Ray Diagrams
Light, Sound and Waves

What are rays?

Physics Narrative for 11-14 Supporting Physics Teaching

What are rays?

An important point to be aware of here is that a ray diagram is a theoretical construction. It something that you draw for a purpose. The ray diagram is certainly not intended as a faithful reproduction of the actual real world set-up. It is a way of representing a process that includes a point source of light and rays – both of these are theoretical in nature.

In the real world we have light beams travelling away from lamps and some people refer to very narrow beams as pencils of light.

In the theoretical world we have rays. We draw these, often on paper, as lines from which we can predict the paths that the beams will take.

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