Light imitates art
View Sequence overviewStudents will:
- explain what an object look likes when it is observed through water.
- gather evidence to explain the scientific phenomenon of refraction.
- determine which explanation of the scientific phenomenon of refraction best suits the evidence they have collected.
Students will represent their understanding as they:
- draw diagrams of objects viewed through water.
- contribute to class discussions about refraction.
- write and draw labelled diagrams to explain their investigation results.
In this lesson, assessment is formative.
Feedback might focus on:
- students’ observations regarding what happens as the beam of light meets the plastic cup and water. Are they able to identify that the path of light changes as it is transferred through different transparent material other than air, such as water?
- students’ analysis of evidence. Are they able to determine which scientific explanation their evidence supports?
Whole class
Class science journal (digital or hard-copy)
Materials to create a word wall
Optional: Demonstration copy of Line of light investigation planner Resource sheet
Demonstration copy of Exposing the illusion Resource sheet
Each group
Clear plastic cup, preferably with no ripples or patterns on it
Pencil
Access to water
Piece of card, approximately 20cm x 20cm
Ruler
Scissors
Torch
Each student
Individual science journal (digital or hard-copy)
Line of light investigation planner Resource sheet
Lesson
Re-orient
Revise what students learned in Lesson 4, focusing on transparent materials.
The Inquire phase allows students to cycle progressively and with increasing complexity through the key science ideas related to the core concepts. Each Inquire cycle is divided into three teaching and learning routines that allow students to systematically build their knowledge and skills in science and incorporate this into their current understanding of the world.
When designing a teaching sequence, it is important to consider the knowledge and skills that students will need in the final Act phase. Consider what the students already know and identify the steps that need to be taken to reach the level required. How could you facilitate students’ understanding at each step? What investigations could be designed to build the skills at each step?
Read more about using the LIA FrameworkIdentifying and constructing questions is the creative driver of the inquiry process. It allows students to explore what they know and how they know it. During the Inquire phase of the LIA Framework, the Question routine allows for past activities to be reviewed and to set the scene for the investigation that students will undertake. The use of effective questioning techniques can influence students’ view and interpretation of upcoming content, open them to exploration and link to their current interests and science capital.
When designing a teaching sequence, it is important to spend some time considering the mindset of students at the start of each Inquire phase. What do you want students to be thinking about, what do they already know and what is the best way for them to approach the task? What might tap into their curiosity?
Read more about using the LIA FrameworkSeeing it through
Discuss what students think they know about two very common transparent substances: water and plastic.
- How would you describe something that is transparent?
- Can you always see through plastic clearly? Why? Why not?
- What types of plastic can you see through?
- What types of plastic can you not see through?
- Can you always see through water clearly? Why? Why not?
- What happens when you try to look at something through plastic or water? What do you see?
Refer to any questions students might have asked during the course of the sequence about plastic or water.
Pose the question: What do we see when we look through ‘clear’ plastic? Or ‘clear’ water?
The Inquire phase allows students to cycle progressively and with increasing complexity through the key science ideas related to the core concepts. Each Inquire cycle is divided into three teaching and learning routines that allow students to systematically build their knowledge and skills in science and incorporate this into their current understanding of the world.
When designing a teaching sequence, it is important to consider the knowledge and skills that students will need in the final Act phase. Consider what the students already know and identify the steps that need to be taken to reach the level required. How could you facilitate students’ understanding at each step? What investigations could be designed to build the skills at each step?
Read more about using the LIA FrameworkThe Investigate routine provides students with an opportunity to explore the key ideas of science, to plan and conduct an investigation, and to gather and record data. The investigations are designed to systematically develop content knowledge and skills through increasingly complex processes of structured inquiry, guided inquiry and open inquiry approaches. Students are encouraged to process data to identify trends and patterns and link them to the real-world context of the teaching sequence.
When designing a teaching sequence, consider the diagnostic assessment (Launch phase) that identified the alternative conceptions that students held. Are there activities that challenge these ideas and provide openings for discussion? What content knowledge and skills do students need to be able to complete the final (Act phase) task? How could you systematically build these through the investigation routines? Are there opportunities to build students’ understanding and skills in the science inquiry processes through the successive investigations?
Read more about using the LIA FrameworkA view through water
Students work in collaborative learning teams to investigate what happens to a pencil when it is viewed:
- through an empty clear plastic cup.
- through a plastic cup that is ¾ full with water.
One student holds the pencil behind the cup and moves it so that students can view the pencil:
- in the middle of the cup.
- at each side of the cup, noting what happens while the pencil moves from side to side.
- as it is brought closer and moved further away from the cup.
Teams record their observations as labelled diagrams in their science journals.
The Inquire phase allows students to cycle progressively and with increasing complexity through the key science ideas related to the core concepts. Each Inquire cycle is divided into three teaching and learning routines that allow students to systematically build their knowledge and skills in science and incorporate this into their current understanding of the world.
When designing a teaching sequence, it is important to consider the knowledge and skills that students will need in the final Act phase. Consider what the students already know and identify the steps that need to be taken to reach the level required. How could you facilitate students’ understanding at each step? What investigations could be designed to build the skills at each step?
Read more about using the LIA FrameworkFollowing an investigation, the Integrate routine provides time and space for data to be evaluated and insights to be synthesized. It reveals new insights, consolidates and refines representations, generalises context and broadens students’ perspectives. It allows student thinking to become visible and opens formative feedback opportunities. It may also lead to further questions being asked, allowing the Inquire phase to start again.
When designing a teaching sequence, consider the diagnostic assessment that was undertaken during the Launch phase. Consider if alternative conceptions could be used as a jumping off point to discussions. How could students represent their learning in a way that would support formative feedback opportunities? Could small summative assessment occur at different stages in the teaching sequence?
Read more about using the LIA FrameworkWhat did you observe?
Share student observations.
- What did you observe before water was added?
- What did you observe after water was added?
- What happened when you viewed the pencil directly behind the container?
- It was magnified.
- Can you think of some other objects that magnify?
- Eye glasses, magnifying glass, telescope.
- What happened when you viewed the pencil through the curved edge of the container?
- It disappeared.
- Why do you think that happened?
Record students’ observations and ideas in the class science journal.
The Inquire phase allows students to cycle progressively and with increasing complexity through the key science ideas related to the core concepts. Each Inquire cycle is divided into three teaching and learning routines that allow students to systematically build their knowledge and skills in science and incorporate this into their current understanding of the world.
When designing a teaching sequence, it is important to consider the knowledge and skills that students will need in the final Act phase. Consider what the students already know and identify the steps that need to be taken to reach the level required. How could you facilitate students’ understanding at each step? What investigations could be designed to build the skills at each step?
Read more about using the LIA FrameworkIdentifying and constructing questions is the creative driver of the inquiry process. It allows students to explore what they know and how they know it. During the Inquire phase of the LIA Framework, the Question routine allows for past activities to be reviewed and to set the scene for the investigation that students will undertake. The use of effective questioning techniques can influence students’ view and interpretation of upcoming content, open them to exploration and link to their current interests and science capital.
When designing a teaching sequence, it is important to spend some time considering the mindset of students at the start of each Inquire phase. What do you want students to be thinking about, what do they already know and what is the best way for them to approach the task? What might tap into their curiosity?
Read more about using the LIA FrameworkHow does light travel through water?
Review what students have learned about light, how it travels and how it helps us to see.
Discuss with students: If light helps us to see objects, then what is happening to the light rays in the water before they reach our eyes to make the bottom of the pencil disappear?
Pose the question: What happens to light when it travels through water?
The Inquire phase allows students to cycle progressively and with increasing complexity through the key science ideas related to the core concepts. Each Inquire cycle is divided into three teaching and learning routines that allow students to systematically build their knowledge and skills in science and incorporate this into their current understanding of the world.
When designing a teaching sequence, it is important to consider the knowledge and skills that students will need in the final Act phase. Consider what the students already know and identify the steps that need to be taken to reach the level required. How could you facilitate students’ understanding at each step? What investigations could be designed to build the skills at each step?
Read more about using the LIA FrameworkThe Investigate routine provides students with an opportunity to explore the key ideas of science, to plan and conduct an investigation, and to gather and record data. The investigations are designed to systematically develop content knowledge and skills through increasingly complex processes of structured inquiry, guided inquiry and open inquiry approaches. Students are encouraged to process data to identify trends and patterns and link them to the real-world context of the teaching sequence.
When designing a teaching sequence, consider the diagnostic assessment (Launch phase) that identified the alternative conceptions that students held. Are there activities that challenge these ideas and provide openings for discussion? What content knowledge and skills do students need to be able to complete the final (Act phase) task? How could you systematically build these through the investigation routines? Are there opportunities to build students’ understanding and skills in the science inquiry processes through the successive investigations?
Read more about using the LIA FrameworkLight through water investigation
Demonstrate how to cut a small slit, approximately 2-3mm wide, in a piece of card. Then demonstrate how this slit in the card can be used to focus the beam/ray of light, making it easier to follow.
Discuss what is meant by the term ‘bird’s eye view’: to view something from above.
Using the Line of light investigation planner Resource sheet, students work in collaborative teams to investigate what happens when a beam of light travels through water. In this investigation students will focus the light ray using the slit in the card, then:
- shine the light ray through an empty glass.
- shine the light ray through a glass that is 3/4 full with water.
- draw a labelled ray diagram, from a bird's eye view, to illustrate their observations.
Students should not complete the Explaining results section of the sheet at this stage—this will be done at the end of the Integrate step of this lesson.
The Inquire phase allows students to cycle progressively and with increasing complexity through the key science ideas related to the core concepts. Each Inquire cycle is divided into three teaching and learning routines that allow students to systematically build their knowledge and skills in science and incorporate this into their current understanding of the world.
When designing a teaching sequence, it is important to consider the knowledge and skills that students will need in the final Act phase. Consider what the students already know and identify the steps that need to be taken to reach the level required. How could you facilitate students’ understanding at each step? What investigations could be designed to build the skills at each step?
Read more about using the LIA FrameworkFollowing an investigation, the Integrate routine provides time and space for data to be evaluated and insights to be synthesized. It reveals new insights, consolidates and refines representations, generalises context and broadens students’ perspectives. It allows student thinking to become visible and opens formative feedback opportunities. It may also lead to further questions being asked, allowing the Inquire phase to start again.
When designing a teaching sequence, consider the diagnostic assessment that was undertaken during the Launch phase. Consider if alternative conceptions could be used as a jumping off point to discussions. How could students represent their learning in a way that would support formative feedback opportunities? Could small summative assessment occur at different stages in the teaching sequence?
Read more about using the LIA FrameworkWhat happened?
Using the QCER framework as a guide, invite each team to share their results. Reiterate the question that each team has answered: What happens to light when travels through water? Teams share their observations and possible explanations for what happened.
Using a demonstration copy of the Exposing the illusion Resource sheet, introduce the three claims and the accompanying ray diagrams that potentially explain what happened to the beam of light as it travelled through the water:
- The light is reflected by the glass and does not reach my eyes.
- The light reflected by the pencil bends when it goes from air to water and does not reach my eyes.
- This is the most accurate explanation. Read the accompanying professional learning Refraction of light through water for further explanation.
- The light reflected by the pencil gets trapped inside the glass and does not reach my eyes.
Discuss each claim with students and determine which claim they think is best supported by the evidence they collected. Record this claim in the class science journal.
Introduce the term ‘refraction’ as the scientific term to explain what is happening when light travels through water. Explain that light travels at different speeds as it is transferred through different transparent materials such as air, water and plastic. As the light changes its speed where the two materials meet, it changes the angle which the light travels.
Students revisit their Line of light investigation planner Resource sheet and complete the explaining results section.
Reflect on the lesson
You might:
- add new words and images to the word wall or glossary.
- add to the W and H sections of the TWLH chart.
- discuss how the learning from this lesson will be relevant to building their light sculptures at the end of the sequence. If parts of their sculpture will be viewed through transparent materials other than air, what impact might this have?
- Optional Low Tech: Use a ‘fishing rod’ made of string with a magnet attached to catch metal weights in the bottom of a bucket of water. The refraction (bending) of light can mean the fish appear closer to the person than they really are. If the person is directly above the bucket, then the difference is less noticeable.
Refraction of light through water
What happens when light travels through water?
Transparent materials, such as air, water and glass, allow light to transmit through them to see objects beyond them. Sometimes objects appear distorted when viewed through transparent materials, for example, a straw in a glass of water. The distortion is caused when light is transmitted through two different transparent materials, such as air and water. This can change the angle of the light slightly where the two surfaces meet in a process called refraction. In the wave model, refraction occurs because the wave travels at different speeds through the two transparent materials.
During this lesson, students investigate the direct effect that water has on light by directing a thin beam of light through a glass of water. Light passes through the centre of a clear plastic cup of water with little refraction. This allows the whole pencil to be seen. The convex shape of the water in the cup can also magnify objects by refracting the light reflected by an object before it meets your eyes.
When the light ray enters the curved surface of the side of the cup, it will be refracted (change angle) slightly as it enters and leaves the water (light travels slower through water than through air).
An object might appear to disappear if it is positioned behind the curved edge of the cup because the light reflected by the object is bent in another direction and does not meet your eyes.
Thus, it is the second of the claims presented in the Exposing the illusion Resource sheet that is the most accurate explanation of what is happening.
The first claim is contradicted by the evidence, because in the accompanying diagram, the beam of light does not travel through the water, meaning we would not be able to see the pencil at all.
The third claim is also contradicted by the evidence, because in the diagram the light is trapped inside the glass, meaning we would also not be able to see the pencil even if we changed our viewing position.
Refraction has some important uses, for example, in eyeglasses to correct focus so objects don’t appear blurred. The convex shape of the magnifying glass refracts the light so that an object appears larger than if it were to be viewed through air alone.
Transparent materials, such as air, water and glass, allow light to transmit through them to see objects beyond them. Sometimes objects appear distorted when viewed through transparent materials, for example, a straw in a glass of water. The distortion is caused when light is transmitted through two different transparent materials, such as air and water. This can change the angle of the light slightly where the two surfaces meet in a process called refraction. In the wave model, refraction occurs because the wave travels at different speeds through the two transparent materials.
During this lesson, students investigate the direct effect that water has on light by directing a thin beam of light through a glass of water. Light passes through the centre of a clear plastic cup of water with little refraction. This allows the whole pencil to be seen. The convex shape of the water in the cup can also magnify objects by refracting the light reflected by an object before it meets your eyes.
When the light ray enters the curved surface of the side of the cup, it will be refracted (change angle) slightly as it enters and leaves the water (light travels slower through water than through air).
An object might appear to disappear if it is positioned behind the curved edge of the cup because the light reflected by the object is bent in another direction and does not meet your eyes.
Thus, it is the second of the claims presented in the Exposing the illusion Resource sheet that is the most accurate explanation of what is happening.
The first claim is contradicted by the evidence, because in the accompanying diagram, the beam of light does not travel through the water, meaning we would not be able to see the pencil at all.
The third claim is also contradicted by the evidence, because in the diagram the light is trapped inside the glass, meaning we would also not be able to see the pencil even if we changed our viewing position.
Refraction has some important uses, for example, in eyeglasses to correct focus so objects don’t appear blurred. The convex shape of the magnifying glass refracts the light so that an object appears larger than if it were to be viewed through air alone.