Global Civilizations

The intent of this blog was to show my progress studying the content of the Global Civilizations curriculum I helped produce in 1992. I expected to update it with current examples from my life as time went on.

My Photo
Name:
Location: Las Vegas, NV, United States

We have been gardening together since the fall of 2001. John sifts the soil and Lee grows the greens. We prefer greens and roots in the winter and harder stemmed veggies in the summer such as peppers and cucumbers. John looks after his worms and tumbles compost. Lee tracks the seeds and the work schedule here in the northwest Mojave Desert.

Sunday, April 29, 2012

Solar System Calendar Clock

The purpose of this toy is to help identify the planets in their orbits from earth and appreciate the difficulty in deducing a heliocentric solar system from observed phenomena.

This is my first "clock."  The right ascension has been divided by two to represent a more familiar 12-hour clock face.  The relative positions of Saturn, Jupiter, Mars, Earth and Venus are given by the purple, orange, red, yellow and white disks.  Since it is my first, there are problems.  Perhaps you can make a better one.

I would hope you could populate the edge of your clock with the proper positions of familiar stars from your vantage point on earth.  Also include the relative motion of your planets in terms of their orbital period on a 12-hour dial.  For example, Saturn's orbital period is about 30 years.  That means, on average, that dial would move about four hours in ten years.  Venus on the other hand, would move an hour and a half in only a month!

If you are looking at the night sky regularly, you will no doubt have no need of such a simple device to recognize your planets.  I live in the city and get curious only every so often.

I used multicolored six-inch foam disks from a local crafts store.  You can use construction paper or what ever is handy for you.  I would hope it would be something you could use again and again as the years go by.  For us, there will be an eclipse near here next month.  Of course this would not show that event, but you could see how you could build one to represent the earth, the moon and the sun in such a case.  On the other hand, the transit of Venus across the surface of the sun should be a clear bell ringer for this calendar clock!

Labels: , , , ,