S&H

  

 

1. Image of the Sun

Place a pair of binoculars in an open window in the direct path of the sun’s rays.

Stand a mirror in front of one eyepiece so that it throws an image of the sun on to the

opposite wall of the room. Adjust the mirror until the image is sharp, and darken the

room.

You would risk damaging your eyes if you looked directly at the sun through

binoculars, but you can view the bright disc on the wall as large and clear as in the

movies. Clouds and birds passing over can also be distinguished and. if the binoculars

are good even sunspots. These are a few hot areas on the glowing sphere, some so big

that many terrestrial globes could fit into them. Because of the earth’s rotation, the

sun’s image moves quite quickly across the wall. Do not forget to re-align the

binoculars from time to time onto the sun. The moon and stars cannot be observed in

this way because the light coming from them is too weak.

2. Sun clock

Place a flowerpot with a long stick fixed into the hole at the

bottom in a spot, which is sunny, all day. The stick’s shadow

moves along the rim of the pot as the sun moves. Each hour

by the clock mark the position of the shadow on the pot. If

the sun is shining, you can read off the time. Because of the

rotation of the earth the sun apparently passes over us in a

semi-circle. In the morning and evening its shadow strikes the

pot superficially, while; it midday, around 12 o’clock, the light

incidence is greatest. The shadow can be seen particularly

clearly on the sloping wall of the pot.