does the surface of water have a different refractive index than the water below?or how do you explain this?
550478
Refrective index water should be the same throught, provided that all the other conditions are the same throughout -- such as temperature, presense of impurity, etc.\n\nIts not the refrective index of water alone that determines whether light will be reflected or not or at what angle the light should be projected to be reflected. When you are talking about the surface of the water, you are really talking about the interface between water and air. When you are talking about "under the water", light is not changing media.
892508
yes why not ,light can pass through water        the answer is as follows    except opaque medium light can pass through any medium  but light cannot pass as much fast as in the air medium because acc:theory of huygens light can move fast in rarer medium than in denser medium
825837
yes......\nlight can travel with or without a medium... water is a medium.... can be considered a transparent material..... so light can pass through water... in other mediums, liike opaque and translucent, light may either be absorbed or half absorbed and half transmitted...
694338
Yes, it does, this is due to refraction, which is the bending of light. Images in water always appears nearer, and thus seems larger! n_n
643823
You can also only see out of the water in a 98 degree cone.  That means, when you look at an angle greater than 49 degrees from the vertical, you don't see out of the water, you see the reflection from inside the water.
65772
Light can pass through anything transparent, eg space, air, water, glass etc.  In a vacuum, light travels at 300,000,000 metres per second.  However, when light penetrates e.g. glass, it slows down since it finds it more difficult to travel through it.\nWhen light enters a boundary (e.g. the water's surface) at an angle which is not perpendicular to the surface, refraction - the bending of light - is observed.  One common occurence of this is the fact that a drinking straw looks bent in a glass of water.\n\nRefraction is governed by Snell's law which states that Refractive index = sine angle of incidence/sine angle of refraction.  The Refractive index 'n' is a ratio of the speed of light in a medium when compared to the speed of light in a vacuum. n = c/ c in medium.\nA similar effect is observed when water waves travel from deep to shallow water.  The waves slow down but increase in amplitude (height).
558537
Good question.  The reflectivity of a surface is very sensistive to a film and with specialized equipment, submonolayers can be detected.  I knew somebody that was studying thin films of water on silver and she said she noticed a difference.  I think that was about 10-100 monolayers that she was working with.  My guess is about 50 nanometers.
498079
nothing stupid about the question. \n\nthe refractive index depends on the wavelength. this is given by Cauchy or Sellmeier equations.\n\nif you want the equation the link is : -\n\nhttp://en.wikipedia.org/wiki/Sellmeier_equation\n\nthe refractive index decreases with increasing wavelength.\n\nnow the wavelength of various components are ; -\n\nColor    Wavelength (nm)\n\nRed       780 - 622 \nOrange    622 - 597\nYellow    597 - 577\nGreen     577 - 492\nBlue      492 - 455\nViolet    455 - 390\n\nclearly red which has a higher wavelength will have lesser refractive index and hence will bend lesser than violet which has higher refractive index and bends more..\n\nother useful links are-\n\nhttp://en.wikipedia.org/wiki/Refractive_index\n\nhttp://csep10.phys.utk.edu/astr162/lect/light/dispersion.html\n\nhttp://en.wikipedia.org/wiki/Dispersion_(optics)\n\ni hope this will help :)
994799
REFRACTION IS THE PHENOMENA\n\nWhen light travels from one medium to another, it bends. In other words, it changes direction and moves at different speeds in different mediums. This property of light is called “refraction”. \nWe also know that white light is made up of different colours. Different colors of light have different frequencies. Except in vacuum and air, they travel at different speeds in different mediums.\nIf you were to allow a beam of light to pass through a simple prism, it will bend when it enters the prism, when it leaves the prism it bends again. The different colours of the white light travel with different speeds inside the prism. The slanted surfaces of the prism makes the different colours emerge separately, thus in addition to bending light as a whole, a prism separates white light into its component colors. This splitting of light into its component colours is called dispersion, where prism is a dispersing element.\nThis is exactly what happens when the sun rays hit droplets of water. When the sunlight strikes a raindrop, the light is refracted (bent) because the light is moving from one medium(air) to another( water). Drops of rainwater can disperse light in the same way as a prism.. When the light comes out of the water droplet, the sun's rays (white light)have now been split into their component wavelengths (colors). In this way, each individual raindrop behaves just like a prism, dispersing white sunlight into its seven component colors and a rainbow is formed. \nThe rainbow we see is thus a result of many, many raindrops bending the sun's rays.
961174
When the suns rays heat up the air above a surface and the heated air is appearing to shimmer (different index of refraction) then that can appear as a mirage (for water for example). I think some mirages (along the highway) are pure imagination and others (water in the desert) are also partly wishful thinking.
209316
The liquid is transparent if you can see the pencil. The reason the pencil looks that way is refraction. The light travels differently through the water, so it bends and doesn't go in the same straight line that it was. So you see half in the air, straight, and half in the water, at a different angle. Try putting the pencil in slowly. You will see it is only the part that is in the water that looks bent. Other liquids (oil, rubbing alchol) bend the light different amounts so the angle is different. Try it and see.
1101763
Well....moving water has a different refractive index to still water. So if you can monitor the intensity of color using the color of the light from still water you will see a change in the color when the water is moving. It is then possible to see that movement in the water is taking place. \nThe speed of movement maybe be also indexed as a change in refractive index. \nSo, it would be possible to run some controlled experiments and determine convection of water in some form of useful units.
170004
It is dependant on the curvature of the Earth to your hight above or below sealevel.\n\nHere is the dumbed down general answer pulled from the article below:\n\n"Suppose you're standing at the edge of the sea, with your toes at the waterline. Your eyes are about 1.5 meters above the sea.\n\nAs the resolution of the normal eye in broad daylight this dip is an easily visible angle. So, although the angle is small, it is hardly negligible, even for a naked-eye observer standing at the water's edge. Clearly, dip is an appreciable effect for all real-world observations. \n\nBefore considering a more realistic situation that includes refraction, notice that the dip of the Earth. The distance to the apparent horizon: about 2 1/3 nautical miles"
7107
Well mostly the difference in colour of the oceans is due to the muddy and unclear waters. no waters have colour. But it is just the colour of reflection. Please see the site i am listing below. It is a q & a type forum only!!\n\n\nYou may get your answer here too!!\n\nWe see the water  great masses, seas, lakes, rivers, with colors: blue,  green, gray, \nsometimes brownish. But if one picks up a pot of that water the aspect is not colored.  \nSo the color is an optical phenomenon that is observed only when a large volume of water \nis considered and it depends on several things:\n-The water reflects the sky, so its color depends upon the sky colour at that time, and if \nit has white or grayish clouds.\n-At other hand  the water colour depends also from the material that is found  mostly into \nthe sea  water.\nThere are life there…animal and vegetal, a lot,included the  phytoplankton, microscopic \nplants that either float or are suspended there.  And of course there are  dissolved and \nsuspended also inorganic and organic matter coming from the sea floor and from rocks.   \nColor is the result of  optical interactions from the incident  solar light and the \nbillions of microscopic particles present.\nWhen the light of the sun reaches the sea surface different phenomena happen, part is \nreflected, part is absorbed and some is scattered. These phenomena happens with the water \nitself, the dissolved organic and inorganic matter and the suspended particles.\nThe colour of sea water depends upon  the distribution of these facts. It is blue for clear \nocean water and shifts to darker for less transparent or more turbid waters, and depends \nalso from the depth and transparency of the considered layer of water. And that colour can \nbe seen from space! That is why our planet Earth is called the "blue planet". Isn´t that \nwonderful?\nAnd thanks for asking NEWTON!
515706
The atmosphere is made up of several layers,each one with a varying density.Thus,the speed of light differs in different layers of the atmosphere and the light gets refracted(deviated from its path when it travels from one medium to another)when passing from one layer of atmosphere to another.Due to this refraction of light in the different layers of the atrmosphere,stars appear to twinkle
340597
there's not too much difference, other than  the density which causes the drag coefficient. however, water has surface tension, which may be slightly important in causing greater drag
803594
The previous two answers are correct.  The surface of a still body of water is one of few naturally occuring situations producing a clear reflection.  Gravity, molecular motion, the freedom of molecules in a liquid to move to positions of lowest energy, and an index of refraction that differs from air all contribute.  Mercury is much better, since its reflectance is nearly 100%.  The surface of a pool of mercury is a nearly perfect mirror.