Why Does Light Disappear When the Source is Turned Off?

[Rose Garden]

A light source emits light in all directions, and the light travels at light speed, yet when we shut off this light source, all the light rays immediately disappear. I just thought about this and it just seems so strange. When we think of a sound source, we can shut off the sound source but the sound already emitted would keep traveling and echoing. But what about light, when the light source is turned off, what happens to the photons, how can the light already emitted just disappear?

 

[mathman]

One difference between light and sound is the speed. Sound in air travels about 1000 ft./sec., while light goes around 186000 miles/sec. You can hear the sound echoes because of the time it takes to die off, while for light the die off is essentially instantaneous.

 

[Rose Garden]

ok there's just so much I don't know: what makes light give off light?

 

[Alhakiki]

wow That question is more than just a simple question! Nice!

 

[sardar]

This is a great question and one that has been studied by scientists for many years. The phenomenon you are describing is known as light extinction or light absorption. When a light source is turned off, the light rays that were traveling in all directions immediately disappear because they are either absorbed or scattered by objects in the environment.

Photons, which are the fundamental particles of light, interact with matter in different ways depending on the properties of the material. Some materials, such as glass or water, are able to absorb and scatter light very effectively, causing the light to disappear when it enters the material. Other materials, like air, are less effective at absorbing and scattering light, so the light can travel further before being absorbed.

In the case of a sound source, sound waves are able to travel much further and continue to echo because they are not easily absorbed by the air. However, light travels at a much higher frequency and energy level than sound, making it more easily absorbed by materials in the environment.

Additionally, the speed of light is so fast that it appears to disappear immediately when the light source is turned off. This is because light can travel at approximately 299,792,458 meters per second, making it nearly instantaneous to the human eye.

Overall, the disappearance of light when a light source is turned off is a result of the properties of light and the interactions it has with matter. Scientists continue to study this phenomenon in order to better understand the nature of light and its behavior in different environments.