ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related institutions.
*****************************************************************************
Hi all,
In December I had asked for help from this list to identify people to
participate in measuring shadows from a one-meter stick at noon on Dec. 21.
With your help we were able to generate wide-spread participation.
Following is a description of our continuing efforts to collect and record
similar information for the equinox on March 20. The information below
also contains a sample of data collected in December. You may want to try
to use this data to predict the length of a shadow from a one-meter stick at
noon in your area on March 20. Our experience suggests that doing these
measurements takes a great deal of effort but does open the door for the
development of scores of student generated questions that can lead to
quality inquiry. It is going to take some time to determine how this
activity may contribute to the development of understanding of the
Earth/Sun/Moon system and annual changes. If you or others you know would
like to participate and have their data included in our database please pass
this information on:
The International Shadow Investigation,
On December 21, 2004 we measured shadows from a one meter stick and received
some very good data from Australia to Alaska. A sample of the data is
listed below. We are now continuing the project and will be collecting
shadow data for the equinox on March 20, 2005. Participation in December is
not necessary to do the March measurements. Following is the information if
you wish to participate:
If you want to participate just measure the length of a shadow (in
centimeters) cast by sunlight from a vertical 100 centimeter (one-meter)
stick onto to a horizontal surface. This needs to be done as close as
possible to local or true noon on or about March 20, 2005. Optionally, if
time permits, we are also looking for similar data from moonlight from a
full Moon at midnight as close as possible to March 25 (the date of the full
Moon).
The time for making the observations should be as close as possible to local
or true noon (when the Sun or Moon is halfway between rising and setting).
A good estimated time for making Sun shadow measurements is about 12:30 PM
Standard time or 1:30 PM Daylight time. Estimated times for measurements
from the light of a full Moon are about 12:30 AM Standard time or 1:30 AM
Daylight time. Advanced Astronomers may want to find the exact times for
true noon or midnight (i.e. Sun or Moon transit). To do this, go to the
U.S. Naval Observatory website at
http://aa.usno.navy.mil/data/docs/RS_OneDay.html. and look for the Sun
transit and Moon transit times.
AFTER YOU MAKE YOUR OBSERVATIONS PLEASE SEND THE FOLLOWING INFORMATION BY
E-MAIL TO [log in to unmask] :
* First name(s) of person(s) making the measurements
* Was this measurement for shadows made by sunlight or moonlight?
* Date of measurement
* Time of measurement
* Length of shadow in centimeters
* Your latitude and longitude. To find latitude and longitude for your
location or a place near you, go to http://www.heavens-above.com/ and click
on "Select your location from our huge database." Then select your country
and a city near you.
* Location (City/State/Country)
OPTIONALLY advance astronomers may want to include the following
information:
* Length of daylight on the day the observation was made. There are
several ways to find the length of daylight. Local newspapers, an almanac,
or astronomy magazines may have the information or you can access
http://encarta.msn.com/media_701500905/Hours_of_Daylight_by_Latitude.html.
for information on daylight by latitude.
* What was the height of the Sun or Moon? See the table at the end of
this e-mail for calculating the heights or altitudes based upon the length
of the shadows made.
* What direction was the shadow was pointing?
MORE COMPLETE INFORMATION:
The Science Center of Inquiry in Fountain Hills Arizona, USA, sponsors an
international collaborative effort to record the length of shadows from a
one meter stick at various times during the year (i.e. the solstices and
equinoxes). The effort is an extension of an IDEAS grant funded by NASA
through the Space Science Telescope Institute and information collected will
be available at no cost.
This is a world wide project, that began in December 2004, to record the
length of the shadow cast by a vertical one meter stick at local or "true"
noon in December, March, June, and September on the longest, shortest, and
in-between days of the year called the solstices and equinoxes. As an
option we are also seeking similar data for shadows created by full
moonlight at midnight. All persons are invited to participate and
participation in the December data collection is not required for
participation at this time.
FOLLOWING ARE SOME SAMPLE MEASUREMENTS FROM ON OR NEAR DECEMBER 21, 2004. A
complete list of shadow measurements is available by e-mail to
[log in to unmask] . MAYBE YOU CAN PREDICT THE LENGTH OF MARCH
SHADOWS BASED UPON THESE REPORTED OBSERVATIONS. What questions may this data
help develop? What patterns can we find?:
Shadows from SUNLIGHT on or about 12/21/05:
Alaska USA: Lat.: 61.2N Shadow length: 978 cm Altitude Sun: 6 degrees
Day length: 5.4 hrs
WA state USA: Lat.: 45.6N Shadow length: 254 cm Altitude Sun: 21 degrees
Day length: 8.5 hrs
Ohio USA: Lat.: 40N Shadow length: 200 cm Altitude Sun: 27 degrees
Day length: 9.3 hrs
Arizona USA: Lat.: 32.2N Shadow length: 140 cm Altitude Sun: 35 degrees
Day length: 9.9 hrs
Mexico City: Lat.: 19.5N Shadow length: 93 cm Altitude Sun: 47 degrees
Day length: 11 hrs
Australia: Lat.: 33.9S Shadow length: 15.2 cm Altitude Sun: 81 degrees
Day length: 14.4 hrs
Australia: Lat.: 36.1S Shadow length: 23.8 cm Altitude Sun: 76.6 degrees
Day length: 14.6 hrs
Shadows from MOONLIGHT on or about 12/26/05:
Alaska USA: Lat.: 71.3N Shadow length: 97 cm Altitude Moon: 46 degrees
Night length: 24 hrs
Ohio USA: Lat.: 40N Shadow length: 24 cm Altitude Moon: 76 degrees
Night length: 14.7 hrs
Arizona USA: Lat.: 36.6N Shadow length: 10.5 cm Altitude Moon: 84 degrees
Night length: 14.3 hrs
Mexico City: Lat.: 19.5N Shadow length: 16 cm Altitude Moon: 81 degrees
Night length: 13 hrs
Australia: Lat.: 33.9S Shadow length: 168 cm Altitude Moon: 24 degrees
Night length: 9.64 hrs
Australia: Lat.: 36.1S Shadow length: 225 cm Altitude Sun: 24 degrees
Day length: 9.4 hrs
If you wish to calculate the height of the sun in degrees by using the
length of a shadow from a one-meter stick, we have a complete table that we
can send you. Following is a partial table.
Shadow(cm) Altitude in degrees
1143.00 5
567.13 10
373.21 15
274.75 20
214.45 25
173.21 30
142.81 35
119.18 40
100.00 45
83.91 50
70.02 55
57.74 60
46.63 65
36.40 70
26.79 75
17.63 80
8.75 85
0.00 90
We hope to receive your data:
Bill Schmitt, Executive Director & Science Partner
The Science Center of Inquiry (480) 816-6094
[log in to unmask]
***********************************************************************
More information about the Informal Science Education Network and the
Association of Science-Technology Centers may be found at http://www.astc.org.
To remove your e-mail address from the ISEN-ASTC-L list, send the
message SIGNOFF ISEN-ASTC-L in the BODY of a message to
[log in to unmask]
|
