Hello I am Jared. welcome to our channel of FunScienceDemos. Have you ever
been driving in a car going up a mountain, or flying on a plane, and the insides of your
ears felt weird? It is almost like a pop inside. Well, what is going on with that? Well, that is
the big idea today. Through science we have discovered that there is lots of air surrounding our planet
held in place by gravity, and that air is pushing down on us from all directions - and that pushing
down creates pressure. Scientists like to measure that pressure with an instrument or a tool called
a barometer, and we are actually going to make our own barometer right now. We only need a few
simple materials to make our barometer. It is super kid-friendly - a scissors, a balloon, some
kind of firm rigid container that will hold up so that I can stretch the balloon over top, a
flat toothpick works best, or a straw, or anything that I could attach to the top of the balloon, and
a little bit of glue to hold my pointer there. Here is what everything is going to look like
when we are finished. This jar here is my barometer. I have my balloon stretched over top, my little
pointer is glued to the top, and that pointer is going to move up and down as the pressure changes.
How do I mark those changes? Well, that is what this bottle is for. I am going to put little marks as that
pointer moves up and down, so I can keep track of the air pressure. I do not really need blue water, or
any water in this bottle - I filled it with water so it could be a little more sturdy and heavier,
and I use blue because blue is cool. So now let us make our own. What I am going to do is I am going to
be cutting the bottom part of this balloon off, and I want to make sure I am careful. You might
want to have adult supervision but but a simple cut is all we need. Next I am going to stretch my
balloon over top of my container and snap it into place. Now, when you do this you might find that the
balloon sort of loosens up. That is okay. If you get a rubber band, stretch the rubber band around your
container. What you can do is tug on the balloon, and get everything nice and tight. Now I have a
little membrane or a piece of rubber, in this case latex balloon, that is going to measure my
air pressure. You know what this actually is kind of like? It is kind of like the inside of my ears.
I have this little film membrane inside my ears that actually responds to air pressure pushing
them. Now you can use pretty much anything for a pointer. I have seen lots of straws and I have made
them with straws and pins and all kinds of things. I found that the flat toothpick works really well
for this design, so what I need to do is attach my flat toothpick to my balloon. I am just going to use
a small little dab of glue. Now, that is a big dab of glue, so how do I fix that problem, or that mistake?
So, I am going to take an other flat toothpick. I am just going to take some of that glue off. Sometimes
science is messy. I can even use my finger, and all I want is just a little bit of glue, that is all I
need, and now I can attach my toothpick. I have to let it dry, and then my barometer is ready to go.
Take a look at the barometer I made before. When I made this barometer, my toothpick was lined up with
that mark. Well, now my pointer has moved up. Well, what made it move? All the air has added pressure
and it is pushing down on the balloon, and if you look carefully, the top of this balloon is actually
flexed in, which makes my pointer move up, and if it is reversed - if the pressure is not as heavy or as
high - my balloon will actually bulge out, which will make my pointer go down. Air pressure at work. So
we have made a little working model, so you can see how the barometer actually works in real time. This
model works pretty simply. I have my little tiny barometer inside, with a balloon stretched across
the top, and this contraption is just a little plastic container that I stretched the balloon
over. I left the bottom part of the balloon there so I can tug on it, and I can increase the pressure
inside this jar by grabbing here and pushing down, and I can decrease the pressure by pulling up - kind
of like our giant earth. So here is how this works: I push in to increase the pressure, I pull up to
decrease the pressure, Now, let us zoom in and take a closer look at my barometer, and see what it is
doing while I am pushing in and pulling up so let us start playing around with the pressure. I am going
to push in, increase pressure, pull up, decrease the pressure, push in, increase the pressure, pull
up, decrease the pressure, in, up, high pressure, low pressure, high pressure, low pressure, high pressure,
low pressure. So, what is the big deal with all this air pressure? Well scientists like
to measure air pressure because it actually tells us what the weather is going to be like.
If it is an area of high pressure, scientists have discovered that the weather typically
is pretty nice, but if it is an area of low pressure, the weather can be pretty lousy -
rainy, stormy... If you want to learn more about weather or weather instruments, check out our
links in the video description. Weather is so cool, sometimes it is warm! thanks for watching