Saturday, January 23, 2016

Becoming Banneker: Making Movements in Space Meaningful on Earth

As I wait for the blizzard to end here in Stewartstown, I thought I would do another blog post about the latest unit I just completed.  So let's start with the performance expectations for this unit.   Using the topic based arrangement- "Space Systems: Stars and the Solar System".

Students who demonstrate understanding can:

5-PS2-1. Support an argument that the gravitational force exerted by Earth on objects is directed down. [Clarification Statement: “Down” is a local description of the direction that points toward the center of the spherical Earth.] [Assessment Boundary: Assessment does not include mathematical representation of gravitational force.]

5-ESS1-1. Support an argument that differences in the apparent brightness of the sun compared to other stars is due to their relative distances from the Earth. [Assessment Boundary: Assessment is limited to relative distances, not sizes, of stars. Assessment does not include other factors that affect apparent brightness (such as stellar masses, age, stage).]

5-ESS1-2. Represent data in graphical displays to reveal patterns of daily changes in length and direction of shadows, day and night, and the seasonal appearance of some stars in the night sky. [Clarification Statement: Examples of patterns could include the position and motion of Earth with respect to the sun and selected stars that are visible only in particular months.] [Assessment Boundary: Assessment does not include causes of seasons.]

As you may recall, the two questions I filter all curriculum through are:

  • Why am I doing this?
  • What will it help me to do?
If this is the starting point, what are the practical application for students  in Baltimore County?  As it turns out, there has been (and still is) a very practical application- calculating location.  For hundreds of years, people have used the stars and Sun as a guide.  It also turns out that Baltimore County had a local expert on the subject.  

In 1731, Benjamin Banneker was born and through his own study became an expert surveyor. Eventually, his skills were recognized by Andrew Ellicot and Mr. Banneker became part of the an important survey team.  The team that would eventually layout Washington, D.C.   

Mr. Banneker was able to use Polaris to measure latitude and the movements of Jupiter's moons to measure longitude.  The precision he was able to achieve with his tools and techniques could be measured to within a meter.   For comparison, the first GPS I used for recreational purposes was +/- 3-5 meters.   



So, here is how it works.   Latitude is easy.  Measure the angle of Polaris off the horizon using a sextant or clinometer and you have the latitude.  Finding Polaris gets me into comparing star magnitudes and which stars are visible at certain times of the year.  Two great resources to help show students the stars during the day.  Stellarium and Celestia  offer the opportunity for student to control time (#DoctorWho).  

Longitude is and has historically been the chief problem.  With latitude, you have a starting point called the equator.  Longitude has no natural starting point.  The prime meridian is an artificial starting place.   However, if you know when something happens in Greenwich and can see it happen where you are, then you can find longitude by finding the difference in time.  

Mr. Banneker would use an ephemeris of Jupiters' moons.  The ephemeris allows the user to know when one of Jupiter's moons is coming out of eclipse.  Observing Jupiter requires at least a six inch telescope.  It also requires a night sky.  These are problems given the confines of school hours and budgets.  

For my students, we will use Solar Noon.  Solar noon occurs at 12:00 only twice during the year. Beyond that, it ranges widely 16 minutes +/ - from 12:00 depending on the time of the year.  This relates to the "Equation of Time".   So how do you find Solar Noon?  At Solar Noon, the Sun produces the shortest shadow of the day.  See the complicated device (below) for measuring that shadow.  This picks up the performance expectation on the length and angle of shadows.  


This leaves the PE on gravity.  This one took me a while to figure out.  I shows up in two ways in the unit.  First, I did go a little beyond the standards by asking the question "Why is everything spinning in space?"  I could not resist a model which demonstrates this phenomena so elegantly.  




The second way is through measuring time.  Benjamin Banneker reverse engineered a clock from a pocket watch he borrowed.  His hand-carved wooden clock used a simple weight pulling down on a spool controlled by an escapement to regulate time.  The development of accurate clocks is what finally made it possible to measure longitude.  


About six minutes into the video above, you will see the host build a clock out of raw wood pieces.  I found a version of the same thing on Thingiverse.  It was interesting to get it working.

In the performance assessment, students are responsible for calculating their location to the nearest full degree or about 111 km of their actual location.  More importantly they have to explain how they calculated the location.  

Sunday, January 17, 2016

Is Curriculum a Guide or a Script?

It has been a while since my last post.  Actually, it seems like a lifetime ago.  I will diverge from my normal discussion of science curriculum for a moment, but will bring it back around.  Just stay with me.

Last July, my father was diagnosed with an extremely rare form of cancer undoubtedly from exposure to Agent Orange during his year of service in Vietnam.  He was a helicopter pilot and was tasked with spraying the herbicide.  He told me that due to the prop wash, he would come back soaked in it.

My father just prior to deployment in 1968.

I was out of the office almost all of November due to the complications he has endured through this process.  I've learned more about the science and art of medicine in these last few months than I ever wanted to know.  At one point, I found myself sitting at my father's bedside with my mother and the oncologist as we discussed treatment options.  The Mayo Clinic was consulted and a treatment regime was prescribed which had been deemed effective for most patients.  I say "most" because my father has a rather complex medical history.  Complex enough that it should qualify him for a season of "House".

The oncologist read through the recommendations with us and reviewed  my father's most recent test results.  Based on these results, he decided to follow a slightly different regime.   As of this posting, my father has seen a 70% reduction in the "bad cells" and we are hopeful that by the end of January to be in remission.

What are the lessons to be learned here?

  • A set of treatments was prescribed.  
  • Test results prior to treatment indicated a modified, more individual course of action.    
  • The treatment is proving to be successful. 
  • There is an art and science to treatment.  


Let's get back on the topic of this blog.  My primary job, at the moment, is developing curriculum based on the Next Generation Science Standards for the throngs of teachers in my system. This curriculum is a suggested course of action.  It provides many of the components needed to assist teachers in developing mastery of the standards in students.  Now, I'm not comparing myself to the Mayo Clinic, but the expectation is that I am the local expert on the NGSS.  Now I could complete this analogy but I think you know where I am going.  Teachers are the doctors and students are the patients.

What is the purpose of curriculum?  As a teacher, I lived two very different realities when it came to curriculum.  As a kindergarten teacher, I had no curriculum.  I based my instruction on the end of grade level expectations.  I had to make up curriculum on my own.  As a high school science teacher, I received curriculum from my supervisor.  A three inch thick binder.  Blue with a green cover as I recall.  I remember looking through it and realizing that, while it had good lessons it did not meet the needs of my students.  Once again, I had to make up my own curriculum, but at least I had a starting point.  

The idea of following a curriculum, chapter and verse, never occurred to me. I always viewed curriculum as a guide developed by people who have a pretty good idea about what most kids need.  We'll call this a science.  It was then my job as a teacher to find the best fit for my students. That takes a little science and a lot of art to make that happen. Great teachers are almost poetic.

As I discussed back in October (Articulating Expectations into a Personalized Learning Environment), I outlined a new set of curriculum expectations developed by my school system.  In summary,  through pre-assessment, we formatively use data to diagnose where students are before instruction starts.  The result is multiple groups of students consuming instruction based on their instructional need in the same room.

 I would hope that the merits of small group instruction are self-evident, but consider this.  In one of my prior jobs, I worked with "gifted" students.  How many of these students coast through instruction they have already mastered?  Conversely, how many students endure instruction for which they are not ready?  

The question is, then what.  How do you logistically manage a class like this. At the secondary level, there are more options.  Students can take different classes.  At the elementary level, it is more self-contained.  A reality lost on many people outside (and some inside) education.

So, I am opening a dialogue to discuss these ideas.  I am going to host a webinar on February 2 (Ground Hog Day) to develop some concrete strategies for all of us.  Click on this hyperlink at 7:00 PM (EST).  The rough agenda will be as follows.


  • I will discuss the specifics of the curriculum framework I developed   (I am open to other ideas.)
  • Start building a set of management strategies for teachers
  • Think beyond the current realities of classroom instruction.  Do we need a different concept of what a classroom is?  What does the field of  educational technology need to offer us?  Do we need to "Amazonify" how students access content? 
I look forward to talking with you at the webinar!