GRorbits

Relativistic Orbits of Matter and Light in the Equatorial Plane of a Schwarzschild Black Hole

INSTRUCTIONS

This Java software allows you to view and manipulate orbits predicted by Newtonian mechanics and by general relativity. The menu items at the top of the display and the buttons at the bottom are self-explanatory. (For an explanation of rain coordinates, see Exploring Black Holes, page B-4 and the following pages.)

• To set the angular momentum L/m of the orbiter, do one of the following:
  
  
  1. Drag the L/m slider right or left, or
  2. Click to the right or the left of the L/m slider for small changes, or
  3. Click on the display L/m = . . . and enter a numerical value.



• To set the energy E/m of the orbiter, either:
  
  
  1. Drag the black dot in the upper right display up or down, or
  2. Click on the display E/m = . . . and enter a numerical value (the mininimum energy will be the value of the effective potential at the current radius.)



• To set the initial position of the orbiter, either
  
  
  1. Drag the black dot in the upper right display right or left, or
  2. Click on the red line where you want the dot to be located, or
  3. Click on the display r = ... and enter a numerical value.

NOTE: Setting the angular momentum limits the available energies; setting both angular momentum and energy limits the initial radii.

Java applet GRorbits is released with no warranty under the GNU GPL public licence. The source code of the applet together with more info about GNU GPL can be found here.