[♪ INTRO]
Hey there, everyone!
Squeaks and I were enjoying some peppermint treats.
They taste so cool and wintry!
But now we want to try another kind of winter dessert.
And Squeaks thought of gingerbread!
And I thought… why don't we have a tasty treat and do a little science by building a gingerbread house!
[Squeaks squeaks]
That’s a great idea, Squeaks!
Let’s make the Fort out of gingerbread!
We should have a plan before we get started.
That’s what engineers do when they design buildings.
Part of that plan includes picking the materials we should use,
and what properties those materials should have.
Properties are characteristics or qualities that make a material special.
They're the things you can notice about a material just by using your senses,
like what color it is or how hard or soft it feels…or how sweet it tastes.
For example, take the top of this table.
How would you describe it, Squeaks?
[Squeaks squeaks]
Oh , yeah.
The surface feels smooth and hard.
And it certainly looks blue.
Those are all examples of properties.
Our Fort’s walls and roof are going to be made of gingerbread cookies.
So what properties should our cookies have?
[Squeaks squeaks]
Oh, I agree!
It’s important that the cookies taste good!
But that property isn’t going to help our gingerbread Fort be strong and sturdy.
Let’s think of another property that might help.
There are lots of recipes for gingerbread.
Some make soft chewy gingerbread
and some make gingerbread that's more crunchy.
[Squeaks squeaks]
Exactly, Squeaks!
The cookies we use can’t be too soft,
or the walls will crumble and the Fort won’t stand up!
We’ll need cookies that are a little bit harder.
Walls in any building, gingerbread or not,
have to be strong and hard enough to hold up a roof.
But they also can’t be too firm,
because then they’ll shatter under all the weight they’re trying to support.
So our gingerbread has to be pretty hard, but also a little bendy,
so it can both stand tall and hold up our Fort’s roof without breaking.
We’ll also want to make sure we bake the cookies so they’re completely done.
Do you remember when we talked about heat changing the properties of eggs,
how it can make them go from goopy to hard?
Well, the heat from our oven will change the properties of cookie dough, too.
It changes soft dough into crisp cookies.
Which we’ll need for our gingerbread walls and roof,
as well as any other pieces to get that perfect Fort shape.
So, what do you say, Squeaks?
Let’s put on our engineer hats and draw a picture of the pieces we need!
Okay! We have a drawing, or model, of what our gingerbread Fort might look like
when we’re done building!
We have the right cookies, baked, cooled, and cut into the right shapes!
Now, how do we get the cookies to stand up straight and not topple over?
We need to get the edges of the walls to stick together.
So what’s a material that has the properties of feeling sticky and tasting good?
[Squeaks squeaks]
Oh, icing! That's a great idea, Squeaks!
But like we did with our gingerbread,
we have to choose an icing that has the right properties.
Icing that’s too thin won’t be strong enough to hold the pieces together.
And if it’s too runny, it won’t dry quickly… and the pieces of our Fort will fall over.
[Squeaks squeaks]
You’re right, this is kinda tricky!
But engineers don’t give up!
Let’s give our icing a try and see what happens.
It took a little work, but we’ve gotten the walls up, and the roof is in place!
We used icing as glue to stick the walls and the roof of the Fort together.
[Squeaks squeaks]
Yep, it’s time to decorate our gingerbread Fort!
We need to be careful that we don’t put too much stress on the walls and the roof
by adding a lot of heavy stuff.
[Squeaks squeaks]
Yeah, stress. But stress in buildings isn't quite the same as the stress our bodies feel
if we’re anxious or sad about something.
Stress is made of the forces that are pushing and pulling on the materials in our Fort.
If the roof is very heavy with decorations, it puts a lot of stress on the walls.
If there’s too much stress, the icing we used to hold the Fort together
won’t be strong enough…and the walls will fall apart.
A lot of stress might even cause the cookies to break!
So I think we should add only a few decorations at a time,
stick them on with icing, and then wait for the icing to dry.
Do you agree?
[Squeaks squeaks]
Nice.
And while we’re waiting, we can snack on a little bit of leftover gingerbread.
[Squeaks squeaks]
Thanks for joining Squeaks and me here at the Fort.
If you want to keep learning and having fun with us and all of our other friends,
be sure to hit the subscribe button, and we'll see you next time on SciShow Kids!
[Squeaks squeaks]
[♪ OUTRO]