noun
incidence
The arrival of light or another incoming force at a surface.
The diagram marks the angle of incidence of the light ray.
Etymology
The Latin verb means to fall upon. The physical sense preserves that arrival when a ray or other incoming influence reaches and strikes a surface.
More examples
- She adjusted the mirror to change the incidence of the beam.
- The surface reflected rays arriving at different angles of incidence.
- The experiment examined normal incidence on the glass.
Forms
incidence
Similar words
- reflection
- Reflection is a ray’s return from a surface; incidence concerns its arrival at the surface.
- refraction
- Refraction is bending as a ray enters a new medium; incidence is its arrival at the boundary.