Cartesian Diver

 

Cartesian Diver

Cartesian Divers are easy and fun to create in the classroom. I use divers to teach density, buoyancy and Pascal's Law. 

In my experience, having the students read the directions and help each other is the most successful method. 

Cartesian Diver Directions Book

This year I created a simple book that students used to create their diver. I created the book and uploaded it to Edmodo. This allowed students to move at their own pace. Students also helped each other out and explained pictures or directions that were confusing to some as I walked around the room.

Hierarchy of Learning

It has been proven multiple times that when an individual has to teach a concept, the concept goes deeper in their mind and they are more likely to retain the information, For my homework, students have to teach the density and buoyancy to 3 people in high school or older. 

Cartesian Diver Be-The-Teacher Homework

Each student takes his/her diver and explains why the diver moves and how it moves. I explain that students can teach their parents, other teachers, the principal, their coach, basically anyone who will listen (except other students at the school).

This is actually my secret plan to expand scientific knowledge. By having students teach other people what they are learning, they reinforce the content for themselves and they spread science knowledge to the general population. It also helps students to connect their curriculum outsider of our classroom.

It's amazing to see 8th graders playing with a bottle and making a diver move up and down. They are so proud of themselves. There is a real sense of accomplishment when they are done. In my opinion, this gives them pride in their work and boosts their self-esteem. 

Let's talk about the science behind this activity...

When the diver is first put into the water, there is a bubble of air inside the diver. This air pocket makes the diver less dense than the surrounding water and so the diver floats or has positive buoyancy. When the bottle is squeezed, Pascal's Law is applied. Pascal's Law states that pressure exerted anywhere in a confined fluid is transmitted equally in all directions throughout the fluid (Encyclopedia Britannica). By squeezing the bottle, pressure is applied to the diver. This pressure reduces the size of the bubble inside of the diver. This makes the diver more dense then the surrounding water and the diver sinks or has negative buoyancy. When the bottle is released, the pressure is released and the bubble expands - decreasing the density, making the diver float and have positive buoyancy. 

This is a great activity to discuss how molecules in a gas move. When their is less space for the gas to move-in, then the gas is more dense. If there is more space, the gas is less dense. 

When teaching, I try to connect to previous ideas and concepts we have learned about in the classroom. It's a great way to show students how everything is connected and a great way to remind them of what they already know or access their prior knowledge allowing them a pathway to connect their new knowledge.

Life Cycle of Stars

>>Click on any of the images to find where I got them from.<< 

Physically interacting with materials, helps to ingrain ideas and concepts into students' minds. I try to have a physical activity for most of the concepts I introduce in my science class.
                           
While reading about star life cycles and looking at pictures of stars in their different life cycles is beautiful, I was looking for something more. Something that would get and keep my students' attention. Enter in...Life Cycle of Stars Balloon Activity.

This image is one of the best I've found. It shows a variety of stars. The only problem I have is that students don't realize it is a cycle that really has no beginning or end.

More like this

I came across Star Cycle with Balloons on the Communicating Astronomy website.

This activity is a lot of fun!!! But it didn't teach everything I wanted to teach and it didn't have all the resources I need. I've made my own activity, presentation and worksheet that you can download it on my Teachers Pay Teachers Store.

Here is a short description of the activity -
          Students are given colored balloons with Jellybeans inside. The balloons represent different colored stars. The Jellybeans represent the different thigns the stars turn into at the end of their life cycle. Students go through the life cycle of a star by adding air to their star/balloon as it ages. Eventually their star/balloon will turn into a Red Giant and go Supernova or turn into a White Dwarf. This requires the teacher to pop the star/balloon, which brings lots of squeals and excitement. Then their star baby turns into a Black Hole, Neutron Star or White Dwarf. It's lots of fun to ask the students, "Who turned into a Black Hole today?" Students are good at remembering who turned into what.

Excerpt of Teacher Explanation of Activity

One of the Slides in my Life Cycle of Stars Presentation (all slides include links to picture sources)

Star Life Cycle Worksheet

When I teach, I try to use as many learning modalities as possible (Here is a short article on a few different modalities on Education.com. If I can bombard students with information in as many ways as possible, I can almost guarantee something will stick!

Kinesthetic and Tactile learners tend to need physical activities. For this activity, blowing up the balloon and then seeing and holding the remnants will help students remember the stages.

Visual learners tend to need visual input to understand a concept. During the activity, I show images of Supernovas, White Stars, etc. This helps reinforce the different types of stars and objects that we are discussing.

Auditory learners prefer hearing what to do and listening to information. While I conduct this activity, I continually explain all parts of the activity orally. I ask questions of the students and engage them in conversation. This helps all students to pay attention.

Here are some of the remnants of the star activity

I hope you have fun teaching science!!