Hi, I am Jared, welcome to our channel Weather Demos.
You know, it seems weird to think about, but through science we have discovered
there is actually water in the air all around us.
And the water in the air, it is not a solid
like these ice cubes. It is not a liquid, it is actually a gas and it is spread out
evenly in the air. Now, depending on different things like temperature,
the air can actually hold different amounts of water.
So in the summertime when it is warmer, the air can hold a lot more water.
In the winter when it is colder, it cannot hold as much water in the air.
And scientists can actually measure that amount of water in the air using a tool
or instrument
called a hygrometer. That is a big word and it sounds really complicated and
scary,
but we are actually going to make our own version of a hydrometer using really
simple,
everyday materials. So the tools and materials you will need to make
our hygrometer? We will need a hammer, scissors,
a stick of gum-and this is important- you need the kind of gum that is wrapped in
that
foil wrapper. Some toothpicks, a nail-that is gonna punch a hole-
a marker, and we need something to act as a base. You could use a piece of wood, a
piece of thick cardboard.
We are going to use a can. So we are going to start with the foil.
Let us take the gum out of the wrapper, and I do not need this entire sheet of foil.
I am going to
fold it in half, cut it in half and make a little pointer out of it.
Fold it in half,
open it up, take my scissors, cut it in half,
and now I want to put a little point on the end. Snip,
snip, so I have a foil pointer.
First step. Now I need to actually
poke a hole in my can. So I am going to use a nail
and a hammer to do that. I want to try to get it in the center,
and I am not going to drive the nail all the way through, I just want a small hole.
So I am going to tap it, tap it again,
make it a little bigger.
You can see, we have a start of a small hole.
Now I am going to take my toothpick and fit it in. Now, if
the hole is too loose, we can fix it with some tape.
What I am going to do is a wrap
some tape around my toothpick to make it a little wider.
Now my toothpick
is nice and snug. Problem solved.
So, I have cleaned up my area and I have my can,
my toothpick, my little foil pointer, a marker
and some tape. Now I just have to attach my pointer to my toothpick.
Now, I want it lower on the can, I do not have to go all the way at the top of
the toothpick, I want it lower on the toothpick. I want it lower on the
toothpick.
I am going to attach the tape to the foil. The toothpick is pretty skinny, so I am actually
going to have to wrap
the tape. You might even want to take the toothpick
out of the can to wrap it. I am going to wind this up
and just wrap it right around my toothpick.
Now I can stick my toothpick back in and I am almost there.
We zoomed in so you can see this next step.
I need to take the tip of my pointer, and what I am going to do is bend it
so it sticks out
on my can. Because I am going to use my marker
to put little marks to see if I can measure the amount of water in the air.
So now I need to make marks so I can see if there is more or less moisture in the
air.
I need my starting mark, so I am going to line it up with where my pointer is right now.
All I am doing is putting a little line. Now, this hydrometer works
on a really simple concept and idea. If there is more moisture in the air,
this little foil pointer is going to want to unravel.
It is going to want to (swish) open up. So I am going to put another line
over here and I am going to write an
H next to it because that means it has high
humidity, high moisture in the air. And it is going to want to actually
curl tighter if there is low humidity, so I am going to put another line here
and right an L. So now I have a really simple hydrometer.
But does it work? Well, here is the fun part. Now, to show you how this works I
need
moisture in the air. And really, I have the tool right on me.
(Puffs out breath) My breath. My breath is nice and warm and moist.
How can I show you that? How can I show you that gas?
Well, I have something here. This is a cup of water.
Watch what happens to the outside of the cup when I breathe on it
with a puff of my air.
Did you see it fog up? Well, that is because when I breathe on it,
the moisture in my breath, the moisture in the....
when I breathe on it, it seems to almost fog up. Well, what is that?
That is the water in my breath. Let us see if our hydrometer
will actually respond. So we have moved the camera so you can get a better angle.
And you cannot see my pointer yet, but if this works,
that pointer should move over to the H.
Let us see if it works. I am going to breathe on it.
It is moving slowly.
It is moving more.
It is coming around the bend.
It is at H.
We have moved the camera back out front so we can talk about what we just saw.
Why did that pointer, why did our hygrometer work? Well, there was water
in my breath.
And when I breathed on it, that wrapper actually
responded and reacted. That water made it
open up. Different things actually can absorb that water in the air.
Paper absorbs water in the air. Believe it or not, our hair
can absorb water in the air. Did you ever have a really bad hair day and you wonder why?
Well, a lot of times it is because of the water in the air.
Water is all around and scientists can use tools
to measure that water. So why would scientists want to measure the amount of
water in the air?
Well, the amount of water in the air leads to all kinds of cool weather
things;
rain, snow, sleet, clouds, storms. It all has to do with how much water is in the air.
Science is so cool. Weather is so cool. If you want to learn more about weather,
check our links in the video description.
Thanks for watching.