The "screening" of light emitted by a point light source

'Filter' three beams of light from the LED lamp, mark them with a pencil on a piece of paper and extend them to the light source. Answer the questions.

Light propagation and beam

Light spreads in space in a straight line. The direction in which the light rays travel is shown in the diagrams as straight lines, which we call light rays.

Instructions for the experiment

Light from a point source

What to note

We can call the bright stripe that appears on the paper in an experiment a ray of light. However, we should note that rays of light are purely the work of physicists - they do not exist in nature.

Why did we invent them?

Light rays show the direction in which light propagates. Since we can also see and know that light travels in a straight line, we can also understand where the light came from.

Applying this knowledge to this experiment, we get a picture that describes the light from a point source.

Light from a point source

Point light source

A point light source is a light source in which light is emitted from a single point.

The characteristics of the LED lamp used in the experiment are that its rays fill a solid angle of . In the experiment, check if this statement is correct
In the textbook there is a picture like this. In what way is this situation different from, or similar to, the experiment?

How to summarise

One might ask, how many rays are emitted from a single point source? We chose three and plotted them. If we had arranged the system of slits a little differently, we would have had a picture with slightly shifted beams. If we drew the rays in all the possible slit locations in the house, we would get one area densely packed with rays, which is the same beam we started the exercise with.