these are some what less related  to the balloon project, i was initially considering them as possible fuel for the balloons but it never got developed to a functional point.  each video shows a combination of .6ish grams saltpeter and .3-.5ish grams of sugar.  i used powdered sugar, white granulated sugar, and natural sugar.  the sugar is the actual fuel of the reaction, the saltpeter is an oxidizing agent.

 

some other ballooning that hasnt made it into prezi

these are a few attempts we made at a balloon constructed with some light weight trash bags and a gondola constructed of small bits of wire and a foil wrapped soylent candle.  after watching some of the videos here i realized that theyre all fairly similar, and mostly kinda boring..... 

balloon fig newton's

newtons first law plays into the action of the balloon in several ways.  the balloon obviously will not move without a force acting on it.  however the balloon is at the mercy of any small breeze that is present.  since the balloon has such a small mass in comparison to the surface area it is very easily affected by the force applied to it by a small breeze.  none the less, if the balloon could function in a completely still environment once it over came its static inertia it would travel in a straight line.  

the second law is the one that caused us the most substantial challenge.  the force needed to set the balloon in motion must be enough to over come the acceleration due to gravity that is acting on it.  in order for this to happen the envelope of the balloon has to have a large enough volume and a significant enough rise in heat to create enough bouncy to lift the entire contraption.  one of the complications that happened repeatedly was that we were not getting a large enough rise in heat to lift the entire balloon, however it was still very susceptible to breeze moving it horizontally, and setting it on fire. 

the third law is probably the most tricky in regard to this project, in that the actual force creating lift is the cooler atmosphere pushing against the warm envelope.  although this principal is actually quite common, particularly in air bubbles rising in water and being able to use a straw to drink.  the colder air is denser then the warm air, as the warm air becomes hotter it becomes progressively less dense, making it still lighter then the surrounding cold air.  at this point the pressure of the cooler air pressing in on the balloon can become significant enough to cause the lighter air to be forced upward.  in this case the envelope is exerting force back onto the surrounding air, which is exerting force on the balloon in terms of pressure.

so these are a few videos of our latest attempt at flying.  and so far our most successful!  this balloon was approximately 1.15 cubic feet of internal volume, and used 13 candles on this attempt.  12 of the 13 candles were "relighting" candles, which typically contain magnesium, which will increase the heat produced.  the videos missed the most awesome part of the attempt, i'm not sure if that was due to point of view or the pausing of recording (we had an issue with an excessively large video file that caused my phone some problems when transferring it).  one of the strings used to connect the fuel sources to the canopy was wrapped around the support for the fuel source, however when it achieved its maximum buoyancy the envelope was pulling that string taught with no parts of the envelope being other wise supported.  the total weight of the balloon as tested was 30 grams, the estimated weight of the envelope alone was about 11 grams.  my current attempts at constructing the gondola portion have been less oriented toward building something lightweight enough to catch flight, and primarily aimed at creating a stable base for the candles with a form that can be adapted to a lightweight version.  at this point in our endeavor it seems primarily useful to provide a stable base for the candles and something that the envelope is not likely to lift, for the sake of finding a balance between the construction of the envelope and the heat source before releasing a balloon of doom on the world at large. sadly this balloon caught fire for the second time during this test, and i believe clearly demonstrated the effectiveness of the alum solution.  the fact that the tissue paper was able to catch fire, be blown out, and continue with the test is rather impressive.  following this i will post a picture of the fuel source and the inside of the envelope after the test, which shows quite a bit of discoloration that would have likely caused the tissue paper to catch fire if it had not been treated with alum.