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Paper Plate Education
"Serving the Universe on a Paper Plate"

Video Excerpts: Altitude Measurer 

The following pictures and narration are excerpted from the Paper Plate Astronomy  video.

For this activity we will make an astrolabe-like device for measuring (in degrees) the altitude of  celestial objects up from the horizon.

Dsc00001.jpg (21290 bytes)Using a foam plate with 36 scallops around the perimeter, mark and label ten degree increments from zero through 90.  

Dsc00002.jpg (17782 bytes)From the 90, draw a line across the diameter of the plate.

Dsc00003.jpg (17444 bytes)Place a straight edge along the diameter and draw another line parallel to and above the diameter.

Dsc00004.jpg (19356 bytes)As shown here, on the flat part of the plate in from each edge draw two perpendicular lines between the horizontal lines.

Neatly cut across the plate along the upper line.

Dsc00005.jpg (20922 bytes)Then cut in along the diameter as far as the short line you just drew... And repeat that on the other side.  

Score the perpendicular line from the horizon up to the top edge...and bend the tab back one way.

Dsc00006.jpg (18570 bytes)Repeat that on the BACK side of the other edged of the plate and bend that tab back the opposite way.

For clarity we put red lines along the top of our viewing sights.  

Dsc00007.jpg (19957 bytes)From the center of the plate, midway along the diameter line, suspend a weight from string.

Dsc00008.jpg (185004 bytes)When using the altitude measurer to sight a star, the plate can not appear open.   Rather, the sides of the plate are unseen and the two gun sights should be side by side.   

Dsc00009.jpg (177921 bytes)If the near gunsight is lower, then you are aiming too high...

Dsc00010.jpg (177107 bytes)If the distant gunsight is lower, then you are aiming too low...

Dsc00011.jpg (176074 bytes) They should align together with the target visible along the edge of the plate    

Though the targeted celestial object shown here looks like the sun, you must never use this device to view the sun directly.  Eye damage can result.

Dsc00012.jpg (134844 bytes)Have a partner read the angular measurement off the front of the plate.


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Copyright 2012 Chuck Bueter.  All rights reserved.