For a long time people have been worried about the question: why are the veins blue and the blood red? Experts took up this issue, trying to find and substantiate the answer as accurately as possible. Surgeons were among the first to notice this feature of the veins.
Recently, there was a new theory in the press about this phenomenon, it was voiced by David Irwin from Sydney, who works at the University of Technology. According to him, the veins appear blue because they are perceived as such by human vision, and also influenced by the characteristics of the blood and the light absorbed by the skin.
How does human vision perceive the color of veins?
And so, why the veins are blue is yet to be seen. As you know, light waves are different, respectively, they have a similar length. The longest are red, and the shortest are purple, in the space between these two types there are other shades. The eyes begin to distinguish them when the waves enter the field of view. Red waves are not very noticeable under the skin,because they are at a distance of 5-10 millimeters, also because of their size they do not stand out much. Another reason was hemoglobin, which is in the blood, it is he who absorbs the red color.
Why are the veins blue on my arms? In order to see the blue color, it is enough to shine an ordinary white light on your hand. With a different light, such as blue, the veins will not be visible, since this light is easily reflected and scattered without getting into the skin. With white, not tanned skin, blue veins are especially visible.
How the sun affects the color change
Also why veins are blue is affected by normal sunlight. This happens because the tissues of the body absorb red rays, while the blue ones, on the contrary, pass through. The light passes through the fabric a couple of times: inward and backward, during which time the fabrics absorb the red light, while the blue remains intact.
The sun's rays move according to this principle:
- First, they enter the tissue, then they pass through the skin, subcutaneous fat layer, vein walls and enter the venous blood.
- The sun contains the colors of the rainbow. Venous blood has colors: blue, red, yellow, based on this, we can conclude that the blood reflects these colors, and absorbs the other four colors.
- Reflected three colors move in reverse order: they pass through the veins, fat layer and tissue, and only then become visible to the eye.
Opinion of surgeons
The question of why the blue veins did not bypass the specialists, they put forward a new theory. The fact is that the vessels arefrom a dense white substance like an oilcloth. Unlike arteries, which are deep under the skin and have dense walls, veins are transparent in color, so you can clearly see that dark blood flows through them. When overlaid with colors, blood is dark cherry and the veins themselves are white-gray, the result is blue.
Conclusion of German scientists
The most accurate justification for why the veins are blue was given by German experts. In addition to words, they offered facts that prove the appearance of color:
- this color is perceived by the brain;
- blood absorbs light;
- the skin itself reflects this color.
The most noticeable veins are on white skin, because it hardly absorbs light. The color of different wavelengths hits the skin, the red tint has the greatest length and therefore it is reflected by other vessels. Vision will perceive the image that is displayed from the tissues. In the case when the vessels are near the surface of the skin, then almost all of the blue color will absorb the blood, and the rest will be presented as red.
In the case when the vessel is very deep, the light will be reflected before it reaches it, and the person will not see it at all. Practice shows that the vessels display more red color, but the brain perceives it as purple and gives out information that it is allegedly blue.
