Friday, December 7, 2012

Expected Results

good idea
The problems we have had this week in science have been almost entirely my fault.  I did not spend enough time preparing for the hands-on portion of our study.  In the past, I have found that a quick check to be sure we had all of the necessary items for any experiments or demonstrations was enough to guarantee successful activities.

Nope.  Not this week.

My first mistake was changing from our favorite tried and true science guru, Janice VanCleave, to something unfamiliar.  While the Photon U book appeals to our sense of humor and desire for quick and easy demonstrations of scientific concepts, it does not seem to produce the same level of learning for my boys.  Also, out of the five experiments we tried, only two gave anything close to the kind of results we were expecting.  With the Janice VanCleave series, we have had a few experiments fizzle in the past, but it has been a very rare occurrence.

fudged data
Our first lesson in the light portion of our current science unit focused on the different colors that make up visible light.  To demonstrate that each color has a different wave length, the Photon U book had an activity called stretching rainbows.  We had six different colors of thread representing six colors in the visible light portion of the electromagnetic spectrum.  The directions were to line up the thread along its corresponding wave on the diagram, then cut the thread.  When we had a sample of each, we were to lay out the threads and compare the lengths.  This idea sounded fun when I quickly paged through the book a few weeks ago.  In reality, you have no idea how difficult it is to keep a piece of thread in place well enough to get accurate length pieces to compare!  In the end, JT's blue thread was much longer than his indigo, so he trimmed a bit off to get the desired result.  That is really not what I want to be teaching them about science.  We do NOT want to alter our data to meet our expected results!  I should have spent the time and tried it myself before handing the assignment over to the boys.  Hindsight is 20/20, right?

I guess I forgot that bit before we moved on to our next lesson.

Lenses were the next topic we covered.  The book had a nice little model of a lens you could make using cardboard, tape, and saran wrap.  Once you cut a round hole in your cardboard square, you covered the hole with saran wrap, secured it with the tape, and added water until you had a lens.  Trying to get the perfect amount of water on that piece of saran wrap, that kept getting too wrinkly to see through, also turned out to be a bit of a flop.  EM did enjoy pipetting water all over the classroom, so I guess it wasn't a total loss.

romantic candle light experiment
Our last attempt at using the book came yesterday.  Looking at how our eyes interpret images and use light was actually clearly demonstrated with this activity.  We filled a glass candle holder with water, placed a candle about 10 cm away and observed the upside-down flame on the piece of paper held another 10cm behind.  However, the table we were to fill out in the book was unclear and not really much of an addition to what we were learning.  Mostly it just confused us.  We decided to scrap that part and instead played with our display for a bit on our own.  I had an old bottle of corn syrup in my science supply cupboard, dated 2009, that we deemed sufficiently aged for such an experiment.  We replaced the water with corn syrup and observed how the reflection seemed clearer with the thicker liquid.

close up
Overall, the boys still learned some things about light this week.  It would have been a much smoother journey had I taken the time to try out each experiment on my own in advance.  Sometimes I know I rush through my prep time, hoping the magic homeschooling moments will carry me through.  Many times they do. But, being a good scientist, I can't fudge the data when they don't.     

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