When we view Sun or even a bulb why do we see light as radial rays around it?
545742
Simple answer:\n\nA ray that does go not into your direction doesn't has a chance (unless reflected by something) to go into your eye and be "seen". If it gets reflected in a diffuse way for example by a wall and then goes into your eye you see a bright spot on the wall. If it gets non-diffuse reflected by a mirror you see an image of the bulb.\n\nWelcome to the world of geometric optics ;) ! \n\nIf follow the light ray in the other direction like a "see ray"  you get the principle of all the ray tracing computer programs that produce these nice computer images and animated movies.
270833
1) Generally, rays of the sun which is called radiation lay between 400 nm (nano meter) to 700 nm.\n2) Below 400 nm is called ultra-violet and above 700 nm is called Infra-red.\n3) Both are invisible to the human naked eye.\n4)Infrared radiation is used to obtain pictures of distant objects and the detection of infrared radiation is used by astronomers to observe stars and nebulae.
852339
Well, obviously the sun doesn't stop outputting light just because we're cloudy.  We're still getting 1120 W/m^2 through the atmosphere.  It's just being reflected, scattered, or absorbed by clouds, moisture, etc.\n\nSince clouds appear white from space, that says that a big chunk of the sunlight that would otherwise have it the ground winds up sailing off into space.
793828
We see things in different colours because light (usually white) reflects off surfaces and reach our eyes with a different frequency, for some is absorbed. When NO light reach our eyes, it simply appears as black. You can see this as some form of 'natural default' (i coined this term myself). \n\nTo help your understanding, think of seeing a piece of paper filled with different patches of colours and holes, placed in front of vaccuum space. The black that you see will be the holes where no light get bounced off. \n\nHope this helps=)
160214
They also occur as a circle, if you're in a plane (i was in a microlight) above mist/cloud it's the most spectacular sight, I looked down and there was a circular rainbow. It has to do with the fact that you're viewing it from one point, all the rainbow is relative to you.
12251
The scientific answer is very long which involves dipole scattering, charged particles vector potential and much more.  There is a simple answer though.  Think of how prism works.  When a light hits the prism, what happens?  The answer is the prism breaks the white light into visible color, red, orange, yellow, green, blue, and violet (these are the rainbow color).  Our atmosphere is filled with dust particles.  So when sun ray hits the particles in the atmosphere, it breaks the white light like the prism.  The color blue has the strongest wavelength out the rainbow colors.  Therefore, it effects more than the red and green wavelength, causing the surrounding air to appear blue.  But during the sunset, the sun light passes farther through the atmosphere causing them to deflect and decrease the blue color. So sunset appear to be red.
1124409
because at that time it is below the horizon and its rays are reflected to us by different layers of atmosphere.while comoing to us it is diffused
497775
Stars, except for the Sun, although they may be millions of miles in diameter, are very far away.  They appear as point sources even when viewed by telescopes.  The planets in our solar system, much smaller than stars, are closer and can be resolved as disks with a little bit of magnification (field binoculars, for example).\n\nSince the Earth's atmosphere is turbulent, all images viewed up through it tend to "swim."  The result of this is that sometimes a single point in object space gets mapped to two or more points in image space, and also sometimes a single point in object space does not get mapped into any point in image space.  When a star's single point in object space fails to map to at least one point in image space, the star seems to disappear temporarily.  This does not mean the star's light is lost for that moment.  It just means that it didn't get to your eye, it went somewhere else.\n\nSince planets represent several points in object space, it is highly likely that one or more points in the planet's object space get mapped to a points in image space, and the planet's image never winks out.  Each individual ray is twinkling away as badly as any star, but when all of those individual rays are viewed together, the next effect is averaged out to something considerably steadier.\n\nThe result is that stars tend to twinkle, and planets do not.  Other extended objects in space, even very far ones like nebulae, do not twinkle if they are sufficiently large that they have non-zero apparent diameter when viewed from the Earth.
735058
If you shine a flashlight in a dark room, the beam of light must hit an object in order for you to see it. If there is nothing to obstruct the light, then you will still see a dark room despited the flashlight. The same is with the sun, the planets are visible because they obstruct the light and reflect it back to our eyes. Everything else is black because there is nothing there.
414202
(m)\n\nAs the sun begins to set, the light must travel farther through the atmosphere before it gets to you. More of the light is reflected and scattered. As less reaches you directly, the sun appears less bright. The color of the sun itself appears to change, first to orange and then to red. This is because even more of the short wavelength blues and greens are now scattered. Only the longer wavelengths are left in the direct beam that reaches your eyes\n\nThe sky around the setting sun may take on many colors. The most spectacular shows occur when the air contains many small particles of dust or water. These particles reflect light in all directions. Then, as some of the light heads towards you, different amounts of the shorter wavelength colors are scattered out. You see the longer wavelengths, and the sky appears red, pink or orange
768582
Bees can see UV rays. UV rays are part of the electromagnetic spectrum and has a bit shorter wavelength than the light we see.  It is this type of energy that gives us a sunburn.  Most flowers are very colourful although sometimes they are a plain white to us.  To a bee though, because they can see UV rays, which reflect more light, the flower to them looks very colourful.
962965
Here's what happens: imagine you're standing with the Sun at your back looking at a water drop. As a light ray from the Sun hits the drop, it is bent inwards, toward the center of the drop. It bounces off the back of the drop (coming towards you again) and then refracts again on its way out. As a result you see the light ray appearing to come from some point behind the drop, that is, on the opposite side of the sky from the sun (which is where you see rainbows!) \n\n\nBut what about the colors? It turns out that each color of light is bent a little bit differently - red light is bent the least and violet the most. So, each color appears to be coming from a slightly different place behind the water drop. \n\nThe rainbow is circular because only drops located at certain places on the sky (in a circle around the point opposite the Sun) redirect the light exactly back toward your eye. It's only the light from those drops that you see, and hence you see a circle.\n\nanother explaination: This is difficult to envision and to describe, but we'll use some real common sense objects for our model. Picture yourslf standing in front of a tunnel, like you might find under a bridge - a nice even, round, smooth tunnel. Now, if you cast a shadow parallel to the ground, like a shadow from a power line (not the pole, the line - which is parallel to the ground) and let the shadow fall inside the tunnel, you can imagine that the shape of the shadow on the ceiling of the curved tunnel looks as though it is arced, even though the source of the shadow is a straight line. Can you picture that? This is what is happening in the atmosphere. The rainbow is actually a straight line, since light travels in a straight line. Its just that the straight line is falling across a 'fish bowl' like pocket of moist, reflective air, like our tunnel in the model. The rainbow appears, therefore, to be an arc.
581391
as the earth spins on it's axis the distance from any one given point on earth to the sun changes throughout the day. Near midday the sun is directly above you and closest to you, thus it is very bright. As the day goes your point on earth spins away from the sun, making it further away, and you are also seeing it through all the dust in the atmosphere, making it less bringht and appear yellow/red.
490916
In geometrical optics with a pointlike sun the airplane would cast a shodow on the surface.\n\nBut: 1) The sun isn't pointlike but appears as a disc in the sky, so if light from diffent edges of the disc would cross under the plane ther would be no sharp shadow anymore, from a viewpoint on the surface the plane wouldn't cover the sun as whole\n\n2) Light is a wave, so geometic optics is not the whole story, there is refraction that bends the light into the shadow region. That's what you call "refill the void".
99063
What you see outside at night is a mixture of these:\nStars (like the sun)\nPlanets\nSattelites\nGalaxies
271966
It is a division of light into the color spectrum as it passes through water droplets, and it's also a reflection.\n\nAnd the source of the light to the droplets to your eyes is at an angle of 42 degrees relative.  If you were standing on the edge of a cliff, and the sun was behind you, you would see a circular rainbow.\n\nThe shape of the rainbow has to do with the shape of the water droplet.
52478
When light is refracted off of droplets of water it enables you to see all the colors that make up white light (sunlight, even light from bulbs.) creating what people more commonly refer to as a rainbow. \n  Go outside on a sunny day and spray the waterhose if you have one. If you look very carefully, you can see that the rainbow you created is not just a semi-circle, but a full circle! The bottom half is harder to see, but it is there. The reason rainbows don't look like that when we see them outside is because we are too low to the ground to see the rest.