We admire the color of the water of the seas and oceans, we say that it is dark blue, or sky blue, or something else, but it is not enough for scientists to see and admire, they need to know why all this is happening.
In the 19th century, the Swiss geographer F.A. Forel invented a device that measures the color of water. He created a scale from chemical solutions that always have the same shades. This scale is called a xantometer.
It was necessary to prove the obvious. The color of water, like the color of any body, is determined by the ability to transmit or reflect any colors of the solar spectrum. Snow, for example, reflects White color, ice skips sunlight through and through, and therefore transparent, and the water in the ocean transmits and reflects at the same time the blue color of the spectrum. At the same time, it was believed that the water itself is absolutely colorless.
In 1883, the Belgian scientist Spring conducted an experiment with distilled water. He proved that even in a closed tube even purified water retains the blue color obtained from the spectrum for some time.
In addition, it became clear that the color of the water does not depend on the smallest particles, the dispersion of which is the cause of the heavenly blue. Spring proved that water, getting into the rays of the spectrum, absorbs the red and dark parts of the spectrum, and lets through the blue, and itself turns blue for a while.
In addition, the color of the water in the seas and oceans is influenced by its chemical composition... In the oceans, most often it is dark blue, only in some places it takes on a slightly different shade.
Occasionally, the ocean water appears red or takes on an olive tint. Studying the phenomenon, scientists came to the conclusion that such staining occurs due to algae in the water and having a similar color. It is they who give the ocean such a disturbing color.
Suspended particles, which the sky owes its blue, sometimes end up in the ocean. Off the shores of the oceans, you can often pay attention to the green shades of the water, which can be explained by the presence of suspended particles in it. But most often we can admire the blue surface of the ocean.
Why is the sea blue?
Why is the sea blue, because the water itself is transparent? And even if you take seawater and pour it into a decanter, it will also be transparent.
Wrong answer: because the sea reflects the sky and it is blue.
The color of the sea that we see is the result of the scattering of sunlight by the thickness of the sea water.
Water transmits light unevenly - it scatters short waves better, and long ones worse. The short waves correspond to the blue part of the spectrum, and the long ones correspond to the red. In a decanter, you look at a thin layer of water into the light, so the difference in the transmission of the rays is invisible. And in the sea, you see the result of the scattering of sunlight by a multi-meter water column. Therefore, blue light is less absorbed in water, and in the light that comes out of the water, most of all blue.
by the way
Best of all, water does not reflect blue, but purple... And even better - ultraviolet rays. That is why there is a danger of getting on the seashore sunburn higher than away from water bodies.
On maps and pages of atlases, seas are drawn in blue and light blue. In the literature, they are also often credited with this color. Children who learn from fairy tales often ask their parents: "Why is the sea blue?" Not every adult will correctly and easily answer a child to such a question. A person who has been to the sea may be confused, because he knows that the color of the water is changeable and depends on many factors.
Physics of light
In the second half of the 18th century, the genius Isaac Newton first decomposed ordinary sunlight into its constituent color spectrum. For this, the scientist passed a thin beam through triangular prism... The light refracted and displayed on the receiving screen in the form of a tape consisting of seven colors. In all experiments, the color sequence was kept the same. Today children remember it with a simple phrase:
- Everyone (the first letter of the word means red);
- Hunter (orange);
- Desires (yellow);
- Know (green);
- Where (blue);
- Sits (blue);
- Pheasant (purple).
Newton went further: he sent the decomposed colored rays of the spectrum to a converging lens and again received white light. Having understood the nature of the sunbeam, the great physicist continued his experiments, revealing deeper and deeper physical properties light and mechanisms of color appearance.
With the help of filters, he removed individual colors from the spectrum, mixed different shades with each other, studied their relationship, which he reflected on the spectral circle, which later received the name "Newton's Color Circle".
Based on his research, the scientist made three fundamental conclusions:
- Color does not exist without light.
- White light contains all colors, it is just that the eye is not able to distinguish them, for example, as it is able to distinguish individual sounds in a musical chord.
- For the colors of the spectrum, the principle of addition operates, mixing different spectral waves with each other, you can get all kinds of color shades.
Some bodies of water seem green to us, others blue, others blue. The water collected in a transparent container is transparent. In order to put everything in its place, consider the physical properties of water.
Water color
Clear water is blue. However, the intensity of the shade is so low that it is impossible to notice it in a small container. If you fill a large glass aquarium with water, the blue color will become visible to the naked eye.
What influences the hue? The human eye sees reflected light rays, so it is important which of them the substance absorbs and which reflects. The spectrum of visible sunlight is composed of all the colors of the rainbow.
The water molecule absorbs the red and green parts of the spectrum, and reflects the blue. This gives the water a bluish tint. The thicker the water layer, the more intense its color.
Natural bodies of water
In theory, this is blue, in nature, pure and identical colors are rare. Why is the water in the sea blue? Far from the coast, oceans and seas have great depth and appear black and blue or purple to the observer. Closer to the shore, the water becomes lighter: bluish, greenish, color sea wave etc.
Why is there such a difference? The intensity of color and shade is influenced not only by the thickness of the water layer, but also by the presence of suspended particles. Off the coast, in the pelagic layer, there are many algae and biological remains. Some of them enter the seas from land. Phytoplankton is green because it contains chlorophyll. It reflects the green part of the spectrum and absorbs the red and blue. The presence of algae determines the greenish nature of the shade of coastal waters.
Depth and color
The depths of the sea and sandy deserts have a lot in common - they have very few living beings. Satellite images clearly show which seas are rich in living organisms and which are not.
Why the sea blue, and not, say, green? Since in the center, these reservoirs are deep. Along coastline the color of the water is greener, therefore, here a large number of marine life... In the deep blue biological diversity poorer, like hot desert spaces.
To answer the question why the sea is blue, consider a change in the color of an object immersed in it. The yellow submarine near the surface will seem to us as it really is.
The deeper it sinks, the more difficult it is for the sun's rays to reach it. With each meter, the amount of light that reaches its surface decreases, which is associated with the reflectivity of both the water itself and the particles of animate and inanimate nature in it.
At a depth of thirty meters, the submarine will appear bluish-green to the observer. This is due to the fact that most of yellow-red spectrum will be absorbed by water. When it is several tens of meters lower, water molecules will absorb the green spectrum as well. As a result, the yellow submarine will take on a dark blue tint.
The ocean contains many more suspended particles than clean water... At the same depth in the first case it will be much darker than in the second.
in the ocean
Marine and does not have the ability to glow. Everything that can be seen under its surface looks like this in reflected sunbeams... I wonder why rivers and seas are blue, because daylight is not blue? Near the surface, it is almost the same as above water.
The maximum proportion of radiation falls on the yellow-green segment of the visible spectrum. The color of the sea depends on which part of the spectrum is reflected and which is absorbed. This complex mechanism was described in detail by geophysicist V. Shuleikin at the beginning of the 20th century.
The molecules that make up the ocean vibrate and rotate at different intensities, which affects the reflectivity and absorbency. They easily absorb red rays, while blue ones reflect. For this reason, observers above the sea see it bluish or purple.
Red rays are absorbed in the first meters of depth, green - closer to 100, and blue - only in the second or third hundred.
Transparency of the seas
The transparency of water in the world's oceans depends not only on the physical properties of the liquid, but also on the organisms and particles it contains. The mud is created by planktonic creatures, mud and suspensions of various substances. Least of all benthic unicellular organisms are found off the coast of about. Easter. Therefore, the waters there are the most transparent in comparison with other parts of the World Ocean.
The seas are scattered across the surface the globe... Some of them are in the tropics, the other in the poles. Some of them are dominated by heavy rainfall and little sunny days... A number of seas are in arid regions with high intensity solar radiation... These indicators also affect the color of the sea as seen by the observer.
Thus, having studied all the physical properties of water, we can now confidently answer the question of why the sea is blue.
Surely each of you has visited the sea coast at least once and plunged into the blue-blue sea. But does the sea always seem blue? Not at all. The seas are of different colors... For example, in northern seas the water is dark green; off the coast - brown or yellow. The sea becomes gloomy lead-gray in stormy weather.
And the color of the sea depends on the water column in which daylight is scattered and reflected. Molecules of pure sea water reflect and return blue rays to the sea surface. If there are a lot of green algae in the water, then the sea looks green. Mineral particles and humus, as well brown algae give the sea a brown or yellow color.
Not in vain Yellow Sea so called. The fact is that rivers bring from land great amount particles, so the water of this sea has a yellow color.
AND Red sea quite justifies its name - brown microscopic algae give the water red color.
By the way, the color of the sea surface is influenced by the color of the sky - if there is not a cloud in the sky, blue tones are enhanced, and dark clouds give the sea a lead-gray color.
You will probably be interested to know the answer to the question: why Black Sea is it called that way? Is this also a matter of algae?
It is worth noting that the Black Sea has changed several names. There are several hypotheses about the origin of this particular name. For example, sailors believe that the sea is called "Black" because there are very violent storms during which the water in the sea darkens. However, storms in the Black Sea are not frequent guests, and the color of the water during a storm changes in any sea, not only in the Black Sea.
Why is the sea blue?
- sea plants. Especially algae and corals, as well as sand or clay;
- depth. As a rule, where the water is deeper it is darker, and vice versa, near the coast it is almost transparent.
This is due to the fact that the seawater column scatters sunlight. And since blue is less absorbed by water, the sea appears to be blue.
Water passes light unevenly, short-wave water dissipates better, and long-wave water dissipates worse. Short waves correspond to the blue part of the range, and long waves correspond to the reddish part of the range. In a glass you are looking at a thin layer of water, as a result of this, the discrepancy in the transmission of rays is hardly noticeable. And in the sea, we see the effect of light scattering by a multi-meter water column. As a consequence of this, blue light is absorbed to a lesser extent in water, and in the light that is obtained from water, blue is most significant. By the way, water displays better not blue, but purple, it also displays ultraviolet rays better. This is why the risk of sunburn on the ocean shore is higher than in the distance from the seas.
Because water absorbs the rest of the color waves. Blue can penetrate deep under water, unlike red, yellow and green. Because of this, deep waters are often bluer than shallows.
Well, and one more obvious reason- the sea reflects the sky, copying its color.
Because blue sky reflected in it.
But the sea really seems to us blue at a superficial glance, and the whole point is in two reasons. The first, the most obvious, is the reflection of the sky in the water. The second reason lies in the scattering of sunlight by the water of the sea itself. And the spectrum b = blue is less absorbed by water, which is why the blue sea. The color of the sea will also depend on the pollution and calmness of the sea.
If you need an answer for a child, say that in the deep sea, like in a mirror, the blue sky is reflected. And in the shallow one can see the bottom and therefore the sea is of the same color as the bottom.
And because the pools so want to be like the sea, they are laid out with blue tiles.
For the same reason the sky is blue.
The sun's rays are scattered in the atmosphere according to Rayleigh's Law, which states that the intensity of radiation scattering is inversely proportional to the fourth power of the wavelength. That is, the answer given at the Physicotechnical Institute sounded like this: because, lambda is in the fourth degree . That is, beams with a shorter wavelength are scattered more strongly. In the spectrum, this will be the blue-blue part of the spectrum.
The color of the sea depends on its depth, time of day, sky color, amount of plankton, water pollution, light scattering. If the sea is calm, clear, and the sky is blue or blue, then the water will also be blue. This can be said to be the normal standard state of the sea and its standard color, which is why the sea is called blue in folklore.
The reflection of the sky has its own effect on the color of the sea, but it is not significant. A blue color it is the result of the scattering of sunlight by seawater. The fact is that water, like all other substances, absorbs some rays and reflects others. And white sunlight, as many know, in turn consists of other rays. different color... Light passes through the water column; unevenly short light waves (red, yellow), water scatters better, and long (blue) waves are much worse.
Taken if that from http://whyy.ru/pochemu_more_sinee/ but I think this answer is enough for you
Sea water appears to be blue to us, as does the sky, for reasons related to the molecular scattering of sunlight. Short-wavelength (ultraviolet) radiation of light waves, related to the blue part of the spectrum, is much better scattered by water and air molecules than long-wavelength light radiation. Therefore, the transparent environment looks blue to us.
The color of the sea that we see is just the result of the scattering of sunlight by the thickness of the sea water. Water transmits light unevenly - it usually scatters short waves better, and long ones worse. Short waves usually correspond to the blue part of the spectrum, and long ones - to the red. And looking at the sea, we see it blue, or greenish, but it is transparent.
Why is the sea blue, isn't the water itself transparent? This question also interested François Forel, who, back in the 19th century, created an analogue of the current xantometer... Trout tried to measure the shade of water on a scale of chemical solutions. But, no matter how the experiments took place, the color remained transparent anyway. Sometimes, there is an opinion that the sea reflects the sky in itself. The most famous experiments in this matter were carried out by the researcher Spring
Thus, the sea does not reflect the sky, but it emits the blue color of the spectrum.
In addition, the color of the sea depends on other factors:
Loading...
