Topic: The spectacle in the sky

Target Group

Pupils of the fourth grade of primary school.

Core Curriculum

Grade 4

General requirements

III. Shaping attitudes – education.

1. Careful observation of natural phenomena, accurate and meticulous carrying out of experiments, using the instructions while taking measurements and experiments, taking notes and developing results.

Specific requirements

I. Ways of learning about nature. Pupil:

1) describes ways of learning about nature, gives the differences between experiment, experience and observation.

The general aim of education

Students explain how rainbows and halos are created.

Criteria for success

• you describe dispersion of white light;

• discuss examples of experiments in which white light is dispersed;

• you will explain how rainbows and halos appear around the Sun or Moon.

Key Competences

• Communication in the mother tongue;

• Communication in foreign languages;

• Mathematical competence and basic competences in science and technology;

• Digital competence;

• Learning to learn;

• Social and civic competences.

Methods / forms of work

Work with the film, presentation, educational discussion, conducting experiments.

Individual work, work in pairs, work in groups and collective work.

Teaching aids

• abstract;

• interactive or traditional board;

• tablets / computers;

• a few unused, preferably recorded, CDs (one per group).

Lesson phases

Introduction

1. The teacher defines the purpose of the lesson and informs students about its planned course.

2. The teacher gives the topic of the lesson. Students write it in their notebooks.

Realization

1. The teacher initiates a discussion about the properties of white light. He asks students if they know what light dispersion is and if they can give any examples of it.

2. The teacher introduces a film showing an experiment that aims to split white light. The teacher instructs the pupils to set a research question and hypothesis together and to write them down in the form provided in the abstract. Then the teacher displays the video and the students record their observations and conclusions. Selected students present them to the class. The teacher assesses the accuracy of the students' observations.

3. The teacher divides the class into four- or five‑person groups. Each group receives one recorded CD. The teacher recommends students to view them in sunlight or artificial light. Students should pay attention to the rainbow patterns appearing on the discs.

4. On the basis of the abstract, the students make notes explaining the creation of rainbows and halos.

5. Students, working individually or in pairs, perform interactive exercises to consolidate knowledge acquired at earlier stages of the lesson.

Summary

Students ask questions, ask for additional explanations and complete their notes.

Homework

Students carry out the opposite experiment to light dispersion, aiming at combining its component colors, according to the instructions contained in the abstract (exercise No. 2). The multi‑colored disc, which should be prepared for the experiment, can be printed on a color printer.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

The spectacle in the sky

The sunlight seen by man is white. It turns out, however, that it is not just one colour. In fact, it is a mixture of many parts seen by us as different colors. The full range of light reaching us from the sun consists of a whole range of colors available to human sight, namely: red, green and blue, and all the colors between them – there are infinitely many of them. How do we know it? It has been proven a long time ago with a glass object called a prism. The phenomenon that we observe thanks to the prism is called the dispersion of light.

Can we prove that light dispersion if we do not have a prism? Yes, we can do simple observation for this.

Not only the prism splits the light. Water drops also have this property. As a result of the sunlight falling on the border of air and water, it diffuses. When the drops of water float in the air during falling rain, while the cloud is illuminated by the sun's rays, a very impressive phenomenon appears called a rainbow.

It is worth remembering that a rainbow does not exist in a particular place. It is only an image perceived by the observer. A few people watching the rainbow from different places at the same time see it a bit differently.

Another light phenomenon in the atmosphere is a halo. It is a luminous circle that surrounds the sun or moon. The part of the sky visible inside the circle is clearly darker than the rest. Halos are caused by the refraction of light on ice crystals or inside them, in cirrus clouds.Explain under what circumstances you can see the dispersion of light.

• White light can be split into its component colors.

• A device used for splitting light is the prism.

• The splitting of light is related to the formation of optical phenomena, e.g. rainbow and halo.