What happens to the intensity of infrared light rays when the lamp is moved closer?

When a lamp emitting infrared light rays is moved closer to a surface, the intensity of the light rays actually increases. This is due to the inverse square law, which dictates that the intensity of light is inversely proportional to the square of the distance from the light source. As the distance decreases, the area over which the light is spread also decreases, leading to a higher concentration of light rays per unit area. This results in an exponential increase in intensity as you move closer to the source.

This concept illustrates how light behaves: at shorter distances, each unit of area receives more energy, thus increasing the perceived intensity. This principle is particularly important in therapeutic applications where precise dosing of energy is critical. Understanding this relationship helps practitioners optimize treatment parameters to achieve desired therapeutic outcomes.