2007-07-31 14:21:57 · 6 answers · asked by Bemo 5 in Science & Mathematics ➔ Physics
If you live in your home - how do they see you at the grocery store when you are shopping? - because you left home before being in the grocery store. Light is the same - it left the thing being seen before you see it. Our perception is always delayed.
Light is tangible - it is perceived. We perceive the thing itself by the light from it - in some ways the light is more tangible than the object.
We can feel the object - but the feeling is transmitted by electrical signals through our body to our brain - even more slowly than the speed of light.
What's interesting, is that although it seems odd that we can see something even after it no longer exists - this should come as no surprise - since we did not see the thing in the first place until after it existed!!! The stars, for example, were in existence for years before we could see them - they may fizzle out years before we stop seeing them - however, we see them for exactly as long as they existed - just out of phase with their physical existence.
2007-07-31 14:42:22 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Your question is flawed... light is tangible. Light exerts pressure on matter when it strikes the matter (albeit exceedingly small). The difference in the energy level of the absorbed and reflected light is converted into kinetic energy of the material struck by the light.
And since the speed of light is finite (300,000 km/sec), even if the emitting source disappears, we will be able to "see" the emitting source until all the light currently between us and the source reaches our eyes.
Secondly, our eyes have what is referred to as "sensory memory"... if nothing "overwrites" the image on the retina, you will continue to "see" it for a significant fraction of a second until the memory fades from the retina, even if the source of the image is no longer there.
2007-07-31 21:31:23 · answer #2 · answered by ianmacpherson55 3 · 2⤊ 0⤋
Are you referring to when you can see light from a star that no longer exists?
It's like when you cut off the source to a river. The people down stream don't notice that the source has been stopped until the last of the water reaches them.
Light works like that except it moves at much higher speeds and over much greater distances.
2007-07-31 21:29:15 · answer #3 · answered by Gwenilynd 4 · 2⤊ 0⤋
Ain't Hollywood just GREAT!!! Never in history has so many been fooled by so few with so small an object . . . (pardon me Mr Churchill!) You all go from the foolish presumption that what you see as stars are what "scientists" and "stronomers" want you to believe: Heavenly bodies that float around in space . . . Hogwash! I've seen exactly that same thing at the local planetarium, and Hollywood does it so often with cycloramic backdrops, etc. It's nothing more than a matt black cloth with little holes in it and the lights shining through these small holes fool all of you! Trust me, I've worked in the movie industry and I know exactly what is cooking with them stars! Shoot the scientists and astronomers - they're bullsh*tting you all!!!
2007-08-01 10:33:40 · answer #4 · answered by Anonymous · 0⤊ 0⤋
light exists as photons which travel at around 186,000 m/s. It takes the light time to reach us and so exists long after the light source ceases to be as in the case of stars that are no longer 'shining'.
2007-07-31 21:32:21 · answer #5 · answered by poonspoonspoony 1 · 0⤊ 1⤋
Who says light isn't tangible? A photon has no mass while at rest, but in motion, it does, right?
2007-07-31 21:26:10 · answer #6 · answered by Anonymous · 0⤊ 1⤋