Geodesic


Direction Angles

Choose the type of the geodesic and its initial values.
The direction angles are given with respect to the local reference frame {e(i)}.

Note that the local reference frame is defined with respect to a natural local tetrad of the space-time, compare Tetrad directions.

Keyboard handle

Key Description
Ctrl + K Decrease ξ by 'step'
Ctrl + Shift + K Increase ξ by 'step'
Ctrl + C Decrease χ by 'step'
Ctrl + Shift + C Increase χ by 'step'


Sachs/Jacobi

If the geodesic type is "lightlike_sachs", the Jacobi parameters are shown in the "Sachs/Jacobi"-tab.


Note that the cross section of the light bundle (ellipse) is scaled to unity.