 students
x: 3 students
y: 0 students
z: 0 students

A sample "p" response (from student 0500):

Astronomy midterm question: bigger, more luminous stars always cooler or hotter?

Astronomy 210 Midterm 2, fall semester 2014
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked:
Pd: Are the bigger, more luminous stars always the cooler stars?
Sa: You wouldn't be right because "more luminous" means more energy output, which means bigger and hotter.
Discuss why this answer is incorrect, and how you know this. Explain using Wien's law, the Stefan-Boltzmann law and/or an H-R diagram.

[*] answers.yahoo.com/question/index?qid=20141031235350AAd46qs.

Solution and grading rubric:
  • p:
    Correct. Uses Wien's law, the Stefan-Boltzmann law and/or interprets H-R diagram to discuss how a more luminous star does not necessarily have to be both bigger and hotter, by comparing:
    bright/larger/cooler vs. dim/smaller/hotter stars;
    bright/larger/(same temperature) vs. dim/smaller/(same temperature) stars;
    bright/smaller/hotter vs. dim/larger/cooler stars;
    bright/(same size)/hotter vs. dim/(same size)/cooler stars.
  • r:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. Or as (p), but may instead compare:
    (same brightness)/smaller/hotter vs. (same brightness)/larger/cooler stars;
    brighter/larger/hotter vs. dim/smaller/cooler star;
    thus not sufficiently discussing why the response would not always be correct.
  • t:
    Contains right ideas, but discussion is unclear/incomplete or contains major errors. At last discussion demonstrates understanding of Wien's law, H-R diagram and/or the Stefan-Boltzmann law.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least attempts to use Wien's law, H-R diagram and/or the Stefan-Boltzmann law.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion not clearly based on Wien's law, H-R diagram and/or the Stefan-Boltzmann law.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 70158
Exam code: midterm02s0vA
p: 20 students
r: 14 students
t: 6 students
v: 3 students
x: 1 student
y: 0 students
z: 0 students

Section 70160
Exam code: midterm02n4Rs
p: 20 students
r: 7 students
t: 2 students
v: 2 students
x: 2 students
y: 0 students
z: 0 students

A sample "p" response (from student 1327) comparing a bright/larger/cooler star versus a dim/smaller/hotter star:

A sample "p" response (from student 5656) comparing a bright/larger star that has the same temperature as a dim/smaller star:

A sample "p" response (from student 5309) comparing a bright/smaller/hotter star versus a dim/larger/cooler star:

A sample "p" response (from student 1795) comparing a bright/hotter star that has the same temperature as a dim/cooler star:

Astronomy current events question: Fornax Dwarf Spheroidal Galaxy globular cluster formation theories

Astronomy 210L, fall semester 2014
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!)
Søren Larsen , Frank Grundahl, Georgia Bladon, "The Riddle of the Missing Stars," (November 20, 2014)
http://www.spacetelescope.org/news/heic1425/
Hubble Space Telescope observations of globular clusters in the Fornax Dwarf Spheroidal galaxy present questions regarding theories of the Milky Way's:
(A) supermassive black hole mass.
(B) ratio of luminous to dark matter.
(C) number of spiral arms.
(D) red dwarf population.
(E) globular cluster formation.

Correct answer: (E)

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

Astronomy current events question: Jupiter's Red Spot color origins

Astronomy 210L, fall semester 2014
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!)
Preston Dyches, "Jupiter's Red Spot Most Likely A Sunburn, Not a Blush," (November 11, 2014)
http://www.jpl.nasa.gov/news/news.php?feature=4372
Jet Propulsion Laboratory scientists propose that the color of Jupiter's Great Red Spot is due to chemicals reacting with sunlight, based on comparing observations with:
(A) increased activity due to solar flares.
(B) correlated auroral activity.
(C) decreasing wind speeds.
(D) samples brought back by the Cassini mission.
(E) experiments in Earth-based laboratories.

Correct answer: (E)

Student responses
Sections 70178, 70186
(A) : 8 students
(B) : 7 students
(C) : 4 students
(D) : 5 students
(E) : 13 students

Astronomy current events question: observing effects of C/2013 A1 (Siding Spring) on Mars' atmosphere

Astronomy 210L, fall semester 2014
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!)
APPEL news staff, "A Rare Event Offers Insight into Solar System Origins," (November 24, 2014)
http://appel.nasa.gov/2014/11/24/a-rare-event-offers-insight-into-solar-system-origins/
NASA and European Space Agency spacecraft are measuring the effects on Mars' atmosphere due to dust deposited by a:
(A) reactivated volcano.
(B) nearby comet.
(C) small asteroid impact.
(D) planet-wide sandstorm.
(E) solar flare.

Correct answer: (B)

Student responses
Sections 70178, 70186
(A) : 5 students
(B) : 29 students
(C) : 1 student
(D) : 2 students
(E) : 0 students

Astronomy quiz question: type Ia supernova in distant galaxy

Astronomy 210 Quiz 7, fall semester 2014
Cuesta College, San Luis Obispo, CA

An observer in San Luis Obispo, CA detects a type Ia supernova in a distant galaxy right now. An observer inside that distant galaxy, very close to that location would observe right now a:
(A) nova.
(B) supergiant.
(C) white dwarf.
(D) type Ia supernova.
(E) medium-mass main-sequence star.
(F) (None of the above choices, as there is nothing left at that location right now.)

Correct answer (highlight to unhide): (F)

A type Ia supernova occurs when a white dwarf star takes hydrogen from a close binary companion star such that its carbon-oxygen core will have sufficient pressure to undergo fusion, and explode and completely destroy itself.

The finite speed of light results in information of events that occurred in the past taking time to reach distant locations, such that when we observe this type Ia supernova, the white dwarf has already exploded and is no more. An observer much closer to that location would have already seen that type Ia supernova explosion before us, and will now observe nothing remaining at that location.

Section 70158
Exam code: quiz07su4R
(A) : 1 student
(B) : 2 students
(C) : 13 students
(D) : 8 students
(E) : 3 students
(F) : 12 students

Success level: 33% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.17

Section 70160
Exam code: quiz07n0Lb
(A) : 2 students
(B) : 1 student
(C) : 13 students
(D) : 1 student
(E) : 2 students
(F) : 13 students

Success level: 45% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.24

Astronomy quiz question: products of fusion in the sun's core

Astronomy 210 Quiz 7, fall semester 2014
Cuesta College, San Luis Obispo, CA

Fusion reactions in the sun's core produced the:
(A) hydrogen in the sun.
(B) gold and silver in Earth's crust.
(C) heat inside Earth's core.
(D) lithium in car batteries.
(E) (More than one of the above choices.)
(F) (None of the above choices.)

Correct answer (highlight to unhide): (F)

The sun is a medium-mass main sequence star, so it is currently fusing hydrogen into helium in its core.

Hydrogen is merely the raw ingredient of the universe, and was created in the first few moments of the big bang, while lithium was produced by fusion few minutes after the start of the big bang.

Massive stars fuse hydrogen into heavier elements in their cores up through iron, and as a result of undergoing a type II supernova they produce heavier elements than iron, such as gold and silver. These heavy elements from the remnants of a previous generation massive star would then be incorporated into the formation of Earth in the early solar system.

The heat in Earth's core was produced from the conversion of gravitational potential energy during its formation, and also from the radioactive decay of unstable heavy elements (produced by a type II supernova of a previous generation massive star) in its core.

Section 70158
Exam code: quiz07su4R
(A) : 14 students
(B) : 12 students
(C) : 4 students
(D) : 1 student
(E) : 8 students
(F) : 5 students

Success level: 16% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.17

Section 70160
Exam code: quiz07n0Lb
(A) : 8 students
(B) : 7 students
(C) : 1 student
(D) : 1 student
(E) : 4 students
(F) : 10 students

Success level: 35% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.51

Astronomy quiz question: temperature and fusion

Astronomy 210 Quiz 6, fall semester 2014
Cuesta College, San Luis Obispo, CA

Fusion requires high temperatures in order for nuclei to move quickly enough to:
(A) overcome gravity.
(B) overcome repulsion.
(C) create convection currents.
(D) break heavy elements apart.

Correct answer (highlight to unhide): (B)

Atomic nuclei repel each other due to their constituent protons; this repulsion can only be overcome when the nuclei approach each other rapidly enough at temperatures much higher than room temperature.

Note that response (D) refers to nuclear fission.

Section 70158
Exam code: quiz06sPp7
(A) : 15 students
(B) : 24 students
(C) : 3 students
(D) : 0 students

Success level: 60% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.42

Section 70160
Exam code: quiz06nb3R
(A) : 7 students
(B) : 15 students
(C) : 5 students
(D) : 1 student

Success level: 58% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.63

Physics quiz question: volume expansion of engine coolant

Physics 205A Quiz 7, fall semester 2014
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e Problem 13.15

"2013 Subaru Forester - First Drive"
NRMA Motoring and Services
flic.kr/p/dAcTtq

A 2014 Subaru Forester 2.0XT Premium uses 8.9×10–4 m3 of liquid coolant[*]. Assume that the coolant is undiluted propylene glycol (volume expansion coefficient 7.3×10–4 K–1)[**]. If 5.0×10–5 m3 of coolant is released into the overflow reservoir due to thermal expansion (ignoring engine volume expansion), the increase in temperature was:
(A) 44 K.
(B) 54 K.
(C) 77 K.
(D) 8.1×102 K.

[*] 2014 Forester Owner Manual (Ver. B), Fuji Heavy Industries Ltd. (2013), p. 12-8, techinfo.subaru.com/proxy/71914/pdf/ownerManual/071914_2014_Forester/MSA5M1403BrevSTIS_18.pdf.
[**] dowac.custhelp.com/app/answers/detail/a_id/7213/related/1/session/L2F2LzEvdGltZS8xNDA2MzEyODAwL3NpZC9QVjVweWItbA%3D%3D.

Correct answer (highlight to unhide): (C)

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

β·∆T = ∆V/V,

such that:

T = ∆V/(β·V) = (5.0×10–5 m3)/((7<.3×10–4 K–1)·(8.9×10–4 m3)) = 76.958596275 K,

or to two significant figures, the change in temperature is an increase of 77 K.

Response (A) is 3·β/∆V; response (B) is 3·(V/∆V); and response (D) is ∆V/((6.9×10–5 K–1V), where 6.9×10–5 K–1 is the thermal volume expansion coefficient of the aluminum engine block, used in a subsequent problem on the same quiz.

Sections 70854, 70855, 73320
Exam code: quiz07cO4t
(A) : 4 students
(B) : 10 students
(C) : 45 students
(D) : 5 students

Success level: 70%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.84

Physics quiz question: comparing changes in internal energies

Physics 205A Quiz 7, fall semester 2014
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e Conceptual Question 14.1, Practice Problem 14.5, Comprehensive Problem 14.75

"French Press Coffee II"
Christian Kadluba
flic.kr/p/57FhdB

0.040 kg of coffee grounds at 25.0° C is placed into a French press container with 1.4 kg of 90.0° C water. The coffee grounds and water are allowed to reach thermal equilibrium. Ignore the effects of evaporation and phase changes, and heat exchanged with the environment or container. Specific heat of coffee grounds[*] is 1,700 J/(kg·K). Specific heat of water is 4,190 J/(kg·K). After reaching thermal equilibrium, the __________ had the greatest change in internal energy.
(A) coffee sample.
(B) water.
(C) (There is a tie.)
(D) (Not enough information is given.)

[*] Hans Dieter Baehr, Karl Stephan, Heat and Mass Transfer (2nd ed.), Springer-Verlag (2006), p. 368.

Correct answer (highlight to unhide): (C)

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

Qext = ∆Ecofee + ∆Ewater,

where for an isolated system, Qext = 0, such that:

0 = mcoffee·ccoffee·(Tcoffee, f – 25.0° C) + mwater·cwater·(Twater, f – 90.0° C),

which can be subsequently solved for the final equilibrium temperature (Tcoffee, f = Twater, f = 89.255139872° C, or 89° C to two significant figures. While this means that the coffee experienced a larger temperature change than the water, the coffee experienced the same amount of thermal internal energy change (an increase) as the change in thermal internal energy of the water (a decrease). This can be seen by looking back on the transfer/balance energy conservation equation:

0 = ∆Ecoffee + ∆Ewater,

–∆Ecoffee = ∆Ewater.

Sections 70854, 70855, 73320
Exam code: quiz07cO4t
(A) : 12 students
(B) : 7 students
(C) : 45 students
(D) : 0 students

Success level: 70%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.53

20141212

Physics quiz question: thermal resistance of wall insulation

Physics 205A Quiz 7, fall semester 2014
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e Problem 14.55, Comprehensive Problem 14.85

"Speedy Installation"
CertainTeed Corporation
certainteed.com/products/insulation/fiber-glass-insulation/317371

A 0.91 m2 area section of CertainTeed SMARTBATT™ fiberglass insulation with a thickness of 8.9×10–2 m has a thermal conductivity of 4.2×10–3 watts/(m·K)[*]. The thermal resistance of this section of insulation is:
(A) 3.4×10–4 K/watt.
(B) 23 K/watt.
(C) 2.4×102 K/watt.
(D) 2.9×103 K/watt.

[*] certainteed.com/resources/30-45-062.pdf.

Correct answer (highlight to unhide): (B)

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

R = d/(κ·A),

where d is the thickness of the object that heat must conduct through, and A is the cross-sectional area, such that:

R = (8.9×10–2 m)/((4.2×10–3 watts/(m·K))·(0.91 m2)) = 23.286237572 K/watt,

or to two significant figures, the thermal conductivity of the wall is 23 K/watt.

(Response (A) is κ·A·d; response (C) is 1/κ; response (D) is 1/(κ·A·d.)

Sections 70854, 70855, 73320
Exam code: quiz07cO4t
(A) : 1 student
(B) : 60 students
(C) : 3 students
(D) : 0 students

Success level: 94%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.21

Physics quiz question: Space Shuttle High-temperature Reusable Surface Insulation (HRSI) silica tiles

Physics 205A Quiz 7, fall semester 2014
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e Problem 14.67

"File:STS-129 Crew Equipment Interface Test 1.jpg"
(Source: NASA)
commons.wikimedia.org/wiki/File:STS-129_Crew_Equipment_Interface_Test_1.jpg

The bottom of the Space Shuttle is covered with an area of 250 m2 of High-temperature Reusable Surface Insulation (HRSI) silica tiles (emissivity 0.90) to withstand temperatures of 1,920 K during reentry into the atmosphere.[*][**] Assume that the environment is 0 K. During reentry the rate of heat per time radiated by the bottom of the Space Shuttle is:
(A) 4.3×105 watts.
(B) 6.9×105 watts.
(C) 1.7×108 watts.
(D) 2.1×108 watts.

[*] wki.pe/Space_Shuttle_thermal_protection_system.
[**] Andreas Ulovec, "Space Shuttle Landing," math2earth.oriw.eu/publications/04_Space%20shuttle%20landing.pdf.

Correct answer (highlight to unhide): (C)

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

Power = –e·σ·A·((Tobj)4 – (Tenv)4),

where a negative value for power corresponds to a net amount of heat being removed (radiated) from the object, while a positive value corresponds to a net amount 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).

Then the power radiated by the bottom of the Space Shuttle is:

Power = –(0.90)·(5.670×10–8 watts/(m2·K4))·(250 m2)·((1,920 K)4 – (0 K)4),

Power = –1.736861983×108 watts,

or to two significant figures, the magnitude of the heat radiated per time is 1.7×108 watts.

(Response (A) is e·A·Tobj; response (B) is e·σ·A·(Tobj)4; response (D) is σ·A·(Tobj)4/e.)

Sections 70854, 70855, 73320
Exam code: quiz07cO4t
(A) : 7 students
(B) : 4 students
(C) : 51 students
(D) : 1 student

Success level: 80%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.75

20141211

Physics quiz archive: temperature, thermal equilibrium, heat transfer

Physics 205A Quiz 7, fall semester 2014
Cuesta College, San Luis Obispo, CA
Sections 70854, 70855, 73320, version 1
Exam code: quiz07cO4t



Sections 70854, 70855, 73320 results
0- 6 :  
7-12 :   **** [low = 9]
13-18 :   *******
19-24 :   ******************** [mean = 24.2 +/- 5.5]
25-30 :   ********************** [high = 30]

Astronomy quiz archive: Milky Way, cosmology

Astronomy 210 Quiz 7, fall semester 2014
Cuesta College, San Luis Obispo, CA

Section 70158, version 1
Exam code: quiz07su4R


Section 70158
0- 8.0 :  
8.5-16.0 :   **** [low = 7.5]
16.5-24.0 :   ******************
24.5-32.0 :   *********** [mean = 25.0 +/- 6.8]
32.5-40.0 :   ****** [high = 36.5]


Section 70160, version 1
Exam code: quiz07n0Lb


Section 70160
0- 8.0 :  
8.5-16.0 :   ******* [low = 11.0]
16.5-24.0 :   ************* [mean = 22.4 +/- 7.4]
24.5-32.0 :   ******
32.5-40.0 :   ****** [high = 36.5]

20141210

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

Astronomy 210, fall semester 2014
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.
"The Arecibo message! I never knew about this message and found it very interesting."

"Wow! LEGO® bricks assemble themselves in washing machines just like stuff in our universe! How incredible. I really want to try this."

"The Miller experiment--it's super cool that atoms tend to hook up with other atoms to make both simple and complicated molecules."

"The Drake equation--I don't completely understand it but I find it interesting that we were able to come up with a scientific equation that tells us where there is life in the galaxy of not."

"The 'Here is Today' presentation is interesting to me because it portrays the obscure numbers of time, that are often hard to relate to, in a way that is easier to comprehend."

"How there was a [purported] reply from a radio signal in a crop field. I've heard about these before and how its possible to do this over night. In fact there was a show about it on TV. However, no one really knows, all myths, could be true could not, but thats the fun in it."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"How is it possible that math (the Drake equation) can determine whether or not there is life on planets other than Earth? I know that it includes many factors but it seems like too complex of a idea for a mathematical equation."

"I don't understand how longer, more complex molecules could change their environment more than those that were shorter."

"I didn't really understand what Julia Child was saying in the beginning. But I understood the rest of the presentation and the reading."

"I'm confused on chemical evolution because it just isn't a clear topic in my head. Can't wrap around it."

Briefly describe a difference between life and non-living things.
"Living things are adaptable and build and destroy and eat, and they eat a lot."

"Being human or a zombie."

"My pet rock hasn't moved since I got it. On the other hand, my cat has been killing things and meowing since day one."

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.  ***** [5]
Somewhat important.  *********** [11]
Important.  ******* [7]
Very important.  ********** [10]

Briefly explain your answer regarding the importance of knowing whether there may be life elsewhere other than on Earth.
"I think it would be fascinating to see how life was created elsewhere. How similar or different we are compared to them would be interesting. Maybe it would help people see themselves as human instead of fighting each other for control or minor differences that can be easily fixed if discussed. Knowing how far the other species has gotten would maybe give us ideas as to what the next stage in our growth could be."

"I mean I am not worried about other life out there, but if we came to the conclusion that there was, that would be pretty rad."

"Knowledge is always important."

"Whether or not there is life elsewhere could either greatly effect us here on Earth or have such little effect that it wouldn't matter."

"It would be interesting to know but I wouldn't do anything about it."

"I think it would be cool to know if there was another form of life out there, but I do not strive to know and research about it. I would also not want us humans to go and be nosy in another planet's life."

"BECAUSE ALIENS, BRO!"

"I would just really like to know if there is life elsewhere. Maybe we could help and teach each other?"

Which type of star would be least likely to have a planet that could support life?
Massive.  ***************** [17]
Medium-mass.  ** [2]
Low-mass (red dwarf).  ************* [13]
(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).
"Massive stars have a short lifespan."

"I think it would be a low-mass star like a red dwarf because it gives off so little heat compared to medium-mass or massive stars that terrestrial planets would cool down too fast and there wouldn't be time to create tectonic plate shifts or life."

"The star has to be perfect, not too hot and not too cold. If we look at the type our sun is, we use a similar match."

Describe what the Drake equation is used for.
"Drake equation starts out with well-established values, and multiplies progressively less reliable factors to estimate the number of advanced technological civilizations in the Milky Way."

In your opinion, how plausible is it that the Chilbolton message is a reply from extraterrestrials?
Implausible.  ******** [8]
Not very plausible.  *********** [11]
Somewhat plausible.  ************* [13]
Very plausible.  * [1]
(Unsure/guessing/lost/help!)  [0]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Please explain the chemistry-to-biology part cause I'm lost--if there is no fossil evidence and hasn't been seen in nature or been made in a lab, how do we know that's how we came to be?" (That's why it's still a hypothesis that we need to find more evidence to in order to prove or disprove it.)

"Can you explain the grading system before the final? And how to determine whether or not we should take it?" (Your course point total is cumulative, and determines your letter grade compared to the scale set at the start of the course. Your course point total cannot go down, it can only go up as long as you still accumulate points. The final is worth 100 points, and it is up to you if you want to take it to make the next grade jump, or skip it if you want to settle for your current grade.)

"I'd like to confirm that if I have an 'A,' I really don't need to take the final and I'll keep my 'A?'" (Yes, that is possible.)

"I hope we one day do in fact come into contact with extraterrestrial lifeforms."

"I LIKE TURTLES." (Maybe that's what the extraterrestrials will look like.)

"It's been real, and it's been fun. But it ain't been real fun."

"Thank you so much for being a great teacher P-dog! I truly enjoyed this class the most this semester!"

"Eksjxnenxkx." (Woghaosdif. GHxp.)

20141209

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

Astronomy 210, fall semester 2014
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.
"The behavior of atoms--to be specific, their tendency to form molecules in the presence of energy."

"The 'Here Is Today' website. That was really cool to put into perspective how tiny today really is the grand scheme of things."

"The Drake formula, I can't believe an equation that is 50% SWAG is considered legitimate and that people have the gall to assume humans are the only organisms capable of our kind of 'advancement.'"

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"How evolution plays into studying extra-terrestrial life--if our DNA can become specialized over time, it seems like it would be very difficult to identify other life forms if they have evolved differently than us."

"Got stuck trying to decipher the Arecibo Message."

"The Drake equation because there is so much to it."

"I don't understand how single-celled organisms suddenly became more than that, because it seems remarkable that just happened."

"What would need to occur in order for there to be life on other planets."

Briefly describe a difference between life and non-living things.
"Living things extract energy from their environment in order to maintain themselves, survive, and reproduce. This is a process that nonliving things would not partake in."

"Something alive can interact with its environment in some way. Algae and single-cell organisms can, rocks cannot. Sorry rocks. :("

"All living things contain carbon. Not all things that contain carbon are living, though."

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.  ** [2]
Somewhat important.  ******* [7]
Important.  ****** [6]
Very important.  ****** [6]

Briefly explain your answer regarding the importance of knowing whether there may be life elsewhere other than on Earth.
"Human girls don't like me, so I figure an alien girl might."

"I'm really curious about it and I've always been super-interested in it, but it doesn't bother me that I'll probably never know."

"Finding other life will only complicate the world today."

"It may provide answers to fundamental questions, such as the origin of life. Aside from that, we should also realize that life can not last forever on Earth."

"I don't think it really matters. I believe in God."

"If there really is life out there, I would like to experience the feeling humanity would have of 'we aren't alone' and the age of illumination it might bring."

Which type of star would be least likely to have a planet that could support life?
Massive.  ******* [7]
Medium-mass.  * [1]
Low-mass (red dwarf).  ********** [10]
(Unsure/guessing/lost/help!)  *** [3]

Briefly explain your answer to the previous question (type of star least likely to have a planet that could support life).
"Red dwarfs have very little on them to support life and very few resources."

"From what we know from observations, a large star would expand its fuel rapidly, then go supernova which makes the probability of life existing such a star basically impossible."

"Massive stars only live for a few million years while the evolution for living things can take billions of years."

Describe what the Drake equation is used for.
"A probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy."

"I honestly don't know."

In your opinion, how plausible is it that the Chilbolton message is a reply from extraterrestrials?
Implausible.  *** [3]
Not very plausible.  ******** [8]
Somewhat plausible.  ******** [8]
Very plausible.  [0]
(Unsure/guessing/lost/help!)  ** [2]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"We all know it was you who made that crop circle, P-dog. It's okay, though, your secret is safe with us."

"Do you think there is life beyond Earth? Do you really think there might be some other sentient life elsewhere in the universe?" (Yes on both. I would totally bet on it. Like, a dollar.)

FCI post-test comparison: Cuesta College versus UC-Davis (fall semester 2014)

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

Cuesta College
Physics 205A
fall semester 2014    
UC-Davis
Physics 7B
summer session II 2002
N56 students*76 students*
low  4  3
mean    14.0 ± 6.312.9 ± 5.5
high2926

*Excludes students with negative informed consent forms (*.pdf)

Student's t-test of the null hypothesis between Cuesta College FCI post-test scores and UC-Davis FCI post-test scores results in p = 0.28 (t = 1.08, sdev = 5.86, degrees of freedom = 130), thus there is no significant difference between Cuesta College and UC-Davis FCI post-test scores.

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

Physics 205A fall semester 2014 sections 70854, 70855, 73320
<initial%>= 34% ± 18% (N = 75)
<final%>= 47% ± 21% (N = 56)
<g>= 0.21 ± 0.24 (matched-pairs); 0.20 (class-wise)

Student's t-test of the null hypothesis for Cuesta College FCI pre-test scores versus post-test scores results in p = 0.0002 (t = -3.88, sdev = 5.77, degrees of freedom = 129), thus there is a statistically significant difference between Cuesta College FCI pre-test and post-test scores.

This Hake gain is comparable to previous semesters' results for algebra-based introductory physics at Cuesta College (0.17-0.33), but also slightly higher than previous gains for algebra-based introductory physics at UC-Davis (0.16), and for calculus-based introductory physics at Cuesta College (0.14-0.16), as discussed in previous postings on this blog.

Notable about this Physics 205A class at Cuesta College during this fall 2014 semester is the requirement that students read and answer questions on the textbook and lecture slides before coming to lecture (in a "flipped classroom"), 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 a brief written explanation of a selected question submitted by each student every lecture), open-ended labs, and the continuing use (since fall semester 2011) of flashcards rather than electronic response system "clickers" (Classroom Performance System, einstruction.com), to engage in "think-pair-share" (peer-instruction).

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:

20141208

Online reading assignment: heat transfer applications

Physics 205A, fall semester 2014
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 a presentation on heat transfer applications.

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.
"Thermodynamics can create potentially profitable consumer products."

"Cooper Cooler™ cools beverages by spinning them, we will test if spinning the can will cool the beverage faster. Coffee Joulies™ have a phase-changing material that will allow the liquid (most likely coffee) to be cooled down to drinking temperature and retain the heat longer."

"Each of these products are designed to either encourage or inhibit heat loss."

"A space blanket works as a silverbody in cool conditions, reflecting heat radiated by the body back into the body. A trash bag would not work as well in cool conditions, as it would absorb heat from the body and radiate it away into the environment."

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.
"The science used to create the products use technology that I am not familiar with. It would be beneficial to understand what causes the products to either cool things off and/or insulate."

"I did not find anything confusing about this presentation. I understood it all."

The primary heat transfer process that the Cooper Cooler™ uses to chill beverages is:
conduction.  ********************** [22]
convection.  ************************** [26]
radiation.  ** [2]
(Unsure/guessing/lost/help!)  ******* [7]

How plausible do you think these claims for the Cooper Cooler™ are?
(Only modal responses shown.)
"The Cooper Cooler™ can chill a soda in one minute": somewhat plausible [42%]
"Because it's spinning and not shaking your carbonated beverages, you don't have to worry about them exploding": somewhat plausible [35%]

The primary heat transfer process that the Coffee Joulies™ uses to moderate and maintain coffee temperatures is:
conduction.  ****************************** [30]
convection.  **************** [16]
radiation.  ****** [6]
(Unsure/guessing/lost/help!)  ***** [5]

How plausible do you think these claims for Coffee Joulies™ are?
(Only modal responses shown.)
"One 'bean' for every four ounces of coffee cools right down to 140° in a few seconds": somewhat plausible [33%]
"Keeps coffee at 140° for two full hours": not very plausible [37%]

The primary heat loss process that any blanket (regardless of type) should prevent in typical "emergency survival conditions" (on Earth) is:
conduction.  ********* [9]
convection.  ********** [10]
radiation.  ******************************* [31]
(Unsure/guessing/lost/help!)  ******* [7]

How plausible do you think heavy-duty garbage bag material will be just as effective as a space blanket for typical "emergency survival conditions" on Earth?
Implausible.  ****** [6]
Not very plausible.  ********** [12]
Somewhat plausible.  ******************** [20]
Very plausible.  ********* [9]
(Unsure/guessing/lost/help!)  ********** [10]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"The Coffee Joulies™ become liquid because they are absorbing heat, but then they give back that energy and become solid again?" (Yes.)

"Cooper Cooler™ could chill my wine and get me drunk much faster."

"I don't understand who needs a Cooper Cooler™--I feel like it's one of those appliances like a pizza maker which only has one use and better alternatives."

"How would the carbonated drink will not explode from spinning and not being shaken?" (Sounds like an experiment that just has to be done.)

"How expensive are we talking for the Coffee Joulies™? I was gonna ask for a printer for Christmas but those beans just made it to the top of the list." (Before you decide what to ask for this Christmas, get your science on in laboratory with the Coffee Joulies™.)

"Garbage bags are the obvious choice, you can use them to dispose of waste or as a blanket in an emergency situation. Take that science!" (Bam! Pow!)

"I am wondering how true these claims are and if my guesses were correct."

"What do you recommend we do in order to prepare for the final next next week?" (Look through the sample problems in the Final Exam study guide, and the equations on the sample Final Exam cover sheet.)

20141207

Astronomy current events question: light source SDSS1133

Astronomy 210L, fall semester 2014
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!)
Francis Reddy, "NASA's Swift Mission Probes an Exotic Object: ‘Kicked’ Black Hole or Mega Star?," (November 19, 2014)
http://www.nasa.gov/content/goddard/nasas-swift-mission-probes-an-exotic-object
Observations from NASA's Swift satellite of dwarf galaxy Markarian 177 indicates that its unusual light source SDSS1133 may be a __________ ejected from two merging galaxies. (A) cloud of dark matter. (B) high-energy pulsar. (C) wormhole. (D) hypernova. (E) supermassive black hole.

Correct answer: (E)

Student responses
Sections 70178, 70186
(A) : 4 students
(B) : 5 students
(C) : 1 student
(D) : 4 students
(E) : 25 students

Astronomy current events question: Curiosity rover examines chosen rocks

Astronomy 210L, fall semester 2014
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!)
Guy Webster, "Second Time Through, Mars Rover Examines Chosen Rocks," (November 18, 2014)
hhttp://www.nasa.gov/jpl/msl/second-time-through-mars-rover-examines-chosen-rocks
NASA's Curiosity Mars rover has returned to an outcrop at the base of Mount Sharp in order to:
(A) recharge its solar cells.
(B) recheck its position.
(C) avoid winter sandstorms.
(D) sample selected rock formations.
(E) boost signal reception from Earth.

Correct answer: (D)

Student responses
Sections 70178, 70186
(A) : 6 students
(B) : 0 students
(C) : 2 students
(D) : 17 students
(E) : 4 students

Astronomy current events question: detecting dark matter with GPS

Astronomy 210L, fall semester 2014
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!)
Mike Walterbeek, "Hiding in Plain Sight: Elusive Dark Matter May Be Detected with GPS," (November 17, 2014)
http://www.unr.edu/nevada-today/news/2014/finding-dark-matter
University of Nevada, Reno researchers proposed detecting dark matter by tracking:
(A) GPS time signal discrepancies.
(B) sunspots.
(C) Voyager 2 signals from outside the solar system.
(D) star formation rates.
(E) changes in Earth's rotation rate.

Correct answer: (A)

Student responses
Sections 70178, 70186
(A) : 25 students
(B) : 3 students
(C) : 5 students
(D) : 5 students
(E) : 1 student

20141203

Online reading assignment: Milky Way history, big bang clues (SLO campus)

Astronomy 210, fall semester 2014
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 history of the Milky Way and big bang clues, a comic strip adaptation of of Neil deGrasse Tyson's "The Most Astounding Fact" 2008 interview for TIME magazine, and Minute Physics' video explanation of Olbers' paradox.


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 really liked the first generation stars. It was a really pretty picture but it was also neat to learn that there was only hydrogen and the first massive stars started fusing it into heavier elements and that it was free of metals. So that was really cool and something I'll remember."

"I though the video of why the night sky is dark was very interesting, also how we can see parts of the night sky with no stars at all. A universe where no stars existed at the time."

"I was informed that the Big Bang was literally not a bang. I thought it was a bang the whole time and it started at a certain position. This is interesting to me because the power of reading helps clarify false assumptions."

"Lookback time."

"Olbers' paradox/question. I never thought about why the night sky was dark and not bright."

"It blows my mind that all of the elements in our bodies were created by hydrogen fusion in massive stars."

"Everything interested me in this section, this is the section I have been looking forward to the most. Finding out the beginnings of our galaxies and the beginning of our universe. Definitely interested in the theory of the big bang, makes a lot of sense when you think of the expanding aspect of the universe."

"The difference between metal-rich and poor stars"

"By the time the universe was a few minutes old all the protons and neutrons that are in our bodies had come into existence."

"OMG this week is SO AWESOME. The idea that when we look at the darkness of space what we're actually seeing is a time before stars blows my mind."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
"The space in between galaxies is expanding, but where does all this space come from?"

"The metallicities of the Milky Way and the difference between metal poor and metal rich. It was just confusing because there is so much information about it and I think I need someone to explain it to rather than just reading it."

"Olbers' paradox/question is still pretty confusing. It's confusing that the universe is limitless but finite. There isn't an edge?"

"I'm confused why we are talking about Facebook relationship statuses."

"I found it confusing that the universe is infinite but has a finite age."

"I don't understand cosmic expansion. How are all of the galaxies moving apart from each other? What is causing this?"

"If the universe is expanding are more and more stars being created at the edge of the universe? If so how is this possible?"

"How can just hydrogen change all the way into planets with self-sustaining ecosystems and create lifeforms?"

Indicate how the amount of these elements in the universe have changed over time.
(Only correct responses shown.)
Hydrogen: decreased [44%]
Metals (elements heavier than hydrogen and helium): increased [81%]

The outermost layers of __________ are more abundant in metals (elements heavier than hydrogen and helium).
extremely old stars that formed a long time ago.  ********* [9]
young stars that formed very recently.  ************************** [26]
(There is a tie.)  [0]
(Neither, as stars cannot have metals.)  [0]
(Unsure/guessing/lost/help!)  * [1]

Indicate what produced these elements.
(Only correct responses shown.)
Helium in the sun's core: the sun [22%]
Carbon in your body: another star, in the past [50%]
Calcium in your bones: another star, in the past [39%]
Iron in your blood: another star, in the past [44%]
Gold and silver from mines: another star, in the past [36%]

People breaking up a relationship are most likely to update their Facebook status to "single":
on Valentine's Day.  **** [4]
during spring break.  ***************** [17]
just after Thanksgiving.  ********* [9]
on Christmas Day.  ** [2]
(Unsure/guessing/lost/help!)  **** [4]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
"Wait, the animation you used for the expansion of the universe was zooming in--but if the distances between galaxies is increasing, shouldn't the galaxies be the things moving in the slides?" (If you lived in one of those galaxies, you would observe all other galaxies moving away from you.)

"You're most likely to see 'single' FB status updates a few days before the Mid-State Fair starts during the summer."

"Can you go over some more of where the elements were produced in class, please?" (Yes.)

"What I found confusing was the speed of light and how images we see actually differ from what is actually out there." (Light takes time to travel. Like if you just today received a postcard from your significant other breaking up with you--but then realizing your significant other actually broke up with you a few days ago.)

"What was before the big bang? If the universe started at a single point that keeps expanding, how did it start?" (One interpretation is that nothing existed before the big bang. Time (or more precisely, anything that could even keep track of time) was undefined, so "what existed before" may debatably not be answerable. And keep in mind that the universe did not start at a single point, the distances between everything everywhere in our infinite universe a long time ago were zero, and the distances between everything everywhere have been expanding ever since--at least this seems to be supportable by observational evidence.)

"If the idea of the blackness of the sky simply being a time before stars is true, though, wouldn't we have some kind of record of brand new stars/galaxies appearing and taking up a heretofore unoccupied space in the sky?" (Yes, that is what the closer galaxies (more recent lookback time) look like.)

Physics presentation: heat transfer applications

Let's now shift gears and preview the various heat transfer phenomena you will be investigating during the last laboratory of this semester...

A Cooper Cooler™, where beverages are spun while being sprayed with ice water:
"The Cooper Cooler™ chills beverages on demand ninety times faster than a refrigerator, and forty times faster than a freezer. So that means you can chill a bottle of wine in six minutes, and your sodas in one minute... And because it's spinning and not shaking your carbonated beverages, you don't have to worry about them exploding."
If you choose, you can investigate whether these claims are valid with an actual Cooper Cooler™! (Video link: "Cooper Cooler - Rapid Beverage Cooler.")

Or Coffee Joulies™:
"Fresh coffee is often too hot to drink when it's first brewed. This is especially true when you throw it in your insulated travel mug and you head out to work, and you're waiting and you're waiting for it to cool down enough and you carry it around and you can't even drink your coffee..."

"[Coffee Joulies™ are] shaped like giant coffee 'beans' made of stainless steel. You just drop these in your hot coffee, one 'bean' for every four ounces of coffee, and it cools right down to 140° in a few seconds, that's the perfect temperature for drinking. Then the Coffee Joulies™ hold your coffee at that temperature so you can take your time and enjoy it."

"The secret is inside--there's a proprietary substance that's encapsulated inside the steel 'beans' and it's called a phase-change material. This one has a melting temperature of exactly 140°, so when you put it in your hot coffee, it absorbs the heat, cooling all the coffee around it, so it's completely liquid inside the steel 'bean.' Then the phase-change material slowly releases that heat back into the coffee until it becomes a solid again. And in our tests, they kept coffee at 140° for two full hours..."
Again, in laboratory, you can choose to investigate these claims--however, not with actual Coffee Joulies™ (they're somewhat pricey), but with packets containing the same phase-change substance (food-grade sodium acetate). (Video link: "Coffee Temperature Regulator.")

And reflective "space blankets," used in emergency survival situations to retain body warmth, compared to plain heavy-duty garbage bags:
"I'm a big fan of using heavy-duty garbage bags for temporary survival... But as your sole survival device, you just need to know that an emergency space blanket like this works really well...[but only] in space, which where they're designed to be used, where radiative heat loss is the primary means of heat loss."
You can also choose to investigate whether a garbage bag or a space blanket would be more effective for emergency conditions...here on Earth. (Video link: "The Problems With Space Blankets.")