When to Use the Photon Sphere & ISCO 3D Explorer - Best Sessions and Limits
Open Photon Sphere & ISCO 3D Explorer when you want to see exactly how a black hole's spin reshapes the photon-orbit and ISCO geometry, or to teach the prograde/retrograde rule with real formulas - not to run a numerical-relativity simulation or trace an actual photon trajectory.
A spin-up lesson
A lesson starts at a*=0 (Schwarzschild) to read the textbook 1.5 Rs / 3 Rs values, then drags the spin slider toward the Thorne limit (a*=0.998) to watch the prograde rings pull in toward the horizon and the retrograde rings push outward, reading the exact numbers off the facts panel at each step.
Sessions this explorer does not fit
Sessions this page does not fit are viewing an artistic accretion-disk glow with no spin control - use the Black Hole 3D Explorer for that - or exploring a general spacetime-curvature teaching grid - use the Spacetime Curvature 3D Explorer. Walk the controls in the step-by-step guide.
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