Photos and descriptions of Second Grade science outreach program on Air at James Buchanan Elementary School.
Our Blanket of Air James Buchanan Elementary
School, Academic Year 2012-2013
Grade 2
Dr. DeLeo came into our classrooms to describe the Earth's atmosphere, our wonderful and life-giving blanket of air. He talked to us about what happens as we go higher and higher. We all knew that the air gets thinner and thinner until it is so thin that you can't even breathe. In fact, if you go up high enough, you are in outer space and there isn't any air at all. The air also gets colder as we go higher. The photo on the left shows the Earth from about 200 miles up (NASA). Notice the thin blanket of air that surrounds the Earth.
We talked about the highest place on Earth, Mount Everest. At the top, about 5 miles up, the air is so thin that you need to use oxygen masks most of the time. The photo just to the right shows Mount Everest, and the one on the far right shows what it looks like from the top.
Photos above from http://erigreste.files.wordpress.com/2008/11/everest_west_view.jpg (left photo, 4/25/11) and http://www.project-himalaya.com/dispatches/2006/i06-everest/88a-summit-pan.jpg (right photo, 4/25/11)
Since Weather is one of the science units we are studying this year, we talked next about what happens when air is heated up. Many of us already knew that hot air rises, and cooler air falls. Weather patterns on Earth are driven by this effect as the sun heats the Earth's surface and the air above it. Dr. DeLeo demonstrated that hot air rises by placing a spiral piece of paper above a hot light bulb. The rising hot air pushed on the paper and made it spin. You can see this in the VIDEO on the right by clicking the play button.
Dr. DeLeo told us that our blanket of air pushes on us; it exerts a force on us (and everything) of about 15 pounds on every one-inch square. That's like the weight of 3 bags of sugar pushing on each square inch of our body! We don't get crushed because there is an equal force pushing from the inside out as well. Since a force is a push or a pull, we can easily demonstrate how two forces can be in balance, like in the photo on the left. However, if one hand, say the left hand, pushes harder, both hands - and anything in between - will move to the right.
Dr. DeLeo demonstrated the effect by dropping some lit matches into a flask (a special bottle) and then placing a hard-boiled egg on top of the opening. The amazing thing that happened is shown in the sequence of photos to the right and below.
Dr. DeLeo explained that when air is heated, it expands and takes up more space. (Since each volume of air is now lighter, that's why hot air rises.) When the match goes out, the air cools and pulls in (it contracts, the opposite of expands). As the air pulls in, it sucks in the egg. Looked at another way, the force of the air pushing the egg from the outside down into the bottle is greater than the force of the air inside the bottle pushing up, so the egg gets pushed in!
To see VIDEOS of the eggs going into the bottles, click the play button on the photo to the right.
We thought this was really amazing, and funny. Some of us even wanted to eat the egg. But Dr. DeLeo said that scientists usually don't eat the experiment!
We tried the same thing again, but this time using an iced tea bottle, with an opening that was too small! To see VIDEOS of the eggs going into the smaller bottles, click the play button on the photo to the right. What a mess!
Dr. DeLeo showed us that when he blows into the bottle, the egg comes out, sometimes so quickly that Dr. DeLeo almost swallows it, like in the VIDEO on the far left!
Dr. DeLeo explained that, when he blows into the bottle, the air goes around the egg, and pushes the egg out from the inside! Even before Dr. DeLeo explained it, one of us explained it in the VIDEO just to the left.
For our final adventure, Dr. DeLeo brought in a box with a large hole in one end, and a smaller hole in the other. The large hole was covered with a clear plastic shower-curtain liner.
When you wacked the plastic with your hand, a ring of air, called a ring vortex, came out the other end. A tornado is a vortex, but it is not wrapped in a circle like a ring vortex. You can see it blowing a student's hair in the photos on the left, and the teacher's hair in the photos below.
Dr. DeLeo brought a fog maker, like the kind they use in movies to make fake fog. Now we could really see the rings of air! He aimed them at the ceiling, and then at us, as you can see in the VIDEO on the right!
To the left and below are photos of one of our teachers and Dr. DeLeo using the ring vortex box.
The photos to the left and below show Dr. DeLeo using the ring-vortex box to put out candles that we were holding!
We had lots of fun learning about air!
I hope you have enjoyed this web presentation as much as we enjoyed sharing the actual learning experience with your son or daughter. Although we have endeavored to exclude photographs where permission has been denied, it is possible for errors to occur. If you would like us to remove a photograph of your son or daughter for any reason, please send me an e-mail message at lgd0@lehigh.edu or call me at 610-758-3413, and we will remove it promptly. Please note that we will never associate a child's full or last name with a photograph except in circumstances where special permission was explicitly provided. Thank you. Gary DeLeo.
