20170525

Presentation: marketplace astronomy (results)

Let's compare your results with students from a previous semester. Here is the word tag cloud generated by Wordle.net for astronomy-related car makes and models. Frequently-listed cars are larger, while cars used only once are smallest. How many of these cars were you able to list? Anyone have cars not listed here?

Here is the word tag cloud for astronomy-related food brand names from a previous semester. Again, frequently-listed brands are larger, while brand names used only once are smallest. How many of these brand names were you able to list? Anyone have brand names not listed here?

Astronomy-related non-food brand names from a previous semester. Again, how many of these brand names were you able to list? Anyone have brand names not listed here?

Now we have potentially interesting astronomy topics from another previous semester. A lot of you are looking forward to learning about "black holes" this semester. Anyone have interesting topics not listed here?

And potentially confusing astronomy topics from another previous semester. "Black holes" is prominent here as well! Anyone have interesting topics not listed here? (Some of you may consider "math" as potentially confusing--yes, there is an algebra math prerequisite for this course, but there are no explicit calculations as we'll be focusing on graphs, dependencies, and proportionalities--essentially math without equations.)

And we have time to answer a few of your questions and comments.

"If you discovered a planet, P-dog, what would you name it?"
I would name it after my wife. I would name it: "Mrs. P-dog."
"Do you believe in aliens? Or life on other planets?"
Yes, and yes. I would bet money on it. I would bet $1. And I would win. But if I lost, it'd just be $1.
"Do you think Pluto should still be a planet?"
Let me tell you a story of my senior year in high school, way back when. I turned 18 during my senior year, and that was a big deal because you only needed to be 18 to be able to purchase and drink alcohol. My senior year was awesome. Commencement was awesome. Graduation parties were awesome...until a few years later, when the legal drinking age was raised from 18 to 21. And there was no grandfather clause. So before, it was legal for me to drink; but afterwards, I was no longer allowed to drink anymore. And that wasn't fair... So when it comes to Pluto, which was a planet, and then rules were changed so it is now no longer a planet, and there was no grandfather clause--I say, suck it up, Pluto.

Previous posts:

20170519

Online reading assignment question: advice to future students

Astronomy 210, spring semester 2017
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.)
"Show up for class, do the reading assignments and don't miss the quizzes! Don't be afraid to ask questions, everybody can learn from them!"

"Don't miss any classes! Also, study as much as you can, otherwise enjoy working with P-dog."

"Read every chapter and all the presentations. Also review past quizzes and tests."

"Do homework! There isn't much but it is definitely worth it!"

"Be sure to read the chapters before you go to class and to practice certain things that P-dog gives to you."

"Go to class! Ask questions even if you think you sound dumb."

"Don't be close-minded, do your homework, and open your mind to all the wonderful aspects of our universe and knowledge."

"In order to succeed in this class is to ALWAYS show up, pay attention, read the book, and ask questions."

"First rule of astronomy class. Don't talk about astronomy class. Second rule. Find a partner who is good at what you aren't and don't just find a buddy to piss and moan with."

"In order to succeed, you must do the homework every week. If you do not, You WILL be lost when you come to class."

"Keep up because this class takes off running."

"Come to every class, especially if you have a hard time understanding the content!"

"Do all the readings and the homework. Study for the quizzes and midterms. Use all the resources that the teacher provides!"

"Do all the extra credit you can, because in the end those few points can make or break your grade. Always show up to every class because if you don't you'll be completely lost when you finally do. And always to the reading assignments, they are easy points and boost your grade as well. The cumulative point grade system is awesome! Thanks P-dog!"

"Go to class. It helps your grade and is fun. Confusing parts of the book are thoroughly explained when you ask."

"Just have basic knowledge about solar system planets and compass directions, as well as moon phases and everything should make sense and come together from there."

"Do well on the quizzes and then your grade on everything else will do better."

"Know the quiz information, do your home work, and relax its a good class!"

"Go to class because the lectures aren't boring, you don't exactly have to take notes, and the group activities help your grade. Do the homework because it is not stressful if you try your best and it helps your grade in the long run. Go to office hours to ask P-dog how to prepare for a quiz if you are unsure. He will help you prepare then and there."

"Always do the reading, and come to EVERY CLASS with questions."

"Attend class and take notes."

"Complete every single online reading assignment! Review pre class presentations, at least skim them! Study for quizes and save them to study for mid terms and finals! Do the extra credit opportunities. And DEFINITELY show up to class for in class activity points. Do this and you will get an A. It's easy!"

"Success is based on the amount of time you are willing to spend on the reading assignments which include book, and the online presentations, as well as showing up for every class and taking notes with your quiz packet in hand and already filled in. P-dog is very thorough with the material he supplies to make you a shining star."

"Do the reading assignments, read the book, study the quizzes."

"Do the work early, this class is made very convenient for you, everything you need to know is on the website. The reading assignments are informative and very creative. Also, don't be afraid to ask questions, this is the best class to ask questions in, and it can be confusing at some points, but P-dog makes it easy to understand and relatable."

"Do the online reading assignments before class."

"Do the reading and the online reading assignments! The reading is easy to do and most of the time you can get by without taking detailed notes or anything, and the assignment is really important because it previews what you'll be learning about next."

"Show up to class, every time. Take notes, participate in group work, do all of the readings and homework to prepare yourself for class, review often, and STUDY often."

"Don't ever be lazy in this class. It can be very easy to fall behind and just do the assignments before the next class but it is imperative that you read along in your book and complete every assignment, so the next class you know what is going on and ask questions for what you are lost on."

Astronomy final exam question: star cluster more likely to have white dwarfs?

Astronomy 210 Final Exam, spring semester 2017
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked and answered:
Curi: Star cluster A is 12 billion years old, while star cluster B is one million years old. Which star cluster will have more white dwarfs?
arsl: Star cluster A.
Discuss whether this answer is correct or incorrect, and how you know this. Explain using the properties of mass and stellar lifetimes, evolution of stars, and star cluster ages.

[*] answers.yahoo.com/question/index?qid=20110402021909AA2fbXz.

Solution and grading rubric:
  • p:
    Correct. Understands that star cluster A will have more white dwarfs (while star cluster B would not have any) because:
    1. medium-mass stars become white dwarfs well after the end of their main-sequence lifetimes (approximately 10 billion years, much longer than one million years); and
    2. medium-mass stars in the younger star cluster B will not have had enough time to become white dwarf, while the medium-mass stars in the older star cluster A will have had enough time to become white dwarfs.
  • r:
    Nearly correct (explanation weak, unclear or only nearly complete); includes extraneous/tangential information; or has minor errors. At least discusses white dwarfs as end-stages of medium-mass main sequence stars, but does not explicitly discuss that a million years is not enough time for that to happen.
  • t: Contains right ideas, but discussion is unclear/incomplete or contains major errors. Argues that an older star cluster would be more likely to have end-stage stars than a younger cluster.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Garbled discussion of properties and evolution of stars.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion other than that of the properties and evolution of stars.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 30676
Exam code: finalSBr6
p: 5 students
r: 9 students
t: 14 students
v: 5 students
x: 2 students
y: 0 students
z: 2 students

A sample "p" response (from student):

Astronomy final exam question: are globular cluster stars metal-poor or metal-rich?

Astronomy 210 Final Exam, spring semester 2017
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked and answered:
anon: Are stars in globular clusters considered metal-rich or metal-poor?
Cirr: Since globular clusters formed a long time ago, their stars have been fusing for a long time, and so will be metal-rich.
Discuss why this answer is incorrect, and how you know this. Explain using the properties of mass and stellar lifetimes, evolution of stars, and star cluster ages.

[*] answers.yahoo.com/question/index?qid=20100307080114AA5ua6g.

Solution and grading rubric:
  • p:
    Explains why the answer is incorrect, because:
    1. stars in globular clusters ("formed a long time ago") will be metal-poor, having formed from essentially just hydrogen; as
    2. newer stars are metal-rich, having formed from hydrogen enriched with metals produced by and released from previous generation stars that have undergone supernovae explosions.
  • 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. Typically has only one of (1)-(2) complete and correct.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Garbled discussion of properties and evolution of stars, such as breaking down of metals; masses and evolution rates.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion other than that of the properties and evolution of stars.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 30676
Exam code: finalSBr6
p: 12 students
r: 5 students
t: 12 students
v: 2 students
x: 4 students
y: 0 students
z: 2 students

A sample "p" response (from student 1231):

Another sample "p" response (from student 4321):

A sample "t" response (from student 1214):

A sample "v" response (from student 1236):

Another sample "x" response (from student 8008):

20170518

Astronomy final exam question: hottest supergiants the biggest stars possible?

Astronomy 210 Final Exam, spring semester 2017
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked and answered:
Pdg: Are the hottest supergiants the biggest stars possible on an H-R diagram?
qcp: They are.
Discuss whether this answer is correct or 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=20170323215116AASJ9GS.

Solution and grading rubric:
  • p:
    Correct. Discusses how the Stefan-Boltzmann law and/or H-R diagram shows that the hottest supergiant is not necessarily the largest possible star, as the cooler supergiants would be larger.
  • 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. At least discussion demonstrates understanding of the Stefan-Boltzmann law and/or H-R diagram. May have instead conflated "brightest" with "biggest" that the hottest supergiants would be the most luminous supergiants possible, or that the hottest main-sequence stars would be the most luminous stars possible.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. At least attempts to use the Stefan-Boltzmann law and/or H-R diagram.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion not clearly based on the Stefan-Boltzmann law and/or H-R diagram.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 30674
Exam code: finalnmSS
p: 8 students
r: 3 students
t: 4 students
v: 2 students
x: 1 student
y: 0 students
z: 0 students

Section 30676
Exam code: finalSBr6
p: 16 students
r: 1 student
t: 12 students
v: 5 students
x: 1 student
y: 0 students
z: 2 students

A sample "p" response (from student 1866):

Another sample "p" response (from student 6850):

A sample "t" response (from student 8959):

Another sample "t" response (from student 9433):

Astronomy final exam question: star cluster more likely to have red giants?

Astronomy 210 Final Exam, spring semester 2017
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked and answered:
Curi: Star cluster A is 12 billion years old, while star cluster B is one million years old. Which star cluster will have more red giants?
arsl: Star cluster A.
Discuss whether this answer is correct or incorrect, and how you know this. Explain using the properties of mass and stellar lifetimes, evolution of stars, and star cluster ages.

[*] answers.yahoo.com/question/index?qid=20110402021909AA2fbXz.

Solution and grading rubric:
  • p:
    Correct. Understands that star cluster A will have more red giants (while star cluster B would not have any) because:
    1. medium-mass stars become red giants at the end of their main-sequence lifetimes (approximately 10 billion years, much longer than one million years); and
    2. medium-mass stars in the younger star cluster B will not have had enough time to become red giants, while the medium-mass stars in the older star cluster A will have had enough time to become red giants.
  • 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. May have conflated red giants with red supergiants, which are massive stars that have ended their very short main-sequence life, and concludes that star cluster B would have more red supergiants.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Garbled discussion of properties and evolution of stars.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion other than that of the properties and evolution of stars.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 30674
Exam code: finalnmSS
p: 1 student
r: 3 students
t: 7 students
v: 6 students
x: 1 student
y: 0 students
z: 0 students
A sample "p" response (from student 6877):

Astronomy final exam question: white dwarf vs. red dwarf metallicity

Astronomy 210 Final Exam, spring semester 2017
Cuesta College, San Luis Obispo, CA

An astronomy question on an online discussion board[*] was asked and answered:
Chr: Which dwarf star will have more metals? White dwarfs or red dwarfs?
t153: White dwarfs will have lots of metals compared to red dwarfs.
Discuss why this answer is correct, and how you know this. Explain using the properties of mass and stellar lifetimes, evolution of stars, and star cluster ages.

[*] answers.yahoo.com/question/index?qid=20110318182328AA0dt07.

Solution and grading rubric:
  • p:
    Understands that white dwarfs are more metal-rich than red dwarfs because:
    1. white dwarfs are the end-stage of the core of a medium-mass star, and are composed solely of metals (carbon and oxygen); and
    2. red dwarfs are main-sequence stars that are still fusing hydrogen into helium (which is not considered a metal).
  • 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. May base argument on white dwarfs being metal-rich due to being born more recently and incorporating metals from a previous generation star, while red dwarfs would have been born long ago during a metal-poor universe.
  • v:
    Limited relevant discussion of supporting evidence of at least some merit, but in an inconsistent or unclear manner. Garbled discussion of properties and evolution of stars, such as breaking down of metals; masses and evolution rates.
  • x:
    Implementation/application of ideas, but credit given for effort rather than merit. Discussion other than that of the properties and evolution of stars.
  • y:
    Irrelevant discussion/effectively blank.
  • z:
    Blank.
Grading distribution:
Section 30674
Exam code: finalnmSS
p: 2 students
r: 4 students
t: 6 students
v: 2 students
x: 4 students
y: 0 students
z: 0 students

A sample "p" response (from student 6877):

A sample "t" response (from student 0907):

A sample "x" response (from student 9355):

20170515

Education research: MPEX pre- and post-instruction results (Cuesta College, spring semester 2017)

The Maryland Physics Expectations survey (MPEX, Redish, Saul, and Steinberg, 1998) was administered to Cuesta College Physics 205B (college physics, algebra-based, mandatory adjunct laboratory) students at Cuesta College, San Luis Obispo, CA. The MPEX was given during the first week of the semester, and then on the last week of the semester, to quantify student attitudes, beliefs, and assumptions about physics using six question categories, rating responses as either favorable or unfavorable towards:
  1. Independence--beliefs about learning physics--whether it means receiving information or involves an active process of reconstructing one's own understanding;
  2. Coherence--beliefs about the structure of physics knowledge--as a collection of isolated pieces or as a single coherent system;
  3. Concepts--beliefs about the content of physics knowledge--as formulas or as concepts that underlie the formulas;
  4. Reality Link--beliefs about the connection between physics and reality--whether physics is unrelated to experiences outside the classroom or whether it is useful to think about them together;
  5. Math Link--beliefs about the role of mathematics in learning physics--whether the mathematical formalism is used as a way of representing information about physical phenomena or mathematics is just used to calculate numbers;
  6. Effort--beliefs about the kind of activities and work necessary to make sense out of physics--whether they expect to think carefully and evaluate what they are doing based on available materials and feedback or not.
Cuesta College
Physics 205B spring semester 2017 sections 30884, 30885
San Luis Obispo, CA campus
(N = 25, matched pairs, excluding negative informed consent form responses)

Percentage of (favorable:unfavorable) responses
Overall   Independence   Coherence   Concepts   Reality link   Math link   Effort   
Initial   52:2537:2740:3149:3472:0956:1874:10
Final   52:2745:2144:3150:3074:1153:2656:23

Previous posts:

20170514

Education research: SPCI statistics (spring semester 2017)

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 spring semester 2017 section 30674
N = 18 (matched-pairs)
<initial%>= 36% ± 14%
<final%>= 64% ± 16%
<g>= 0.43 ± 0.22 (matched-pairs); 0.43 (class-wise)

Astronomy 210 spring semester 2017 section 30676
N = 35 (matched-pairs)
<initial%>= 33% ± 17%
<final%>= 57% ± 16%
<g>= 0.32 ± 0.24 (matched-pairs); 0.36 (class-wise)

This semester's SPCI pre-instruction scores scores are comparable to results from previous semesters at Cuesta College, while the post-instruction scores and gains for section 30674 are slightly higher than those of section 30676, and some previous semesters.

20170513

Astronomy quiz question: sun as source of Earth elements and core heat?

Astronomy 210 Quiz 7, spring semester 2017
Cuesta College, San Luis Obispo, CA

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

Correct answer (highlight to unhide): (F)

Stars produce metals (elements heavier than hydrogen and helium) in their cores during their giant/supergiant phases, up through type Ia/II supernovae explosions. Along with their unused hydrogen, these metals are then scattered into the interstellar medium, which are then incorporated into later generations of stars (or planets). Since all of elements listed above (lithium, iron, gold and silver) and core heat comprise Earth today, they cannot be elements nor energy produced by the sun within its core, as both sun and Earth formed from the same gas/dust cloud at the same time.

Section 30674
Exam code: quiz07N4rR
(A) : 3 students
(B) : 0 students
(C) : 2 students
(D) : 1 student
(E) : 7 students
(F) : 6 students

Success level: 34% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.40

Section 30676
Exam code: quiz07Sl1M
(A) : 7 students
(B) : 1 student
(C) : 1 student
(D) : 6 students
(E) : 16 students
(F) : 9 students

Success level: 26% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.42

Education research: ECCE statistics (spring semester 2017)

Students at Cuesta College (San Luis Obispo, CA) were administered a shortened version (22 out of 45 questions) of the Electric Circuit Concept Evaluation (David Sokoloff, University of Oregon) during the first and the last week of instruction. Physics 205B is the second semester of an algebra-based introductory general physics course covering optics, electromagnetism, and modern physics, with a mandatory adjunct laboratory component.

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:

Physics 205B spring semester 2017 sections 30882, 30883
N = 24
<initial%>= 24% ± 14%
<final%>= 35% ± 10%
<g>= 0.11 ± 0.23 (matched-pairs); 0.14 (class-wise)

This semester's ECCE post-instruction score is slightly lower than results from previous semesters at Cuesta College, and this semester's gain is slightly higher than most previous semesters.

Previous posts:
  • Education research: ECCE statistics (spring semester 2015).
  • Education research: ECCE statistics (spring semester 2014).
  • Education research: ECCE statistics (spring semester 2012).
  • Education research: ECCE statistics (spring semester 2011).
  • Education research: ECCE statistics (fall semester 2010).
  • Physics quiz question: alpha decay product of bismuth-209

    Physics 205B Quiz 7, spring semester 2017
    Cuesta College, San Luis Obispo, CA

    Bi(209,83) has the longest known half-life of any isotope that undergoes alpha decay, with a half-life of 1.9×1019 years[*].

    Bi(209,83) undergoes alpha decay to become:
    (A) Tl(205, 81).
    (B) Tl(207, 81).
    (C) Bi(209, 82).
    (D) Po(209, 84).

    [*] Pierre de Marcillac, Noël Coron, Gérard Dambier, Jacques Leblanc and Jean-Pierre Moalic, "Experimental Detection of α-Particles from the Radioactive Decay of Natural Bismuth," Nature, vol. 422 (April 24, 2003), 
pp. 876-878 nature.com/nature/journal/v422/n6934/full/nature01541.html.

    Correct answer (highlight to unhide): (A)

    Bi(209,83) is a nuclide with 83 protons, and 209 nucleons, and thus has 209 – 83 = 126 neutrons. When it undergoes alpha decay, it emits a helium-4 nucleus (He(4,2)) that contains two neutrons and two protons, such that the resulting nuclide has 81 protons, and 124 neutrons, and thus has a total of 81 + 124 = 205 nucleons, and so the result is Tl(205,81).

    Sections 30882, 30883
    Exam code: quiz07N4ci
    (A) : 10 students
    (B) : 11 students
    (C) : 3 students
    (D) : 2 students

    Success level: 38%
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.71

    Physics quiz question: activity decrease of bismuth-209

    Physics 205B Quiz 7, spring semester 2017
    Cuesta College, San Luis Obispo, CA

    Bi(209,83) has the longest known half-life of any isotope that undergoes alpha decay, with a half-life of 1.9×1019 years[*].

    It will take __________ for a sample of Bi(209,83) to decrease its activity by 1.0%.
    (A) 1.9×1017 years.
    (B) 2.8×1017 years.
    (C) 2.7×1019 years.
    (D) 3.8×1019 years.

    [*] Pierre de Marcillac, Noël Coron, Gérard Dambier, Jacques Leblanc and Jean-Pierre Moalic, "Experimental Detection of α-Particles from the Radioactive Decay of Natural Bismuth," Nature, vol. 422 (April 24, 2003), 
pp. 876-878 nature.com/nature/journal/v422/n6934/full/nature01541.html.

    Correct answer (highlight to unhide): (B)

    The activity of a sample is given by:

    R = R0·(1/2)(t/T1/2),

    where T1/2 is the half-life. Solving for the time t it would take for the activity to drop down to R = 0.990 (assuming R0 started at exactly 1, as it "decreases its activity by 1.0%" down to 99.0%), then:

    (R/R0) = (1/2)(t/T1/2);

    ln(R/R0) = (t/T1/2)·ln(1/2);

    t = T1/2·ln(R/R0)/ln(1/2);

    t = (1.9×1019 years)·(ln(0.990/1)/ln(1/2) = 2.754918242×1017 years,

    or to two significant figures, it will take this sample 2.8×1017 years to decrease its activity by 1.0%.

    (Response (A) is 1% of T1/2; response (C) is the time constant τ = 1/(T1/2·ln(2)); response (D) is the time it would take for the sample to decrease its activity by 99% (or decrease its activity down to 1%.)

    Sections 30882, 30883
    Exam code: quiz07N4ci
    (A) : 12 students
    (B) : 7 students
    (C) : 5 students
    (D) : 2 students

    Success level: 27%
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.57

    Physics quiz question: comparing rate of radioactive decays

    Physics 205B Quiz 7, spring semester 2017
    Cuesta College, San Luis Obispo, CA

    Two samples currently have certain amounts of a radioactive isotope, an embedded gaseous daughter element (which is the byproduct of the radioactive decay process), and inert material (which is not involved in the decay process). In terms of decays per time, __________ is more active.
    (A) sample A.
    (B) sample B.
    (C) (There is a tie.)
    (D) (Not enough information is given.)

    Correct answer (highlight to unhide): (C)

    The rate of radioactive decays per second depends on the amount of radioactive isotopes. Since both samples contain the same amount of the same type of radioactive isotope, then they will have the same rate of decay.

    Sections 30882, 30883
    Exam code: quiz07N4ci
    (A) : 6 students
    (B) : 15 students
    (C) : 5 students
    (D) : 0 students

    Success level: 19%
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.43

    Physics quiz question: Feynman diagram vertex interpretation

    Physics 205B Quiz 7, spring semester 2017
    Cuesta College, San Luis Obispo, CA

    This Feynman diagram vertex depicts a pion (π) that is __________ charged.
    (A) negatively.
    (B) neutrally.
    (C) positively.
    (D) (This vertex is not possible, as it is invalid.)

    Correct answer (highlight to unhide): (B)

    This Feynman diagram vertex is valid, so tracing the straight line with arrows from left-to-right (the convention used in this class) shows a proton still remaining a proton, so the pion that is emitted must be neutrally charge (π0).

    Sections 30882, 30883
    Exam code: quiz07N4ci
    (A) : 4 students
    (B) : 16 students
    (C) : 6 students
    (D) : 0 students

    Success level: 62%
    Discrimination index (Aubrecht & Aubrecht, 1983): 0.36

    Physics quiz question: Feynman diagram interpretation

    Physics 205B Quiz 7, spring semester 2017
    Cuesta College, San Luis Obispo, CA

    This Feynman diagram depicts a(n) __________ process.
    (A) β.
    (B) β+.
    (C) electron capture.
    (D) (This process is not possible, as it is invalid.)

    Correct answer (highlight to unhide): (D)

    This Feynman diagram vertex is invalid, because it violates charge conservation. Tracing the proton line left-to-right shows that it converts into a neutron, and so the outgoing intermediate vector boson must be positively charged (W+) to conserve charge for that vertex. However, at the bottom vertex it is not possible for the neutrally charged neutrino (ν) to absorb that positively charged intermediate vector boson in order to convert to a negatively charged electron.

    Sections 30882, 30883
    Exam code: quiz07N4ci
    (A) : 9 students
    (B) : 12 students
    (C) : 6 students
    (D) : 0 students

    Success level: 0%
    Discrimination index (Aubrecht & Aubrecht, 1983): 0

    Physics quiz archive: radioactive decay, Feynman diagrams

    Physics 205B Quiz 7, spring semester 2017
    Cuesta College, San Luis Obispo, CA
    Sections 30882, 30883, version 1
    Exam code: quiz07N4ci



    Sections 30882, 30883 results
    0- 6 :   **** [low = 0]
    7-12 :   ************** [mean = 10.5 +/- 6.1]
    13-18 :   *****
    19-24 :   *
    25-30 :   * [high = 27]

    20170512

    Astronomy current events question: Pan's equatorial ridge

    Astronomy 210L, spring semester 2017
    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!)
    Tony Greicius, "Pan Revealed" (March 16, 2017)
    nasa.gov/image-feature/jpl/pia21436/pan-revealed
    The thin ridge around the equator of Saturn's moon, Pan, imaged by NASA's Cassini spacecraft may have been formed from material:
    (A) gathered from Saturn's rings.
    (B) flattened between two colliding smaller moons.
    (C) flung out during rapid rotation.
    (D) ejected from ice geysers.
    (E) from moonquake faults.

    Correct answer: (A)

    Student responses
    Sections 30679, 30680
    (A) : 13 students
    (B) : 4 students
    (C) : 8 students
    (D) : 3 students
    (E) : 1 student

    Astronomy current events question: landslides on Ceres' surface

    Astronomy 210L, spring semester 2017
    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!)
    Elizabeth Landau, "Landslides on Ceres Reflect Ice Content" (April 19, 2017)
    nasa.gov/feature/jpl/landslides-on-ceres-reflect-ice-content
    Images of __________ on the dwarf planet Ceres from NASA's Dawn spacecraft may be evidence of a substantial amount of water ice just under its surface.
    (A) tectonic plate motion.
    (B) landslides.
    (C) cryovolcano flows.
    (D) water vapor geysers.
    (E) wet salt deposits.

    Correct answer: (B)

    Student responses
    Sections 30679, 30680
    (A) : 5 students
    (B) : 8 students
    (C) : 2 students
    (D) : 9 students
    (E) : 5 students

    Astronomy current events question: metal ions in Mars' upper atmosphere

    Astronomy 210L, spring semester 2017
    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!)
    Bill Steigerwald and Nancy Jones, "NASA's MAVEN Reveals Mars Has Metal in its Atmosphere" (April 10, 2017)
    nasa.gov/press-release/goddard/2017/metal-mars
    Metal ions detected by NASA's MAVEN spacecraft detected in Mars' upper atmosphere may have come from:
    (A) tiny meteoroids.
    (B) its past volcanoes.
    (C) the solar wind.
    (D) the greenhouse effect.
    (E) seasonal sandstorms.

    Correct answer: (A)

    Student responses
    Sections 30679, 30680
    (A) : 14 students
    (B) : 6 students
    (C) : 3 students
    (D) : 0 students
    (E) : 4 students

    20170510

    Astronomy quiz archive: Milky Way, cosmology

    Astronomy 210 Quiz 7, spring semester 2017
    Cuesta College, San Luis Obispo, CA

    Section 30674, version 1
    Exam code: quiz07N4rR


    Section 30674
    0- 8.0 :   * [low = 6.5]
    8.5-16.0 :   ******
    16.5-24.0 :   ***** [mean = 20.9 +/- 7.7]
    24.5-32.0 :   *****
    32.5-40.0 :   ** [high = 36.0]


    Section 30676, version 1
    Exam code: quiz07Sl1M


    Section 30676
    0- 8.0 :   **** [low = 4.0]
    8.5-16.0 :   ********
    16.5-24.0 :   ************** [mean = 20.1 +/- 7.4]
    24.5-32.0 :   ************
    32.5-40.0 :   ** [high = 36.5]

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

    Astronomy 210, spring semester 2017
    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 really liked the timeline website you showed us. It was really cool to keep hitting okay and have it go further and further, making you're personal lifetime seem really small. Also made me realize next week is just one week out of the hundred of thousands I will have in my lifetime."

    "The amount of time Earth has had to evolve and develop; I came to the conclusion that we will never see something completely extraordinary in our lifetime. But that amount of time itself is something amazing and interesting to think about how things looked and different experiences we could have if we traveled back in time for one day."

    "The timeline diagram that moved and continued to squish today into nothingness really put things into perspective for me."

    "How heat sources can create complex organic molecules, and that this may be the source of the first life on Earth. I knew scientists had an idea of how life had began, but I never knew the specifics and how simple (at least in concept) it could be."

    "Life beyond Earth is a very intriguing subject. The fact that there could be other life that we don't even know of yet, is fascinating. The amount of universe that we still have yet to discover is mind boggling. To think that we are the only life form is not only ignorant but kinda scary. With all the planets out there, there has to be life beyond humans."

    "The Miller experiment. I, amongst most people, always found it peculiar how elements that developed from explosions in the universe came together to form such infinitely specific and complex creatures such as human beings. The Miller experiment was interesting to read about because it gave a little insight into how things like electricity and other materials can actually produce organic life."

    "The definition of life--it had never occurred to me how vague the term can be perceived. I could see how one could argue for various interpretations."

    "The concept of life on other planets and being able to one day discover that life."

    "I found it interesting that there have been crop circles in the field next to that radio telescope in England for three years in a row in 2001."

    "I did not know what crop circles were, and was most fascinated by the video. Very intriguing, regardless of their validity to extraterrastrial connection."

    "Obviously the most interesting thing I saw in the presentation previews was the video of crop circles popping up next to a radio tower sending out signals to space. It was interesting because that image of the face was crazy. THE TRUTH IS OUT THERE!"

    "The Drake equation to estimate how many planets in the galaxy have technological civilizations was really interesting. Someone had to determine the equation but so much is unknown that it still doesn't really tell us anything."

    Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
    " The timeline is hardest for me to grasp. The idea that mammalian evolution occupies such a small space in this process but can conceive it in its entirety. I guess it suggests that human evolution is just a manifestation of a much more comprehensive evolution."

    "Since Earth is approximately 4.543 billion years old. How much time does Earth have left before it disappears? is there a way to calculate its lifespan? or compare it to other planets to get an idea of how long earth will be here along side with the possibility that the human race will be too maybe a million years from now."

    "The relevance and process of developing DNA. I get that it was supposed to relate to the creation of life, but the whole idea is somewhat confusing in relation to astronomy."

    "How did someone, whether it be from our planet or another make these crop circles?"

    "The Drake equation. I found all of the different components confusing and it was not adding up for me on the presentation previews, but I did not look up more information in the textbook on account of lack of time. Oh, and what the heck was that LEGO® page about?"

    "The Drake equation is confusing to me. Its confusing to me because its something that we use to compare and find life in other places in the galaxy and things like that, but we don't have half the information to actually follow through with the equation to figure it all out. I'm wondering what its actually used for/the point because we can't actually finish it."

    "I didn't find anything confusing, everything was straightforward for me."

    "DRAKES EQUATION, HALP."

    Briefly describe a difference between life and non-living things.
    "Something alive should manipulate its environment in order to grow and make a new generation of things that can manipulate its environment, it should be able to adapt."

    "Simple molecules assemble in a naturally short time, but this is not life, it is the start of life. With chemical evolution simple molecules assemble and get more complex. The longer and longer the molecular chains grow the more complex and the chain now contains enough information to manipulate its environment, this is the start of living things."

    "Living things assimilate other (non-living and living) things. Non-living things do not."

    "Living things thrive, adapt, reproduce where as there is no observable energy of any process for the non-living."

    "My dog, and a rock."

    "All living things contain carbon?"

    "Non-living things aren't living."

    Rank the 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: about 1 billion years [19%]
    Time for the first types of simple single-cell life to evolve into fishlike creatures: about 3 billion years [14%]
    Time for fishlike creatures to evolve into more complex land-based animals today: about 0.5 billion years [52%]

    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.  *** [3]
    Somewhat important.  ***** [5]
    Important.  **** [4]
    Very important.  ********* [9]

    Briefly explain your answer regarding the importance of knowing whether there may be life elsewhere other than on Earth.
    "Any kind of discovery of life would be important information. I am very curious to see if Earth is the only planet that harbors life, it wold be interesting to learn more about our universe."

    "It would be very interesting to see how life on other planets evolved compared to ours."

    "Knowledge of extraterrestrial life is very different from contact with extraterrestrial life. Even if tomorrow, we found evidence of life outside of Earth, it likely wouldn't affect the average person alive today, at least not significantly."

    "We need to stop being so arrogant and start understanding that life is eternal and infinite. I kinda believe everyone values themselves and their life in a way that doesn't necessarily even correlate with their time in existence on this planet, let alone the entire universe. If people were open to the idea of aliens than we could probably not ourselves so seriously and it may actually help us develop as a peaceful world."

    "If there is life other than on Earth out there it would be an extraordinary find. I'm a strong believer that we cannot be the only ones in the universe, it is too ignorant to think so. the find of life on another planet can either be the end of us as a human race or a blessing to further our species and adapt to live in a space age futuristic era."

    "It would be incredibly interesting to see how life evolved differently on another planet, but it isn't necessary to know for sure."

    "It doesn't necessarily make a difference to me, but it would be interesting to find out."

    "As long as they don't want to eat us, I don't think we should bother them. Humans don't have a very good track record of discovering new creatures/populations and treating them well."

    "It is important for me to know how much truth there is to the X-Files."

    Which type of star would be least likely to have a planet that could support life?
    Massive.  ************** [14]
    Medium-mass.  * [1]
    Low-mass (red dwarf).  *** [3]
    (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).
    "A massive star--the shorter a star's lifetime, the less likely that life would have the time to evolve into complex forms."

    "Massive stars don't have a long enough life span for intelligent life, let alone single cellular organisms to emerge."

    "Massive stars have a much higher fusion rate therefore they die exponentially faster and have much hotter surface temperatures, less than ideal to sustain life."

    "Massive stars have the shortest lifetimes, therefore it would be very difficult for life to form since it takes so much time to develop."

    "I'm going to say least likely would be a red dwarf as it is the coolest... the sun is a medium mass in the main sequence stars, a red dwarf is even less bright, not making it optimum for having a planet with complex forms of life."

    "I am unsure what the answer is."

    Describe what the Drake equation is used for.
    "The Drake equation is supposed to determine the number of technological civilizations in the Milky way."

    "A equation that describes factors that are essential for life and a technological society to occur."

    "To calculate the number of stars in the Milky Way?"

    "I'm still a bit lost on this portion."

    In your opinion, how plausible is it that the Chilbolton message is a reply from extraterrestrials?
    Implausible.  *** [3]
    Not very plausible.  ****** [6]
    Somewhat plausible.  ********* [9]
    Very plausible.  * [1]
    (Unsure/guessing/lost/help!)  ** [2]

    Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.
    "If the reply in Chilbolton is written in some type of code, what is the best possible way to decode it?"

    "How long would it take you to make your own crop circles?"

    "Do you believe that there is intelligent life in the galaxy besides on Earth?"

    "Do you think finding alien life would go down Star Trek or War of the Worlds style?" (I'm thinking more like StarCraft. #justsaying #thoughtsinchaos)

    "Are you going camping this summer and if so where?" (Nothing definite so far, but maybe here, here, or maybe here, but I really want to go back to here. But definitely doing one of these.)

    "I will miss my reading assignments and surveys. Thank you P-dog for your creativity in presenting astronomy."

    "Q: What is the biggest lie in the entire universe? A: 'I have read and agreed to the Terms of Service.'"

    20170509

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

    Astronomy 210, spring semester 2017
    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 awesome we have a lesson on aliens."

    "I found the analogy of the universe history being related to one year in the book very helpful. Likewise, the link to 'Here Is Today' really put our place in history into perspective."

    "There is an equation to find out the number of technological civilization in Milky Way."

    "I found the concept of the drake equation to be really interesting. Life on other planets really interests me."

    "I think that it's interesting to think about communicating with life outside of Earth, but people are people, and some people don't want everyone to know the truth--so I would love some valid proof! Hopefully in our lifetime!"

    "I enjoyed reading about how science is trying to figure where other life forms could exist. Just because it may be possible for a star to help provide life on a planet doesn't mean it will or does."

    "The Chilbolton reply was interesting because it's one form of proof that there is intelligent life out there."

    Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.
    "How can astronomers tell if a planet has water, life, etc.?"

    "That chemical evolution is not yet life."

    "Something I found confusing was the Drake equation and the single-cell life the most."

    "I found the timeline for evolution very confusing, as it was hard for me to read the chart in the book."

    "The formula used to calculate possible civilizations in the Milky Way is ridiculous."

    Briefly describe a difference between life and non-living things.
    "A living thing has to be able to adapt. If it does not adapt, it cannot survive and will be non-living."

    "Life needs certain chemicals and certain atmosphere regulations in order to survive, while something non-living doesn't need this. An example is a plant and a rock being thrown into space, the plant will die while the rock will be fine."

    "Living things participate in the process of extracting energy to maintain itself to survive and reproduce, non-living things don't."

    "A living thing has to be able to manipulate its environment."

    Rank the 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: about 1 billion years [15%]
    Time for the first types of simple single-cell life to evolve into fishlike creatures: about 3 billion years [15%]
    Time for fishlike creatures to evolve into more complex land-based animals today: about 0.5 billion years [46%]

    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.  *** [3]
    Somewhat important.  ****** [6]
    Important.  *** [3]
    Very important.  * [1]

    Briefly explain your answer regarding the importance of knowing whether there may be life elsewhere other than on Earth.
    "It's pretty naïve to think we are the only living beings in the universe, but it is important that we find proof so people can open their minds and eyes!"

    "I think it's very important. I personally want to know. There is so much space out there in space, there is no way we are the only living species out there."

    "I believe it's important to communicate with other life sources to compare what works on each planet and then we can find the most ultimate sustainable way of life. By learning each others' behaviors and mistakes as well as successes."

    "It'd be really cool to see if any other planet had similar life to ours, and if they were close enough to maybe expand our existence."

    "I think sometimes ignorance is bliss. Most of the time conflict would arise from knowing too much. One group would see the other as a threat and that leads to war."

    "I don't think there is life other than on Earth but some legit proof would be cool."

    "For now, it is simply a curiosity. However, if we were ever reached out too, we would then need to prepare."

    "I've got more important things to do."

    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).  **** [4]
    (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).
    "Since we are life on Earth, and Earth goes around the sun, and the sun is a medium-mass str, then that would be the most likely place for other life to survive."

    "I would say a massive star just because it has a low life time and it won't even be complex since it might die real quick."

    "Because massive stars will die fast cause their life span is very short."

    "I think that a low mass star would be the least likely because it isn't hot enough to have a greenhouse effect, life wouldn't be sustainable. Medium mass stars would be the most likely seeing as the sun is a medium mass star, and we are searching for 'Goldilocks' planets that are close enough to the star to have enough heat but far enough that they're not hella hot."

    Describe what the Drake equation is used for.
    "To make an educated guess about life on other planets."

    "It helps narrow down the possibilities for which planets could possibly support life."

    "The Drake equation is used to conclude an estimate of the number of active extraterrestrial civilizations in the Milky Way."

    "The Drake equation is used for the number of civilizations in the Milky Way galaxy whose electromagnetic emissions are detectable."

    "Estimate total times of communicative civilizations in our galaxy"

    In your opinion, how plausible is it that the Chilbolton message is a reply from extraterrestrials?
    Implausible.  ** [2]
    Not very plausible.  ******* [7]
    Somewhat plausible.  *** [3]
    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.
    "The last quiz is extra-credit? Do we have to do anything special for it or do we automatically get it?" (You just have to take the survey on star properties, so we can compare how much you've learned about stars relative to what you knew at the start of this semester.)

    "Do you believe in extraterrestrials?" (Yes. I'd bet, like, $1 on it.)

    "Who is the Drake equation named after?" (Not this Drake, but this Drake.)

    20170508

    Online reading assignment: QED, strong, weak interactions

    Physics 205B, spring semester 2017
    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 presentations Feynman diagrams (Phillip "Flip" Tanedo, Cornell University/USLHC Collaboration) and quantum electrodynamics (QED) (Christopher "Bot" Skilbeck, cronodon.com).

    "The Feynman family poses by the famous camper"
    Ralph Leighton
    symmetrymagazine.org/article/may-2014/saving-the-feynman-van

    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.
    "Quantum electrodynamics describes how light and matter interact. It is the first theory where full agreement between quantum mechanics and special relativity is achieved."

    "Interactions of charged particles can create imaginary particles and violate energy conservation, as long as it is within the energy-time uncertainty principle. Sometimes imaginary particles will 'become real' if real particles leave the electron."

    "Repulsive force between electron pairs and positron pairs occur because of a virtual photon being emitted, which exist as momentum. Virtual particles can phase in and out of existence spontaneously according to the energy-time uncertainty principle. There are four fundamental forces in the universe: electromagnetic, strong, weak, and gravity. Nuclear force, the force mediating proton-neutron interactions, also originates from emission of virtual particles."

    "How to draw a single Feynman diagram and that there is an electron than can absorb or emit a photon into a positron and it can go the other way. There are also incorrect ways to draw Feynman diagrams and I know that time has to travel from left to right."

    "You absolutely have to read the diagram from left to right, and I can tell you what's happening in the simpler diagrams."

    "I have a strong grasp of Feynman diagrams from the online presentation as well as the introduction during our lecture of the previous week. These diagrams are visual and conceptual which makes easier to get a grasp of."

    "Honestly, not much."

    "Not a single thing."

    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 still have a hard time understanding how to draw a Feynman diagram. I still don't understand how to tell what is a virtual electron or photon."

    "I'm not really sure how you tell the charge of the photon."

    "I am a bit confused on how to determine the charge of some of the intermediate particles such as bosons."

    "I find it confusing when the exchange particle is not drawn straight up and down, it makes me think it happens over time and is not an instant exchange."

    "Everything."

    "All of it! No really, I definitely do not get this."

    The above (valid) Feynman diagram depicts an electron exerting a (repulsive) electric force on another electron. The charge of the "virtual" photon (γ) exchanged between them is:
    negative.  [3]
    zero.  [13]
    positive.  [4]
    (Unsure/guessing/lost/help!)  [2]

    The above (valid) Feynman diagram depicts two nucleons exerting (attractive) forces on each other. The charge of the pion (π) exchanged between them is:
    negative.  [2]
    zero.  [5]
    positive.  [10]
    (Unsure/guessing/lost/help!)  [5]

    The above (valid) Feynman diagram depicts weak force interaction between a proton and a electron. The charge of the "intermediate vector boson" (W) exchanged between them is:
    negative.  [4]
    zero.  [3]
    positive.  [8]
    (Unsure/guessing/lost/help!)  [7]

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

    "I <3 you P-dog. This year of physics has been great. Thank you so much."

    "More explanation of gluons please!"

    "Is it possible for me to ask this question from multiple parallel universes?"

    "I am so so lost in this subject... lost as in like a dark post-apocalyptic place... so not a good lost."

    "How do we know the virtual particles are there if we can't see them?"

    "Please go over the more obscure particles, i.e. quarks, pions, etc."

    "Interesting to see how this relates to the physical world!"