Hi, everyone.

Welcome to this science lesson.

I'm really excited and glad you decided to join me today.

So, we're going to be learning about changing the direction of light and the impact that it has.

We've got lots of learning to do today, so let's get started with the lesson.

So, the outcome for our lesson today is I can explain how reflective materials are used to change the direction in which light travels.

So, we're going to think about some keywords in our lesson today.

So you may have heard of these words before or you may have used them earlier in this topic.

So, we've got a few words here.

Reflected, direction, model, angle, and periscope.

So, don't worry too much if you're not too sure about these words 'cause we're going to talk through all of them in today's lesson.

We've also got some definitions here.

So what I'd like you to do is pause the video here, and with your talk partner, have a go at taking in turns to read the definitions.

Once you have completed that, I would like you to click play and continue with the lesson.

Great job, everyone.

Well done.

So, our lesson today is split up into two parts.

So we're first going to think about reflected light changes direction, and then we're going to think about how light can travel around corners.

So, let's get started with the first part of the lesson.

So, Aisha and Sam are talking about what happens when light from a light source reaches the surface of an object.

Sam says, "I think light hits an object then stays on the object to make it look bright." And Aisha says, "I think light hits an object and then bounces off the surface of the object." What do you think? Do we think Sam is correct? Do we think Aisha is correct? Or do you think something else? Great job, everyone.

Well done.

So, when light hits an object, it bounces, or is reflected, off the object's surface.

So, light reflecting off the surface of an apple.

So, if we have a look at this diagram here.

So, we've got the sun, we've got an apple, which is the object, and the black arrows there show how the light is reflected.

What do you notice about what happens to the reflected light? So look carefully at the diagram.

What do you notice about it? Great job, everyone.

Well done.

So, the arrows on the diagram show that light travels towards the object and then is reflected away from the object.

And this is what Sam has observed.

When light is reflected off a surface, it changes direction.

So, we can see here the light from the sun hits the object, but then actually is reflected.

We can model light using a tennis ball and a wall.

If you roll a ball against a wall, it bounces off and travels in a different direction.

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

So, if we're rolling the tennis ball and it hits the wall, it's actually going to bounce off and travel in a different direction.

This is similar to light.

So, we've often used different models and analogies and diagrams to help us understand scientific concepts.

So, if you change the angle which the light hits the surface, the angle of reflection will also change.

So, you've got an aerial view of a ball rolling against a wall at a wide angle.

And another diagram here, an aerial view of your ball rolling against a wall at a narrow angle.

So, the angle at which the is hitting the wall is different in both of these diagrams. So, will the ball roll away from the wall at the same angle each time? Hands up for yes.

Hands up for no.

Great job, everyone.

Well done.

Let's do a quick check of our learning.

When light is reflected off the surface of an object, A, it changes direction, B, it travels through an object, C, it continues in the same direction.

If you need to, go back to some of the earlier slides in the lesson just to double-check your learning.

What do you think? A, B, or C? Great job, the answer is A, it changes direction.

Let's move on to the next question to check our learning.

True or false? Rolling a tennis ball against a wall is a scientific diagram to help us understand what happens when light is reflected off surfaces.

Do we think that's true or false? Great.

The answer is false.

Let's think about justifying our answer.

So, do we think it's because A, tennis balls do not reflect light, so cannot help us to understand reflected light? Or B, rolling a tennis ball is a scientific model to help us understand reflected light? Well done.

The answer is B.

So, let's move on to the first task of today's lesson.

So, model and observe reflection.

So, the first part is to model the way light is reflected off surfaces using a tennis ball.

Experiment by rolling the ball against the wall to see how its direction changes.

So, this is essentially the diagram of what you're going to be doing practically.

So, use a tennis ball, and I would like you to roll the ball against the wall to see how its direction changes.

Now try rolling a ball towards the same point on the wall from different angles.

What happens? What do you notice? And then, I would then like you to use this to explain to somebody else how light is reflected.

You may want to record yourself doing the explanation, or you may want to write down some sentences.

But pause the video here, have a go at modelling the way light is reflected, so using that tennis ball on the wall, but also having a go at explaining how light is reflected.

If you need to, go back to some of the earlier slides just to ensure you have a good understanding before you complete today's task.

Off you go, and we'll go through an example answer really soon.

Great job, everyone.

Well done.

So, let's look at an example answer.

So, when I rolled the ball straight towards the wall, it bounced back to me along the same line.

When I rolled it from a wider angle, it bounced away at a wider angle in the opposite direction.

I think this might be what light does when it is reflected off the surface of an object and changes direction.

Did you get something similar to this in your explanation or did you do something a little bit different? Well done for having a go, 'cause it was quite tricky to explain what you saw.

So, the next part of the task is to observe reflection.

So, I would like you to darken the room.

So, turn the lights off and maybe put the blinds down or shut the curtains, and shine a torch against a mirror and find the direction of the reflected beam.

You can do this by identifying a surface that the reflected beam hits.

So, let's look at this example.

We've got a torch and we've got a mirror.

So, have a go at following these steps to observe reflection.

Then, I want you to try again at wide angles and narrow angles.

What happens? What do you notice? Off you go.

Super job, everyone.

Well done.

So, let's look at some examples.

So, the first example says here we've got a mirror and a torch and a reflected light.

When I held the torch under the mirror facing upwards, the light was reflected down to the floor.

And in the second example, we've got the reflected light, the torch, and the mirror.

When I held the torch above the mirror facing downwards, the light was reflected up to the ceiling.

Did you see these things as well or did you see something a little bit different? Well done for having a go.

Another example here.

We've got the torch, a mirror, and reflected light.

When I held the torch facing the mirror, the light was reflected back onto the wall.

And the next example.

When I held the torch at a wide angle to the left of the mirror, the light was reflected at a wide angle on the wall to the right of the mirror.

Did you find the same, or did you find something different? Well done for having a go at completing this task.

I know that it was a little bit tricky and you had to explore using the torch and the mirror, but fantastic work, everybody.

I'm so impressed.

So, we're now going to move on to the second part of the lesson today.

So, we're going to think about how light can travel around corners.

So, mirrors are highly reflective.

They are used to help us see things.

Remember, we only see things if light reflects off them into our eyes.

When we look at things in mirrors, we are looking at light reflected off the object onto the mirror and then reflected off the mirror to our eyes.

So, we've got different things.

We've got an eye, the mirror, a book, and a light source.

So, the light source hits the book, then to the mirror, and then we can see with our eyes.

So we got the light source, the book, the mirror, and also the eye.

Can you explain how we use car mirrors to see what's happening behind us? So, in a car, we have a range of different mirrors to help us drive.

So, we've got a rearview mirror in a car, and we've also got a wing mirror in a car.

So, pause the video here and have a think with your talk partner.

Can you explain how we use car mirrors to see what's happening behind us? Have a think.

Great job, everyone.

Well done.

So, light travels from the sun to the object, which in this case, if we're thinking about cars, would be a car behind us.

And the light is reflected off the object, and in this case, it's the car to the mirror.

And then, the light is reflected off the mirror into our eyes.

There's quite a few different steps there.

Well done, everyone, for having a go at this question.

Let's do a check of our learning.

Which of the following shows the pathway of light that allows us to see a car behind us in a rearview mirror? Is it A, sun, car behind, rearview mirror, our eyes? B, our eyes, rearview mirror, car behind, or sun? Or C, sun, rearview mirror, our eyes? If you need to, go back to the last couple of slides to refresh your memory.

Have a think about the answer to this question.

Which of the following shows the pathway of light that allows us to see a car behind us in a rearview mirror? Have a think.

Excellent work, everybody.

The answer is A.

So if we go from sun to the car behind, the rearview mirror, and then to our eyes.

Well done, everyone.

So, we know that light travels in straight lines and we know that light does not curve around corners.

So, can we use a reflection to make a light travel around corners? Have a think with your talk partner.

How can we use a reflection to make a light travel around corners? Have a think with your talk partner and jot down some of your ideas.

Excellent work, everyone.

Well done.

So, because mirrors are highly reflective, they are sometimes used deliberately, that means on purpose, change the direction of a beam of light.

If you position a mirror opposite a corner, the beam hits the mirror and is reflected in a different direction.

Reflected light can be used to help us see things around corners.

If we position mirrors carefully, we can see objects which are around corners.

So, only if the mirrors are positioned in this particular way would we be able to see the objects that are around corners.

So, we can see here the light source going to the book, bouncing off the mirror, and that's how we're able to see the object.

A periscope is a piece of equipment designed to help people see around corners or over walls.

Has anyone seen a periscope before? Wow, well done.

So, it is a tube containing mirrors arranged at the correct angle to reflect light to your eye.

So, a periscope can be used for lots of different things and are quite commonly used in submarines and armoured vehicles.

So, how would periscopes be useful in these examples? Have a think with your talk partner and maybe jot down some ideas on a whiteboard.

How would periscopes be useful in these two examples? In a submarine, but also in an armed vehicle.

So, how would periscopes be useful here? Great job, everyone.

Well done.

So, periscopes can also be handheld.

So, periscopes are a great way to be able to see, at a distance, see what's happening around you without being seen yourself.

So, let's have a go at this question.

What is the name of the piece of equipment designed to help people see around corners or over walls? A, a portascope.

B, an optiscope.

C, a periscope.

Or D, a mirrorscope.

So, have a think about the learning we've just completed.

Which piece of equipment is designed to help people see around corners or over walls? Great job, everyone.

The answer is C, a periscope.

Let's move on to our next question.

Which of these diagrams correctly shows light reflected by mirrors? So, look really carefully at these diagrams. They do look quite similar, but they are all a little bit different.

So, we've got A, B, and C.

So, which of the diagrams correctly shows light reflected by mirrors? Pause the video here, come up to the screen a little bit closer so you can see a little bit better.

Think really carefully and look really closely.

Off you go.

Great job, everyone.

The answer is A.

So, let's go unto our next task.

So, the first part of this is I would like you to set up a mirror maze to make a beam of light hit a target.

So, lay a torch flat on a large piece of paper pointing towards the middle.

Put your target somewhere else on the paper, not in line with the torch.

So, in this example, they've used a toy car, and that's their target.

But actually, you can use any other object.

Using mirrors to change the direction of the beam of light so that it shines on your target.

So, you'll need a few different mirrors.

And using these mirrors, you'll be able to change the direction of the beam of light so that it shines on your target.

So, we've got an example diagram here to help you.

Then, I would like you to draw a diagram directly onto your paper to show your mirror maze.

So, pause the video here and I'll give you a little bit of time now to set up your mirror maze.

And you may need to play around with some of the positions of the mirrors a little bit before you can direct the beam of light so that it shines on your target.

To help your mirror stick up, maybe you can have some sticky tack to place on the paper so that your mirror can stand up.

You may want to complete this in small groups or in pairs.

Have a go at completing the mirror maze.

And remember, once you've done this, draw a diagram directly onto your paper to show your mirror maze.

Have a go.

Super job, everyone.

Well done.

I'm so impressed with all your mirror mazes.

I know it was a little bit tricky and it may have taken a little bit of time to move around some of your mirrors, but I'm so pleased with all the work you have done and that you've persevered with this task.

So, you may have set up your maze like this.

So, we've got the torch, we've got our paper, and we've got three different mirrors here.

And we can see the light beam is reflecting and would light up the toy car.

The light might have reflected like this or you might have designed a different mirror maze.

So, were yours similar to this, or was your maze a little bit different? Maybe what you can do within your class, you can compare your maze to another group's.

Did you have things that were similar or did you have things that were different? Well done for having a go at this task.

As I said, I know it was a little bit tricky.

The next part of the task was to draw a diagram onto your paper to show your mirror maze.

And your diagram might have looked like this.

So, on our paper here, we've got our diagram to show where the mirrors are, where the toy car, which was the target, where the torch was, and where the light beam has been reflected.

Was your diagram similar or was it a little bit different? Well done for having a great go at this task.

So, we've now come towards the end of today's lesson all about changing the direction of light.

So, we've learned that when light is reflected off the surface of an object, it changes direction.

And we can use scientific diagrams and models and they can be used to show how light travels in straight lines and enters the eye.

And mirrors are sometimes used to deliberately change the direction of a beam of light.

And if we're deliberately changing something, that means we're doing it on purpose.

And a periscope has angled lenses or mirrors to enable you to see over walls or around corners.

And we saw earlier in the lesson that periscopes are used as part of armoured vehicles but also as part of submarines as well, because they'll be able to see over walls and around corners.

So, well done for all of your work today.

You've worked incredibly hard and you've shown a really good understanding of the direction of light and how this can be changed.

I'm so impressed with all of your work.

So, well done, everyone.

I hope you have a great rest of the day and I'm sure I'll see you very soon in the next science lesson.

Bye-bye.