Contextualization

Planet Earth is where we call home, a mysterious and wonderful place filled with countless natural beauties and with a complex and lively environment. Understanding the large sphere that orbits around the Sun is essential so we can know more about ourselves, our place in the universe and how our planet functions.

The Earth’s sphericity, for example, is a key concept that has impacts on various aspects of life as we know it. The Earth is not a perfect sphere, such as a soccer ball, but it is rather an oblate spheroid, that is, its shape is flattened on the poles and bulges at the equator.

This shape contributes to the distribution of solar heat, the ocean currents, and the air masses in the atmosphere. Ultimately, these effects determine the climate of the planet as well as its biomes. Additionally, the planet's rotation and this shape have an effect on the velocity of air currents and water circulation, allowing heat exchange between the equators and the poles.

Introduction

The Earth, its physical characteristics, its division between land and ocean, its shape, and movements are central concepts for understanding other disciplines, like Geography, History, Biology and even the Economy.

And that is the reason that this project was designed: to explore all these central concepts! Together, we are going to take a dive into the depths of our planet, discovering its secrets and marvels. And you don’t have to go to the far end of the planet to do so: with simple experiments and accessible resources, we can explore the Earth’s sphericity, the continents, oceans, and even more.

This project is designed to foster collaborative work and knowledge building through reliable sources. It also encourages students to practice the contents they learn in class.

Are you ready to jump on board this adventure?

Resource Suggestions

Below you can find a few references and materials for the project, which may also be useful to complement the work in class:

1. National Observatory - Educational material on the Earth’s sphericity.

2. Nostalgia Channel – Explanatory video (in Portuguese) on the shape of the Earth and how it’s not a perfect sphere.

3. Manual do Mundo Channel – This video shows how Earth is “flattened” at the poles.

4. Science Everyday Channel – Video (in Portuguese) about the Earth's sphericity and experiments on how to prove that the Earth is round

5. BBC News Brasil – An article on the Earth’s shape with information on how and why this was discovered and proven.

Practical Activity

Title: "Exploring the Earth in the Classroom"

Project Objective:

The main objective of this project is to create an environment of practical learning, through which the students are able to explore concepts related to Earth’s shape, its division into continents and oceans, and to learn how the spherical shape and rotation affect how objects behave

Detailed Project Description

The students are going to be divided into small groups of 3 to 5 students and they are going to have to carry out a series of hands-on activities and experiments, with the purpose of showing how the Earth is spherical and that it’s divided into continents and oceans

Necessary Materials

• 1 Ball, which is going to represent the Earth
• Construction Paper (for representing continents)
• Colour Markers (for drawing and writing on the sphere)
• 1 meter stick (as a Gnomon)
• Ruler
• Pencil and paper
• Flashlight
• Compass

Detailed Step by Step:

1. Understanding Earths Sphericity: Using the globe to represent the Earth, and with the help of the markers, the students are going to draw the North and South Poles, as well as the equatorial line. Encourage debate and stimulate reflections upon the Earth’s shape (Oblate Spheroid) and on why it isn’t perfectly round.

2. Representing Continents and Oceans: With the construction paper, the students will be making cut-outs for each of the continents, which will then be glued onto the model of the Earth. They are encouraged to think about how the Earth is mostly divided between land areas (continents) and water (oceans), and how these two are distributed on the planet.

3. Creating Shadows with the Earth (Gnomon): Students are to fix the stick on the ground, and by positioning the flashlight at specific angles, emulate how the Earth rotates around the Sun, simulating different hours of the day. Then they will record on the paper how the tip of the rod (gnomon) produces different shadows throughout the day and how the length and position change with respect to the position of the flashlight.

4. Report in Written Document: Once all the previous activities have been concluded, students should elaborate on their conclusions in a report. They must include the theoretical concepts learned throughout the whole experience, talk about methodology and the experiments they carried out, as well as their findings, conclusions and references consulted. In this final document they must include the following sections: "Introduction", with a brief introduction and context about Earth; "Development", where the main ideas learned are highlighted and the experiments relate to theoretical knowledge; "Conclusion", in which they summarize the project and their learning and, lastly, the "Bibliography" with references to all the materials that they consulted for support.

Project Deliverables

As the final deliverables of this project, the students must present:

1. The sphere (Earth model) with the continents

2. The shadow recordings of the gnomon throughout the day

3. A written document reporting the whole learning experience. It must include an "Introduction", where they are going to contextualize the learning experience; "Development", where they will describe what they learned throughout the experiments as well as using the studied theory; a "Conclusion" with the main aspects and takeaways, and finally the bibliography with the materials they checked for the development of this task

Students are encouraged to be collaborative and work as a team. They must be able to plan ahead, dividing the tasks into the team members and making the best use of the available time. They also must learn to solve any possible issues that may arise, facing the challenge and being able to appreciate the whole learning process.

This project is much more than an exercise to learn about our planet, it will also be an example of how teamwork and how to use the acquired learning in practice.