Before Einstein, scientists thought that light traveled in straight lines in empty space.
Turn the trail on, and set r = 300, v = 1, angle = 0 to see the curved path of a light ray.
When angle is set to -60, the light ray passes closer to the black hole and experiences stronger gravity and greater spacetime curvature.
Try angle = -75.
Try angle = -75.6 to see a loop-the-loop.
This suggests that the possibility of light orbiting around a black hole! Find the conditions for circular orbit by setting v = 1, angle = 0 and experimenting with various r values. Hint: when the object moves closer to the black hole after clicking Start, r is too small, and when the object moves farther from black hole after clicking Start, r is too large. Narrow the gap between speeds that are too small and too large.
Is this circular orbit stable or unstable? Answers.
Experiment 1: Falling Into a Black Hole
Experiment 3: Investigation of Stable Circular Orbits
Experiment 4: Investigation of Unstable Circular Orbits
Experiment 5: Investigation of Spiral Orbits