Does Moss Grow on the North Side of DVHS Amphitheatre?

Does Moss Grow on the North Side?

by Michael Peterson

Astronomy/Physics Research class

May 2004

Abstract: This lab is centered around a long-standing theory that moss grows on the north side of any given object. In order to further test this theory I have taken digital pictures to analyze on a computer the amount of moss on a basis of defined sections of a circular amphitheater at our school. Moss grows on the steps of the amphitheater. Each section represents a number of degrees. I later laid out all the pictures in order from east to west and found the sections then used the computer to analyze the sections identified on my panoramic. The equation I used was Asin(W Section=Delta) =Yzero to determine as the expected outcome, I compared the difference between the two peaks of data to decide whether or not my hypothesis was true. I found that the moss does not grow on the north face of the amphitheater.

Hypothesis: Greatest concentration of moss and the location of based on casual observations I believe that moss doses grow on the north face of the Deer Valley amphitheater to great precision, north determined by the North Star.

Procedure:

1. I took pictures of the Deer Valley amphitheater, standing in the center of the amphitheater and slightly turning between each picture creating a series of overlapping pictures covering the whole amphitheater. Where I stood in the amphitheater, I made sure that I stood in the same place on each take. The time of year, I took all of the pictures on the same day. Sun imbalance, all these pictures were taken on a cloudy day so the sun is guaranteed equal sun distribution throughout.

2. I put together a panoramic picture made of all of the overlapping pictures by laying them all out on the table, finding the points of overlap in each image, then taping the pictures together to form the panoramic image.

3. I found the sections on the panoramic image using the lines in the concrete as section borders, the lines are regularly spaced.

4. I conducted density slices on NIH image on a sectional basis. The sections are selected by cropping out the sections in each image that is not within the current section of interest. The density slice is done by focusing on the dark range by sliding the assigned false color minimum and maximum rating over shades of gray that represent pixels within the pictures and thereby replacing each shade of gray on the slider covered by the assigned false color on the actual image with the assigned false color. Creating a single color for a limited range of brightness that can be measured by the image processor just by clicking measure. This will measure the color generated by the density slice.
This is an example of a density slice image creating a false color for all the dark colors in the section.

5. I wrote results on a sectional basis using a table that could used to make a graph.

Data Table: Here is the data. Moss Count is the area, in pixels, of the moss (colored red using a density slice) in the picture.

section	Moss Count
1	12385
2	13731
3	17579
4	18769
5	22762
6	21599
7	27079
8	34484
9	36192
10	57015
11	59345
12	56244
13	45192
14	53248
15	54257
16	61550
17	52223
18	59260
19	36630
20	41241
21	34118
22	25623
23	23186
24	15557
25	14663

Model:

6. I compared sectional data on a single graph and estimate the equation, using the different variables in the sine wave, sliding the number bar on each variable to match the curve with my data points. The equation used to estimate the moss maximum is Asin(W Section=Delta) =Yzero. Yzero is 36996, A is 26253, W is 0.251 and Delta is 4.32. The curves maximum height is at section 13.99. the values ere adjusted to make the model fit the data.

This is the graph that came out of my data. The dots on the graph are data by section and the continuous line is the line of best fit to the line of dots. Sections 6, 13, and 19 are sections with steps in the way causing slight decline in moss count

7. I compared due north determined by Polaris versus the hypothetical moss north using the picture with the celestial north and the moss north on the panorama. Mr. Adkins moved around the edge of the amphitheatre until the North Star was directly over my head. This is what I call 'Real North.' Moss North is where the maximum growth of moss was from my graph.

This image is my comparison image that I took with celestial north in view and moss north in view. The Celestial north is at section 10.75, that area of this image is labeled celestial north and moss north is at 13.9 labeled moss north. The amphitheater has a diameter of approximately 40 meters. Celestial north was identified by lining up where I stood and the North Star (Polaris) at night by walking around the amphitheater and finding that point. While walking around I was constantly comparing the North Star and where I stood taking the picture using a meter stick edge. That point would then become known as celestial North.

Conclusion: Due to my or original hypothesis being wrong I have a new hypothesis that the moss grows away from the sun in the heat of the day. The heat of the day is generally about late afternoon between 3:00 PM (15:00 HRS) to 4:00 PM (16:00 HRS). To find this out I would have to find the local heat of the day using Deer Valley High School’s own weather station. This topic bears further investigation, which is surprising.

References:

Data analysis was performed on a Macintosh computer using the public domain NIH Image program (developed at the U.S. National Institutes of Health and available on the Internet at http://rsb.info.nih.gov/nih-image/)".

Comment from teacher: Just for the record, the maintenance staff cleaned the moss off of the amphitheatre a couple of days later as a part of routine maintenance. Michael just happened to be ready to take pictures at the right time--a couple of days later, and he couldn't have done the project. We have a nice looking campus and the custodial and maintenance staff do a great job making it look nice with a staff that is far too small for the workload. We appreciate them and wouldn't want anyone to think we're pointing out a deficiency in their work. JA

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