Stuck in someone else's frames? break free!

LET THERE BE LIGHT!

Fix a small mirror on a windowsill so that light from the sun is reflected on a large sheet of graph paper on the wall inside. If the sun does not shine directly through the window, a mirror can be attached to a tree or some other fixed object to reflect it inside. Or, maybe you have more than one window in your house or in your classroom.

Each day mark the location of the reflected sunlight on the
graph paper. If you have the opportunity to observe a solar eclipse, it is interesting to begin marking several days before and to continue marking several days after the
eclipse.

DUH remember not to look directly at the sun. Not ever. DUH

Here's a pretty swell sundial:

Use a protractor to make a half-circle on a 10 inch square of cardboard. Divide the circle into twelve 15 degree angles and number them. Determine the latitude of your school.

Some latitudes are given below:

St. Paul, Minnesota 45 degrees
Los Angeles, Ca. 34 degrees
Miami, Florida 26 degrees

Get a piece of stiff cardboard, and cut a triangle that is
the same as the number of degrees of latitude of your school. Fasten the angle to the half-circle with tape. Place the instrument in sunlight so that the triangle points directly north. (North is best determined by noting the direction of the line made when the shadow is at its shortest length.) The shadow line is along the north-south line.

The shadow cast will indicate the time of day in your
location. Similar sundials can be made by sticking any
upright object such as a pencil or dowel in the ground and
slanting it to the angle of latitude in the direction of
north.

Mark the top of the shadow every hour for many days and
connect the marks to see changes in the apparent course of
the sun.

At a public park, I once saw a sundial with a place marked
for a person to stand. Standing in that spot and looking at the indications, your shadow would be cast appropriately, so that you could tell the time of day. Would that be valid all year?

Cut a round cardboard carton in half lengthwise. Glue a bead to a length of thread. Fasten the thread through the centers of the carton's ends.

Place the instrument on a level windowsill or outdoors in
precisely the same position each day by lining the thread up in a north-south direction. The thread's shadow will show sun time. Mark the interior of the carton at fifteen minute intervals where the bead's shadow is cast. By connecting these marks you will note a shift in the sun's apparent path with the seasons.

Would this information invalidate the time-of-day sundial?

Contact Spike

We publish two newsletters a couple of times a month. To subscribe, send a blank email to the appropriate email address.  Topica will send you a message asking if you really intended to subscribe - just click reply - that's it!

freerecipes-subscribe@topica.com

jewishrecipes-subscribe@topica.com

Tired of Geek Speak when
you have Computer Questions?