This is a collection of images created while developing the geodesic integration code. Geodesics are computed from a numerically given metric tensor field. The analytical Kerr metric was used as a test case and sampled to a grid to have a numerical representation to be checked against the analytic solution. Geodesics approaching a rotating black hole. Promotion image created for the Max-Planck Institute for Gravitational Physics (Albert Einstein Institute), Potsdam.

Data and visualizations by Marcel Ritter

• Following images illustrate geodesics and acceleration with different parameters. Fan of geodesics approaching a static black hole. Arrows illustrate the spatial components and color the time component of the coordinate acceleration towards the black hole. The white sphere shows the event horizon. Fan of geodesics approaching a rotating black hole. Lines represent trajectories of photons, speckles show spatial coordinate acceleration and the line color illustrates the coordinate acceleration in time. The white sphere indicates the center of mass and shows the event horizon of a static black hole. Geodesics integrated by different numerical schemes. Left: Euler, Right: DOP853 (Runge Kutta 8th order). Spatial coordinate acceleration as arrows (top) and as vector speckles (bottom). Geodesics approaching a rotating black hole. The angular momentum is increased from left to right and top to bottom. Geodesics and a rotating black hole showing the effect of different values of the angular momentum.

• Visualization of the coordinate acceleration field around a black hole: Visualization of the coordinate acceleration field. Top: arrows, Bottom: vector speckles. Right: Initial speed of (1,0,0), blue arrows. Left: Zero initial speed. Spatial coordinate acceleration shown at 3 cubic slices around the center of mass. The angular momentum is increasing from left to right and top to bottom. Spatial coordinate acceleration shown randomly distributed around the center of mass. The angular momentum is increasing from left to right and top to bottom. Spatial coordinate acceleration shown at 3 cubic slices around the center of mass from 6 axis aligned camera direction. The angular momentum is increasing from left to right and top to bottom.