Laguna’s Lessons

I have been reading up on some of the common household appliances that make use of the heat technology we are reading in Chapter 10.  Some are very challenging to explain but I think it is important to be able to apply the concepts we learn to actual real life experience. 

Some interesting appliances are the toaster (how does it know when to pop the toast out?), the thermostat (why does the heater turn on and off throughout the day?), the refrigerator (will leaving the door open cool the room down?) and the coffee maker (my favorite!) 

I thought it would be fun to research these together and then share what we learn using some kind of online tool.  Our options are as follows.  Share by making blog comments, add to a mind map on Thinkature, or create a new Pageflakes page.  I can’t wait to work together on this.  Check out the links and leave me a comment. 

 Here is how we felt before leaving for Christmas break. 

 Here is how we feel now that we have returned from our refreshing break!

(Actually, these are pictures from Sydney’s science fair experiment.  The water in the container represents cerebrospinal fluid and the first egg sustained damage because it lacked enough protective fluid.)

One of the things I like about teaching is that every few months we have a fresh start with a new marking period.  I like to look at the blank grade sheet and realize that every student has another chance to be successful.  Everyone has the opportunity to get on the 100% homework list, go for the honor roll, or strive for the goals they set for themselves. 

I set goals for myself at this time as well.  My goal for this marking periods is to have students take advantage of the podcast kit, cameras, and microphone to create projects that help other people learn about and appreciate science. 

We watched a fun video from Jefferson Labs today that I think can serve as an example.  In the video, two people demonstrate a simple science concept, insulation, using liquid nitrogen to get our attention.  The video was interesting to watch and also helped us appreciate that our observations can be explained by applying science concepts.  What sort of videos can we produce that would make people say, “Wow, now that’s interesting!”  I wonder what ideas the eighth graders on our team can contribute to a video project.

A student is making a podcast while her group performs a lab experiment.

Our podcasts are up an running!  Here are some things I have learned.  Windows media files need to be converted before they can be uploaded to the server but there are free online tools to solve that problem.  Movies have to be small in order to upload them – which is good in a way since long movies can get boring. 

I’m so proud of all the students who created movies, uploaded pictures, and made Power Point presentations for their online science fair projects!  One student even made a Voice Thread!  Cool!  Look for these projects to be featured on our wiki in the near future!  In the mean time, enjoy some of our podcasts from this year and last.  http://podcast.qcsd.org/users/mrslaguna/

Today students learned how to use some common science equipment to boil water and collect the steam.  This process has a name called distillation.  I never cease to be amazed at the way the temperature of the water stops at rising at precisely 100°C.  We know that energy is still begin added to the water in the test tube, yet the temperature does not increase beyond the boiling point.  Where does all that energy go?  Let’s see if anyone remembers… 

Can you explain where all the added energy goes once the water reaches the boiling point?

Are you an independent, self-directed learner?  That is one of the goals for my students this year.  And I was so impressed last week to see that many of the students in my science and math classes are stepping up to this challenge. 

Here is one example that was really amazing.  During my prep period I was working on getting the students grades on my computer when Greg came into the classroom.  He wanted to collect some more data for his last experiment so that he could revise his lab report (completely optional by the way.)  I said, “sure!” and Greg got to work.  I didn’t really talk to him again until he left. 

In that time he started the Data Studio software, assembled and connected a pressure sensor to the computer,  conducted an experiment, organized the results in a data table, reformatted the graph for printing, and made a color printout of the volume and pressure graph…without any help.  Wow.  My students rock! 

Sometimes we are told what to do and how to do it so often that we forget to take the initiative and take charge of our own learning.  I think learning is really only fun when it is self-directed.  What do you think?  Can you share an example of a time when you learned something on your own?  Was that a good experience?  Or do you prefer being guided by a teacher when you learn something new?

So many people have misconceptions when it comes to science!  In our class this week we explored a question that most people would think was common sense.  What happens to the temperature if you fan a thermometer.  Armed with our trusty lab notebooks and the scientific method we explored the question.  I think most students thought, “What’s the point?  Of course the temperature will drop!”  But that was not the case.  The temperature stayed the same throughout the experiment no matter how hard we fanned the temperature sensors! 

The first step is recognizing the misconception but the harder part is changing our minds to see the correct concept.  We need “fixedconceptions!”  Why do you think fans cool us down if the fan isn’t altering the air temperature?  Hint – read about evaporation and see if that helps!  Let us know what you think the answer is.  We will conduct another lab experiment using water, isoproynol, and ethanol to wet the temperature sensor before we begin fanning. 

What is causing the pressure to rise in this graph from Tina and Colette’s group?  Is the pressure rising because progress reports go home next week?  No.  That’s not it!

 Boyle’s law would help to explain what is happening.  As the volume of air in the syringe was decreased, the pressure continued to increase.  The molecules of gas in the syringe were being squeezed into a smaller and smaller space.   Try this fun simulation!  Can you think of some real life situations that can be explained using Boyle’s Law?  Let’s hear your ideas! 

Well, it sure beats dieting!  Mike’s ingenious experiment confirms it!  Objects weigh less when they are submerged in water!  We used the Pasco force sensor to measure the weight of an object above the water and again after it had been submerged.  Here is a challenge for you.  Can you explain why the object weighs less under the water?  Don’t forget to use the term, “buoyant force.”

Mrs. Ford was correct!  The mystery subject from the 10/26/08 post is a close-up of a fly eye!  Great guesses everyone!  Flies have compound eyes. Click here to read more! 

This is the fly that was annoying everyone in class on Friday and Derrek rescued us from his unrelenting attacks!  If you have something you would like to see under the dissecting microscope just let me know!  You might be surprised at what you see! 

I’ll have to agree with anyone who thinks that this fly is not half as cute as the spider was.  There’s no competition!  Check out the flies on this page.  One looks like it is wearing sunglasses!

I took this picture after school on Friday.  Can you tell what it is?  Post your ideas below.