Online reading assignment: diffraction

Physics 205B, spring semester 2018
Cuesta College, San Luis Obispo, CA

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

The following questions were asked on reading textbook chapters and previewing presentation on diffraction.


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.

"Diffraction is the spread of light from a single slit. A smaller W (slit width) results in a larger spread angle. This spread angle is the destructive region which is the boundary of most of the diffracted wave energy."

"I understand the idea behind waves spreading after traveling through a single slit. The smaller the slit, the larger the half angle of the spread will be. Also the formula is based on the half angle."

"I understand that when the width of a slit gets smaller the 'spread' increases. And when the width of a slit gets bigger the 'spread' decreases."

"Smaller width means more spread."

"Honestly all I understood was the terminology."

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.

"Most of the presentation seemed fairly clear and to the point. I could possibly use some more clarifications on what exactly the minima angle represents and the difference between the half-angle and the minima angle."

"When reading from the book I didn't really quite get the difference between the central bright fringe and the dark fringes. I don't really understand how to find the central bright fringe whereas the dark fringe is just the formula presented in the book and online lecture."

"What the relationship between the first minima and spread angle?"

"Although I understood the relationship between W and θ, I dont know how to actually calculate that. I am sure we will go over this later."

"The laser hair screen slide was the only part of this lecture slide that was confusing, I just would need to see another example and I will probably be ok."

Match the single slit parameter with its symbol. (Only correct responses shown.)

Width of a single slit: W [97%]
Wavelength of light passing through the slit: λ [97%]
Direction, as measured from the centerline: θ [97%]

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

"I'm scared of how easy this lesson was." (Hmmm.)

"Would these calculations help when deciding where to put a harbor?" (Or designing a sound system. Or a telescope. Or anything to do with minimizing (or maximizing) the spread of water, sound, light, or any other types of waves.)

"Why do we reference a half-angle instead of the angle showed? How does squinting play a part in how well we can see?"

"Lab reports due Monday?" (Yes. Like every Monday now, for the rest of the semester.)

"To get the bonus turn-in credit for the lab reports, we have until the end of the first 10 minutes of class on next Monday? Or should we give it to you this Wednesday? (Either is fine.)

"I miss the old classroom." (I do, too; but Physics 205B usually gets put into 2401 instead of 2402, and you do not want to be in 2401 (the biology forum).)

"I honestly just raced through this because I'm in Utah trying to shovel snow, put chains on and make it back into town." (Let's see if you made it back.)

"Hey, how has your holiday weekend break? (Eh. Got a lot of things done, but still need to grade your lab reports. I'll get to them this weekend.)

Online reading assignment: runaway planets, jovian planets, and dwarf planets (oh my!) (NC campus)

Astronomy 210, spring semester 2018
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 runaway planets (Venus and Mars), jovian planets (Jupiter, Saturn, Uranus and Neptune), and the dwarf planets (and the International Astronomy Union classification scheme).


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 didn't know our moon was part of Earth; crazy to think what we look at every night was once on the same surface."

"The history of the planets--I thought it was cool that there was background information on Venus and Mars it really helps to remember the planets and how different they are."

"The history of the moon was interesting, and drawing it out in class helped me understand it a lot more than only talking about it. I also thought the section in the text about water on Mars was cool to know about."

"How Venus and Mars differed from Earth despite having the same components to make a hospitable planet. It shows how the systems on Earth are in a specific balance, and throwing that off could be disastrous."

"Venus' runaway greenhouse effect, because this is a prime example of what could end up happening to Earth. Especially when considering the similarities between Earth and Venus, both rocky and about same size with complex atmospheres and similar surfaces. It also raises the question of was their life on Venus at some point that was inevitably killed off."

"The diffrences between core temperatures of the different planets in our solar system."

"How the differences between Jupiter's and Saturn's appearances can be attributed mostly to their distances from the sun. I'd thought before that perhaps their atmospheres had been composed of radically different layers, but it appears that in general terms, they're closer to the same. I thought it was cool how the differences in distance and heat from the Sun could cause whole shifts in the positions of the two planets' atmospheres' layers."

"The method of determining whether an object is a planet or not."

"Funny just how Pluto is no longer considered a planet because it's missing one criterion."

"What makes a planet a planet, and why Pluto is no longer considered one. This was interesting to me because I knew it wasn't considered a planet, but I never knew why until now."

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

"I'm still a little confused about the electromagnetic spectrum and was having a hard time understanding the group worksheet we did in class. How do we know where telescopes should be set up to see certain areas of the spectrum?"

"Overall the section was interesting to me because of the comparison about the planets, however I feel like I may have a hard time remembering the differences between them just because of all the different planets."

"How Venus suffered from the runaway greenhouse effect but Earth hasn't?"

"What it means that Venus is a runaway greenhouse. I understand that it results in an extremely hot and dense atmosphere, but don't quite understand how."

"The different types of volcanoes on planets. How can the crust be different on each planet to not allow the magma to flow out?"

"Probably the difference in types of planets, I understand that there are rocky and gas planets, but I have trouble getting the idea of a gas planet in my head. It's just hard to imagine a giant ball of gas that just sits in space held together with no surface whatsoever."

"Nothing in particular was particularly confusing, but it was all overwhelming to take in at once. Trying to keep all the planets separate is challenging. I did find that I didn't quite understand why Uranus rotates on its side, compared to Neptune."

"Why Pluto isn't a planet anymore. like it used to be what happened!??"

"Nothing, really."

Identify the relative amounts of these characteristics for Venus, compared to Earth. (Only correct responses shown.)

Interior core heat, today: about the same as Earth [52%]
Geologic activity, today: less than Earth [71%]
Volcanic outgassing, up until now: about the same as Earth [57%]
Heat from the sun: more than Earth [81%]
Amount of atmosphere, today: more than Earth [48%]

Identify the relative amounts of these characteristics for Mars, compared to Earth. (Only correct responses shown.)

Interior core heat, today: less than Earth [90%]
Geologic activity, today: less than Earth [86%]
Volcanic outgassing, up until now: less than Earth [57%]
Heat from the sun: less than Earth [86%]
Amount of atmosphere, today: less than Earth [81%]

Which jovian planet has the coolest interior temperatures?

Jupiter (most massive).	[0]
Saturn (most prominent rings).	[0]
Uranus (least active weather patterns).	*********** [11]
Neptune (farthest from the sun).	******** [8]
(Unsure/guessing/lost/help!)	** [2]

I believe Pluto should be a planet.

Strongly disagree.	[0]
Disagree.	******* [7]
Neutral.	******** [8]
Agree.	**** [4]
Strongly Agree.	** [2]

Briefly explain your answer to the previous question (whether Pluto should be a planet).

"My opinion is only based on original and traditional naming rights."

"Just because it is missing one componet but why name it a planet if it really wasn't:/"

"I honestly don't care whether or not it is a planet or dwarf planet; I think that yes, it is smaller than the average planet but that shouldn't change the fact that it is or isn't a planet due to its inactivity and relationship to the sun."

"Well, by the astronomers' criteria, Pluto does not fit the bill and should be classified as so. I don't have a personal connection to Pluto...unlike some other people, and I don't care much if it gets demoted."

"I agree with what you said in class about Pluto being a planet and then all of a sudden not. I dont really have a side as to wether it is a planet or not. To be honest I really don't care whether they make it a planet or not."

"Not massive enough to clear its own orbital path, therefore definition-wise it's not a planet, while it may have enough gravity to pull itself into a ball it doesn't meet all three qualifications for being a planet."

"Pluto is an ice ball of rock far out into space that we never see from Earth nor does it have much meaning to it, though, I feel as if it should be a planet. We know Pluto exists, and that's all that matters, therefore it should be a planet."

"According to the IAU rules and classes, pluto should not be a planet. It may answer 'yes' to the first two questions, but it does not dominate its orbit, because it is too small/doesn't have enough mass."

"Because it was a planet, so there must be some sort of evidence as to why it was named that previously."

"I always grew up thinking it's a planet, then people started saying it isn't a planet and I dont know too much about it to know if it isn't or not."

"Pluto is a dwarf planet and so therefore, is a lot smaller compared to the other planets in our solar system. It has shown to also not hold a lot of activity."

"I don’t really know."

"I'm fine with whatever the scientists and astronomers decide on. It seems like an ice ball to me so I'm not stressing. But if you asked the 10 year old me, I'd say make Pluto a planet again."

"I agree because it has an atmosphere and geological features like every other planet."

"I can understand why the IAU changed their minds about Pluto being a planet, it doesn't really fit the criteria of what is considered a planet. I think it is a good call to consider Pluto a dwarf planet."

"I don't agree or disagree on whether Pluto should be a planet or not because I am unsure what I would classify it as."

"It was a planet before and it's something that is in our solar system so it should be considered a planet."

"Pluto has an atmosphere and a geological surface."

"Pluto has a small atmosphere and it also orbits the sun. It is also not a satellite because it is round. I also really like Pluto so I think it should be a planet."

"I don't disagree with the criteria set by the IAU. It seems like if Pluto were to be considered a planet, then we'd have to add a few more similar objects to the planet list because they are similar to Pluto."

"Pluto is just an icy rock that is part of the Kuiper belt. If we considered Pluto a planet, we would have to consider all those other icy rocks in the belt planets too, which is just crazy talk."

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

"Can we go over the electromagnetic spectrum super-quick again? I'm still a little confused...maybe give two examples/questions in class to discuss?"

"Can we go over a little more in detail the difference between Neptune and Uranus. They seem to be too similar to me."

"Ummmm...what's the big deal why do people care about the classification of Pluto anyways?"

"pls halp."

Physics quiz question: polarized light transmitted through two polarizers

Physics 205B Quiz 1, spring semester 2018
Cuesta College, San Luis Obispo, CA

Polarized light passes through two polarizers with polarization axes turned as shown below.


The total fraction of the incident light intensity transmitted through both polarizers is:
(A) 0.
(B) 0.19.
(C) 0.38.
(D) 0.56.

Correct answer (highlight to unhide): (B)

The fraction of the diagonally polarized light that passes through the vertical polarizer 1 is cos²θ, where the angle θ = 60° is measured between the diagonal polarization of the light entering polarizer 1 (60° clockwise from vertical) and the transmission axis of polarizer 1 (vertical). The light after passing through polarizer 1, but before passing through polarizer 2 is now vertically polarized, having a polarization that matches the transmission axis of polarizer 1.


The fraction of this vertically polarized light that passes through polarizer 2 is again cos²θ, but where the angle θ = 30° is measured between the polarization of the light entering polarizer 2 (vertical) and the transmission axis of polarizer 2 (30° counterclockwise from the vertical).


Thus the fraction of light that passes through both polarizer 1 and polarizer 2 is:

cos²(60°)·cos²(30°) = (1/4)⋅(3/4) = (3/16) = 0.1875,

or to two significant figures, 0.19 of the original unpolarized intensity.

(Response (C) is (1/2)·cos²(30°), which would be the fraction of unpolarized light that would pass through both polarizers; and response (D) is cos²(30°)⋅cos²(30°).)

Student responses
Sections 30882, 30883
Exam code: quiz01AM0l
(A) : 4 students
(B) : 25 students
(C) : 5 students
(D) : 1 student

Success level: 71%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.45

Physics quiz question: water wavelength in spharelite

Physics 205B Quiz 1, spring semester 2018
Cuesta College, San Luis Obispo, CA

Light of wavelength 476 nm in water (index of refraction[*] of 1.33) with an incident angle of 16.0° 
is transmitted into sphalerite (index of refraction of 2.43). (Drawing is not to scale.) The wavelength of this light traveling through sphalerite is:
(A) 196 nm.
(B) 261 nm.
(C) 358 nm.
(D) 870 nm.

[*] physics.info/refraction/.

Correct answer (highlight to unhide): (B)

The relations between the index of refraction and the speed of light, for water (medium 1) and for spharelite (medium 2) are:

n₁ = c/v₁,

n₂ = c/v₂,

where the given (or assumed to be known) quantities, unknown quantities, and quantities to be explicitly solved for are denoted. Also the relations between wavelength, speed, and frequency are:

λ₁ = v₁/f₁,

λ₂ = v₂/f₂.

However, the frequency of the light in spharelite is the same as the frequency it has in water, such that:

f₁ = f₂,

(v₁/λ₁) = (v₂/λ₂),

λ₂ = λ₁·(v₂/v₁),

λ₂ = λ₁·((c/n₂)/(c/n₁)),

λ₂ = λ₁·(n₁/n₂) = (476 nm)·(1.33/2.43) = 261 nm.

(Response (A) is (476 nm)/(1.33); response (C) is (218 nm)/(2.43); response (D) is (476 nm)⋅(2.43/1.33).)

Sections 30882, 30883
Exam code: quiz01AM0l
(A) : 4 students
(B) : 28 students
(C) : 1 student
(D) : 2 students

Success level: 80%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.64

Physics quiz question: diamond-air interface total internal reflection?

Physics 205B Quiz 1, spring semester 2018
Cuesta College, San Luis Obispo, CA

Light with an incident angle of 44.8° in diamond strikes the interface between diamond (index of refraction[*] 2.418) and air (index of refraction 1.000). (Drawing is not to scale.) As measured from the normal, the angle of the transmitted ray in air is __________ 44.8°.
(A) less than.
(B) equal to.
(C) greater than.
(D) (There is no transmitted ray in air.)

[*] physics.info/refraction/.

Correct answer (highlight to unhide): (D)

The critical angle for light incident on a diamond-air interface is given by:

θ_c = sin^–1(n₂/n₁) = sin^–1(1.000/2.418) = 24.43°.

Since the incident ray in diamond has an angle greater than the critical angle, it is totally internally reflected back into diamond, and thus there is no transmitted ray in air.)

Student responses
Sections 30882, 30883
Exam code: quiz01AM0l
(A) : 2 students
(B) : 0 students
(C) : 8 students
(D) : 25 students

Success level: 71%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.45

Astronomy quiz question: phase during partial solar eclipse

Astronomy 210 Quiz 2, spring semester 2018
Cuesta College, San Luis Obispo, CA

A partial solar eclipse will be visible for observers in portions of South America and Antartica on February 15, 2018[*]. During this partial solar eclipse, the moon will be in its __________ phase.
(A) new.
(B) first quarter.
(C) full.
(D) third quarter.
(E) (Depends on the time of day.)

[*] timeanddate.com/eclipse/solar/2018-february-15.

Correct answer (highlight to unhide): (A)

During any type of solar eclipse, the moon is directly between the sun and Earth, and must be in its new phase.

Section 30674
Exam code: quiz02npP4
(A) : 15 students
(B) : 6 students
(C) : 3 students
(D) : 0 students
(E) : 0 students

Success level: 66% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.63

Section 30676
Exam code: quiz02sn4E
(A) : 21 students
(B) : 4 students
(C) : 11 students
(D) : 4 students
(E) : 0 students

Success level: 54% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.91

Astronomy quiz question: planets visible at sunset?

Astronomy 210 Quiz 2, spring semester 2018
Cuesta College, San Luis Obispo, CA

The locations of Saturn, Earth, and Jupiter are shown in the diagram below (not to scale, and orbits have been simplified as circles instead of ellipses).


Which planet(s) will be visible at sunset?
(A) Saturn.
(B) Jupiter.
(C) (Both of the above choices.)
(D) (Neither of the above choices.)

Correct answer (highlight to unhide): (C)

If a line is drawn from Earth to the sun, the observer at sunset (6 PM) is located perpendicular that line. Since Saturn and Jupiter are both above that horizon line, they will both be visible at that time, where Saturn would be low over the east horizon, and Jupiter would be low over the west horizon.)


Section 30676
Exam code: quiz02sn4E
(A) : 17 students
(B) : 4 students
(C) : 13 students
(D) : 6 students

Success level: 35% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.45

Astronomy quiz question: planets visible at midnight?

Astronomy 210 Quiz 2, spring semester 2018
Cuesta College, San Luis Obispo, CA

The locations of Saturn, Earth, and Jupiter are shown in the diagram below (not to scale, and orbits have been simplified as circles instead of ellipses).


Which planet(s) will be visible at midnight?
(A) Saturn.
(B) Jupiter.
(C) (Both of the above choices.)
(D) (Neither of the above choices.)

Correct answer (highlight to unhide): (A)

If a line is drawn from Earth to the sun, the observer at midnight (12 AM) is located along that line, in the middle of the night side of Earth. Since Saturn is above that horizon line, it will be visible at that time, and would be located somewhere high in the sky. (Since Jupiter is below that horizon line, it would not be visible at midnight.)


Section 30674
Exam code: quiz02npP4
(A) : 18 students
(B) : 2 students
(C) : 3 students
(D) : 1 student

Success level: 77% (including partial credit for multiple-choice)
Discrimination index (Aubrecht & Aubrecht, 1983): 0.09

Astronomy quiz archive: eclipses/history of astronomy

Astronomy 210 Quiz 2, fall semester 2017
Cuesta College, San Luis Obispo, CA

Section 70158, version 1
Exam code: quiz02Sdi3


Section 70158

0- 8.0 :	** [low = 3.0]
8.5-16.0 :	********
16.5-24.0 :	****************** [mean = 22.0 +/- 7.8]
24.5-32.0 :	***********
32.5-40.0 :	***** [high = 36.5]

Section 70160, version 1
Exam code: quiz02NoL4


Section 70160

0- 8.0 :	* [low = 6.5]
8.5-16.0 :	******
16.5-24.0 :	*********** [mean = 23.3 +/- 8.4]
24.5-32.0 :	******
32.5-40.0 :	***** [high = 40.0]

Online reading assignment: atmosphere problems, Earth, the moon, Mercury (SLO campus)

Astronomy 210, spring semester 2018
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 problems caused by the atmosphere for telescope observing, Earth, and the impacted worlds: the moon, and Mercury.

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.

"That we are literally living in the ocean of air. This was interesting because I never thought of all the ripples and things we see underwater in a scientific way."

"Atmospheric turbulence and the explanation of our 'ocean of air.' I had no idea that the atmosphere could cause views through a telescope or the human eye to be distorted. I enjoyed the super neat way you chose to explain it, too."

"That turbulence causes the twinkling that I see in stars. I had never really thought of it that way, and it really served to cement a thought in my head about nature."

"The reason behind why stars twinkle--I just assumed their brightness caused that but it is how its light bounces around once it goes through our atmosphere."

"Light pollution interested me because depending on where you are and how little or how much light pollution is in the sky affects how many stars you can see with the naked human eye."

"The greenhouse effect; more specifically the dangers of too much greenhouse effect. When the suns energy is converted to infrared light and is unable to escape the interior becomes too hot and almost deadly. The child being trapped in the car and in danger of dying from heat exhaustion is the perfect example of too much greenhouse effect."

"What really caught my attention was the continental drift, and the comparison to gravy skins. I am a huge fan of the day after Thanksgiving leftovers and know very well what the gravy looks like when its not hot. This was a very personal and easy visual for me."

"The youngest and oldest features of the moon and Mercury, because it's really cool that some parts of the moon are older than others, especially since it had never occured to me that some parts were older than others."

"I had never heard of the large impact hypothesis which explains how the moon was supposedly formed and that was just interesting because id always wondered where the moon comes from."

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

"I guess that the only thing that would be confusing for me is that of adaptive optics. Is the mirror that is flexible an actual mirror? How does the computer measure what is actual disturbance?"

"Active optics confuses me because I am not sure how it affects the atmosphere turbulence."

"How someone can make an image such that is has the actual shape after turbulance from the atmosphere (twinkling stars)."

"The problem of the opacity of our atmosphere. And mostly the electromagnetic spectrum."

"I didn't really understand the history of Earth's moon and how it formed. I am also confused about how lava plains were made. Please go over that."

"I was having a really hard time understanding the order the things that shape the moon and Mercury. The book was really unclear and I read it multiple times but I am still confused."

"How Mercury actually formed is still confusing."

A large modern optical telescope in outer space would have images with better __________ than a comparable ground-based telescope.

brightness.	*** [3]
resolution.	**************** [16]
magnification.	** [2]
(None of the above choices.)	[0]
(Two of the above choices.)	**** [4]
(All of the above choices.)	****** [6]
(Unsure/guessing/lost/help!)	**** [4]

Stars to appear to "twinkle" in the night sky because of...

"Stars twinkle because of turbulence in the atmosphere of the Earth. As the atmosphere churns, the light from the star is refracted in different directions. This causes the star's image to change slightly in brightness and position"

"Stars twinkle from our perspective because we are seeing them through our turbulent atmosphere, which bends the light and creates the apparent flashing look."

"They are moving?"

"Gases reacting with one another and causing flares?"

Identify how carbon dioxide enters and how it is taken out of Earth's atmosphere.
(Only correct responses shown.)

Enters atmosphere from: volcanoes [41%]
Taken out of atmosphere by: oceans [38%]

Identify the oldest (longest ago) to the youngest (most recent) features on the moon.
(Only correct responses shown.)

Craters partially filled in with flat lava plains: oldest (formed longest ago) [43%]
Flat lava plains: middle [20%]
Craters on top of flat lava plains: youngest (formed most recently) [31%]

Identify the oldest (longest ago) to the youngest (most recent) features on Mercury.
(Only correct responses shown.)

Large crater basins: oldest (formed longest ago) [57%]
Lava-filled lowlands: middle [40%]
Long curving ridges: youngest (formed most recently) [57%]

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

"Is there less atmospheric turbulence in Hawaii, where a lot of the largest telescopes are? Is that why Hawaii is such a good place for telescopes?" (I think the one of the main reasons why is that the jet stream (the main source of upper atmospheric turbulence) does not typically pass right over Hawaii most of the time.)

"Could you please go over the details of the surfaces of the Moon and Mercury?"

"How do they decide what a young/old feature on a planet is?"

"I was a little bit confused by the explanation of the creation of the moon. Is there a definite answer as to how it was created, or just the high probability that it was created as fragment of a planetary collision?" (The large impact hypothesis is actually not only supported by geologic evidence in rocks brought back from the moon; it is the only hypothesis remaining that is supported by that evidence.)

"Will there be study guides posted for the midterms and final?" (Yes, and there will be review sessions as well.)

"Where does P-dog get his fresh haircuts?"