Final answer:
The brightness of light when you double your distance from the light source becomes one-quarter of the original brightness, as per the inverse square law. A light source appears four times dimmer when the distance is doubled, demonstrating this principle at both practical and astronomical levels.
Step-by-step explanation:
When you move twice as far away from the light source, the brightness at the new distance compares to the old distance as one-quarter as bright. This is due to what is known as the inverse square law for light, which states that light intensity drops off proportionally to the square of the distance from the light source.
If you are initially 2 meters away from a light source and move to 4 meters away, you are now twice the distance from the light source. According to the inverse square law, the brightness or intensity of light you receive is (1/2)², which equals 1/4 of the original intensity.
Similar principles apply to astronomical distances, like stars. The star Alpha Centauri A, for example, emits about the same energy as our Sun but appears much fainter due to it being astronomically farther away, showcasing the profound effects of the inverse square law at cosmic scales.