The most important thing to remember is that we can only see an object when light from the object enters our eyes. The object must be a source of light (for example sun) or else it must reﬂect light from a source (for example the moon), and the reﬂected light enters our eyes.
Light rays are straight lines with arrows to show the path of light.
Light rays are not real. They are merely used to show the path that light travels.
Did you still remember, light travel in straight line?
Formation of shadows is the evidence that light travel in straight line.
1. Are light ray real ? Explain.
2. Give evidence to support the statement:" Light travels in straight lines". Draw a ray diagram to prove this.