ELTM6: A (Past) Career, Rife with Experiments

Most would say that, in the end, all that matters is what you did. The words you said, the promises you made, the intentions you had: all are irrelevant if there was no net change in the end-result; no improvement to validate your life’s efforts.

I am not one of those people. Yes, actions do matter but in the absence of explanation, of motive and, most importantly, of a clear sense of what’s desired; a collective vision, then how do we even know the desired destination? How are we to see what’s been done? How can we judge its effectiveness; its value? How can we possibly expect any system wide strides forward?

On August 30, 2013 I retired from 30 years of service to the public education system of this province and if I learned only one single lesson along the way, it is this: if the pursuit of education is to be truly successful then it cannot be the product of a collection of skillful individuals, each toiling away and bound by the administrative structures—whether real or imagined—within which they live. It needs, rather, to be a group effort; a cooperative venture fuelled by the right motivators and carried out by teams of highly skilled professionals, each lending their particular expertise in support of a mission that is greater than all of us. Yes, it requires putting our egos aside, rendering our selfish needs as secondary to those of others and venturing way out past our areas of comfort.

Educators are united by a common goal: the betterment of educational practice through the skillful utilization of the appropriate set of tools and methods. In some ways we live in a time of plenty. We certainly live in a time of great change. Over the past few decades we have seen the introduction of wondrous devices well adapted to the fields of communication and data management. Applications of that know-how to our field of education are many. What’s more, as the body of knowledge grows it transforms whole fields of practice. The view on the horizon is ever changing.

We also live in a time of great trepidation. There have been many false starts; many failures. What’s more, the risks and time investments associated with change are so great that many are seemingly unwilling to make even the first steps forward.

We have all witnessed it, many times.

In 1991 I was privileged to be able to attend one of the week-long workshops sponsored by the provincial DOE, under the direction of Wilbert Boone and facilitated by Frank Shapleigh. During a one-week period, at Gander, that summer I along with about 20 others was immersed in te practice of using digital interfacing technologies in the high school science lab. Our cohort assembled, from scratch, photogates and connection boxes then went on to use them to perform all sorts of mechanics labs such as studies of uniform and accelerated motion as well as to investigate things like Newton’s second Law of motion and the Impulse Momentum theorem. We also used store bought sensors to work with light, sound, temperature and pH.

To say the least, on a personal level, it was transformative. I returned to my school and immediately took steps to change my ways. That year I purchased and assembled five photogate kits and, in addition, led a fundraising drive which also purchased a multipurpose lab interface along with probes for motion, light, sound and temperature. In just one year my physics class was transformed forever, as was my math class due to the fact that I was also able to get my hands on a whole bunch of TI graphing calculators, but that’s another story.

Not only did the labs give great results and enable students to do things they could not even dream of doing otherwise but they were also enjoyable as they gave you the opportunity to get god data and to further investigate what-ifs. While I enjoyed the labs on motion and on Newton’s Laws, I particularly enjoyed the one in which we measured the speed of sound.

It worked like this: You got some plastic pipe between 1.5 m and 2 metres long and closed off one end. You put a microphone at the open end and set the interface to display the sound waves it picked up onscreen. It looked like the picture below.

Apparatus for measuring the speed of sound. Note the microphone mounted on the lab stand, located just left of the plastic pipe.
Apparatus for measuring the speed of sound. Note the microphone mounted on the lab stand, located just left of the plastic pipe.

You set the system to only take one sweep and also set it so it would only start—be triggered—by a loud noise. You then put your hand by the mike and snapped your fingers. The snap triggered the system; turned it on. The computer would then display the wave form that was your finger-snap on the screen. It also displayed, just a short time later, the sound of the echo of your snap from the closed-off end of the pipe. It looked like the picture below.

speed-of-sound-021
The resulting graph. Note the three sets of bumps. The first is the snap, the second is the echo from the back of the pipe. The third is a secondary echo from one of the walls in the room.

You then took two measurements: the time difference from any part on the waveform for the snap and the corresponding part on the reflected waveform. This was the time needed for the sound to travel from the mike to the back of the pipe and back again. You then carefully measured the distance from the mike to the back of the pipe. Twice this distance—the round trip—was the distance covered. Since the speed of sound equals the distance divided by the time you could then calculate, accurately, the speed of sound.

For the apparatus and the images shown, from my own notes, I got 325 m/s on a day when the room temperature was 25 degrees C. That’s quite a good figure!

It never stopped. In my subsequent service in distance education I was able to continue using the interfacing technology in the physics labs. Even today the CDLI, the organization from which I recently retired, continues to use that technology in its ongoing support of labs in physics, chemistry and biology.

But it was not the case for everyone who attended. I recall in particular overhearing two colleagues from a different institution discussing this new technology. It’s nice, they agreed, but they wouldn’t be integrating it into their classes. They judged it important that students still use stopwatches and ticker timers and continue to construct graphs and tables using pencil and paper.

They were also wrong. It took over a decade but, in time, as those colleagues departed their replacements did whole-heartedly adopt and champion the new methodology.

It’s not easy, though and people can’t be expected to do it unless (1) they are encouraged and supported and (2) they do it for the right reasons. Even then there are no guarantees.

Next: Making Sense of this

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11 thoughts on “ELTM6: A (Past) Career, Rife with Experiments

  1. Points well taken and historical significance noted Maurice. I can remember my own physics classes from high school (’74-’78) and college (’78-’82) in which we used stop watches and meter sticks, exclusively. Now, as I pass the physics labs at my place of employment I see none of that … all of this has been replaced by computers and a sea of monitors. I am pleased however, when I stroll past lecture classrooms, that at least some professors still use the chalk board to derive lengthy mathematical arguments. I can recall that the hall in which my physics lectures were delivered in college had three chalk boards across the front of the room … each could be lifted to reveal another and another board behind (9 boards in total) … it was fun to watch the custodial staff clean the boards after each class. There is one large lecture room here at school which is surrounded on all sides by chalk board. I don’t know why, but I love seeing the professor doing board work. As I walk past the same classroom during the hour-long lecture … the professor is at another position at the board … leaving bits and pieces of equations in his wake. I know you’ll say that it’s the old-fashioned way of teaching … but I get the same thrill watching that as I do watching ice cream being made with a genuine antique Hit-n-Miss engine (http://en.wikipedia.org/wiki/Hit-and-miss_engine). That being said … without risk-takers and innovators like you and your colleagues … we’d still be using stop watches. Thanks for your vision and for your willingness to participate and for thinking outside of that proverbial box. D

    1. I started to reply here but started rambling so much, decided to make a follow-up post. By the way, it looks like we started University in the same year. How well I recall 1978–I was far from hone and really didn’t have a clue but I had one thing going for me: I KNEW I didn’t have a clue 🙂 It’s been such an interesting journey and one thing remains–the knowledge that there’s still so much ahead!

  2. I am trying to recapture the “digital revolution in the lab”… In the early 1990s I was teaching at the university and still had to force students to evaluate the reciprocal lattice of crystalline samples by evaluating the paper output of the X-ray diffractometer using pen and ruler. (And I can also remember that, on using that diffractometer in my own research, I seemed to have been the person who always had to refill the paper…).
    I remember an intermediate stage of revolution that happenend then which was actually a lot of fun: As budgets were low we could not switch to devices with built-in electronic interfaces – but the electronics engineer at the department built all that interfaces himself (I also learned in passing that at the university in contrast to industry labour is not considered an expense as “staff is here anyway”.) The best or worst was getting digital output from a nano voltmeter that actually used that delicate red “pre-digital tube-light-style” display of numbers.

    1. The first set of photogates and boxes (I used 1/4 phono plugs at the end of the photogates and plugged them into boxes that redid the signal for a 9-pin RS-232) were assembled in my kitchen. I did up five interface boxes and ten photogates. When we first moved to distance education we also used hand-assembled photogates and interface boxes. Over time, as budgets permitted, we replaced the home-made photogates with ones made by Pasco Scientific. These had better mounts that could be clamped to lab stands. It’s been 23 years now since I started using interfacing and I still swear by it. Each year I give a workshop at Mamorial University for our undergrad pre-service Science teachers and every year I have fun 🙂 The lab instructor thinks I’m doing him a favour but the reverse is actually true. I love “playing with the toys with my friends.” 🙂
      These are the ones I like:
      – photogates (and a simple device called a picket fence) for doing experiments in studying constant motion (d-t and v-t graphs), accelerated motion (d-t and v-t) graphs, measuring g by just dropping a picket fence through a photogate and measuring the slope of the v-t graph.
      – ultrasonic motion detector for investigating Newton’s 2nd law (varying F while holding m constant, then varying m while holding F constant), checking the impulse-mmentum theorem (run a cart, tracked my the motion sensor to find v, into a force sensor then plot a graph of F vs. t during the impact and get the area under it to find impulse), investigate the work-energy theorem by using a falling mass to accelerate a cart (plus falling mass) then measuring v(final) to whow that work done by the falling mass is equal to the linetic energy of the system (just before the mass hits ground, of course).
      – microphone to show the doppler effect, beats and, of course to measure te speed of sound.
      – light sensor to study the inverse square law (just move a light source away from it in a dark room and plot light intensity vs. distance) and to study period and frequency of waves (students capture light from incandescent and flourescent bulbs and note that the wave frequency is 120 Hz–it would be 100 for you, of course as you use 50 Hz AC)
      There are others, of course–pH and temoerature probes are used a lot in chem, for example.
      I am particularly fond of using the interfacing equipment as (1) it is versatile (2) gives great results and most importantly (3) gets the students used to the fact that in physics we use abstract constructs to represent physical phenomena and the interface gives LOADS of ways of doing this.
      Oh, and I am a geek 🙂 and this is my idea of fun.

      1. Whoops–I almost forgot that since the system can track multiple sensors we can measure several things simultaneously. Besides the impulse momentum theorem experiment where we track v and F simultaneously there’s also conservation of p where we track the motion of several moving objects at once.

      2. The opportunity has arisen a few times but each time, after I checked it out I respectfully declined as the business model was always based on generating income by selling equipment. This meant that success for the business was tied to moving product volume and not in affecting educational outcomes–a flawed and morally questionable model.
        At the moment I am operating as an independent education consultant. Here’s what I do (at the moment): confer with clients and determine what it is they need to achieve. I then construct he eLearning package hat does that and wrap it inside a Learning Management System (preferably Desire2Learn). My business model is not based on maxing out the volume of hours for any particular client (as I have sufficient clients to keep me busy anyway), but, rather, on getting the best possible outcomes at a competitive price. I am comfortable with that 🙂

    1. LOL, Jane, like a wise former student (Brian N.) said to me around 20 years ago, “It’s not like a light bulb; you just can’t turn it off.” This idea started out as the outline for a talk I gave around 2 months ago and I decided to flesh it out some over the winter. Hey you have to do something on the days when it’s too bad to get out!

      1. And a bonus for the recipients of your good ideas. You’re right about having something to do when it’s bad out there. Now, on top of everything else, they’re calling for freezing rain tomorrow. I’m not sure which will be worse, freezing rain or rain. Our rooftops are FULL of snow, so not wanting rain. I’m guessing that because you are online you have not lost your power. I gather, then, that you are among the lucky ones in NL at the moment. Life is an adventure when you live in the north!

      2. Hah–it comes and goes. I actually uploaded and published “applying Kuhn” in a blackout. My laptop gives 4-5 hours n the battery and the phone makes for a great WiFi hotspot. At the moment, thankfully its back but NL-Hydro and NL-Power have rolling blackouts in place while they deal with the cold and bring the erst of the grid back on.
        That freezing rain is due to hit here on Tuesday. I can’t wait 🙂

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