aplavin

True, the disk is rendered optically (and geometrically) thin. This is done so that real-time performance is attained on devices like phones – volumetric GR rendering would be significantly more expensive. The jet (zoom out to see it) is rendered with full volumetric effects, because it's just special relativity there.

Fortran punchcard style to render black holes?! That's really going full circle to the origins, I really enjoyed reading about Luminet's work some time ago.

The technology has come a long way indeed! The first simulations of how a black hole would look like are from 1979, by Jean-Pierre Luminet – take some time to find and look at them, it's super impressive what they achieved using that era tech! Now, we can get much higher-resolution ones in real time on any smartphone.

I work in the Event Horizon Telescope, studying jets accelerated by black holes, and immediate black hole surroundings as well. I do ray tracing / radiative transfer simulations, and this app is an adaptation of those simulations – with the primary focus on being physically accurate under reasonable assumptions.

And totally, I enjoyed listening to Kip Thorne's lectures and talking to him, he gives them in a very approachable style while remaining honest!

One side of the accretion disk is indeed brighter than the other – in the default view in the app, the bottom part is brighter. The effect appears quite clearly visible to me, although the exact contrast depends on the colorscale mapping. Here, I tried to find a colorscale that works well for both the disk and the jet, which naturally means the leading/trailing edge contrast can be less than in the linear mapping. Hope it explains the visual effect!

Kerr vs Schwarzschild (static vs rotating black holes) is a much smaller effect visually – that's why it is so hard for us to measure black hole spins (= how fast they are rotating) observationally, even with the Event Horizon Telescope.

Thanks for sharing – as someone who studies black hole environments daily, I didn't even think of such a phobia existing!

I wonder if some tricks, adjustments are feasible, to minimize the effects of these phobias? I see these visualizations as a pathway to make understanding such a complicated, unintuitive object more accessible – and would be great to make it even more accessible, if it makes sense... Happy to chat more, brainstorm some solutions.

Looks interesting from the first glance! I should probably try that game – having both the artistic and realistic pictures in mind :)

If this app turns the entire screen black, this probably means WebGL is not supported :)

Black holes don't really "suck in" light. Whatever falls onto the black hole itself gets deleted, of course – but otherwise, it bends light rays towards its center. That's why the app shows distortion + black circle in the in middle in the camera mode.

In my experience, on Android, it definitely relies on camera: AR doesn't work in dark room, and barely works in slightly-lit room. So it must be fusing camera + accelerometer + ...