Measuring Altitude with Your Hand
The North Star is an extremely valuable tool for explorers, because it is straight up from the north pole of Earth and always shows us where north is.
IF this way is north, which way is south? East? West?
[Point out those directions.]
If the North Star is directly over the North Pole, where in the sky would you find the North Star if you were standing at the North Pole?
[Straight up.]
DIGITAL EFFECT: Teleport to North Pole
Crossfade the scene to today, noon at 90°N latitude and your theater’s local longitude. Use to demonstrate Polaris’ location at the zenith at the North Pole. Turn on position information for reference.
DIGITAL EFFECT: Highlight Polaris
DIGITAL EFFECT: Unhighlight Polaris
As you move southward from the North Pole, the North Star is seen lower and lower in the sky. If we take a journey south for several days, we see the North Star get lower and lower in the sky.
DIGITAL EFFECT: Teleport Equator
Crossfade the scene to today, noon at 0° latitude and your theater’s local longitude. Use to demonstrate Polaris’ location on the horizon at the equator. Leave position information on for reference.
DIGITAL EFFECT: Highlight Polaris
DIGITAL EFFECT: Unhighlight Polaris.
Turn daylight up and down rapidly to simulate days going by, and move the latitude south by a few degrees so that its movement is noticeable.
Where would the North Star appear in the sky if you were at the equator?
[On the horizon.]
If we travel northward, will Polaris appear to get higher or lower in the sky? [Higher.]
You can use your hands to measure the height of Polaris. Try it.
DIGITAL EFFECT: Teleport 40 Degrees
Crossfade the scene to today, noon at 40°N latitude and your theater’s local longitude. Used to demonstrate Polaris’ location at an intermediary height above the horizon.
DIGITAL EFFECT: Highlight Polaris
Highlight Polaris. Use as a reference for the audience while they take their hand measurement of the height of Polaris above the horizon.
Demonstrate how to hold hands or fists to make a measurement of the altitude of Polaris. Any way of doing this is fine, as long as you do it the same way every time.
DIGITAL EFFECT: Unhighlight Polaris.
Let’s make a journey of many days. See if you can tell if we have traveled north, toward Canada, or south, toward Mexico.
DIGITAL EFFECT: Travel to 30 Degrees
Travel to 30°N latitude and your theater’s local longitude over 15 seconds. During the “travel time,” fade the atmosphere and the Sun on (over 2 seconds) and off (over 2 seconds) three times to simulate the passage of time over many days—even though no time is actually changing. Make a 4 second delay between the fade down and the following fade up of the atmosphere so the stars are visible for more of the “trip.”
DIGITAL EFFECT: Highlight Polaris
Highlight Polaris so the audience may confirm travel southward (Polaris is lower).
DIGITAL EFFECT: Unhighlight Polaris
Unhighlight Polaris and fade off the position information.Measure Polaris again with your hand.
Have we gone toward Canada or Mexico? [Mexico.]
Just by using their hands, explorers can tell roughly how far north or south they have traveled.