Hot Air Balloon (The Second Attempt)

After our last attempt to build a working Hot Air Balloon using the Egg Lander, Mr. Chung thought it was necessary that we try again. Unfortunately, this time was no different from the last time. Even though we got the opportunity to bring in our own materials to make the Hot Air Balloon, none of them worked. Why is that?

Instead of being placed in the same group as our Egg Lander, we each got placed in a different group with different people. To start out with, we discussed the best way to build the Hot Air Balloon. In order for a Hot Air Balloon to work, it is necessary that the structure at the bottom should be light, and the amount of candles and the size of the bag should be proportional. If there are not enough candles, there won’t be enough fuel for the bag to fill up with oxygen and allow the structure to rise. Our group decided, with the suggestion of Mr. Chung, to use kabob sticks since they were firm and strong, as well as light and easy to use. We also decided to use a very thin paint drop sheet as the bag since it is light and comes in a big size which can be cut to preferred dimensions. In addition, we decided to use the candles Mr. Chung provided with us last time since they were very light in weight and did not burn out very quickly.

Our group came up with the idea to make the Hot Air Balloon as small as possible, since the smaller the lighter. Because the structure was small, we decided to use as limited number of candles as possible, and therefore should mean that the bag should be small too. We decided to make the structure to have two layers so that the oxygen would not only accumulate on the bottom, but on the top as well, so that the oxygen would rise and cause the bag to expand quicker before the flame dies out or the candle melts. The problematic situation we had was how to light the top candle without making a hole in the bag. In addition, because kabob sticks are thin and the circumference of the candle was wider than the thickness of the kabob stick, we decided to use straws. The straws allowed the candles to be put in the middle of the straw with just enough space cut out on the side of the straw to perfectly fit the candle.

Unfortunately, our design did not work. In the moment, we decided to light only one candle because the bag was too small and we were scared that the lighter might cause a hole in the bag. 

If I were to change something, I would definitely change the size of the bag. The size of the bag greatly impacted and restricted the amount of candles we could put in. I would also have changed the bag itself to something cylindrical with a cover on the top. This allows for the oxygen to accumulate in that space without being wasted and released. I would also increase the number of candles, just in case that while the oxygen is being accumulated into the bag, some of them blow out and are not in a position to be lit again.  

The Moon

The night of September 27, 2012, our Earth & Space class got the opportunity to view the Moon from telescopes provided by an outside source. Because the details of outer space are unknown and can't be seen from the ground with the naked eye, it was necessary that we used telescopes, each with a different magnification. Some telescopes showed the Moon as merely a white dot, while those with a higher magnification showed the Moon in full detail. 

However, even though we got to see the Moon up close and take a picture of it with our camera, what actually is it? 

It is the second brightest object in the sky after the Sun. As the Moon orbits around the Earth once per month, the angle between the Earth, the Moon, and the Sun changes. (1) We see this as the cycle of the Moon's phases. The Moon's current orbital distance, about thirty times the diameter of the Earth, causes it to appear almost the same size in the sky as the Sun, allowing it to over the Sun nearly precisely in total solar eclipses. (1) The matching of apparent visual size is a coincidence. Earlier in Earth's history, the Moon was close to Earth, and had a apparent visual size greater than that of the Sun. 

The gravitational forces between the Earth an the Moon cause some interesting effects. The most obvious evidence is the tides. (1) The Moon's gravitational attraction is stronger on the side of the Earth nearest to the Moon and weaker on the opposite side. Since the Earth, and particularly the oceans, is not perfectly rigid, it is stretched out along the line toward the Moon. (1) From our perspective on the Earth's surface, we see two small bulges, one in the direction of the Moon and one directly opposite. (1) The effect is much stronger in the ocean water than in the solid crust so the water bulges are higher. And because the Earth rotates much faster than the Moon, the bulges move around the Earth about once a day, giving two high tides each day. 

The moon | phases, orbit, and distance from the earth. (n.d.). Retrieved from http://nineplanets.org/luna.html

Hot Air Balloon

After the Egg Lander, we were expected to use the same structure and edit it in a way to build a Hot Air Balloon. Other than the materials that were given to us when we built the Egg Lander for the second time, we also got 10 candles and a garbage bag. Instead of having the requirement that the egg must survive the landing, the Hot Air Balloon must be in the air for a certain amount of time and height. 

Our previous idea for the Egg Lander was a soccer ball shape, where the straws were shaped into large pentagons so that when thrown from a two-story high building, the straws would absorb the shock. The encasing used to hold the egg was a triangular pyramid. This would allow for the egg to have enough space so that when the Egg Lander fell to the ground, the egg would not hit break that easily, but there was also enough space so the egg would not be rolling around during the time of flight. Our group thought that the triangular pyramid was the best to use for the Hot Air Balloon since it was light, and could be used to hold the ten candles. 

In the end, after thinking about it, we decided to use the optimal design Mr. Chung drew on the board. It was crossing two straws one on top of another. However, the problem our group had was how long should each straw be and where should the candles and bag be placed. In the end, our group decided to use the length of two straws with the bending part sticking out, so that the candles will be put into the straw. However, this design would not allow the bag to be held up anywhere. Therefore, we decided to make another cross with a longer length so that the bag could be held up and would not be burnt by the candles. 

Unfortunately, our Hot Air Balloon did not work. When the candles were lighted, the bag released oxygen but did not rise from the ground. There were many reasons for this. Firstly, the structure used to make to suspend the bag and hold the candles was too heavy. Also, there weren't enough candles to make the bag collect oxygen and eventually rise up. In addition, the bag was too small to accumulate oxygen and cause the structure to rise.

  

If I had to change something, I would firstly modify the design. In order for the Hot Air Balloon to rise, the structure must be light. I would make only one crossing of straws and increase the number of candles and place them along the edges of the straw to allow all the oxygen to rise to the bag. I would also increase the size of the bag so that the oxygen would make the size of the bag larger, making it easier and quicker for the structure to rise.

Even though this was the first attempt to build a Hot Air Balloon, and it did not work, it was a fun experience to take apart our Egg Lander and create something different. I enjoyed the fact that for the Hot Air Balloon, the egg was not incorporated because the weight of the egg would change the way it had to be built, as well as the number of candles that had to be included into the structure, making the whole Hot Air Balloon difficult to rise from the ground.

Egg Lander Report (The Second Attempt)

After a second attempt at building the Egg Lander, unfortunately, it failed again! What possibly could have happened?The first time our class built the Egg Lander, we did not have much knowledge on how to start putting together 20 straws, a newspaper, and tape the length of the table. However, now that everyone was able to get the chance to see what was expected, we should all have the knowledge to build a working Egg Lander! Unfortunately, this was not the case...

Mr. Chung put everyone into a new group and each individual participated and described what their previous Egg Lander designed looked like and how they would improve it. The first time each group built an Egg Lander, there were numerous ideas that were designed. For example, some groups made a tetrahedral with two layers (one to hold the egg & one to support the structure), and another group built a structure that enclosed the egg and had straws sticking out from the encasing so that the straws will absorb shock. In the end, our group decided to make a design similar to that of a symmetrical ball and use straws and tape to surround the egg. This will allow the straws to absorb the shock and not impact the egg.

However, this idea was changed once we realized that using this idea might cause one of the straws to penetrate into the egg capsule and cause the egg to break inside. Our group then came up with an idea of making an Egg Lander based on a soccer ball shape. In that way, it is symmetrical, and when the Egg Lander is dropped from the roof of a two-story building, the straws will absorb all the shock due to the large amounts of space of each pentagon. Also, the enclosure of the egg was a triangular pyramid, which allowed the egg to be placed in an area which allowed for just enough room for shock absorbency, but not too much room that the egg will roll around and will break upon impact.

Unfortunately, when the Egg Lander was launched from the roof of a two-story high building, our egg broke. The reason for this is due to the fact that one of the straws supporting the enclosure of the egg was not taped down properly, and got detached during flight. Sadly, during the flight, the egg came out from the enclosure and fell to the ground before the Egg Lander. 

Because this is the second time the Egg Lander was created, there were groups that were able to successfully build a working Egg Lander. Firstly, if I were to keep the same design our group decided to create, I would tape specific areas, such as those that connect one straw to another, just to make sure that during the time of flight, nothing will come apart, leading to a broken egg. However, if I had the choice to redesign (for the third time) another Egg Lander, I would create something that has straws sticking out from the top of the enclosure of the egg. This will allow all the shock to be absorbed when the straw is bent upon landing.

Even though our Egg Lander failed for the second time, the new design allowed for a more open perspective, therefore expanding our knowledge and the way we think. 

Egg Lander Report

On September 13, 2012, our class got the opportunity to throw an Egg Lander we spent time designing and creating for two days down a two-story building. Although it was quite a fun experience building the Egg Lander with only 20 straws, half a piece of newspaper, and two pieces of tape the width of the table, unfortunately, each and every Egg Lander failed. None of the eggs that were held inside survived the impact. Now why is that?

Our group came up with numerous ideas when designing. At first, we thought that if we made a pyramid, when throwing it, the structure would have no problem in determining which side it must land on. However, we realized that if we made this design, the egg would have no support and there will be nothing to absorb the shock upon landing on impact. Then, we came up with the idea of boxing the egg with straws and using the remaining straws to surround the encasing. However, with this idea, we thought the problem would be that we would not have enough tape. In addition, the design must be symmetrical with the same number of straws all around or else there’s a possibility that when landing, the egg will break. Finally, our group came up with the idea of a double layered tetrahedron. The first layer was half the area of the second layer, since it was the section in which the egg was being held. The second layer has a large base so that when that it is thrown from the two-story building, there is a very high chance of it landing on the base, absorbing the shock.

When our Egg Lander was thrown from the two-story building, we initially thought that the egg would firmly remain in the encasing, since we surrounded all the empty spaces with extra straws. However, during the process of falling, the egg slipped out and fell on the ground, destroying it. Also, before the Egg Lander was thrown, we shook the egg. In a raw egg that isn’t shaken, the membrane holds down the yolk at the bottom of the egg. However, when a raw egg is shaken, the membrane will break, distributing the yolk all around the egg, making the weight even throughout. In addition, we did not consider the weight of the egg. We assumed that because it was an egg, it would be light and have no effect on the total weight of the Egg Lander. However, this was also the reason as to why the impact was greater than what was expected. Another factor that our group did not take into consideration is the position in which the Egg Lander would fall to the ground. We thought that because we made the Egg Lander have a large base, this would mean that the probability of it falling on the base is quite high. Unfortunately, this was not the case. Through these careless errors, the result was a failure. However, understanding these mistakes will lead to how we could modify the Egg Lander to have a successful result.

Even though our Egg Lander was one of the two that the majority of the class thought would work, unfortunately, our egg was destroyed pretty badly. When Mr. Chung examined each Egg Lander while it was on display, he said that our group should have made the top section longer. The reason for this is so that upon landing, if the Egg Lander does not fall on the base, the impact will be shared since the sides will be covered with a shock factor. Another modification that should be done is to find a more enclosed casing for the egg. The only support we had was a holder that perfectly fit the egg, with a few space which were stuffed with straw and wrapped around with tape. However, there was also a possibility that during the time of the fall, the straws would come out, loosening the egg from the capsule, and falling to the ground before the model does.

Through this process of designing, creating, and experimenting, we are able to learn what we did wrong and modify these errors, as well as what should have remained the same in order to put together a successful Egg Lander.