Mathematics and Society - OS X Lion Server

\g THE SUNWITHIN QANGE?(PM€: 3)(\4. In sighting an object, the angleformed by the sighting bar and thedotted line is the same size asthe angle formed at the object(alternate interior angles formedby two parallel lines and atransversal). See Figure 7.AlJGLt" ARE T\1ESAME SIZE..As the distance to objects increases,the angle between the sighting barand the dotted line becomes smaller.FIGURE 7III. Use the range finder to try to measure the distance to the Sun. (CAUTION: DO NOTLOOK DIRECTLY AT THE SUN.)1. Because of the danger of looking at the Sun directly, you must change your methodof sighting. Instead of lining up the pins, line up the shadows cast by the pins.After you have properly aligned the range finder try to read the distance to the (Sun from the scale. You will notice that the sighting bar appears parallel to the'sighting line. The angle between the sighting bar and the dotted line is toosmall to measure. See Figure 8.2. Since this range finder cannotaccurately measg.re.,:t;he distancetotoo--surrTryaltering" the···device. Investigate the effectof lengthening the base line(use two boxes side by side).How does this affect the greatestdistance you can accuratelymeasure with the range finder?AlJGLE I:'TOO SMALLTO MEAe,URE:FIGURE 8How long a base line do youthink is needed to measure thedistance to the Sun?883. Disappointing as it may seem the Earth is not large enough to provide a longenough base line. Astronomers have had to find another way to measure the dis- (tance to the Sun. In the activities It's A Gpeat System and Making Waves youwill discover a method.IDEA FROM: In Orbit, Probing the Natural World, Level Ill, Intermediate Science Curriculum StudyPermission to use f:lranted by Silver Burdett General Learning Corporation