Astrophysics

Inverse Square Law

Page 1

Using InverseSquare

The panel on the left hand side of the applet contains a light source; this is the bright white object on the black background. In the upper left is a blue triangle; this is the view port. Click anywhere on the black panel to move the view port to that position, or drag the view port. The view port can not be dragged too far or too near the light source. In the lower left hand corner the distance of the view port from the light source is displayed in centimeters. This value updates as you move the viewport in realtime. In the lower right hand corner, the flux is displayed; this value updates only after you finish moving the viewport, that is, every time you release the mouse button. In the upper left corner, you may see a value labeled "Luminosity;" if it is present, this is the intensity of the lightsource.

To the right of the lightsource display is a table. Every time you move the view port, a new data point is added to the table. You must move the view port twice before any data is plotted.