Logic Flow For 3-Day Investigation Activity

Activity: Touchdown, Safely!

Outline of Daily Progression

• Day 1 - Free-Fall Lab
• Day 2 - Discussion of what the outcomes of the lab mean, and introducing the Egg Drop Activity. (Ideally this would be a Friday so students would have the weekend to build their contraptions
• Day 3 - Test the students contraptions.

Logic Flow:

• Gravity affects all objects.
• We feel the gravitational acceleration cause by Earth the most.
• Gravity on Earth is a form of uniform acceleration toward the center of the Earth.
• Therefore, it acts on all objects that are near Earth's surface equally, pulling them toward the center of Earth. 
•  In a vacuum, gravity causes any two objects to fall at the same rate, regardless of mass.
• Earth's Atmosphere is not a vacuum.
• Air causes friction as you move through it.
• The amount of friction, depends on surface area.
• Therefore, things of different sizes will be affected more, or less by the air resistance.
• We can use air resistance to change the velocity of something as it moves through air.
• Changing velocity of something, changes the length of time it will fall.
• Therefore changing surface area, we can affect time and velocity of a falling object.
• Gravitational Potential energy = mass x gravitational acceleration x height
• kinetic energy = 1/2 x mass x velocity squared
• Force x change in time = mass x change in velocity
• Therefore, we can change the amount of force an object hits the ground with if we change the kinetic energy of the falling object.
• Therefore, changing the velocity an object falls with will change the force it hits the ground with.
• We have 1 egg.
• We have 5 sheets of paper and 1 meter of string -or- we have 100 straws and 1.5 meters of masking tape -or- 3 sheets of paper, 20 straws, 3/4 meter of string, and 1/10 meter of tape
• An egg will crack if it hits the ground with to much force.
• We don't want scrambled eggs at school.
• We are going to drop the eggs from a height of 15.25 meters (50 ft.)
• Therefore, we will need to build a contraption out of the materials provided, that will keep the egg from breaking after it falls 15.25 meters.

Some of the stuff in this logic flow will be brought in from class discussions that occurred prior to working on the Free Fall Lab, but in order to put together a beneficial understanding of the whole activity it was important to put in to the logic flow.

Co-Teaching Experience

Last week I was given the opportunity to co-teach a lab with Dr. Kruse in front of our class.  I can safely say that I learned a lot about the way that I teach, both the things that I do well, and the areas that I need to work on. 

One of the things that Dr. Kruse and I talked about in side conversations had to do with the tone of voice that is used when I teach.  Since this was a lab experience and I knew that I would have to worry about safety, I wanted project my voice so everyone in the lab would be able to hear me when I gave instructions/demos/safety information.  But, as Dr. Kruse mentioned in one of our conversations, there is a difference between a projected voice and a voice of authority.  I know there were points during the class where I tipped more toward the voice of authority, which was not the best for the activity we were doing.  However the points when I was giving out safety information, especially if I were talking to a high school class, I would need to use that tone of voice to illustrate the importance of safety for that section of the experiment.  Knowing when to be a "co-investigator" with the students I think will come over time - it would take getting to know each group of students so that my interactions will be received well.

Throughout the class period I asked questions of the students: to the whole group, and to individual groups.  Questions served two purposes one to encourage and maintain the student's active mental engagement on both the material we were going through in the lab, but also the safety protocols.  In the investigation that we did, we were trying to get to a place where students would have put together a knowledge set about the material in the lab so that they would be able to help another student through the lab.  I wanted them to look at what they were doing and reflect on why they needed to remember something - "What were the most important things you observed that helped you differentiate between powders?" and "Why were these observations important?"  In this way my questions were there as scaffolding for the students to use as they put together that knowledge set.  There were times where I know I went a little over the top and asked more questions than were needed.  In those instances I was asking a question because I could.  It is important to remember that questions should have a purpose behind them, and it is okay to just give students some pieces of information.  One of the most visible of these experiences occurred when I was going through the Bunsen Burner safety demo, and at the end I asked a question for the sake of asking a question.  None of the class answered it, as soon as that happened I knew it was an "over the top" question, but I tried to let it play out, but that didn't happen.  Going forward I will need to keep in mind that if I get to that point again, then its okay to give students that last piece of information, not make them fill in the blanks.

The next two ideas go together hand in hand: asking thought-provoking extended response questions, and giving students time to think and respond (wait time).  For the most part I think I stuck to asking good, thought-provoking questions, but as the time dragged on and there were fewer responses coming back, I fell back on asking lower and lower level questions, even asking several yes or no questions.  When I was asking the thought-provoking questions I had to wait (it seemed like an extremely long time) and give students time to gather their thoughts so they could put together an answer that fit the question.  Most of the time I think that I held a pretty good three or four second wait time right after I asked the question.  I think the point where I began to run into trouble was the wait time between the student response and my next question or response.  I think there were a couple times that I inadvertently cut off a student before the could respond, or might have missed a question.

Overall it was an excellent experience.  Having been in a couple different science classes for practicum experiences, and as a substitute teacher, I have had a chance to practice in a the classroom, but pairing instruction with the awareness needed for in the lab instruction was a new experience for me.  Going into this and realizing that I would be giving students Bunsen Burners, safety was at the forefront of most of my thought processes.  Granted, I was teaching people (this time) who have had some experience in a science lab, but because I was "responsible" I felt like I couldn't let it get out of hand.  Whenever I was addressing a safety concern, or introducing a new piece to the investigation I tried to minimize risk by having every student put down what they were working on, and direct their eyes to the front, then waited till everyone was looking up at me.  I also continued walking around throughout the lab, using my proximity to students to help keep them on task.  It also helped me gauge when to move on to the next section of the lab - as I saw that students were getting done with a particular part around the room, I was able to stop them give more instruction then they would be able to work on the new part that I just gave instructions about. 

Logical Flow for the Collapsing Can Demo

First off, some of the ideas that this demonstration illustrates are hard to understand because there isn't any visible evidence to see - namely we can't see the gas increase in volume with just the can as the example in the demo.  So I would add a parallel demo to be done at the same time, but this would use a filled and tied balloon.

The activity would go as follows:

Fill a balloon about half way (best guess on this would work), have a student calculate its volume by treating it as a sphere, and observe the starting temperature. Write these values on the board. Have a student determine the same values for an open pop can, and write those on the board.  Volume determination for the pop can could be done by filling the can with water, then pouring the water into a graduated cylinder.  Remind them that the can is open and it is a rigid container.

Have students write down a prediction about what they think will happen if the balloon and the can are heated up, and why they think the prediction will happen. 

Heat up the two objects, ask them to describe what is happening. Discuss what is happening in the can - remember its open and a rigid container, so what would happen to the stuff inside it?  Have a student quickly measure the circumference of the balloon, and give it to you on a small piece of paper.  Record the temperatures of the two objects on the board.

After the student measures the circumference of the balloon, quickly put it into a bucket of ice water.  Have students describe what they are seeing.  Do the same for the can. Why does the can do the same thing as the balloon?  Write down the final temp of the objects on the board.

Have students talk with their partners to come up with a description of the relationship that they are seeing in this demonstration.  While they are discussing things, collect data for the circumference of the cooled balloon.

After the class agrees on one that is a fair description of what Charles' Law is introduce them to the nuts and bolts of what the law is, and have them use the data collected during this demo to figure out what the volume of the heated and cooled balloon was, the volume of the gas that started in the can after it was heated.  How can this knowledge help us understand why the can was crushed?  Since we would have talked about the particle nature of matter in class, I would ask them to explain who the number of particles of gas in the can at the beginning of the demo compared to the number of particles at the end of the heating process.  This way they would understand that there is less "stuff" inside the can, even though it has the same volume - hopefully this would help with the idea that the can collapsed, reducing volume.

After they calculate these values I would have the students compare the values they calculated to the ones that I calculated from the observational data.  Why are the values different?  What does this mean for Charles' Law?


Here is how, the logic flow would work with this further modification:

1. The balloon and the can have a specific volume at the beginning of the demonstration.
2. The size of the balloon increases as it is heated up.  The gas that was in the pop can escaped since it was open.
3. Therefore, as temperature increases, volume increases.
4. The size of balloon decreases as it is cooled.  The can gets crushed as it is cooled.
5. Therefore, as temperature decreases, volume decreases.
6. Therefore, there is a relationship between temperature and volume, that can be modeled by the equation for Charles' Law.
7. The calculated values using the equation from Charles' Law are slightly different from the values obtained from experimentation.
8. A law is an idealized relationship that is used to model the relationships that we see in nature.
9. Therefore, the data that we gathered in this real-world demo, will result in values that will be a little different from the values predicted by the law.

Applying Learning Theories to The Collapsing Can

In the last post I wrote about modifying a demonstration to make it into an introductory experience that students could use as a concrete experience in which they could ground their thought processes in.  One thing that was implied by the way modifications were considered, but not specifically addressed was how those modifications fit in with accepted learning theories.

Developmental Learning theory speaks volumes as to how a student may be able to understand more abstract ideas as the develop cognitively.  Since I can't be inside each in everyone of my student's heads I can't know for certain whether or not they are up to the task of tackling an abstract idea like the gas laws.  It would be easier to make sure that everyone has a concrete experience to tie the abstract ideas to, that way no one will get left behind.

Looking at the activity and discussion through the mindset of a Social Learning Theorist, encouraging discussion between all of the students I would be tapping into the idea of the "more knowledgeable peer."  I know there will be times when I will be speaking "teacher" when the students need to hear the ideas in "student."  If one student comes up with a "right" understanding of the idea that we are talking about, then I should try to help students come to an understanding like that.  I would try to foster a discussion that would have them analyze the idea, evaluate its strengths and weaknesses, and when it is apparent that students understand the idea, I would write down what the said along with the formalized idea, that way they have their own words to help them understand what the more complex scientific writings mean.

This lesson could also be looked at through the lens of a constructivist.  By using a foundation based on a concrete example, then scaffolding the experience so that the students will build an understanding of the ideas that are evident in the demonstration, that they will be able to understand and remember.

A Re-Done Demo: The Collapsing Can

What happens if you heat up an opened pop can, then put it up-side-down in a container of cool water? Well if you watch this video you can see what happens.  This demonstration shows the relationship between temperature and volume.  In the end, the ideas behind why the can gets crushed, really don't get conveyed to the observer.

In the clip from the Spangler Science TV, this demonstration has more of a "let me show you what is going on" tone rather than an exploratory tone.  In my experience, those demos that had that exploratory tone were the ones that kept me interested, actually made me think, and I learned the most from.  When I would modify this demonstration, I would go through tell students what the set up was, then do the demo and ask: "What is happening?"  My goal with showing what happens then asking students to describe what they are seeing is to have students figure out a way to explain in their own words.  The way that I scaffold the conversation will help students get to the final conclusion about the temperature and pressure relationship. I would ask questions that would get students to explain that when the can was heated up, the air inside increased in volume and some air was pushed out of the can.  Then I would start asking questions about what would happen to the air inside the can when the it was cooled down with the water.  After a little more discussion, a few more times crushing the can, we as a class would get to the conclusion that volume varies with temperature.  Only after students got this far, would I tell them about the formalized equation and wording that goes along with Charles Law, that way they would have an understanding of the law without getting confused by how wonderfully worded Charles Law is.

The discussions that I would encourage can be done in several ways: large group, small group, think-pair-share, etc.  Depending on what level of my students and the point we were at in the progression of the discussion, I would choose an activity that would benefit the students.  For instance if I were to see that there were more puzzled looks than looks of understanding, I would have students do a think-pair-share, that way I would tap the "more knowledgeable peers" in the class to help get some ideas across in a way that other students may be able to understand more easily.

I like the idea of showing the demonstration as a precursor to discussion, and having students describe what they are seeing - much like what a scientist would do.  Scientists go would do something then try to explain what they are seeing, based on their prior knowledge and the evidence that they have.  Students would also have to be creative in how they were coming up with the conclusions from the data they were interpreting.  I would be able to tie in the NOS by asking questions that get the students to look at the process that got them to the ideas that we were getting at.

The Great Socio-scientific debate...A.K.A. Nuclear Energy..

This past couple of years we've seen some crazy things happen, and when the Fukushima Daiichi Power Plant started having trouble after the earthquake and tsunami, the issue about the safety of using nuclear power came to the forefront again.  So much so that Japan has recently said they will phase-out nuclear power by 2040.  I think that this would be an interesting topic for a chemistry class (or other science class) to look into when they start discussing fission and the heavier elements. 

I think that several good connections to the Nature of Science, using this topic, can be made through carefully planned instruction.  If I were to use this example of a socio-scientific issue as a supplemental way to teach about our modern understanding of the atom, I would definitely touch on these three aspects of the Nature of Science: social, theory laden, and culturally embedded.

The ideas that are important for understanding nuclear energy started with one important aspect of NOS - the social nature of science.  The Manhattan Project was a collaboration of epic proportions with the goal of researching the process of a nuclear chain reaction.  The knowledge necessary for such a program grew out of the collaborative efforts of some of the greatest scientific minds: Einstein, Fermi, and Bohr just to name a few.

The social aspect of the nature of science leads straight into the theory laden aspect.  Each one of the scientists I just listed came to the table with a distinct knowledge and skill set that depended on the areas of science they worked in and the focus that they had before the Manhattan Project.  What we know now is based on the work that was done and knowledge that these scientists brought with them. 

Today the culturally embedded nature of science plays an important role in the debate over whether or not nuclear power should be used.  The pictures of victims from Hiroshima and Nagasaki, the fact that Chernobyl cannot be inhabited for at least another half millennium (on the short side), and the radiation that came out of the Fukushima Daiichi Plant all have an impact on whether or not scientists or the public want to tackle this issue.  Another face of the culturally embedded aspect of NOS in this debate can be seen in the desire to find alternatives to coal and oil as fuel sources.  Even though countries around the world want to find something to power their grids that releases little or no pollution, they tend to turn to wind, solar, and hydroelectric energy before nuclear, even though nuclear power plants are sometimes 40% more efficient energy producers.  Why is that?  Because of the tragedies that I just mentioned, there is the pervasive idea that nuclear energy will never be safe.

My job is not to help students come to a decision about whether or not nuclear power is the future of energy production.  I want students to understand where the idea of using the energy contained in an atom came from, what changes these ideas caused in our understanding of the universe, how what we bring to the table affects what conclusions we draw.  If they come to a conclusion about the use of nuclear energy, more power to them because they made an informed decision when other people might not have done the same.

Glimpses of the Nature of Science in the Earth's Crust

Continents: A Jigsaw Puzzle with no Mechanism was a helpful tool in seeing how to fit different aspects of the Nature of Science (NOS) into a content lesson.  The authors of the article presented the different parts of the content in the way that they unfolded, then posed a question to help students look at a deeper message in the narrative: why things happened in the way that they did; what caused certain things to happen or not to happen; what caused the change, or the resistance to a change, in thought.  This article puts forth several ideas that can be translate into important aspects of NOS: theory laden NOS, empirical NOS, tentative NOS, and the theory-law NOS.

The authors have posed several great questions at key points in the article.  For instance, after reading about how two scientists came to two very different conclusions after interpreting the same data, there was a break in the content where the idea that scientists have to interpret the evidence that they are presented with.  This point presents the opportunity to mention either the empirical and theory laden aspects of NOS - science fact is based on evidence, and the theories that a scientist subscribes to will affect how they interpret the data.  A brilliant move by the authors from my point of view.

In my coursework I've come across the term Nature of Science several times, and in the past, I have had to work to see ways to teach it effectively.  The ideas contained in that seemingly simple phrase are complex and interconnected to the point that you can't always tell where one stops and another starts.  This article/story is a great example of how to bring these behind the scenes structures into the foreground in an way that they can be understood.