Opening

BUILD · SCIENCE · Lesson 4 of 10

An object is inside. Why can’t we see it?

Learning intention

Explain why an object needs light reaching it and then the eye to be seen.

The object has not moved.

Find the missing light path.

Success looks like

Identify that light is needed to see.
Explain that light enters the eye.
Distinguish dim light from complete darkness.

Retrieval

BUILD · SCIENCE · Lesson 4 of 10

What do we already know?

1. Name something that gives out light.

2. Can a plain card make its own light?

3. Which sense uses the eyes?

I do

BUILD · SCIENCE · Lesson 4 of 10

I follow the light

The source gives out light.

The object reflects some light.

Some reaches the eye.

Light reaches your eye

Diagram description

A ray travels from the LED source to an object; reflected light then enters an eye. The eye does not send light out.

I do

BUILD · SCIENCE · Lesson 4 of 10

I remove the source

The object is still present.

No light reaches it.

Waiting cannot create light.

No light: no visual information

Diagram description

An unlit LED, an object and an eye have no light-path arrows. This ideal model excludes all other light.

I do

BUILD · SCIENCE · Lesson 4 of 10

I block one part of the path

A card can stop this light.

Ask whether another path remains.

A path can be blocked

Diagram description

An opaque card stops the source-to-object path. No other light source is included in this model.

Continue within this stage’s shared time.

We do

BUILD · SCIENCE · Lesson 4 of 10

The case conference

Go to interactive investigation

Read cases A and B.

What changed?

What stayed in the box?

Constructed teaching evidence
Case	Box conditions	Constructed observation
A	All light openings sealed; torch off	Object not visible
B	Torch lights object; viewing opening clear	Object visible

W1. Which change explains the new view?

My response — say it, sketch on paper or type

Repair the missing light path

Predict each case, then test the model. These are constructed cases, not a live camera view.

Decision 1 of 3

Case A: all light is excluded. What will be visible?

Choose, test, then explain together. Evidence diagrams appear only after your test. Diagram transitions explain the model; they do not represent real elapsed time. Use Pause model to stop transitions and model controls, or your device’s reduced-motion setting. The printed We do activity provides the paper route.

We do

BUILD · SCIENCE · Lesson 4 of 10

Repair the explanation

C: a small light leak; object faintly seen.

D: no light at all; wait one minute.

Which claim needs correcting?

W2. Why are C and D different?

My response — say it, sketch on paper or type

Hinge

BUILD · SCIENCE · Lesson 4 of 10

What makes seeing possible?

Choose the best explanation.

You do

BUILD · SCIENCE · Lesson 4 of 10

Choose your investigation route

Match the cases.

Explain the light path.

Diagnose a leaky box.

My response — say it, sketch on paper or type

You do

BUILD · SCIENCE · Lesson 4 of 10

Use the evidence

Read or point to one clue.

Record what it supports.

Keep your explanation short.

My response — say it, sketch on paper or type

Continue within this stage’s shared time.

You do

BUILD · SCIENCE · Lesson 4 of 10

Make your own science record

Complete your chosen route.

Use a diagram, words or speech.

Check one answer with the evidence.

My response — say it, sketch on paper or type

You do

BUILD · SCIENCE · Lesson 4 of 10

Check and improve

Does my answer match the evidence?

Have I explained why?

Improve one label or sentence.

My response — say it, sketch on paper or type

Continue within this stage’s shared time.

Review

BUILD · SCIENCE · Lesson 4 of 10

Lundy loop: improve our account

Choose how to share one idea.

Listen to another explanation.

Use evidence to improve our account.

What must our explanation include?

My response — say it, sketch on paper or type

Exit

BUILD · SCIENCE · Lesson 4 of 10

Three quick checks

E1. What do we need in order to see?

E2. Does light enter or leave the eye when we see?

E3. Can we see an object with no light at all?

My response — say it, sketch on paper or type

My science task sheets

Choose one route with your teacher. Shared evidence and the exit sheet appear in every route. Your work stays here while the page is open; save it before closing.

Evidence: four box cases

Constructed teaching cases. The same non-glowing white object stays inside.

A • Light sealed out

Torch off. No light enters. Object is not visible.

B • Torch lights the object

Torch on, aimed at the object. The viewing path is clear. Object is visible.

C • A small light leak

Torch off, but some room light enters. The object is faintly visible.

D • Wait in no light

No light enters. After one minute the object still cannot be seen.

W1. Compare A and B. What changed?W2. Explain why C is different from D.

Route 1 • Find the light

Use cards A–D. Word bank: light / object / eye / darkness.

S1. In which case is the object clearly visible? A B

S2. Complete: We need __ to see.S3. Add arrows to show the order: source → object → __.

S4. A place has a little light. Is it dim or completely dark? Dim Completely dark

S5. Explain why waiting does not make D visible.

Route 2 • Explain the evidence

Make a short record from the case cards.

Task	Case	Why is the view different?
T1	A
T1	B
T1	C
T1	D

T2. Draw and label a light path that lets us see the object.T3. A pupil says the object disappears in A. Correct the claim.

Route 3 • Diagnose a leaky box

A team says its box has no light. They can still faintly see a white object.

X1. Explain why their observation challenges their no-light claim.X2. Suggest one possible route by which light enters.X3. Predict what happens if that route is fully blocked and no other light enters.X4. Explain why identifying the object by touch is not evidence that it can be seen.

Exit and reflection

Point, draw, write or tell an adult.

E1. What do we need in order to see?E2. Does light enter or leave the eye when we see?E3. Can we see an object with no light at all?R1. Which idea did you improve after hearing evidence?R2. What would you investigate or ask next?