Hi, everyone! Squeaks and I have a problem.

We were about to start  cooking lunch, but then we saw

that it's the perfect day to be outdoors.

We're trying to figure out how we can cook

and play outside at the same time…

I know! We can build a solar oven!

Solar ovens are a lot like kitchen ovens.

They're basically boxes that heat up inside,

and that are great at keeping the  heat trapped inside of the box.

If you put food inside of the  oven, the heat cooks the food.

[Squeaks squeaks]

What makes it a solar oven?

Well, kitchen ovens use electricity  or burn gas to make themselves hot.

A solar oven uses solar energy  — or energy from the Sun!

When light from the Sun shines into a solar oven,

it heats up the inside of the box.

This means they're perfect for cooking outside!

You can make a solar oven using  materials you might already have.

Hey, Squeaks — will you help me design our oven?

[Squeaks squeaks]

Awesome!

I've brought some materials for us.

First, we have a pizza box to  use as the main box of the oven,

and I have some tin foil, too.

Tin foil is a great insulator, or  something that's great at trapping heat.

So, it can help us to keep  the heat inside the box.

I'll cover the inside of the box  with tin foil, and tape it down.

Hm, now, we have our first design challenge.

We need sunlight to get into  our box, but if we open the box,

all the heat will get out.

Is there something that we could  change about our box to get

sunlight in, while still keeping the box closed?

[Squeaks squeaks]

A window… that could work!

It will be like how windows can  let sunlight into a building,

even if they're closed.

I'll make a flap, so we can  open and close our “window.”

And kids, make sure that  when you're cutting your flap

that an adult is around to help you.

Normally, windows use glass to  separate the inside and outside.

We want something clear like  glass, that will let sunlight in,

but that doesn't break as easily.  What do you think we should use?

[Squeaks squeaks]

Plastic wrap is a great idea!

We can cover the window in plastic  wrap, and tape it around the edges

to keep the heat inside the oven.

Now sunlight can get into the  oven, and heat up our food!

Uh-oh… I think there's another  problem with our design.

The only sunlight that can  get into our box is the light

that shines straight into our window.

And that's not enough.

So, here's our second design challenge!

How can we get more light into our solar oven?

I've got an idea! Did you know light can bounce?

If you shine a flashlight in a  mirror, the light will bounce off it

and back at you.

And it does this on more than just mirrors!

Anything with a shiny surface can  make light bounce, or reflect.

So if we want to reflect some  sunlight into our solar oven,

we need something shiny!

[Squeaks squeaks]

The tin foil! The tin foil is very shiny!

We can try using that to reflect  the sunlight into the box.

Thanks Squeaks!

I'll tape some tin foil to the section  of lid we cut out to make our window.

If we angle this just right, the  sunlight aimed at the tin foil

should bounce off of it and  shoot straight into our oven!

We can use this pencil to hold  that lid at the right angle.

Next, we'll put the food  on a plate inside to cook.

That leaves us with our third  and final design challenge:

Which color plate should we use?

We have a bunch of paper plates  from Sam the Bat's birthday party.

We have a white plates and black plates.

[Squeaks squeaks]

I'm glad you asked.

The colors matter because dark  colors heat up in the sunlight

faster than lighter colors.

You might have noticed this if  you've ever worn a dark shirt outside

in the summer!

We probably want a dark-colored plate to help us

heat up our food then, don't we?

[Squeaks squeaks]

I agree, let's use the black  plate. That one is darkest.

It looks like we're ready  to test out our solar oven!

How about some pizza bagels?

[Squeaks squeaks]

We're going to head outside  to test our solar oven.

Depending on what happens, we  might make changes to our design.

Maybe we'll paint the entire  inside of the oven black,

or find a shiny mirror to help  reflect more sunlight into the window.

What ideas do you have to make our oven better?

Ask a grown-up to help you to build  your own design, and test it out!

Good luck with your cooking!

And if you'd like to keep  exploring with me, Squeaks, Jessi,

and the rest of our friends,  hit the subscribe button.

We'll see you next time here at The Fort.

[♪ OUTRO]