Numerical simulation of a heavy black-hole merger with horizon deformation (GW190521)

Numerical simulation of two black holes that inspiral and merge, emitting gravitational waves. The black holes have large and nearly equal masses, with one only 3% more massive than the other. The simulated gravitational wave signal is consistent with the observation made by the LIGO and Virgo gravitational wave detectors on May 21st, 2019 (GW190521).

Details on the visualization:
* The „apparent horizon“ of the black holes in the simulation are shown in black. At 0:10 the simulation finds an enveloping apparent horizon that signals the two black holes have merged.
* The gravitational radiation is translated to colors around the black holes. The colors transition from blue, representing weak radiation, to red, representing strong radiation. Specifically, the coloring represents the real part of the gravitational wave strain. The strain is computed from the simulation’s extrapolated waveform, which is shown at the bottom of the screen.
* Only the mass-ratio of the two black holes is relevant for the numerical simulation, not their total mass. The large total mass inferred for the black holes that produced the GW190521 signal only affects the conversion from simulation-time to real-time that is shown at the bottom of the screen. The movie shows approximately half of the observed inspiral duration reported for the GW190521 detection.
* The coloring on the horizons represents the horizons' deformation. Specifically, it shows the two-dimensional Ricci scalar on the surface along with contour lines at 0 and 0.7 (black), as well as 0.891, 1.2 and 1.5 (gray).

Credit: N. Fischer, H. Pfeiffer, A. Buonanno (Max Planck Institute for Gravitational Physics), Simulating eXtreme Spacetimes (SXS) Collaboration

[aSpyIntheHaus]

I find the idea of black hole horizons deforming at the limits of my imagination. It's not that I have an issue with what you're presenting here, far from it. Its just when you imagine matter as it would be found in a neutron star is at the limit for matter being matter, the properties of which are so far removed from anything within the grasp of human experience. (I could be completely wrong on this as I don't know enough about the LHC experiments to say if similar conditions could have been or were tested) Then to have that matter collapse further into a black hole. That part is easy enough to imagine. Its the properties of the event horizon that I struggle to understand and that it could be deformed due to a mutual gravitational field, that is boggling.
Having that enveloping horizon pop into being is a neat thing. It does away with any unnecessary nakedness and makes the whole stretching things out a lot more palatable if it happens behind the curtains. :)
I realise the point to these models is to help validate an help predict future detections of these events as well as help people get an understanding of the significance that these events are literally twisting spacetime such that emits gravitational waves (This alone is epic in it physical significance) so I'm sorry to bang on about matter in its most extreme conditions. The truth is it it highlights this genuinely is a complex thing that requires a lot of hard work to produce something as visually and physically in depth as this. Love your work guys.