light

[maximus]

if light is energy and is indeed tangible, where does the light go which has already been ommited from a light bulb when you turn the switch off

[sylvday]

The light waves (or particles) from the bulb carry on travelling. But because your distance from the bulb is so short, and light travels so fast (286,000 miles per second) the light seems to go out simultaneously with the switch going off. But if you think of a distant star instead of the bulb, then we can certainly see light today, emitted by stars which were "switched off" many years ago.

[MikeMikeMike]

Do you mean why doesn't it just keep bouncing around the room?, so that even when the source of light is gone, the light already emitted continues? Because I don't know, but I thought it might be a helpful clarification.

[trilobite]

The light is absorbed by the surfaces within the room. All materials absorb and reflect light to some degree. It is the part or parts of the spectrum that are absorbed or reflected that decides which 'colour' we see. Put simply a green surface absorbs all the blue, red, orange etc parts of the visible spectrum and reflects green. In theory, a white surface reflects all light and a (matt) black material absorbs all light. However, in practice, there is no such thing as either a perfect 'reflector' or 'absorber' as some of the light will always be absorbed / reflected. In theory, a room lined with 100% reflective mirrors would continue to be 'lit' perpetually even after you switch the bulb off. However, you wouldn't be able to see this 'perpetual effect' as your retinas (or the light sensitive surface of a camera) would absorb this residual light the moment you looked at / filmed it. (And that's ignoring the light that would be absorbed by the bulb and wire material.!)

[Ashley]

But what if you used the two way mirrors which reflect and allow you to see through from one side? This way you could watch without a camara or retina absorbing the light

[crsytal8877]

when u turn on the light where does it come from