I am struck by the apparent contradiction that a photon or light wave can have enough energy to travel such vast distances and yet have so little energy that it can be interrupted so easily.
2006-11-27 15:44:02 · 8 answers · asked by Wannano 1 in Science & Mathematics ➔ Physics
It's not a matter of great energy to travel a large distance. In a vacuum, there is nothing to stop objects. Once in motion, any object will keep going until some for acts on it. A photon(s) of light will travel untill someting absorbs it or reflects it or refracts it. Tissue paper DOES absorb light, depending on the intensity of the light, it will absorb all or a fraction of it. Pretty much anything physical absorbs light, even glass, though the absorption is very small for glass. Of course this is dependent on wavelength, some wavelenths are absorbed more than others and if you go to shorter wavelengths like x-rays, they pass right through the paper. Longer wavelenths like radio waves also pass right through.
2006-11-27 16:56:36 · answer #1 · answered by ZeedoT 3 · 0⤊ 0⤋
bizarre thought but truly relevant in your own mind.
Light travels only in straight lines (as a wave form/frequency) Light can travel indefinite distances without obstruction in its path, but as you say the smallest object can block its path, light doesnt have energy as such to push through space and move things, it just flows as a continuous wave until it is redirected by an object.
As you say the paper can stop it this is untrue, what is happening is the light is redirected/reflected off the object and thus you can see the object. You can see things cos the light is reflected off the object in question. Once reflected the light continues on its new path until something like your hand for example stops the object from being viewd by you.
2006-11-27 23:52:34 · answer #2 · answered by Anonymous · 1⤊ 0⤋
Keep in mind that the total flux (the flow; think giga-firehose) from a star sends so many photons on the journey that a few can get through all the dust of the intervening space, and it only takes a few/sec to register on the CCD's being used.
Added: For those who think that a photon can't be stopped, bunk! #1 evidence is that shadows exist. #2 evidence is that light heats absorbing materials. #3 evidence is the photoelectric effect.
2006-11-27 23:52:56 · answer #3 · answered by questor_2001 3 · 0⤊ 0⤋
No energy at all is needed to travel vast distances. Check Newton's Laws of Motion.
There is a lot of space, and very little matter in it.
2006-11-28 00:41:35 · answer #4 · answered by Happy Camper 5 · 0⤊ 0⤋
Because space is a vacuum, with no (or very little) matter to block the path of the light.
2006-11-27 23:47:35 · answer #5 · answered by joeyamas 2 · 0⤊ 0⤋
Photons are very fast and in empty space, they might as well be boulders. Photons are very small, to small to hurt you or paper, unless, but if you concentrate them, there could be trouble.
2006-11-27 23:54:39 · answer #6 · answered by spir_i_tual 6 · 0⤊ 0⤋
Tissue paper doesn't block light, just filters it. And there's no tissue in space.
2006-11-27 23:51:44 · answer #7 · answered by vigi4x 2 · 0⤊ 1⤋
You have been missinformed, a photon cannot be stopped by a piece of paper.
2006-11-27 23:46:59 · answer #8 · answered by Anonymous · 0⤊ 1⤋