Module+1+-+The+Big+Picture

Module 1. Lesson 1. Where am I? toc


 * I n this module we will begin by looking at some key discoveries and the process, usually long and complex, that led to those discoveries. We begin with the question of how we know where we are on the surface of the Earth.

We started to think about this   problem during the summer session when you worked in teams to discover the polar circumference of the Earth from simple measurements that you could make right here on campus. Everyone had some idea about the polar co-ordinate system and roughly how it works. But how do we use that system and other information to figure out where we are on the surface?

Most of the surface of the Earth is water (about 70%) and there often are no clearly distinguishing features to help you along. As you will see from the readings for this week, it seemed relatively easy for people to figure out what latitude they were at but longitude was a troubling problem that took hundreds of years to resolve.

The solution depended on a highly skilled clockmaker who spent most of his life perfecting and improving clock designs. It was only when a competition was announced to encourage inventors and seamen to figure out how to determine longitude from any location on the globe for the right technology to match up with the right research question.

**

READING ASSIGNMENT:
 So let’s begin by reading about the secrets of ancient navigation techniques at this NOVA site. [] 

DISCUSSION TOPICS:
 1) While you read this article, make a time line of the major discoveries showing the dates and the discovery using a pencil/pen and a piece of paper. Do you notice anything interesting about the spacing and the timing of discoveries? Is this how you might have imagined discoveries would be made? If not, what is different.

2) Try to figure out exactly how a crossbar and a sextant works. You will be making a very similar instrument to measure the heights of distant objects.

LONGITUDE:
 What about longitude? How did it happen that someone figured out how to determine longitude at sea? In 1714, following a maritime disaster, the British Parliament offered a 20,000 pounds sterling prize for the first reliable method of determining the longitude on a ship.

It was well known that longitude can be found by comparing a ship's local time to the time at the port of origin. The challenge is finding a clock—a chronometer—that can keep time at sea, where temperature changes, humidity, gravity and a ship's movement affect accuracy. Early attempts were based on the assumption that astronomy could solve the problem.

Self-taught clockmaker John Harrison believed the answer lay in large mechanical clocks. Through careful observation and experimentation, he invented many adaptations to improve clock accuracy. After decades of work, he realized that pocket watches are a better choice and as a result he decides to redirect his efforts to pursue this smaller technology. It took 50 years from the time of the first announcement of the prize for determining longitude at sea but in 1764, Harrison's watch proves accurate in helping determine the longitude on a six-week voyage to Barbados.



ASSIGNMENTS:
  1) Try finding your position at sea from what you know by playing the game []   Find at least 3 positions in the game and write down how you determined what those positions where in a new entry to the “Assignments” section of your personal Wiki.

2) Modern tools for determining location on the Earth rely on satellites and very accurate clocks. The global positioning system (GPS) technology has revolutionized both everyday life and scientific investigations. To find out how GPS works go to []  and complete the tutorial. In your personal Wiki "Assignments" section write one or two paragraphs comparing and contrasting the basic principles of GPS units and the navigation technique that John Harrison’s invention made possible.

3) Make a clinometer. Instructions are provided as part of the "Making Observation - Phases of the Moon" activity.

4) Once you have a working clinometer that you have tested and are satisfied with you can begin your daily observations of the phases of the Moon.

5) Read through the “Great Challenges” at <span style="font-size: 10.89pt; font-family: Arial, Helvetica, sans-serif;">[] <span style="font-family: Arial, Helvetica, sans-serif; font-size: 120%;"> Can you see yourself involved in research in any of these areas? What interests you? Why? Be prepared to discuss your thoughts on these challenges at our next //<span style="font-family: Arial, Helvetica, sans-serif; font-size: 120%;">Elluminate // <span style="font-family: Arial, Helvetica, sans-serif; font-size: 120%;"> session.