Gravitational Lensing

This interactive simulator explores Gravitational Lensing in Gravity & Orbits. Massive objects bending light. Visual distortion effects. Use the controls to change the scenario; watch the visualization and any graphs or readouts to connect the model with lectures, labs, and homework.

Who it's for: For learners comfortable with heavier math or second-level detail. Typical context: Gravity & Orbits.

Key terms

  • gravitational
  • lensing
  • gravitational lensing
  • gravity
  • orbits

How it works

A toy **point-mass gravitational lens** in the thin-lens / weak-field picture. In the image plane, θ is the angular offset from the lens; in the source plane, β = θ (1 − θ_E² / |θ|²) (with softening ε). That is the same structure that produces an **Einstein ring** when a source lies exactly behind the lens: images pile up near |θ| = θ_E. The background grid lives in the **source** plane; what you see is how it would appear after lensing. Not a full ray-traced metric — a clear, fast 2D mapping for intuition.

Key equations

β = θ (1 − θ_E² / (|θ|² + ε²))
Einstein ring: |θ| ≈ θ_E when source is on axis behind lens