Date: Mon, 12 Feb 1996 17:13:29 -0600
To: noon@lynx.ed.uiuc.edu
From: ksmith@ncsa.uiuc.edu (Kathleen Smith)
Subject: Noon Project 1996

Welcome All, Old and New.....

   Well, we have over 125 sites already signed up for this year's running
of the Noon Project, so I thought I would not send out a general message to
look for more......I think my students and I will be kept busy with the
group we already have.  Now we need to decide on a date.
      The Vernal Equinox is on Wednesday March 20th and I think that's the
best bet.  If it was good enough for Eratosthenes, it should be good enough
for us.....But I know a lot of schools may be on spring break at that time.
 How about send back a message as to whether that date is good or not.  We
can change it if we have a lot of vacationers.....We would try to take the
data anywhere from Tuesday March 19 to Thursday March 21.
        When you send your response try sending it to the reflector address:  
                     noon@lynx.ed.uiuc.edu
That way we can all get the message and make sure the list is working. 
When you respond you may want to say a little about your location, your
grade level, etc.  It's fun to get to know the other folks taking
part.......Here's hoping we have a very sunny March.......Kathleen         
                                                              
Kathleen Smith
Mathematics Teacher
Central High School
Champaign, Illinois   61820




Project name:  THE NOON OBSERVATION PROJECT

Purpose:  Use simple measurements and calculations to
determine the north-south circumference of the Earth.

Content area: Math, trigonometry, elementary statistics,
science, social studies & geography.

Background:   Over 2,000 years ago Eratosthenes made a
remarkably accurate measurement of the earth's north-south
circumference. This project requires collaboration of
students in places at different latitudes of the earth to
make some simple measurements, share data, problem solve the
algorithms required, and then replicate and share their
results. This is a real, practical experiment which  may
provide practice making measurements and using
trigonometry, and statistics.

How to participate: Send a message to me:
     ksmith@ncsa.uiuc.edu
stating your interest in participating. We will then set up
a private conference that will give easy access to one
another as we develop this project.
   Observations: March 19 to Thursday March 21
   Final results shared:  Early April


General Procedures:
1.  At least two sites must collaborate whose latitudes are different
enough to give a significant difference in measurements.

2.  On the given date (or within a day or two on either side,
depending on weather conditions) students will conduct their measurements
outdoor at high noon, local time. (You will need to determine your local noon.
Most radio or TV weather persons can give you this information.)

3.  Using a standard meter stick, at precisely high noon
local time, each team of  students (probably 2/team) will:
  a) lay out a piece of paper flat on the ground
  b) hold the meter stick perfectly vertical( It may be taped to a metal
      book end, set in sand inside a liter plastic bottle, etc.)
  c) mark on the paper the end of the shadow at one
     minute intervals over a ten to twenty minute period.
  d) several measurements should be made by several different
     students or teams of students ... the more the better.
  e) measure the length of the shadow cast by the
     meter stick to the nearest centimeter  and these
     measurements will then be analyzed by the students.
  f) using statistical computations (chosen by the teacher and/or
     students) the class should arrive at what they feel is the
     length of the shadow cast at local noon (which should be the
     time of the shortest shadow).

4.  This length of the shadow  at local high
noon  and the date on which the measurement
was taken will be sent to the other sites involved
in the project.

5.  This data along with the latitude for each site
is enough information to use trigonometry and a simple
proportion to make a fairly accurate calculation of
the Earth's circumference as determined by each pair
of sites.

6.  A spreadsheet for each site of the comparisons with all
other sites will be provided at the end of the project.
The formulas to set up your own shreadsheet will be
provided on request.

Additional details:

1. This project could be the basis for some really good
problem solving for your class. Using your own algorithm,
this could be a contest to see who, using this data, gets
the closest results.  Or, this could lend itself to some
interesting discussions between students at the cooperating
schools to come up with a joint algorithm.

2. This project also will consider whether we should use the
median or modal values of the shortest lengths of the
shadows rather than just a simple average in the calculation
of the circumference of the earth. Which measure will give
the  most accurate result? We will send out a chart showing
the results for each pairing of sites.

3. Plotting of each site on maps using latitude & longitude
will enable each site to calculate north-south distance, and
east-west distance between sites. Knowing the north-south
distance is essential to solving this problem.

4. Background information on Eratosthenes of Cyrene
and his accurate calculation of the earth's circumference
can be found in the online version of  Grolier's Encyclopedia.


We hope you will join us!

Kathleen Smith
Mathematics Teacher
Central High School
Champaign, Illinois   61820