Hello and welcome to today's lesson.

My name is Mrs. Mehrin, and I'm so excited to learn all about how shadows form with you.

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

Your learning outcome for today is: I can explore the size, colour, and features of a shadow, and compare shadows to reflections of objects.

Now we are going to be touching on some of your previous learning about why shadows are formed.

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

Here are your keywords for today.

Now, I am going to be referring to all of these words throughout today's lesson, so you don't need to write them down, but if it does help you to write them down and have them next to you, that's fine.

You can pause the video here and you can do that now.

Off you go.

Fabulous, well done.

And here are all of the definitions for today's keywords as well.

Again, I'm going to be referring to these throughout today's video, so you don't need to pause the video here and write them down, but if it does help you, you can do so.

Fabulous, well done.

Now our lesson today is split into three sections.

Let's begin with the first one, how shadows are formed.

Shadows are everywhere, but what are they? I'll give you five seconds to think about your answer.

If you need longer, you can pause video here.

Off you go.

Fantastic, well done.

So light travels away from a light source until it meets an object.

And shadows are dark shapes that form when some or all of the light is blocked by an object, just like in this picture here.

Now Aisha says, "There was no shadow a moment ago, but when I put my water bottle on the desk, a shadow appeared." Just like this in this picture.

And she's asking why.

So I'll give you five seconds to think about why this shadow has appeared as soon as she's put her water bottle on the desk.

If you need longer, you can pause the video here.

Off you go.

Fabulous, well done.

So when an object blocks out light travelling from a light source, a shadow is formed.

Now, different materials and objects let different amounts of light travel through them.

Some of them let all light travel through them, some of them let some of the light travel through but not all of it, and some don't let any light travel through them at all.

And Jacob says, "I can't remember the words used to describe these physical properties." Can you help Jacob? Can you remember what some of those words were that I used to describe those physical properties above? I'll give you five seconds to think about your answer.

If you need longer, you can pause the video here.

Off you go.

Fantastic, well done.

So we have got transparent materials, and they let all light travel through.

We have translucent materials, and they let some light travel through.

And we have opaque materials, and they do not let any light travel through.

Now, which of these types of material do you think cast shadows? So again, 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.

So translucent and opaque objects do create shadows.

So objects made from translucent materials, such as the plastic jug, they cast lighter shadows because some of the light can still pass through.

And objects made from opaque materials, such as this ceramic jug, cast dark shadows because all of the light is being blocked.

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

A shadow is a dark shape made, A, only when the sun is blocked by natural objects; B, only in bright light; or C, whenever light is stopped or blocked by an object.

So I'll give you five seconds to think about your answer.

If you need longer, you can pause the video here.

Okay, off you go.

Fabulous, well done.

The answer is C.

So whenever light is stopped or blocked by an object is when a shadow is made.

Which type of objects or materials do not let any light pass through them? Is it translucent, opaque, or transparent? So again, I'll give you five seconds to think about your answer, but if you need longer, you can pause the video here.

Okay, off you go.

Fabulous, well done.

It's opaque.

Now here is your first activity.

It says, use a torch or natural sunlight to cast shadows and make notes about what you observe.

So for each shadow, I want you to record its size, its colour, and anything else interesting that you observe when you are casting these shadows.

And I want you to work like a scientist.

I want you to explore different transparent, translucent, and opaque objects and materials.

So I don't want you to just use the same type of materials or just use opaque objects or just translucent.

Try mixing it up and see what results you get from that.

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

Off you go.

Fabulous, well done.

So these are notes that you may have made similar notes to.

So let's have a look.

The shadow from my reading book was rectangular, black, and had very clear edges.

I could change the length of my shadow by moving the torch.

The shadow of my partner's head did not have any features on it, such as eyes, nose, and mouth.

The shadow from my translucent pencil case was the same shape as the pencil case, but not a dark shadow.

So now we are on to the second part of our learning today, what shadows look like.

So Aisha, Jacob, and Lucas made observations about shadows.

Aisha said, "All shadows were the same colour." Jacob said, "The shadow shows the smiley face printed on my drinks bottle." And Lucas says, "An object always makes the same size shadow." Do you agree? So I'll give you five seconds now to think about your answer.

If you need to, you can pause the video here.

Off you go.

Okay, so Aisha was wrong.

She said that all the shadows were the same colour.

Now I want you to have a look at this picture.

Are these shadows the same? I'll give you five seconds to think about your answer, but if you want to pause the video and you want to have a better look at this, that's absolutely fine, you can do so, and you can come back once you're ready.

Okay, off you go.

Fantastic, well done.

So all shadows are dark, but they're not all the same colour.

So here we have a puppet that was cut out of translucent plastic and a puppet that was cut out of opaque cardboard.

And opaque objects make darker shadows than translucent objects, because translucent objects, they let a little bit of light through.

Now Jacob was incorrect as well because he said, "The shadow shows the smiley face printed on my drinks bottle." So what is the difference between the wooden cow and the shadow of the wooden cow? Again, I'll give you five seconds to think about your answer, but if you need longer, that's absolutely fine, you can pause the video here.

Okay, off you go.

Fabulous, well done.

So shadows don't show the features of objects, they just show the shape.

So if you look at this wooden cow, you can see the detailing on the wooden cow.

You can see the flowers on the ribbon that's attached to the bell.

You can make out the spots and you can see lots more detail.

However, on the shadow, you can't make out what colour it is.

You can't tell that the wooden cow is brown.

You can't see any of its spots.

You can't see any of those extra details.

It just shows you the shape.

And Lucas was incorrect as well because he said an object always makes the same size shadow.

Now I want you to look at these two pictures.

Are the shadows the same in these pictures? Again, I'll give you five seconds to think about your answer, but if you need longer, it's absolutely fine.

Just pause the video and come back once you are ready.

Okay, off you go.

Fabulous, well done.

So not all shadows are the same size.

The size of a shadow depends on the distance between the light and the object.

Now I want you to have a look at these two pictures here and I want you to explain to a partner what the pattern is between the distance from the light source and the size of the shadow.

So have a really good look at this and I'd like you to pause the video here whilst you have that discussion with your partner.

Off you go.

Fabulous, well done.

So you may have said things like this.

You may have said that the greater the distance between the light source and the object, the smaller the shadow was.

And you may have said that the shorter the distance between the light source and the object, the larger the shadow was.

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

Which of these items below would form the darkest shadow? Would it be A, B, or C? So which one is going to form the darkest shadow? So I'll give you five seconds to think about your answer.

If you need longer, that's absolutely fine.

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

Okay, off you go.

Fabulous, well done.

So opaque objects cast the darkest shadows because they don't let any light through.

Now let's have a look at this one.

It says, in which setup would the dog have the largest shadow? So think about what we've learned so far, think about what you discussed with your partner.

Which of these is going to show the largest shadow of the dog? So again, I'll give you five seconds to think about your answer.

If you think you're going to need longer, that's fine.

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

Okay, off you go.

Fabulous, well done.

So it would be A because the shorter the distance is between the light source and the object, then the larger the shadow is going to be.

Now, Aisha, Jacob, and Lucas are discussing why the shadow is larger when objects are closer to the light source.

Aisha says, "It's because the object blocks out more of the light when it's closer to the light source." Jacob says, "It's because the object blocks out less of the light when it's closer to the light source." And Lucas says, "It's because the light is brighter closer to the light source." Now I want you to think about this.

Who do you agree with and why? So I want you to pause the video here and just have a think.

Who do you agree with and why do you agree with them? Okay, off you go.

Fabulous, well done.

So out of all of them, it's Aisha who's correct because she said it's because the object blocks out more of the light when it's closer to it, which makes that shadow seem so much bigger.

Now we are onto the final part of your learning today, which is shadows and reflections.

So Laura and Lucas are talking about shadows and reflections, and Laura says, "Shadows and reflections are different words, but they're the same thing." And Lucas says, "They both happen when light is blocked by an object." Now, do you agree with these statements? I want you to have a really good think about this.

I'll give you five seconds to think about your answer, but if you need longer, just pause the video here.

Okay, off you go.

Fabulous, well done.

So Laura and Lucas are not correct.

Sofia tries to help them by showing them a shadow and a reflection of the same object.

So she shows them this.

Now she's got the reflection of a wooden cow and the shadow of a wooden cow.

And I want you to think, what differences are there between the reflection and the shadow? So think about what you already know about shadows and then think about what you know about reflections and have a really good look at this picture as well, that's really going to help you with this question.

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

Off you go.

Fabulous, well done.

So Sofia explains that shadows and reflections of objects are not the same thing.

Shadows happen when light is blocked by an object, and reflections happen when light is reflected off an object to a shiny surface and then off the surface into someone's eye.

And she adds that shadows form where the light has been blocked out, but reflections are usually the same colour as the object.

And shadows don't show the features of the object, but reflections do.

Because if you look here in the window in this reflection of the wooden cow, I can see the colour it is.

I can tell that it's brown.

I can see that it's made out of wood.

I can see those flowers on the ribbon around the cow's neck.

I can see all the patches as well, so I can really make out those details.

Whereas in the shadow, I just can't do that.

Now let's do a quick true or false.

Shadows of objects are not the same as reflections of objects.

Is that true or false? So I'll give you five seconds to think about your answer.

If you need longer, pause the video here, come back once you are ready.

Okay, off you go.

Fabulous, well done.

The answer is true.

They are not the same.

Now let's see if you can justify your answer.

So is it because A, shadows are caused when light is blocked by objects, but reflections are caused when light bounces off them? Or is it B, shadows are caused when light bounces off them, but reflections are caused when light is blocked by them? So again, I'll give you five seconds to think about your answer.

If you need longer, you can pause the video here.

Okay, off you go.

Fabulous, well done.

The answer would be A, shadows are caused when light is blocked by objects, but reflections are caused when light bounces off them.

Now it says to match the word to the correct description.

So you've got reflection and you've got shadow here.

So think about what the correct definition would be for each of those.

So again, I'll give you five seconds to think about your answer.

If you need longer, just pause the video here.

Okay, off you go.

Fabulous, well done.

The answer is this.

Reflection is an image of something which occurs when light rays bounce off a surface, and the shadow is a dark shape made when something blocks the light.

Now, which of these would you expect a shadow to show? Would it be A, the shape of the object; B, the features of the object; or C, the colour of the object? So again, I'll give you five seconds to think about your answer.

If you need longer, you can pause the video here.

Okay, off you go.

Fantastic.

The answer is A, the shape of the object.

Now here is your last task for today, and it says, make a Venn diagram to show the similarities and differences between shadows and reflections.

So here on the left hand side where it says shadows and the circle is not overlapping, you are going to write things that are features of shadows.

On the right hand side where it says reflections and it's not overlapping with the other circle, you're going to write things that are features of reflections.

And right down the middle where the two circles are overlapping, you are going to write things that are features of both of them.

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

Okay, off you go.

Fabulous, well done.

Now, you may have done something like this.

So in the shadow side you may have put dark and do not show features.

In the reflection side, you may have put same features as objects, same colour as objects.

And right down the middle where they overlap and they would be the same, would be the same shape as object and the size depends on the position of the light source.

Now we are onto the summary of your learning today.

A shadow is formed when light is stopped or blocked by an opaque object.

Opaque objects do not allow light to travel through them.

A shadow can be different sizes depending on the distance between the object and the light source.

Shadows do not show the features of an object.

Shadows of objects are not the same as reflections of them.

Now, you have worked so hard, I'm so proud of you.

You've done lots of new learning, you've really persevered, and you have done brilliantly.

So well done for today.