Hello, my name is Mrs. Merin and I'm so excited to be learning all about reflected light with you.

We are going to do brilliantly.

Welcome to today's lesson from the unit light and how it travels.

Your lesson outcome for today is I can explain that we see things when light is reflected from an object into the eye.

Now, I know that learning can be a bit challenging sometimes, but that's okay because it means that we are going to work really hard together and then lots of fabulous new things.

Here is your key words for today.

Now, I am going to be referring to these words throughout the lesson, so you don't need to jot them down, but if it does make it easier for you and you would like to, that's absolutely fine.

You can pause the video here and have a go at writing those down if you would like.

Fantastic, well done.

And here are the definitions for those keywords.

Again, I am going to be referring to these throughout today's lesson, but if you would like to, you can pause the video now and jot them down.

Fantastic, well done.

So our lesson today is split into two parts.

Let's begin with the first part.

Light can be reflected.

So I'd like you to talk to a partner about how we see things.

I'll give you five seconds to discuss with your partner, but if you and your partner need longer, just pop the video on pause and come back when you are ready.

Off you go.

Fantastic, well done.

So we see things when light travels into our eyes and to be able to see something light must travel from that object into our eyes.

So here we have a diagram of a candle and you can see that the candle is the light source and the light from the candle is travelling to the person's eye.

And we can see that the candle is the light source from the diagram because it also shows an arrow pointing towards the eye away from the candle.

So that's another fantastic way that we can do a scientific diagram to show it.

Now we see light sources because the light travels from them into our eyes.

Anything that is not a light source cannot produce light to travel to our eyes.

So for example, this teddy bear is not a light source, but we can see it.

How do you think we are able to see this teddy bear, even though it is not a light source? I'll give you five seconds to think about your answer, but if you need longer, that's fine.

You can pause the video here and come back when you are ready.

Off you go.

Fantastic, well done.

So if an object does not produce its own light, for example, like the teddy bear, we can only see it if light from a light source reflects from the object's surface into our eyes.

So here we have a diagram to show how we see an object that is not a light source.

So the light travels from a light source so in this diagram that would be the sun.

It travels from a light source to the object, which in this diagram is the insect and then into our eyes.

And we can see from this diagram that it's been labelled correctly.

And we can see that the line, that the light source is the sun and that the light is travelling to the insect, which is the object, and then to our eye and the arrows are all pointing the right way as well.

So seeing anything that is not a light source relies on reflection of light.

So if you think about a really dark bedroom where there is no light coming in from either the door or the window, if there is absolutely no light, you cannot see anything in that bedroom.

In order for us to be able to see something in that bedroom, even if it's a little bit dark, there must be some sort of light coming in either from the window or from the door.

Now, light travels in a straight line from a light source.

If it hits a surface, different things could happen.

The light could travel through the surface, or some of the light could be absorbed by the surface.

So in the first example, if the light is travelling through a surface, that surface may be, for example, a window.

Now the light could be reflected by the surface.

So here we've got a candle and the light from the candle is hitting the object.

The light is reflecting off that object and then possibly into our eyes.

So for example, that surface may be a mirror.

So anything that can be seen must either produce or reflect light.

Now, not all surfaces reflect the same amount of light because most surfaces actually absorb some light and they reflect some of the light as well.

So the best surfaces for reflecting light are very smooth, such as glass mirrors or polished metal and both of those things are shiny.

And here we have a picture of a car wing mirror and you can see that the light from other cars is reflecting off this car wing mirror.

Let's do a quick check-in of your learning.

Which of these are needed for light reflection to take place? Is it A, a source of light, B, a mirror, C, the sun, or D, a surface? I'll give you five seconds to think about your answer, but if you need longer, you can pause the video here.

Off you go.

Fantastic, well done.

The answer is A, a source of light and D, a surface.

Well done.

Let's do one more.

It says, "reflection occurs when light travelling towards a surface.

." A, travels through the surface, B, is absorbed by the surface or C, bounces off the surface.

Again, I'll give you five seconds to think about your answer, but if you need longer, just pop the video on pause and come back when you are ready.

Off you go.

Fantastic, well done.

The answer is C, that when it bounces off the surface, that is when reflection occurs.

Now, here is your first task.

It says, "use a ball of string or wool to model how a person sees an object." Aisha says, "I need to think about where the light starts and where it travels to." So the string should represent light travelling from the source to someone's eye.

Now you could take a photo of your model and then annotate it to show what's happening.

So I'd like you to pause the video here and have a go at that activity.

Off you go.

Fantastic, well done.

So you may have created a model like this.

In this picture we have the light source, which is the light bulb.

Now we have string and Aisha has used a ruler to draw this string to make sure that it is a straight line because light travels in straight lines and that line represents the string, which is the light.

Light travels from the light bulb and it's reflected from the book into Aisha's eye.

So that is how Aisha can see the object.

Fantastic work, well done.

So that means that we are now onto the second part of our learning today, which is diagrams can be used to show how we see objects.

So when you look at an object, you can see it because light from its surface is reflected into your eyes.

Our eyes do not produce the light.

Our eyes are not a light source.

Now we can show this using scientific diagrams. So here we have a simple picture of a light source, which is a light bulb, and the straight line here represents the light travelling.

And then we have a simple picture of the eye.

Now the arrow that you can see in the middle, this is called a light ray, and we use light rays in diagrams to represent that the light is travelling.

And this diagram here shows light travelling from a light source into an eye so it's a direct, so it is travelling directly into the eye.

Now when we see things that are not light sources, we can show the path of the reflected light in the diagram.

So here we have the light source and the first light ray shows light travelling from the light bulb to the apple just like this here.

Now how do we see that then? How do we see the apple? Well, what happens is the light from the light source hits the apple.

The apple reflects some of that light.

And then the second light ray now shows the light travelling into our eyes.

And if you look at the light rays, the arrows that are showing the direction of travel here, you can see that they are going in the right direction.

And we put the arrow head in the middle of the line to show the direction that the light is travelling in.

Now Jun has drawn a diagram to show how he sees a bike.

So here we have Jun, we've got Jun's eye, we've got the bike, and then we've got the light source.

Now Jun has made a few mistakes here.

Can you spot what they are? I'd like you now, I'm gonna give you five seconds to have a think about what his mistakes could be.

But if you need longer, you can just put the video on pause and then come back when you are ready.

Off you go.

Fantastic, well done.

So one of Jun's light rays is the wrong way round because in Jun's diagram he's suggesting that his eye is a source of light, which is reflecting off the bike, which isn't true.

So the light source must travel from the light source to the bike then to his eyes.

So the arrow should be pointing in the opposite direction.

The other thing as well is Jun's light rays are not touching the bike.

So that does not scientifically tell us that the light is reflecting off Jun's bike and then into Jun's eye.

They must touch it to show that light reflects off its surface.

Now when you look at an object that is not a light source, you see it because.

A, everything produces light, B, light is reflected from its surface into your eyes, or C, your eyes produce light? I'll give you five seconds to think about your answer, but if you need longer, you can pause the video here.

Off you go.

Fantastic, well done.

The answer is B, light is reflected from its surface into your eyes.

Now let's have a look at this question.

It says, "which of these diagrams correctly shows how we see the hat?" So you are going to need to pause the video here so that you can have a really good look and see which one of those correctly shows how we see the hat.

So pause the video here and then come back once you have your answer.

Off you go.

Fantastic, well done.

So the answer is A.

Now if we have a look at the reasons why the other two are not correct.

Well B, it does show the arrow pointing towards the hat from the light source.

It's travelling from the light source to the hat, which is the correct way around.

But then you can see the arrow is pointing away from the eye and towards the hat, which suggests that the eye is a light source, which we know it isn't.

So if that was the case, then the person would never be able to see the hat.

So B, the arrows on one of them is the wrong way around from the hat to the eye.

Now for C, that one's incorrect because although the arrows are pointing in the right direction, we can see that the lines are not touching the surface of the hat.

Now, here is your second task.

It says "draw, label and annotate a scientific diagram to show how a person uses reflected light to see a book." So here we've got a picture of somebody who's reading a book.

You've got a light source there, you've got the book and you've got the person.

So now you need to create that and make a scientific diagram.

So you need to include a light source, arrows which will represent the path of the light, and you need the person's eye as well.

So in your diagram, your objects should be in two dimensional forms so they should be 2D.

They need to show objects viewed from the side.

They do not need to be coloured in.

So please don't waste any time at all colouring in your objects.

And they should only include objects that are relevant to the science.

Now, don't forget as well that you need to use a ruler to draw your lines because we know that light travels in a straight line.

Now, I would like you to pause the video here so that you can have a go.

Off you go.

Fantastic, well done.

So let's have a look at this example here.

So your diagram may look similar to this.

So we have our light source, which is the light bulb.

We can see that the arrows are pointing in the right direction.

So the light is travelling from the light source to the book.

The lines are touching the surface of the book and the light source and the eye, and we can see that light is being reflected from the surface of the book.

And then the light is travelling into the person's eye.

And we can see that because this person has remembered to draw the arrows in the right direction and they've remembered to draw those lines that show the light rays correctly.

Now what I want you to do is I want you to have a look at your diagram, and I want you to just compare between your diagram and this one.

Is it similar? Have you included all of the things that you were meant to include? Have you made sure it's 2D? Have you ensured that the lines are straight and that the arrows are pointing in the same direction? And do you have all of the three objects there, the light source, the eye, and the book? Just have a really good look at yours and just compare those.

I'll give you five seconds to do that, but if you need to pause the video, you can do here.

Off you go.

Fantastic, well done.

You have worked so hard.

Let's do the summary of your learning today.

We see things when light travels into our eyes.

If something does not produce light, we can only see it if light reflects from its surface into our eyes.

The light travels from a source to the object and then into our eyes.

And scientific diagrams and models can be used to show how we see reflected light.

Now you have done some fantastic learning today.

You've really used your critical thinking and you've learned so much.

You have worked so hard and I'm so proud of you.

Well done.