Final Report

On April 5th, 1977, new land was discovered by the dutch explorer Jacob Roggeveen. He arrived on the island on Easter sunday, thus giving its name “Easter Island”. Now, the Volcanic Island is owned by Chile, and is inhabited by the descendants of the Rapa Nui people, the name given to the civilians living on the island since it was first inhabited. The mystery behind the disappearance of the Rapa Nui is still not completely solved, however many historians believe they destroyed their own civilization through Ecocide, also known as ecological suicide.

What most fascinated explorers that visited the island were the large statues sitting around the perimeter of the island. These statues are called Moais and the actual role of them still remains unknown. Many historians believe that the Moai served for religious and natural purposes, such as serving as a god-like figure, or as a guardian of the island, protecting the inhabitants of outside dangers. The Moai that were placed around the perimeter of the island were not placed facing the sea, instead they were placed facing the island, overseeing and protecting “the lives of their creators”. Historians believed the Rapa Nui built the moai so they could have an object that represented their culture and beliefs.

The Moais were made of tuff, a volcanic rock found on the island, and were carved on quarries, which were located in the mountain. The Rapa Nui first carved the whole statue attached to the mountain and then, once it was complete, they would disconnect it from the quarry and move it to their desired position. Some Moais were placed on ceremonial platforms called ahu, which did not only provide stability but must have also served for a religious purpose. Others had however, two-thirds of their bodies buried underground to stabilize it. What archeologists still try to discover is the way these statues were actually moved. Some say extraterrestrials came down to Earth and moved them. Others say the Rapa Nui tied ropes around the Moai and, by pulling on each side, made it walk. Some even say that they were moved horizontally, rolling on wooden logs. Most of these strategies seem impossible to us because some of these statues had to travel distances up to 9 miles and these methods would be ineffective in such long distances. Some Moais had red hats called Pukao, which weighed an additional two tons. This made the transportation of the statue even more difficult and contributed to the mystery that is still unsolved to this day.

The building of these statues soon began to exhaust the island’s resources. The Rapa Nui were cutting down all of their trees in order to use the logs to roll the Moais and the fibers of the branches to make ropes used to make the Moai stand up. The destruction of the forest brought them to a decline. The lack of palm trees, for example, which were used as a protection against the sun and as a source of food, led to a time period of famine and starvation. On top of that, the land became less fertile and it became much more difficult to cultivate yams.

Some explorers, such as James Cook, claim that the lack of food led to cannibalism on the island. This is proven through the cava cava, wooden figures which presented starvation on the island. They also described that the island was in a state of destruction, with all the Moais removed from their platforms and broken on the floor. This creates a lot of controversy between historians because some claim that the Moais were on the floor as a way of covering the top of tombs for religious purposes.

A lot of the history of Easter Island still remains a mystery and it is our job, as an archeological company, to investigate and corroborate these theories. With our expedition to the Chilean island we will not only answer the eternal question of how the Moai were transported, but we will also unravel the traditions and culture of the Rapa Nui.

A Brief History on the Island

About Us

Artifact Preservation & Co. is a company with pure ambition in mind. We plan and create our projects effectively and thoroughlly. Our essential goal is to "think outside the box" strategy while using our minds and a tad of creativity. Everything created and assembled here is made with happiness and skill, and our work is known for its quality and efficiency. Historians investigating the mystery of the Moais in Easter Island called us in to help transport one of their moais using our excellent knowledge on Physics. Before doing so, however, we decided to make a small-scale plan for the transportation of the real-sized moai. The objective of this project is to determine how we would move a newly made moai from the quarry at the top of a hill, down the hill, and across a rough terrain to reach the ahu. This will not only help us in accomplishing the transport of the Chilean government’s moai, but it may also hint at how the Rapa Nui managed to move all those years ago their own moais.

Our Project

Right after the Chilean government suggested this new challenge, we directly began to prepare the project. We first created our sample Moai, with a mass of 688 grams, maintaining the correct proportions in regard to the real-life Moais. The scultping took our team around 30-40 minutes. Continuing the process, the clay dried up and we decided that having the Pukao was too risky for the assignment, so we left it out. When the Moai was ready and dry, we painted it grey to capture the natural essence of real Moais.

Following that, our team began the contruction of the actual terrain for the Moai to be transported on. We used balsa wood, thin balsa sticks and a thicker wood to create the overall structure of the terrain. We then decorated it with leaves and rocks to recreate the rough landscape of the quarries in Easter Island. The pieces were all assembled and stuck together using a hot glue gun. Achilleas Souras determined the exact measurements of the materials, Maxime Nederpelt and Patricio Pinzón then cut and filed the wood that was needed, and then the pieces were passed over to Saioa Tricquet and Amit Samuel who assembled the terrain and added the decorations. The entire structure was 32cm tall, with a slope of 70º meausring ---, and the base measuring 70cm long and 30cm wide counting from the end of the slope to the location of the ahu. The force of friction of the Moai on the terrain was around 2.2-3N, meaning a mu of 0.42-0.63. To overcome this, our group decided that we would be using a car or some other type of vehicle to transport our Moai because it would greatly reduce the friction and therefore enable it to move.

The Transportation Mechanism

Our initial plan to push the Moai off the cliff with manpower and which will then roll horizontally facing upward. The logs will make it go quickly and gain enough momentum to go on the vehicle. The vehicle will have one wheel planted on the slope and will be perfectly aligned with the log mechanism to smoothly get the Moai on it. The Moai will reach the vehicle with great speed making the car move forward. The car will stop when it reaches the Ahu because we will have put a tiny piece of wood. The final stage of the transportation is getting it on the Ahu facing the slope. We will do this using a pulley and a magnet. The Moai will be wrapped with string and have a hanger on its top. The hanger on the Moai will also be a magnet like the one on the pulley. The string on the pulley will attach to the Moai by itself and it will slowly go up because there will be people up on the pulley base moving the handle (this means we will operate the pulley manually, but we will build it compatible to to fit the average humans). The Moai will be wrapped in the string to preserve it but also once it is on the Ahu, we will make the base rotate by applying grease beneath the ahu to reduce the friction and sticking nails in the ahu to create handles for the people to turn the Moai.We will have people close to the Moai that will slowly unravel the Moai and make it face toward the Island.

Some aspects of the initial plan were really good and we're really successful while we were building it, however most of our ideas for the transportation mechanism failed once we tested them. For example, the logs were a really good idea because they directly modeled one of the theories that historians have on how the Rapanui moved the Moai, by using tree logs and string created from palm trees to roll them off the cliff. This idea actually worked, although we had some trouble getting the string to be tense enough for the Moai to actually be able to roll on the logs. The car was also a good idea, but at the beginning we we thought that the impulse that was being applied on it why would cause a great enough change in momentum to be able to move the Moai and the car when it landed in it. This, however, did not happen because the when the Moai reached the car, the car did not move because it needed a greater force to overcome its static friction. Therefore, we decided to use a pulley mechanism that connected the car with a string which would pull it and give it more force and power to move. To do this, we stuck two wooden planks at each side of the car as a way of creating rails for the car or truck to move in a straight line. Then, we hammered a pulley system to the ground just next to the ahu and attached a loop to the base of the truck. We then decided to make the car stop at the base of the hill and once the Moai landed on it we would remove the blocking system and then connect the pulley to the loop and pull because it would be much faster and more efficient. After that, once the truck reached the end of the terrain, just before the Ahu, we created a second system of pulleys, situated right above the first, in which we connected a string to a second loop that was attached to the top of the Moai. This would represent a crane, or some other big mechanical machine, connecting the pulley to the loop and then manpower would pull on the string and lift the Moai up in the air and pull it into an upright position. The car would then move away with it's own engine, after being disattached from the pulley, and that way the Moai would be lowered onto the platform by slowly untensing the string.

Overall, our errors revolved around the complexity of our transportation ideas and how the physics were applied to a real life situation. We managed to solve those problems and create a successful transportation mechanism for moving the Moais of Easter Island down from the quarry onto the Ahu.

Our Calculations

Based on Newton's First Law of Motion, for our mechanism to commence, man power is used to exert an unbalanced force on the Moai. This causes the Moai, which is at rest, to move. Then, when lifting the Moai to the Ahu using a pulley technique, the force applied to lift the Moai through string is unbalanced and greater. Therefore, the force of tension will pull the Moai up and force it to move it upward. Furthermore, when the car is moving from the slope to the Ahu, the Moai is also in motion. If an unbalanced force were to hit the car, because of Newton’s first law and inertia, the Moai would continue in motion because the force was only acted on the car.

Secondly, according to Newton's Second Law, when the Moai is first pushed, it moves because the net force is not 0 and the force applied is greater than the force of friction, causing the object to accelerate. Later, when the car is still waiting on the slope, with sticks inserted in between its wheels to prevent it from moving, it is at rest and therefore at anet force of 0. Once the stick is removed, the car begins to move because the forces applied to the car are no longer balanced. Finally, when the Moai has to be transported by the pulley, and since the Moai has a great inertia, the force exerted on the Moai has to be greater than it’s pre existing horizontal normal force to cause it to move.

Then, using knowledge from Newton's Third Law, we realized how a normal human being was not able to make the whole transportation mechanism work just by using manpower because it requires a great amount of force. If they were to exert a force to a twenty ton Moai, it wouldn’t move, since the person pushing it would receive an equal and opposite reaction. Additionally, because of its great mass, the Moai will have a greater inertia and therefore will have a greater resistance to change in motion. Therefore, a big force has to be applied for the Moai to overcome the static friction and start moving.

Moving on to the Impluse-Momentum Theorem, when the Moai is pushed onto the slope the impulse it gets causes a change in momentum. The force exerted to move the Moai over a certain amount of time causes the Moai to change its velocity. Therefore, when the Moai is first pushed, the force causes it to change from being at rest to being in motion. When it is being lifted through the pulley mechanism, the force exerted is different and therefore causes a different change in its velocity.

When the Moai is first pushed by manpower it slides down the slope. The force applied on the Moai makes it do work because it causes it to move. When the Moai is being pulled by the pulley both horizontally and vertically, work is also being done because the Moai is physically moving upwards and being lifted in vertical position. Because the work being done to the Moai occurs over a certain amount of time, power is also being applied. If we wanted to transport the Moai from the quarry to the ahu quickly, we would need to exert greater power. Therefore, its preferrable to move it slowly because less power will be required to transport the Moai.

Finally, using basic laws of motion, we discovered that at the top of the hill the Moai has a gravitational potential energy of 215977 Joules and that when it is first pushed, that energy is transformed into kinetic energy, making it possible for it to move.

Conclusions

After finalizing the construction of our transportation mechanism for the Moai we realized how hard it was to build a structure of such a big magnitude and how hard it must have been for the Rapa Nui to create their own mechanisms that successfully worked. We have learned that group work is a challenge and that meeting deadlines and organizing our time is hard especially in such a big project and such an important one. Overall I think our company didn't necessarily gain more knowledge about Easter Island’s history, but instead we learned work ethics that are really important on a regular-day basis such as consistency, responsibility, group work, etc. This was a great project to participate in and we are honored that it was offered to us. If we were presented with such a challenge again we would happily redo it all over again because it has created so many good experiences and has helped us grow as a company and learn from our mistakes.

APC