资讯

BBC2 年
Convex and concave lenses
In a ray diagram, a concave lens is drawn as a vertical line with inward facing arrows to indicate the shape of the lens.
BBC2 年
Convex and concave lenses
In a ray diagram, a concave lens is drawn as a vertical line with inward facing arrows to indicate the shape of the lens.
Nature10 年
Where is the sun?
When we interpret a shaded picture as a three-dimensional (3D) scene, our visual system often needs to guess the position of the light source in order to resolve a convex-concave ambiguity.