Solar Storms and You!

Activity 9: A Soda Bottle Magnetometer....Data

This series of measurements was recorded in Adams, Massachusetts on December 25, 1998...yes, that's Christmas Day!

Local TimeRelative Deflection
(Eastern Standard)(Inches)
8:30AM36.5
9:35AM36.5
11:30AM36.7
12:45PM36.5
2:00PM36.5
2:30PM36.5
2:40PM36.6
2:45PM36.6
2:50PM36.7
2:55PM36.6
3:00PM36.6
3:05PM36.6
3:15PM36.6
3:20PM36.6
3:30PM36.5
8:40PM36.5
8:45PM36.5
10:45PM36.5
The mirror was located 32-inches from the wall, and its natural oscillation period was about 4 seconds so movements damped out within a minute. At this distance (0.82 meters), one inch change corresponds to a deflection of 0.9 degrees. A 1/8-inch movement coresponding to 0.1 degrees was barely visible with the particular 'glint' that was used to track the deflections. A 0.1-inch change corresponded to 0.09 degrees or about 5 arcminutes. the glint was about 1/4-inch wide at the wall. A significant feature of these measurements is that the spot position changes betwen daytime and nighttime positions. It has long been known that the magnetic field of the Earth does indeed have a diurnal variation as the sun rises, transits the local meridian at noon, and sets, with less activity being generated at night than during daytime. It is possible that the above data shows this trend, and it is definitely something for observers to look for in their data!

Another series of observations were made on December 24, 1998 with the following results:

TimeRelative Deflection
10:30AM35.5
11:45AM36.8
12:10AM36.7
1:00PM36.7
2:05PM36.7
3:00PM36.6
3:50PM35.3
4:00PM35.2
4:10PM35.3
4:20PM36.8
4:30PM36.7
4:40PM36.6
4:50PM36.6
5:00PM36.6
5:45PM36.6
9:35PM36.6

The change seen between 3:50 and 4:10PM was due to a slight change in the measurement procedure.

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