Movies

In these movies,the evolution of gravitational waves is shown. Brill waves are pure gravitational waves, which can collapse to a black hole. Low amplitude or "weak" brill waves are just a small distortion of flat space and the initial toroidal wave configuration eventually disperses out to infinity. For very strong Brill waves of large amplitude, the wave will get trapped in its own curvature and form a black hole in its focus.
The two movies here show a subcritical evolution (no black hole is formed) and a supercritical evolution in which a singularity is formed. Very close to the critical amplitude, the regime where the configuration switches from subcritical to supercritical behavior so called critical phenomena occur. It is one of the main tasks of the numerical relativity group to investigate such critical phenomena, i.e. to study the circumstances of the formation of the black hole.

	Subcritical Brill wave (1.02 MB) A subcritical Brill wave (Amplitude=4.5), showing the Newman-Penrose Quantity as volume rendered 'glowing clouds'. The lapse function is shown as an height field in the bottom part of the picture.
	Supercritical Brill wave (1.2 MB) A supercritical Brill wave (Amplitude=6), showing the Newman-Penrose Quantity as seen by an observer above the equatorial plane. The Brill wave configuration does not disperse completely, instead the wave becomes trapped in its own curvature, leaving behind a black hole in the center of the computational domain.

These movies were generated from Cactus simulation data. The visualization was carried out by Werner Benger using the Amira visualization system.