The white Light arrive at the red apples ,red photon are absorbed by  the apple ... The rest of EM radiation go into our eyes ... then we see the red apple <<<< Is that true!?\nIf yes , why the apple absorb red photon ?
200723
Actually it's the other way around, the red is what is reflected and most of the rest is absorbed.  It has to do with the different wavelenths being absorbed by different atoms on the surface.  Some atoms or atomic bonds will reflect certain energies and absorb others.\n\nOr they can absorb energy and re-emit it as a lower energy photon which can also happen.
212992
A couple of years ago there was a study that said that the speed of light is not a constant. I need to look it up and see if I can find it. Now I'm wondering what the reason was behind that claim.\n\nYep, I found it:\nhttp://www.newscientist.com/article.ns?id=dn6092
185456
Or did you mean when light hits an object, rather than lightning?\n\nIn this case, it really depends on the composition of the object and the wavelength of the light.  Generally, some of the light is absorbed into the object in the form of energy, and some of it is reflected back.  For example, a white light shone onto a red postbox will absorb every colour within the white light except for the red wavelengths which will reflect and be seen, hence it appearing red.
629893
I'm imagining that you're looking into a tube with the other end initially open, and then closing the other side.\n\nInitially, you can see light in the tube because photons are continuously streaming out from light sources, into the tube, and bouncing down towards your eye, all at the speed of light. You can observe this light because the photons are falling on your retina and being absorbed and recorded.\n\nWhen the light source is shut off, the photons currently within the tube -do indeed continue to bounce about the tube-, however, they will all quickly reach the end of thier journey, either absorbed as heat by the tube, or by your retina. \n\nImagine a cop looking for speeding cars on a stretch of highway. There is a traffic accident a few miles up the road, blocking all traffic. For several minutes, though, the officer will continue to observe the cars passing by him. After he has observed all the cars that got through before the accident, there will be no more cars observed until the accident is cleared away. If the cars were moving at the speed of light, the traffic would appear to drop to nothing (in this analogy, darkness) almost immediatley.\n\nThis is analogous to what you're seeing, but the difference is that the photons (usually) don't somehow escape, theier energy is absorbed over many, many collisions and reflections.
259979
Radio waves are those radiation waves not visible using the unaided eye:they are ouside of the visual range.TV stations uses radio waves to transmit a signal,but it is the TV set reciever itself that recieves that signal and processes it so that it can be seen.\nHave you ever seen a radio wave?\nThe refracting and reflecting telescopes use visual light.\nThe spectroscope breaks up visible light into its constituant colors and you can see them.\nThe universe is full of radio noise and waves that are an echo of the beginning of the universe.\nTo help you understand:all light is radiation as are all other methods of transmitting any kind of radiant force.\nX-Rays,Gamma waves,neutrons et. al. all radiate out from a source.Sunlight is merely radiation that we can see,the sun is full of radio transmissions that are unseen.\nPS:The leaves of a Black Eyed Susan radiate out from the center.
30880
Light energy is a form of electromagnetic radiation and is found in a segment of the (EM) electromagnetic spectrum. \n\nThe EM spectrum encompasses the entire range of ionizing and non-ionizing radiation extending in frequency from approximately 1023 hertz to 0 hertz, or in corresponding wavelengths, from 10-13 centimeter to infinity. \n\nThis spectrum includes all forms of classical non-ionizing radiation we are familiar with including ultraviolet light, VISIBLE LIGHT, infrared (light) radiation, microwaves, and radio waves. The spectrum also includes ionizing radiation such as cosmic-ray photons, gamma rays, x-rays. \n\nAt eithe end of the visible light spectrum is infared and ultraviolet light and humans cannot perceive these spectrums of light.  Red colored light is longer wavelength of light and visible violet light is shorter wavelength.\n\nFor a cool chart and more in depth descriptin of the EM spectrum check out the Goddard Space Center's special page on this topic. \n\nhttp://imagine.gsfc.nasa.gov/docs/science/science.html   Use the link that says The Electromagetic Spectrum
198150
Boy, you are really time-constrained!  What kind of light?  Edison did an experiment on sending sound over light waves, but was limited to visual light, in air (not laser light, in fiber optics like we use today.)  What equipment have you?\nSuggestions, without knowing much:  Send a beam of light as Morse Code and determine the maximum distances based on different times of day, weather conditions, strength of light beam, type of light beam, acuteness of receiver's eyes.  \n\nOr better yet if you are a computer geek  :), do it with a photo cell as the receiver and send the signal to a computer for analysis and conversion into text.\n\nGood Luck!  Let me know your results!
640451
Since photons are particles and waves they react to electromagnetic fields created by electrons and protons in the medium the photon travels through.\n\nThe measure of how a photon changes in particular mediums is called the refractive index:\nn = c/v\nc is the speed of light in vacuum\nv is the speed in the medium\nn is the refractive index\n\nThe highest refractive number I could find (which means v is much smaller than c) was for \nIodine Crystal .............. 3.34\nBTW - this is why things like diamonds sparkle\n\nEdit:\nSilicon    ....................... 4.24\n\nEdit:\nProblems with saying that a photon's speed was reduced to zero:\n1) Refractive index goes to infinity (not really a problem but still interesting)\n2) Usually means the photon was absorbed (it did not come out of the medium)\n3) Light is a particle/electromagnetic wave, a v of zero creates a standing wave which I thought was wasn't possible for electromagnetic waves\n4) If the photon is merely caught inside the medium bouncing back and forth then v isn't really zero...  Just another way of saying that the photon was absorbed.
3138
Close.  I would say it's because the photons from the object hit a smaller area of the cornea.  If you think of the surface of the cornea as a screen onto which the world in front of the viewer is projected through a lens, as an object is moved away the angle between its top and bottom gets smaller and so the relative size of the object in that projection gets smaller.
4766
When the light speeds up it gains mass, so it should loose mass when it slows down.\n\nSo you are right. Light has zero rest mass. So it will be as if it was non existant when its at rest. But we know when light hits any other particles it converts to energy and reveals its presense ( We humans also detect light with eyes, but its similar process of how objects get hot in summer with light ).\n\nNewton's Corpslcular theory can be very good classical explantion of mass/energy relation of light if every were normal classical photon. But we all know that Newton was wrong, and light will not change its direction slowly to conserve energy, but when it hits any smooth surface it retracts immediately. So its velocity at that point of hitting is zero for very very very short periods of time, and again its back to light speed. So your question does not have a classical or quantum explantion, but reltivity theory can be used to understand it.
4913
Adding to the previous answers: It's not so much that light IS a particle and a wave, it's that it behaves like a particle or a wave depending on the situation. And 'particle' isn't a very good term since it implies mass when it, in fact, doesn't have mass (it does have momentum however).\n\nParticle examples (called 'photons'):\n- Light is absorbed by atoms and molecules in little bundles/packets. Only bundles of an exact amount of energy can be absorbed and/or released.\n- The photo electric effect: When light strikes the surface of metal it can knock electrons off (due to it's momentum).\n\nWave examples:\n- Light interferes with other light in much the same way water waves do (constructive and destructive interference).
67724
Most physicists (like Feynman) will tell you it's definitely a particle.  I think they're full of crap, and it's a wave.  The fact that it can only be absorbed and emited in discrete packets doesn't necessarily mean that it really travels as a particle, and the notion of a particle flies in the face of the double-slit one-photon experiment.
617561
I'd say option B. Each photon contains one fragment of the image. But actually, there are no such things as photon particles. The "waves" that "photon particles" create are actually part of the photon themselves.
633959
It is true. \nLight is a radiation- simply said  it is an energy that flying away from something.What we call light is just a certain range that electromagnetic radiation that we can perceive with our eyes. in reality the frequency of that radiation is much greater that we can see with our eyes. on the low end of it- there the length of the waves are longer are the heat waves. On the high end where we stop seeing violet light - radiation doesn't stop, just waves get shorter and shorter and we call it ultra violet light. Just because we don't see it, it doesn't mean that nature doesn't use it. Flowers have their elaborate patterns in Ultra Violet colors that bees see, that lead them to nectar.
591572
The first website gives a good overview with no math, if you already understand light/waves/atoms skip to the part that I put in paranthesis.\nThe third site is a more advanced and goes more into the consequences.  In case we have different ideas of what laymen are.\nHere's a quick summary:\nquantum entanglement is when one photon of light is split into two equal photons of opposite polarity (direction of the wave disturbance) .  The two photons seem to be linked in a way that is currently innexplicable but demonstratable using interference patterns.  Which I hope you don't consider techno babble, but if you do, just ask what interference patterns are and I'll answer that, too.  That's a quick expanations of what's happening.\nUnless you mean why, the last site does a pretty good job of explaining that we don't really know, but we're trying pretty hard to figure it out.  There are many theories right now.  It'll go over a couple of them.(it's really an excellent paper.  I don't know what level of physics education you have, but it was perfect for me.I'm not a physicist, I'm a chemist.)
535592
You've lost the point of the equation.  Squaring the speed of light will give you the energy released, not an enhanced speed of light.
413226
the energy entering our eyes are a stream of photons, these energizes the "Rods & Cones" in our eyes. these in turn generate an appropriate electrical signal, which is carried to our brains by the optic nervs. the brain analyses the electrical signals and actually searches the immense database of pictorial references we all carry. we actually see the object in our brains. how this happens is still not fully explained. but this is proved that the energy from the photons are converted to electrical signals, another type of energy and transmitted to the brain