Black Hole Simulator
Classroom worksheet · Interactive simulation: https://lkforge.com/tools/physics/black-hole/
Name: Date:
Learning objectives
- Describe how gravity bends the path of light.
- Explain what the event horizon is.
- Relate the Schwarzschild radius to mass.
Variables to change
- Black hole mass
- Light-ray impact parameter
- Viewing angle
Procedure
- Send light rays past the black hole at a large distance and observe their paths.
- Move the rays closer and watch the bending increase.
- Increase the mass and observe the event horizon and lensing grow.
Observations
Note how the bending of light changes with distance from the black hole and with its mass.
Questions
- What is the event horizon?
- What happens to light that passes close to a black hole?
- How does the Schwarzschild radius depend on mass?
- Does a black hole’s gravity differ from ordinary gravity far away?
- Why do we see a dark shadow with a bright ring around a black hole?
Answer key (instructors)
- 1. The boundary around a black hole within which nothing, not even light, can escape.
- 2. Its path bends (gravitational lensing); very close in, it can be captured.
- 3. It is proportional to mass: r_s = 2GM/c². More massive black holes have larger horizons.
- 4. No — at a distance it pulls like any mass of the same amount; the extreme effects appear only close to the horizon.
- 5. Light near the horizon is bent and captured, leaving a dark region rimmed by lensed light.
Massive bodies curve spacetime and bend light. A black hole is so dense that within its event horizon (r_s = 2GM/c²) escape is impossible. Passing light is lensed into arcs and rings, while its distant gravity behaves like any equal mass.