Plastic Bag Hot Air Balloon

We really wanted to try making our own hot air balloon from a plastic bag. There are a lot of different ways to do it, and tutorials. I thought this one looked most promising (the instructions are very detailed). There are 6 videos to watch. We almost, almost got our balloon to fly. It hovered for a moment. But it just wouldn't go all the way up. We tried it first with a dry-cleaning bag (it started to melt before getting very far up, though it did stand up) and then with a small trash can liner we got at church, but it must have still been too thick---or perhaps the folds on top needed to be smoothed out so they didn't get so hot (he shows this in one of the videos).

We would have tried again, but we had no more bags, no more candles, and no more time that day! But it was a really fun project, and not too difficult. The boys did all the measuring and taping/cutting of the straw frame, the foil, etc. by themselves, and I helped with attaching the candles to the foil. I read that you can use hot glue instead of melting the wax, and I think that would have worked better (the wax had a tendency to be unstable). There are other good troubleshooting suggestions on this main page also.

Candle platform

Measuring the bag

Attaching the "frame"

Ready to fly

We do have this on our list of things to do another time! I really think we can get it to work better, so next time I have to have something dry cleaned we'll give it another go!

We also might give one of these methods a try (there are several other tutorials like this one around), but because the heating apparatus is not attached, I'm not sure it would be as effective. Might be worth trying, though.

Fully inflated

Almost!

Albuquerque Balloon Fiesta

[Since I already wrote a long post on the Balloon Fiesta for my other blog, and since I don't believe I have any other school-related observations to share, I'll just reproduce that post here:]

As I believe I've mentioned before, going to the Albuquerque Balloon Fiesta has always been something I've wanted to do, ever since we tried (and failed, due to windy conditions) to see it when I was three years old. I love hot air balloons! When at long last we planned this trip at the correct time of year, I was fully prepared for it to be cancelled due to wind or rain again. But we were hoping, hoping (and praying) that the weather would cooperate! The Friday was rainy and cold, but the Saturday and Sunday were bright and clear and lovely. We were so happy! It was everything we'd hoped, and even better. When the first balloons go up, it's still pretty dark outside, and as they turn on their burners, they light up like floating lanterns in the sky. These first balloons also have little lights floating from their baskets---tiny diamonds below them---see?

Then suddenly the sky starts turning pink, and you walk onto the field and you're surrounded by all these huge, breathing, billowing creatures. They sway uncertainly as they lurch upright, like a genie who's spent too long in his bottle and is feeling rather stiff. I love being in among the balloons. I think they seem friendly, even when they puff fire and make hraaaa! noises at you.

They rise up into the sky a few at a time at first, and then suddenly whole swarms of them are lifting off: stretching and straining upwards and finally breaking free of the earth.

Hundreds!

There are lots of funny ones: floppy-trunked elephants and storks and clocks and penguins.

Those were a big hit with the children.

When the sun comes up, everything becomes, if possible, even more beautiful. Rainbow bubbles catching the sunlight!

They are mesmerizing.

I have experienced nothing like it. The sheer numbers . . . over 700 balloons, I think . . . and the way they loft so simultaneously into the sky around you. It's like you're underwater, watching the whole world float up past you to the surface. I can only imagine how cool it would be to lift off within that colored cloud.

We watched from a different viewpoint the next day. From that distance, there was less of the submerged-by-balloons feeling, but there was the sudden breathless surprise of seeing them suddenly foaming up out of the trees, surging out in waves like bubbles from a bubble machine.

And then spilling over the buildings and right over our heads.

Abe took this picture out the back window of the car. A flock of bright birds following us back to our hotel!

All the way back.

That night we went back to watch them glow again. No flying this time, but they stood in rows and blinked on and off like fireflies. It reminded me so much of the gas lamps that light Embassy Row in London---the sound of the gas hissing gently in the dark; the fuzzy edges of the light, so different from the starkness of fluorescence; the feeling of being in another time. It was beautiful.

There were fireworks to cap it all off; you can see that we are a family that enjoys fireworks. (Sort of embarrassing: need I be quite so stereotypically "ooh-and-ah"-ing?) (Though I do especially like Sebby's dumbfounded expression.) 

The Albuquerque Box

While we were looking up the history of Albuquerque's Balloon Fiesta, we learned about something really interesting called the "Albuquerque Box." It's a wind/weather pattern that happens because of Albuquerque's geographical position. Basically, for this pattern to occur, you need very dry air, a small/enclosed valley, and a place where daytime warms and nighttime cools are widely disparate.

I'm not an expert on this, but as I understand it, when these conditions are right, the cold nighttime air falls down the mountains/mesas to lower elevations. As the sun comes up and starts to warm the upper air, it creates wind between the air layers that makes a strong air current in one direction (south, in this case). As the cold air moves south and away from the enclosing "walls" of mountain, it warms and moves upward in elevation. Another air current then forms, moving the opposite direction, back toward the enclosed valley. The warmer air then cools again, falls, and joins the other current moving south.

You can see why balloonists would like this phenomenon: when it is present, they can take off from one location (the balloon fiesta park, e.g.), fly at low altitude south for a while, and then, when they wish to return, go up higher to catch the "return trip" wind current right back to where they started!  No chase vehicles necessary. :) Of course, the Albuquerque Box doesn't occur all the time, but it's more common in Fall when the Balloon Fiesta takes place, and when it does occur, it makes for great ballooning, apparently! Interesting, eh?

Hot Air Balloon Unit

Hot air balloons (and gas balloons) have a pretty fascinating history. I knew there would be lots of related scientific principles to learn, but I didn't know about the use of balloons as the first "air force" in several wars, notably the Civil War. The book Lincoln's Flying Spies (Gail Jarrow) was really interesting. It was too long for me to read the whole thing to the children, but I read it all myself, and then read excerpts to them, and summarized other parts, and we looked at the pictures.

Of course the highlight of the unit was getting to see the hot air balloons at the Balloon Fiesta in Albuquerque, but we also really enjoyed the Balloon Museum there at the end of the launch field. There were a lot of hands-on activities, some of which we skipped because of the crowds, and we also liked seeing several historic balloons---ones used for transatlantic flight attempts, etc. I feel like it's kind of sad that, because of all the advantages airplanes have over balloons, the impetus to make passenger airships, etc., kind of fizzled out. Not that I don't like airplanes---but there's something so majestic and beautiful about a balloon. I'd love to ride in one of those big zeppelins or airships! :)

I was also just thinking how nice it is to have a usable vocabulary about various subjects. I don't care about knowing all the fancy jargon that only experts use, but it's just satisfying to be able to say (and have the children say), "Look, now the hot air is going through the skirt into the envelope!" rather than "Look at that flap part directing the air into the balloon part!" Or, "He opened the parachute valve!" instead of "The top flap thing is opening!" It's not that big of a deal, but I just like being more accurate and effective in our speech. And I like hearing the children use those words even when they are just playing with each other.

Here's a good overview of how balloons work:

http://science.howstuffworks.com/transport/flight/modern/hot-air-balloon.htm/printable

Parts of a balloon:

http://www.chm.bris.ac.uk/webprojects2003/hetherington/final/Hot_air_balloon_parts.html

A coloring page---no educational value, but it was fun to color rainbow balloons

We watched several videos of hot air balloons and balloon flights:

This one was cool (amazing scenery!): http://www.youtube.com/watch?v=LSV9INvPvQA

This was also good:

http://www.youtube.com/watch?v=77Ej_Ayugxk&playnext=1&list=PL04A9F2900A881539&feature=results_video

And here is Daisy riding in the hot air balloon Abraham built for her! (that's my big exercise ball under the blanket on top) :)