Project 2: The Story
Astronomy is one of the oldest sciences. All one needs to do is look
up on a clear night and absorb the beauty of the star filled sky, or
observe the magnificence of a solar or lunar eclipse. However, there
are also more practical reasons for having an interest in astronomy.
For example, the
Ancient Greeks knew about the connection between the seasons and the
relative orientations of the Sun and Earth. Furthermore, seafaring cultures
were aware that the tides are influenced by the position of the Moon.
Several ancient civilizations placed great importance on astronomical
observations. Hundreds of impressive monuments, such as stonehenge,
that dot the British Isles provide evidence of this emphasis on astronomical
observation. For example, at stonehenge various stones point to the
locations where the Sun and the Moon rise and set at key times during
the year, such as the solstices and equinoxes. Another example is the
great medicine wheel in Wyoming. The medicine wheel, constructed atop
a windswept plateau by Native Americans. The wheel is a circular ring
of stones where certain stones mark important astronomical events, such
as the rising of bright stars and the Sun at the summer solstice.
The Aztec, Mayan, and Incan architects in Central and South America
designed buildings to be astronomically oriented. For example, the city
of Tiahuanaco, in Bolivia, the Temple of the Sun was built with its
walls aligned north-south-east and west with an accuracy of better than
1 degree. The Egyptian pyramids also have their sides oriented north-south-east
and west.
Eratosthenes was only one of several brilliant astronomers to emerge
from the Alexandrine school, which by his time had a distinguished tradition.
For example, one of the first Alexandrian astronomers, Aristarchus of
Samos, had devised a method of determining the relative distances to
the Sun and Moon, perhaps as long ago as 280 BC. He concluded that the
sun is only 20 times farther from us than the Moon. We now know that
the average distance to the Sun is about 390 times larger than the average
distance to the Moon.
However, Aristarchus also made an attempt to determine the relative
sizes of the Earth, Moon and Sun. By observing how long it takes for
the Moon to move through the Earth's shadow, Aristarchus estimated the
diameter of the Earth. He also realized that the Sun and Moon have the
same angular size in the sky, thus based on this observation he was
able to determine the size of the Sun.
Ancient astronomers, particularly those of Greece, gave us a new and
powerful way of thinking about the world. They gave the first clear
demonstration that the tools of logic, reason, and mathematics can be
used to discover and understand the workings of the universe. At the
present time we have tools that we can use to model the universe and
ask very profound questions regarding our model of the solar system
to gain an understanding of our wondrous solar system. This questioning
is what we will do for our 2nd project.
Project 2: The Earth-Sun-Moon System
This project requires quite a bit of planning before hand. You should
create a plan with your teammates on what needs to be done who needs
to do it and how it needs to be done. This includes gathering information
concerning the Earth-Moon-Sun system, determining viewpoints.
It is also useful to keep a log notebook that contains data concerning
what you have done and how your team decided to demonstrate astronomical
concepts. This is useful for two reasons: 1. Allow you and your team
to discuss what needs to be included in your compare/contrast papers.
2. Provide a coherent and concise presentation concerning your project.
Remember that you will have visitors to your web site and they will
want to learn about astronomy as well. Thus, your model will have to
be able to answer questions that users will ask. Some questions are:
- What are the differences between a full Moon and Lunar Eclipse?
- Does the Sun ever rise on the Moon?
- What, if any, do the phases of the Earth look like from the Moon?
- What are differences between sidereal and synodic periods for
the Earth and Moon?
- What conditions are required for a solar eclipse?
- Where are the Van-Allen radiation belts on the Earth and the Moon?
- What are the differences and similarites between the Earth, Sun
and Moon interiors and atmospheres?
Remember: Be on the lookout for astronomical phenomena that may be
difficult to measure and stay aware of how that affects your model as
compared to the real solar system. Also, in order to demonstrate a phenomenon
your team must locate the necessary information. Your text book is a
wonderful resource for the Earth-Moon-Sun system.
Pages 110 - 131, pages 20 - 35 and pages 206 - 221 are very uesful
reading for the 2nd project.
Also the following links have good information concerning the Earth,
Moon and Sun.
The Model
When scientists begin study on a phenomenon they begin with certain
known facts or theories, then create a model based upon what they know
which in several cases is very little. Once they have a model of the
phenomenon a good scientist asks questions that then use the model to
demonstrate or obtain solutions to their questions. If the model does
not provide satisifactory solutions, that is solutions that are physically
reasonable, then the model is thrown away and a new model is developed
and the scientist starts the process again. Therefore one must always
be asking questions, or using your model to demonstrate a physical law,
relationship or concept.
In designing your model you should keep in mind what astronomical concepts
you wish to model. For example, you may decide that you want to know
what the the Sun's path across the sky looks like from the north pole.
Then you would want to place a viewpoint at the north
pole on your Earth. You can think of a viewpoint as looking out through
a camera. In fact, viewpoints are represented by a camera.
Animation
Before you animate something make sure you have all the viewpoints and
objects where you want them. After you animate an object you can no
longer add viewpoints (though in VRcreator there are some ways around
this, there are no ways around this problem in CosmoWorlds) and have
them included in the animation.
Suggestions for the Earth-Moon-Sun
You should decide on a plan
and maybe a timeline on how to finish the project. If you run into a
technical problem that you can't solve ask your neighbors and your instructor.
It is important not to get bogged down on computer related issues when
you are working on your model. Also don't get frustrated when the computer
just won't do what you want it to do. We are on the cutting edge of
new technology (great resume addition) and at times we will have situations
when the software just will not coperate.
When constructing your model it is best to try to get everything lined
up before your begin rotating and animating. Another excellent thing
to do is to change your view from front view to top view or back view.
This gives you a different perspective on the problem and can often
led to new solutions that are not obvious from your current view.
Of, course during the course of the project the instructor will be
questioning each team on what concepts they are attempting to model,
and each team will be expected to ask questions of the instructor and
each other to construct a good project.
