For this project we had to design a Greek invention that was used by the Greeks in ancient times. My Greek invention was the eclipse. Although it wasn’t really an invention it helped the Greeks figure out what date to set the Olympics, and it was also believed to stop a horrible war that would have happened. For my museum exhibit I made a eclipse display with my partner Monica Zimmerer. I was really proud of the exhibit, but it I were to change one thing it would have to be to screw things in the right way and fix some problems we had. Overall I really liked this project and I had a fun time learning everything I did in the project.
here is a picture of our exhibit: |
ProposalHere is our proposal, it includes some facts and things we learned about eclipses:
Eclipses Before
Eclipses are something we’ve all probably wondered about. They have been around for a long time. The eclipse was originally discovered by Thales of Milette. There are two types of eclipses, a solar eclipse, and a lunar eclipse. A solar eclipse is where the moon covers the sun and all you can see is the suns light rays from behind the moon, a ring of light also appears around the moon. A lunar eclipse is where the earth is The Greeks didn't really have specific technology to view he eclipse, they just saw it with their bare eyes. one story about the eclipse was that in Ancient Greece they were about to go to war and this was right before a eclipse was occurring and when the eclipse was going on the Greeks thought it was a gift from the gods to them and they decided to make peace and not go into war. In other words they thought the eclipse was stopping them from going into war. By 450 BC the Greeks were at their highest advantage in their civilization. One certain historian said that Thales could predict the year of which the next solar eclipse would occur. The ancient Greeks also used a special calendar to mark when the next Olympics would happen, and coincidentally the year the Olympics were held was the same year a total eclipse would occur. This special calendar was called the Antikythera Mechanism. A while back some scientist were diving off the island of Kythera, which is located between Greece and Crete. The eclipse did not happen every day but the lunar eclipse happened once a month, so it was not used in everyday life, but the way the tides worked it pulled the moon towards the earth and that's what causes the moon to rotate around the earth. (Figure 1:) In the Lunar eclipse you can see that the earth is in the suns path from getting it rays to hit the moon so the remaining rays of light over cast onto the moon and sometimes this causes the moon to appear as a reddish or orange hue during a lunar eclipse. (Refer to figure 1)
In the Solar eclipse you can see that the Moon is in between the sun and the earth, the way that the moon is positioned the suns rays can not completely cast on the earth because of the moon right in between them , with this happening, some where on the earth, weather in the middle of the ocean or a country a certain part of the earth gets darker from the moon blocking the suns light ray path to the earth. When viewing if you are located at the center point of the eclipse, the moon may look like it has a ring of light around it or as if it is borders with the suns light rays. (Refer to figure 1) One major physics concept that has to do with the eclipse is the tides, the tides have a major effect on the moon because the moon is closer to the earth so its gravitational pull is stronger. This is why the tides rise up to the shore lines. Also when the tides go back towards the ocean this is happening because the earth is rotating away from the moon and it is weakening the gravitational pull away from each other, this is how the moon and the tides work together and overtime they both happen to pull away and pull closer together and relates to the eclipses. Another major physic concept that has to do with the eclipse is gravity, gravity affects the eclipse in such a way when the earth rotates towards and away from the sun and the moon the gravitational pull either get stronger or weaker. This causes the eclipse to be not as strong as a total eclipse, where the three figures, the earth, sun and moon, are aligned perfectly to engage in a total eclipse. with this known, gravity plays a MAJOR part in the eclipses that occur every so often. The sun and the moon both have the same angular diameter which is, 0.5 degrees. And the sun has to actually be 19x the moons diameter, the correct formula would be, aSun=19 x aMoon, where the a stands for the area of the sun which equals 19 times the area of the moon. This equation is also combined with, aEarth=3 x aMoon, as to where the area of the earth is equal to 3 times the area of the moon. And both of these equations imply that, aSun ~ 6 x aEarth, which states that the area of the sun is relevant to 6 times the area of the earth. That is how you would calculate the diameter of the sun. The variables in the equation is just a, and a is standing for the area in this case, so as said above, the area of the sun which equals 19 times the area of the moon. And also, the area of the earth is equal to 3 times the area of the moon. An example problem might be, let say the moon has a radius of 3(IRRELEVANT) you would find its area by multiplying Pi and 3(radius of moon) so that would equal 9.42 and multiply it by the power of , once you do that you would multiply that with 19, and then you would have you area for the sun which would equal 1685.9 aSun=19*aMoon aSun=19*(3*3.14)^2 aSun=19*88.73 aSun=1685.9 Eclipses Now Today, measurements can be made very precisely using reflectors. The reflectors were put on the moon during the ‘Apollo and Lunokhod missions’. These reflectors can measure lunar acceleration and any decrease in Earth’s rotation. To analyze an eclipse, scientists also need high quality telescopes, or even binoculars in order to view how it affects planets and how the moon and the sun ‘interact’. Since a solar eclipse is so bright, scientist must use special glasses or else the sun’s rays can be harmful to their vision, to a degree that they can go blind. A complete eclipse only appears every four years, yet a partial eclipse is visible annually. They do not occur on a daily basis, but on rare occasions, both solar and lunar eclipses will happen in a year. (Figure 2:) Shown on figure 2, is a diagram of a solar eclipse. The Sun is aligned with the moon, thus casting a shadow on the earth’s surface. This shadow has two main parts, the umbra, which is the dark part of the shadow, or the center. The second part is the penumbra, which is the shaded region around the umbra. (Refer to figure 2) (Figure 3:) Shown on Figure 3 is a diagram of a lunar eclipse, and its relationship with the sun and the moon. The sun’s rays are beaming on earth, creating a shadow on the moon, thus a lunar eclipse. (Refer to figure 3) Scientist have arrived at the conclusion that the moon also has to do with the ocean’s wave and the tides they cause. This is because of the moon’s gravitational pull. Since the moon is closer to the earth’s ocean, the attraction is stronger, therefore pulling the ocean waves closer to the surface. This not only happens once a day, but twice. This is possible due to the rotation of the earth. When the earth rotates away from the moon, the gravitational force weakens, allowing the water to go back towards the ocean. Another natural occurrence the moon provides, are black holes. Both of these physics concepts depend on gravity for them to exist or happen. The variable for G is constant, always equalling to: 6.67 x 10-¹¹ N∙m²/kg² (0.0000000000667 N∙m²/kg²). (Equation 1) The law of gravitation is the same for every object in this universe. T² = 4π² r³ Gms (Equation 2) The following equation is represented by variables T, r, G, m, and s. Where T represents time, G represents gravity and r is the distance from the center of the earth. With equation number can prove Kepler’s second law that states that the way planets move also apply to the moon. There are only a few equations you must know. First you must know the equation for gravity, which is expressed in equation 1. Also the distance from the center of the earth to the moon, which is approximately 6640 km.You can then find time, T. The final equation will be : ___ T² ___ = ________4π²________ 6640km³ 6.67 x 10-¹¹ N∙m²/kg² Hands-On Component: The exhibit will be a 3’x1.5’x1” box. It will be painted black (to resemble space) with some stars painted on. The arch, levers, gears, etc. will all be painted black and be made of wooden materials. This will allow the sun and the moon to pop out more. The sun will be bright orange/yellow, and the moon will be white. This exhibit will teach students about eclipses because they will be able to move the sun and the moon in a rotation, similar to the one that happens in space. The notes included will provide further information and any facts needed to understand the concept of eclipses. They will also explain some physic concepts, although these concepts will also be emphasized on the actual hands-on component. The exhibit will be professional because we will have exact measurements, and it will also be neat, and free from glue stains, rough edges. Also it will be esthetically pleasing because the supplies will be wood, which will also make the exhibit durable. The exhibit will be user-friendly because it will contain levers, and gears they can turn. The display’s purpose is for the audience to be able to move the sun and the moon to see their rotation, therefore it will be a hands-on activity allowing students to see exactly how the overlap. This exhibit will also include descriptions of an eclipse and background information on both Modern ideas and ancient Greek's thoughts of eclipses. The sizes will be as realistic as possible. Also, the details will be brief, as to not loose the audiences attention, yet thorough, so no further doubts will be left. |