Contextualization

Theoretical Introduction

Earth, our home in the universe, is constantly moving even though we cannot feel it directly. One of the most fundamental movements that occur with our planet is called rotation. This is the movement that the Earth makes by rotating around its own axis, which is an imaginary line that passes through the North and South poles. This movement occurs from west to east and is responsible for the alternation between day and night that we experience every day. When we observe the sunrise on the horizon, we are seeing one of the most visible results of this rotation movement.

The concept of Earth's rotation is also directly linked to daily periods. A daily period is the time it takes for the Earth to complete a full turn around its own axis. This period is commonly known as a "day" and is divided into 24 hours. However, understanding this is not just a question of memorizing facts; it is about realizing how Earth's rotation directly influences our lives. The regularity of daily periods allows us to develop rhythms of work, rest, and leisure.

By delving into the observation of terrestrial movements, students can begin to understand how such grandiose phenomena can be measured and predicted. Understanding these natural processes is the basis for disciplines such as astronomy, physics, and geography. This knowledge is also crucial for various technologies including GPS navigation, which relies on accurate understanding of the Earth's position and movement.

RICH Contextualization

The rotation of the Earth has a significant impact on our daily lives. Since the earliest sundials to the modern atomic clocks, humankind has sought ways to accurately measure time. These measurements are not merely for our convenience. They have important practical implications, such as the determination of time zones – which are essential for planning activities in a globalized society.

Furthermore, understanding daily periods is intrinsically linked to human well-being. Circadian rhythms, which are biological cycles of approximately 24 hours, are regulated in part by exposure to daylight. These cycles influence everything from our sleep-wake cycle to the release of hormones, illustrating the profound connection between Earth's natural rhythms and our health.

To delve deeper into the subject and foster an informed discussion, I suggest reliable resources:

1. The website of the National Observatory (http://www.on.br) offers detailed information on astronomy and the movement of celestial bodies.

2. The Khan Academy platform has a vast collection of educational videos in Portuguese that cover science and astronomy concepts and can be accessed at https://pt.khanacademy.org.

3. Science textbooks for Elementary School are a great source of information, many of which are available in school libraries.

4. Documentaries available on streaming services such as Netflix, featuring the series "Cosmos", which provide an engaging look into the universe and the Earth.

These sources will provide a solid foundation for students to learn more about Earth's rotation and daily periods, while also inspiring them to develop critical and scientific thinking about the world around them.

Practical Activity

Activity Title

"Explorers of Time: The Dance of Earth"

Project Goal

To explore and understand the Earth's rotation movement and its impact on the alternation between day and night, through hands-on experiments and collaborative activities.

Project Description

Groups of 3–5 students will build a simple model that demonstrates the rotation of the Earth and how this results in the succession of days and nights. They will also monitor and record the variation of an object's shadow over the course of a day, relating their findings to the theory of Earth's rotation.

Materials

• A styrofoam ball (representing the Earth)
• A pencil (Earth's axis)
• A flashlight (Sun)
• A clock or stopwatch
• Graph paper
• A piece of tape
• A piece of chalk or marker
• A ruler or measuring tape
• A camera or smartphone to record observations
• A logbook (notebook or sheets of paper for notes)

Detailed Step-by-Step

Part 1: Building the Earth Model

1. Insert the pencil into the styrofoam ball at the center, representing the tilted axis of the Earth.
2. In a dark room, use the flashlight as the Sun and shine light on the "Earth" (styrofoam ball).
3. Slowly rotate the ball around the pencil, observing how the light hits the surface and creates day and night.

Part 2: Observing the Shadow

1. Choose a sunny spot and mark the position of a vertical object with the tape on the graph paper.
2. At every hour, mark the tip of the shadow with chalk and record the time.
3. Measure and record the length of the shadow throughout the day.
4. Take pictures or make a short video of the shadow changing to include in the report.

Part 3: Records and Analysis

1. Make shadow vs. time graphs from the information collected.
2. Write detailed observations about how the shadow changed throughout the day.
3. Discuss how the observations relate to Earth's rotation.

Project Deliverables

After carrying out the practical part, each group should write a paper according to the following topics:

1. Introduction: Here they will establish the context of the project, explain why the Earth's rotational movement is important, and state the goal of the practical activity.

2. Development: This section should detail the theory of Earth's rotation and daily periods. Additionally, students will describe each step of the activity, including building the model and observing the shadow, and explain the methodology used. Here they will also present the data collected and discuss the observed results.

3. Conclusions: The students will summarize the main points, reflect on what they learned, and conclude about how the project helped understand Earth's rotation and daily periods.

4. Bibliography: All sources consulted during the research and realization of the project should be listed, including books, educational websites, and any other material used.

By the end of the project, students will have developed not only a solid scientific knowledge about the Earth's rotation movement and its effect on daily periods, but also valuable skills in time management, collaboration, communication, critical thinking, and problem-solving.

The duration of the project should be two to four hours of dedication from each student, with a delivery time of one week from the start date.