The Science of Natural Disasters: How to Make Students Aware

Hurricanes, tornadoes, earthquakes, volcanoes, and tsunamis can happen anywhere at anytime. The students I teach in New Jersey may not have experienced a devastating natural disaster first-hand and need to be made aware of disasters worldwide.  Students should also be taught the science behind these  events. Teaching the sciences should involve real-world examples. Using actual examples of natural disasters to teach Earth Science is a great way to make it real for the students.

Since many students in my school are Haitian, teaching earthquakes using the Haitian earthquake example seems to be an obvious choice. But what if any of the students have relatives and loved ones they lost in the earthquake? I am not sure if I am ready to confront that type of issue.

Instead, I would discuss ways in which we could help the people of Haiti. UNICEF helps the children of Haiti. I would like to have a fundraiser for the children of Haiti run by the science classes. The students could have a bake sale in the school to raise money for UNICEF.

How Do Specialized Cells Form?

I know that cells come from other cells, but I had trouble understanding how each cell knows what type of cell it is supposed to be. I went to askascientist.org, and I learned that even though DNA is identical in every cell, not every gene that is encoded by DNA is expressed in every cell (Revollo, 2008). All cells have a set of genes that encode proteins necessary for every type of cell. Each cell also has tissue-specific sets of genes that are unique to a particular tissue or organ. For example, bone cells express bone-specific genes. The cells become specialized for a certain function during an organism's development. A totipotent embryonic cell can become any type of specialized cell, and differentiates due to cues from the environment of the nearby cells (Revollo, 2008). These cues, along with when the signals are received, instruct the cells of the embryo to differentiate.

Revollo,J.Y. (2008). How do specialized cells form? Retrieved from http://askascientist.org

Powerpoint vs. Prezi

I have always used Powerpoint for presentations as a teacher. Just recently I have discovered Prezi, which is a similar presentation tool, but with some key differences. One major difference is that Powerpoint is linear, with slides prepared in a particular order. Prezi, on the other hand, is prepared similar to a concept map or graphic organizer. There is freedom to create the map, and then decide the order you want to present. While presenting, it is easy to change the order it is viewed.

Both Powerpoint and Prezi have interesting slide transitions.Powerpoint allows you to choose how the slides transition. They can change on the click of a mouse or by themselves. Words and titles can show up in many ways as well (such as fly in, fade in, etc.) Prezi spins and zooms in on the different sections, and although the motion of it can make me feel a little bit dizzy, it really makes the information appear to be three dimensional and similar to a satellite view.

Overall, I think both Powerpoint and Prezi are similar in what they accomplish. They both present information in creative ways, but Prezi seems more interactive and exciting. If I have to choose between the two styles, I choose Prezi.

Technology in Science Education

This week I researched internet sites that use technology to aid in teaching Newton’s Laws of Motion to students. The best and most informative site I found is http://physicsclassroom.com . This site uses tutorials for each of the three laws, diagrams, visual aids, video demonstrations, interactive quizzes, links to interactive shockwave files that simulate physical concepts, labs (online and hands-on), photo gallery containing over 1000 physics-related photos, and the “Minds-On Science” internet modules.

The feature that I find the most exciting is the internet modules. There is a large selection of physics topics to choose from, and they can be accessed from any computer. The students work can be done at school or at home, and a success code can be accessed by the teacher. Using technology prepares students for the 21^st century, and it is up to teachers to find the appropriate resources to reach this goal.

The simulations links on this site offer excellent opportunities for the students to work with variables and observe various outcomes. For example, one simulation has the students match eleven position-time and velocity-time graphs to eleven animated motion. Worksheets are also provided for some of the activities through the web site.

Another technology site I found is http://interactivewhiteboardsoftware.com/Science.html . This site offers software for whiteboards (Smart boards, etc.). There are all types of software programs available for math and science on this site including simulations, graphing software, virtual labs, and various lesson packs.

Teaching the skills that prepare students for STEM careers is important in this day and age. I hope these sites help you in your teaching. 

Heat Insulators Experiment

           

This week, I performed an experiment on heat transfer. Before the experiment, I learned that heat is transferred by conduction, convection, and radiation. Conduction takes place when two substances are in direct contact with each other and energy transfers from molecule to molecule. Convection is the method of heat transfer in liquids and gases in which heated molecules in fluids and gases gain higher kinetic energy and move in a circular pattern called convection current. Radiation is heat transfer through space via electromagnetic waves. This week’s inquiry assignment deals with insulators and heat conduction. 

I was asked to use scientific inquiry to determine which materials are the best insulators. I began by gathering the materials: four identical mugs, four rubber bands, one thermometer, hot water, and a timer. I chose to test foil, bubble wrap, polyester material, and a cotton cloth. My initial hypotheses were that the aluminum foil would be the worst insulator since metal is a good conductor of heat and electricity, and the polyester cloth (from a scarf) would be the best insulator. Since this thin polyester scarf has kept me warm in cold weather, I thought that it may be a better insulator than the cotton wash cloth or the bubble wrap.

I poured six ounces of hot water into each mug, covered the tops with the four test materials, and secured them with rubber bands. After thirty minutes, I took the temperature of each to determine which water remained the warmest. My results were as follows: the water covered with foil was 46 degrees C, the bubble wrapped covered mug was 47 degrees C, and both the polyester and cotton cloth covered mugs were 48 degrees C. My hypothesis that the foil would be the worst insulator was correct. The bubble wrap was a bit better. I thought that the polyester covered mug would be the best insulator, but actually the cotton wash cloth was just as effective.

           
One difficulty I faced when doing the experiment was that I only had one thermometer. While I took the temperature of the first water mug, the other three mugs were cooling off. If I had to do this experiment again, I would make sure that I had four thermometers. Even though I do not think that my results would have been entirely different, they could have been more accurate.

If I were to test another material to find a good insulator, I would chose polystrene foam. I read that styrofoam (or polystyrene foam) has trapped air pockets which help insulate material. Fiberglass used to insulate homes uses the same method. Since glass and air are good insulators, small fiber of fiberglass trap air pockets which help keep homes warm.

Inquiry Lesson : Law of Conservation of Momentum

This week I have been provided with a question to explore through a guided inquiry investigation. The question is “What is the effect of large objects colliding with smaller objects?”. To find the answer to this question, I gathered the following materials: large marble, small marble, two meter sticks, paper, and pencil. On a table, I taped the meter sticks parallel to each other about an inch apart. I placed a small marble at the center on the “track” and the large marble at on end. I rolled the large marble toward the smaller one and recorded what occurred on a data table after the collision. I repeated this ten times. Each time the large marble hit the stationary small marble, the large one caused the small one to move in its same direction but at a faster speed.

 Next, I asked a friend to help with another marble collision scenario. She stood at one end of the table and I stood at the other. We rolled the large and small marbles toward each other with about the same force. We repeated this ten times, recording the results on a data table. Each time, the smaller marble changed direction and quickly rolled back in the direction it came from after the two marbles collided. The large marble continued in the original direction, but slowed down after striking the smaller marble.

Before performing this experiment, I hypothesized that when the large, more massive marble hit the stationary small marble, they would both move in the same forward direction. I was sure that the smaller marble would roll faster than the larger one because I knew that the momentum of the more massive marble would transfer much energy to the smaller one. My hypothesis was correct for this first experiment.

For the second experiment in which the two marbles move toward each other and collide, I hypothesized that the large marble would stop in place and the small marble would roll in the direction opposite of its original motion. My hypothesis was incorrect because the large marble did slow down, but it did not stop completely. After thinking about this situation, I feel that if the smaller marble had a bit more mass or traveled at a greater velocity, the larger one may have stopped completely. The mass of the small marble was not enough to halt the motion of the large marble.

The experiments were simple and worked out well. When I do this experiment with my eighth grade class, I may modify the experiment by having the students roll the small marble at the stationary large marbleas well to see what happens. I would probably  have the materials on each table ready for the students. For this particular activity, I would give the procedure to the students. There aren't many multiple ways to make this work, so unless the students can come up with the exact experiment procedure on their own, they won't see accurate results.

To make this activity more engaging, I would make momentum relevant to their lives by using examples they can relate to before the activity, such as sports examples and the motion of amusement park rides. By the end of the activity, I want the students to understand that momentum is not lost when a collision occurs (besides some lost to friction), it is just transferred. I think this activity will be successful in the classroom.

Inquiry Lesson: Reducing Surface Tension

This week I taught a lesson on surface tension and cohesion of water molecules. I led the students through a guided inquiry activity which asked the question "Which liquid, when rubbed onto a penny, can reduce the cohesion of water molecules?". First I had the students perform a control test, which involved using a pipette to count how many drops of water will stay on a clean, dry penny. Then the groups of students were asked to choose a liquid (orange juice, carbonated water, or soapy water) which they thought might reduce the cohesion of the water molecules, causing less drops to stay on the penny. Students made their choices and performed an experimental test. The terms surface tension, cohesion, variable, and control test were reviewed before and after the lesson.

I found that using this inquiry lesson increased student engagement, but it also caused some argument between group members over what liquid to choose and why.