The Very Spring and Root

An engineer's adventures in education (and other musings).

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November 2012

Why Learn Physics?

MinutePhysics posted this video, entitled “Open Letter to the President: Physics Education”, to their YouTube stream.

Summary: The content of high school physics curricula generally stop at around the year 1865, which is an interesting observation. At first it seems quite logical that students should follow the prescribed path from kinematics to dynamics to electromagnetism and from there on to more complex topics if there is time (which of course there never is, so we never get to anything further).

But from another perspective, does one really need an understanding of dynamics as a prerequisite to an introduction to relativity and quantum? I actually don’t think so. The physics discoveries of the 21st century so profoundly changed our fundamental view of the universe and how we relate to it, that most of what came before seems absurdly limited in scope. Quantum Mechanics, for example, starts from very different conceptual foundations than does Newtonian Mechanics; thus, even though one came before the other chronologically, they really have nothing to do with each other conceptually.

I think it would be awesome to teach an introduction to contemporary scientific issues and understanding in high school. The inevitable counterpoint question will of course be, “but when will they use that?” I certainly admit that Newtonian Mechanics and classical electromagnetic theory, though limited in scope and not even technically correct by modern standards,  are far more likely to be “relevant to students’ lives” than quantum, relativity, particle theory, or cosmology. (In other words, Newtonian Mechanics are more readily applicable to every day situations even though their underlying assumptions and framework do not actually describe physical reality as we now know it.)

However, my (opinionated) rebuttal to this counterpoint is that it is, like so much of education policy, shortsighted and focused on the wrong things. What is the purpose of education? More specifically, what is the purpose of high school science education? What should my students be learning in my physics classroom? Though I certainly encourage STEM careers and want to prepare my students for college, the fact of the matter is that very few of them — even under ideal circumstances — will go on to choose further study and careers in science and engineering. If and when they do, they will receive specialized content instruction and training for it. So, yes they should have some introductory content knowledge, but ultimately what is more important for all of my students, including the STEM-bound ones, to come away with in their formative years as they emerge as adult citizens of the nation and world?

I would argue that the best answer to this question is: a sense of place. A perspective that the universe is a beautiful and endlessly fascinating arena full of challenge and discovery — and that therefore, on that principle alone, it is worthy of study and exploration. An understanding of the rigorous tools of scientific analysis and inquiry that have allowed us as a species to discard illusions and improve our lives. Further, a realization that they must use these tools daily as citizens in the modern world as a defense against manipulation by interests who would misrepresent science for self-serving ends.  And lastly, a cohesive story of our human quest for truth — the part that was grounded in empiricism and fueled by curiosity — which has brought us to our present understanding of what we are, where we came from, and where we are going.

Very little of this perspective, by the way, is captured in the present Massachusetts high school physics curriculum [PDF] or standardized accountability tests such as the MCAS. From what I have read, the Next Generation Science Standards are much, much better than what we have now and certainly a huge step in the right direction. But even these standards, on the cutting edge of what American K-12 science education policy is working on, remain far from the mark in my opinion. They remain somewhat impeded by the inertia of 150 years of “this is what we’ve always taught”.

It is only in the context of physics as the true “natural philosophy” — testing whether our human ideas hold traction with reality — that (properly) introducing the most contemporary physical understanding of the universe (alongside those which came before) to our high school students makes sense. Barring that framework for what physics education is ultimately for, I really doubt that our students will learn physics past 1865 until and unless they choose to do so in college — by which point it may be too late to engage them with it anyway. Which means of course, that it may be too late for the study of physics to contribute to the scientific literacy of the overwhelming majority of our citizens.

Keep fighting the good fight, MinutePhysics.

Lesson Plan: Exploring Newton’s 3rd Law in Sports


Unit: Dynamics
Date: November 19th, 2012
Day/Block: Day 3 / A Block
Time Available: 65 min

Teacher Prep:

  • Ensure prerequisite knowledge of: introduction to Newton’s 3rd Law
  • Make slides (including one for Objective and Criteria for Success)
  • Print and copy exit tickets
  • Rehearse lesson and do the work of the students

Lesson Objective:
You will be able to identify action-reaction force pairs and make predictions about motion using Newton’s Third Law.

Criteria for Success:
You will be able to explain what Newton’s 3rd Law says about forces.
You will be able to use Newton’s 3rd Law to predict what forces will act on an object in physical scenarios.

Exit ticket.


[5 min] Do Now

Newton’s 3rd Law tells us that all forces come in action-reaction pairs. List the action-reaction force pairs that you can think of on the red football player. (Hint: Mr. Ratnayake sees at least 4). Draw a free body diagram of the red football player.

[1 min] Making Explicit the Content of the Lesson

Hang on to what you did for the Do Now. We will be returning to it later on in the lesson.

Lesson Objective: You will be able to identify action-reaction force pairs and make predictions about motion using Newton’s Third Law.

Criteria for Success:
You will be able to explain what Newton’s 3rd Law says about forces.
You will be able to use Newton’s 3rd Law to predict what forces will act on an object in physical scenarios.

* Ask students to revoice the objective and CfS.

[10 min] Mini-Lecture 1: Review of Newton’s 3rd Law

[7 min for lecture] Review the main points of the third law.

  • There is no such thing as a single force — forces always come in action-reaction pairs.
  • Action-reaction pairs are the same kind of force acting on different objects.
  • Action-reaction pair have equal magnitude forces acting in opposite directions.

* Ask students, what do you think I mean by “same kind of force”? (Gravity, perpendicular contact force, parallel contact force, etc).
* Ask students, what do you think I mean by “magnitude”? (Strength of the force, size of the force, the value of the number, etc).

[3min for processing time] Take 2 minutes to check with a partner next to you. Look back at your list of action-reaction pairs from the Do Now. Do the pairs on your list fit what we just wrote down about Newton’s 3rd Law? I will ask someone to tell me about what their partner wrote.

* Ask students to name a force pair that their partner wrote down, and why they think it fits the description of an action reaction pair.  Draw the force pairs on the football player.

[10 min] Mini-Lecture 2: Review of Free Body Diagrams.

[5 min for lecture] A Free Body Diagram of an object only shows the forces acting on that object.
Free Body Diagrams do not include the forces that the object itself applies on other things.

Ask yourself: if I were this object, which forces would I feel acting on me?

Block on a surface example. There are two action-reaction pairs:

  1. gravity from the earth on the block, with gravity from the block on the earth
  2. contact force from the block to the surface, with contact force from the surface to the block

Which of these forces do you think the block is feeling? (normal force and weight). Draw FBD.

[2 min for processing time] Take 1 minute to check with a partner next to you. Look back at your free body diagrams from the Do Now. Does your partner’s FBD of the football player obey the rules of a free body diagram?

[3 min for closure on the Do Now] * Have a student draw the free body diagram for the red football player. Use questions for students to correct it if necessary.

[1 min] Instructions for Scenarios

Take 1 minute to read the directions for this next segment. I will call on a student to explain what we are doing for the class.

  • You will be given a scenario and several questions for discussion in your table group.
  • I will call on someone for each part of the discussion questions.
  • If they represent their group well, the whole group gets a stamp.

*Ask students: What are we going to be doing?

[15 min] Scenario 1: Serena Williams — Tennis

[15 min total, 8 min to discuss with group and work out the scenario, 7 min for discussion]

Tennis star Serena Williams uses Newton’s Laws to get the tennis ball to move.

  • Describe the action-reaction force pair that acts to accelerate the tennis ball. What are the forces? In which direction do they act? On what does each force at?
  • Draw a free body diagram of the tennis ball. In which direction is the net force on the tennis ball? Predict what will happen to the tennis ball and racket, using Newton’s Laws.

[15 min] Scenario 2: Ron Weasley — Quidditch

[12 min total, 7 min to think-pair-share, 5 min for discussion]

Quidditch keeper Ron Weasley blocks a quaffle coming in from the left of the image.

  • Describe the action-reaction force pair that acts to block the quaffle at the time of impact. What are the forces? In which direction do they act? On what does each force at?
  • Draw the FBD for the quaffle and the FBD for Ron. In which direction is the net force and acceleration for the quaffle? What about for Ron?
  • Which will accelerate more, the quaffle or Ron? If Ron and the quaffle both experience an equal force from the impact, why are their accelerations different?


[7 min] Exit Ticket

How can you tell if two forces are an action-reaction pair according to Newton’s 3rd Law?

An archery target stops an arrow on impact. The arrow experiences high acceleration to go from a fast speed to at-rest very quickly. Do the arrow and the target experience the same force from the impact? Do the arrow and the target experience the same acceleration? Why or why not?

64 min total:  ~1 min of buffer

Pacing: If necessary due to unexpected time constraint, one of the scenarios can be cut out and the other extended slightly.

Recruiting STEM Professionals into Teaching

When I tell people that I went from working as a NASA research engineer to a transition into teaching physics in urban public schools, the response I most often get is something along the lines of “oh, how noble of you!” or perhaps “what a selfless thing to do!” I’ve been finding it difficult to react to these kinds of statements. There is nothing really wrong with this perspective I suppose, and I certainly don’t wish to appear as if I am ungrateful for the well-wishes of those who clearly intend to be positive and supportive of my career choice. But I have to confess to a nagging discomfort about what it feels like such statements imply.

Why is it assumed that my motivations for entering teaching were altruistic? That it is somehow a step down, or a sacrifice of some kind, or a service, for me as an educated and personally accomplished engineer to enter teaching? Why is this not applauded as a strong career choice to which I was aspiring and then achieved? I mean, it’s not like the BTR admissions process was a cakewalk; in fact, I don’t think I have ever been through such a rigorous screening (not even for NASA), nor have I ever before been in the same cohort with so many uniquely accomplished people as my present colleagues. And so far, teaching is among the hardest things I have done in my life — my no-kidding, dead-serious goal for last week was simply “suck less.” I’m certainly not here graciously bestowing my munificence on the yearning masses.

So why the implicit attitude that teaching is only for them that can’t do? Have we lost sight of the possibility that there could be so many reasons besides money or status to choose a profession? I chose teaching because I know it is an important profession that has a wide impact on people and our nation’s social well-being. I also like the daily challenge and creativity required when trying to manage the intersection of people and ideas all the time. These are important qualities for me.

I have no idea how to fix the tangled paradoxed of teaching entry, but I can say what I would ideally like to have in teaching as a profession. Want more trained scientists and engineers entering teaching? I can’t speak for everyone with a STEM degree, but here’s my stab at what my wishlist would have looked like for teaching just coming coming out of my undergrad with a Bachelors in Aerospace Engineering:

  • Actively recruit me. It probably hasn’t occurred to me that I could teach. Convince me based on how teaching is a meaningful, useful, and challenging career, and be able to truthfully tell me most of the following:
  • The offered starting salary need not be competitive with top engineering jobs, but it should be comfortable and secure.
  • Acknowledge that not all teachers are equal in effectiveness. My salary level above the baseline should depend solely on my merit as an educator.
  • Define merit as an educator as a combination of:
    a) Peer review of my teaching (by other respected teachers/colleagues, highest weight factor)
    b) Positive outcomes for students (prepared for future classes/college, increased scores on authentic assessments of skills that matter)
    c) Contribution to the field (making my practice open and public, publishing and sharing results from both innovation and failure in my classroom, attending conferences, collaborating with and assisting other teachers, mentoring, etc)
  • Acknowledge that not all teaching positions are created equal.
    a) Actively incentivize needed specialties such as STEM, ESL, and Special Education.
    b) Actively incentivize needed placements such as rural and urban schools.
  • Affirm that the following factors are irrelevant to student learning, hence irrelevant to my performance as an educator, and hence irrelevant to my pay/incentives:
    a) standardized test scores
    b) time in grade / time in service
    c) tenure
  • Don’t make tenure a given or a time-dependent milestone. Challenge me to earn it.
    a) The primary factor in granting tenure is the assessment of my peers and colleagues, my fellow educators.
    b) The primary factor in revoking tenure is the assessment of my peers and colleagues, my fellow educators.
    c) Grant me tenure only if I demonstrate the long-term potential to innovate and/or perform exceptionally. If I don’t need to excel to earn it, I don’t feel like it’s an achievement.
  • I recognize that teaching is it’s own profession and that content knowledge is not the same thing as knowing how to teach. But I’m an engineer and I already have a degree.
    a) Don’t try and get me to buy into theory; teach me to teach with case studies and a rigorous, practicum-based program that embeds me in the environment I’ll be teaching in. I’ll learn the theory I need to know through practice. I’ll read the textbooks if I decide to do a doctorate in education, not before.
    b) Don’t patronize me and risk a year of lost learning for students by letting me teach before I’m ready. I don’t want to be coddled — I want to be prepared.

Hmm. Acceptable list for now. I may revise it later. Thoughts from other STEM professionals or post-secondary students? What would teaching as a profession have to look like for you to seriously consider teaching? Would these suggestions improve or harm the perceived status of the profession to you and those with whom you interact most?

BTR at Americorps Opening Day 2012

“Boston Teacher Residency’s 10th Cohort was well represented at the 2012 Americorps Massachusetts Opening Day in Boston. Juliet Buesing and Randyl Wilkerson sang “Lift Every Voice” (the Black National Anthem) and Malcolm Jamal King presented the introduction to what BTR does. Cohort X followed the ceremonies with an afternoon of service at Cradles to Crayons.”


Review of “Majesty’s Offspring” by A.J. Vega

Majesty's OffspringMajesty’s Offspring by A.J. Vega

My rating: 2 of 5 stars

Entertaining reading for the bus, waiting in line, or whenever you have a minute to kill… but it didn’t really make me think. Plot is mildly interesting but not very complex, characters are on the shallow end, and the dialogue is trite. I really don’t think space opera is my thing.

View all my reviews

Keep Calm and Carry On

Ooof. Had my first student blowup yesterday. This particular student is in his senior year, he really needs to pass this class to graduate, and first quarter grades come out this week. And… his quiz grade was not so hot. Long story short: weeks of pent up frustration with physics coming out, pretty aggressively and with lots of swearing. Not a pleasant situation and very uncomfortable. I sat down, not retreating or exacerbating, and tried to calmly explain why I had given him the grade I did. I also tried to gently point out that the time to come in with your misunderstandings is not right before the test.

To be honest, I think in that moment he really needed to vent. I’d like to think that I was able to show that I sympathized with his position and listened to his concerns, but in the moment it was really hard to think. In retrospect I think I handled it decently well, but it’s not the kind of thing that lends itself to easy self-reflection.

I’ll keep an eye out to make sure this student is doing ok and maybe check in with him in a few days.

One more thing to add to the list of things that are really hard about this job… it’s tough to care and not know what to do.