Lesson video

So our key question is what is light? And that's what we're going to be learning about today.

So in this lesson, you're just going to need three things.

The first thing is a piece of paper or an exercise book.

You're then going to need a pencil or a pen and finally, the most important is you're going to need your brain and your brain is going to have to work really hard in this lesson, so let's give it a little rub so it's ready.

Great job, I think you're all ready to start our science lesson.

So light and dark.

That's what we're going to be learning about today.

You can see here there's two pictures on the slides.

And they are of different sources of light.

The first thing for us to learn and for us to know is that light is a type of energy and light can only travel in straight lines.

So on your screen, you can see a picture of a torch and you can see a picture of a firefly and they are both sources of light.

We're going to have a read together about light and dark here.

Now, what's going to happen is that I'm going to read this passage to you.

You can follow it either with your eyes or sometimes what I find helpful is to point with my pointy finger as somebody's reading, so I'm really clear on where we are.

Light and dark.

Light is a type of energy that travels in a wave from a light source.

A wave of light can only travel in a straight line.

Dark is the absence of light.

Absence means there isn't any.

So something is dark when there is no light, when there is an absence of light.

If there is no light from a light source, it will be dark.

A light source is something that gives light, like the sun, fire or a light bulb.

Some light sources can be turned on and off with a switch, like the light from a television or a torch.

Some animals, such as fireflies and glow-worms, are light sources.

They make their own light to attract mates.

Okay.

So now I'm going to have a go at showing you a few types of light sources.

We heard here that a light source is something that gives out light.

There's a special word, emit.

Your turn.

Emit.

Your turn.

The word emit means to give out.

So a light source is something that emits light.

Light can't be made but it's given out from a light source and it travels in a straight line.

It travels in a? Great job.

So we've read that the sun is a type of light source.

A fire is a type of light source.

And so is a light bulb.

Here you can see I've got a light bulb here and you can see that it's giving out lots and lots of light.

You can see the light on my face as well.

That's how you know this is giving out light.

So that's an example of a light source.

You might also have seen candles around your house.

Perhaps you've seen or perhaps you've seen an adult in your house light a candle before.

The candle itself, when you light it is a light source because it gives off light.

I'm going to have a go at lighting the candle so you can see.

so if I light the candle, and if I wait, then you can see that my candle is giving off light.

Okay, my candle is giving off light, so my candle at the moment is a light source.

Okay? If it were dark in a room and there weren't many other light sources, then I might light a candle to act as a light source so that I can see.

Okay, so we've learnt already that a light bulb or a candle are types of light sources.

I'm going to blow the candle out now so we can continue with the rest of our lesson.

Okay.

So let's go back to our slides, here we go, and we're going to move on to the next slide.

So what I want you to do very quickly, this is a recap question, is you're going to write down the answers to these two questions on your piece of paper.

The first question was what is light? The second question is what is dark? Be careful with the second one.

I want you to write one and two and write down your answers now.

Off you go.

Okay, excellent job, year two.

Well done, let's go over the answers and you're going to tick or fix.

So light, and you might not have written the whole thing but you're going to correct it if you missed anything out.

Light is a type of energy that travels in wave form from a light source.

Okay, so it's a type of energy and it travels in wave form from a light source and we've had a look at two light sources so far.

My light, my bulb and my candle.

Secondly, dark is the absence of light.

My turn, your turn, absence.

Say it one more time, absence.

Absence means there isn't any.

So dark is the absence of light.

When it's dark, that means that there is no light coming from any light source.

Okay, great job with your questions.

I'm sure you did a really good job.

You can pause the video now if you'd like to just tick or fix either of those answers.

Fix meaning just make any corrections that you need to make.

Off you go.

Okay, fantastic, you're doing such a good job and learning so much.

Well done, year two.

Let's move on to have a think about some sources of light.

Now, on my screen here, you can see that I've got lots of different pictures.

Now, some of these pictures are sources of light, they give out light.

Some of these pictures are not sources of light and what you need to do is you need to organise them into sources of light and things that are not sources of light.

The easiest way that I would do this is on your piece of paper, I would write down the name of all of the items, so you'd write down sun, apple, firefly, torch, light bulb, candle, chair and sunglasses.

And next to that word, can you give it a tick if it is a light source and a cross if it's not a light source? A tick if it is a light source and a cross if it's not a light source.

Okay? Have a go at doing that now.

You need to pause the video and do that on your sheet of paper.

Off you go.

Okay, fantastic.

So you should done a tick next to the items, which are light sources that emit and give out light and a cross next to those that don't.

Let's have a look at the answers.

So the sources of light.

You've got the sun, which is a very important source of light, a torch and remember, there you can switch it on and off.

The firefly, a light bulb like the one that we saw in my room, and a candle, also like the one that we saw here as well.

And then those things that are not sources of light.

An apple, a chair and the sunglasses.

The sunglasses was a bit of a trickier one.

The sunglasses are actually there to block light, to block light so that the light doesn't go straight into your eye.

So the source of light would be the sun and the sunglasses are there to block out that light.

Okay, fantastic.

If you need to tick or fix any of those answers, perhaps you got one and you ticked one that should have had a cross, you can pause the video now and do any corrections.

And don't worry if you need to do that.

It really helps our brain grow so that we can remember next time.

Off you go, pause the video now.

Okay, fantastic, well done.

Now, let's move on to have a look at having a look at some light examples.

So in these two pictures, light is coming from different places.

I wonder if you can pause the video and you can tell your screen where the light is coming from in each of these two places.

Let's start with this one.

You can tell your screen, the light is coming from? You can whisper it or you screen, ready? The light is coming.

Can you pause the video and whisper it to your screen? Off you go.

Okay, fantastic.

Now, this one was a bit cheeky.

This one was a little bit tricky.

The light is not coming from the window.

The window itself is not a source of light.

The window is letting through the light.

I wonder if you can manage to get what the light source was? The source of light here was from outside.

The source of light was the sun and the light comes through the window.

It looks like the window is the light source but it itself is not creating light.

Light can't be created.

It's letting through the light that's coming from the light source, which is the sun.

Okay, let's have a look at the next picture.

This one's a little bit simpler.

Can you tell your screen, here the light is coming from? Pause your video have a go.

Great, just like my light bulb that you saw here, here the light is coming from the light bulbs and there are three light bulbs, three different sources of light.

Excellent, well done, year two.

Okay, nearly finishing off but just to finish off some recap questions.

Do you think a window is a light source? Can you show me yes if you do.

Can you show me no if you don't? Do you think a window is a light source? A source of light? Yes or no? Well done, you should be showing me no.

The window itself is not a source of light, it lets through the light, which is emitted from a source of light, the sun.

Next question.

Do you think the moon is a source of light? That one's tricky.

Show me yes if you think the moon is a source of light.

Show me no if you think the moon is not a source of light.

Okay, now, the correct answer here is no.

The moon is not itself a source of light.

A source of light is the sun and what happens is the moon reflects the light of the sun.

So the light bounces off the moon.

The moon reflects the light from the sun.

That's why it looks light and bright in the sky but it itself is not the light source.

The sun is the light source.

And the moon reflects the light that comes from the sun.

Okay, I hope you've enjoyed your first science lesson.

You've done some excellent learning and you've learnt loads about light and dark.

I wonder now if you can complete your end-of-lesson quiz, which will be after this video? Good luck and I will see you next time for our next science lesson.