Why do things appear darker when they are wet?

Question

Asked by colleague at work... I have an idea but.. well, we'll see.

Answer 1

I am assuming that you're referring to fibrous substances (cloth, paper, etc.) when asking this question because the most common substances that "get darker" when wet are fibrous. Such substances are not a "flat solid" at the surface, and instead are composed of multiple layers of fibers. But most of these fibers are still the same at all layers, or at least at all the layers that are visible from the surface. They appear to reflect light uniformly unless large distortions are visible (such as individual threads, relief patterns, etc.).

Water is usually absorbed readily into such a substance due to its fibrous nature. The water is held in between the fibers and stored there. However, some of the light which originally reflected from the "deeper" fibers must now pass into (and back out of) a layer of liquid, thus subjecting it to possible reflection, refraction, or any form of general scattering. In fact, some of the reflection is not just at the surface but also from light beneath the surface being reflected back down into the material. And if the material is thin enough, the liquid can help refract some of the light completely through it, thus making it appear "thinner" when wet.

Answer 2

When something is dry, light which hits it generally scatters everywhere. This is non-specular reflection, and holds for most substances that are not glossy or mirrored in appearance. Water makes a good specular reflector, when you wet something, the light that hits the water, rather than scattering everywhere, bounces off it as off a mirror. From most angles, you see less light, but from a few angles you get all the concentrated light from the reflection.

The net result is that most of the time things that are wet appear darker, because the light that hits them is not reflected directly at your eye. Sometimes, they appear much brighter, because the light reflects at your eye. On average, it's about the same, the distribution is just lumpier.

A wet mirror doesn't look darker than a dry mirror, the water can't really do anything to change the situation.

Answer 3

Water has an albedo of 0.2, so 80% is absorbed internally. Most materials will have a higher albedo, so they look darker when wet.

Also, the wet material that reflects light will probably be less random. Since you've got a least in part a flat surface from the water, more light will get absorbed away from the prevailing light source due to the angle of incidence. So while it looks darker in most directions, if you look at it while looking towards the light source,it may appear shiny.

Answer 4

Wet means water molecules are adhered to the substance.

Water layer not only reflects but also refracts; Therefore, we see reflected light by the surface of water on the substance as well as the light that are coming out of the water surface which after entering into the water are reflected by the substance below the water surface.

Thus we distinguish the wet surface from the dry surface. The brightness of the dry surface is more compared to the wet one (due to absorption of light by water surface). Thus they look darker than the other.

Answer 5

good question. that is component of a paradox. issues look darker at the same time as moist. therefore, there should be a replace in albedo (reflectivity), so allow's assume that. i believe the clarification that occurs is that water acts as a lens, permitting more effective mild to enter ther cloth's pores to be absorbed. at the same time., i imagine it acts as a reflect, scattering some mild away at distinct angles (often times moist surfaces look bright, maximum recommendations-blowing?). That mild is lost, reducing the quantity of sunshine it truly is contemplated. So briefly, lots of the lost mild is probable absorbed into the floor by the lens effect, at the same time as different lost mild is scattered through floor mirrored image. the internet effect is then the 'darkening' that occurs. There is usually a moderate 'blue shift' contained in the colour of the mild from the water tendency to duplicate blue from the sky, assisting to make it look darker. the anomaly is that it ought to look components get darker, meaning a lot less mild receives by. even if, if it truly is so, why is it that you'll discover by a moist t-blouse? If more effective mild is absorbed, you need to no longer be able to. that is the position i'm getting my idea that the water acts as a lens, permitting mild to bypass between fibers, reflect off a surace, and are available decrease back out. nonetheless, some mild is lost by absorbtion contained in the cloth and the scattering effect, so inspite of the actual undeniable actuality that that is semitransparent, it nonetheless seems 'darker'

Answer 6

The water molecules mixed with the colors of those things serve as a transparent medium (water is transparent) of light and the refractive index decreases and more light passes into the things' deeper parts and are darker as darkest is when no light is reflected. If the things are dry their surface reflect most of the light of their color back and are brighter than wet things.

Answer 7

Wet substances absorb more and reflect less light.

Answer 8

color is perceived by the variations in how light is absorbed by an object and reflected back to us... when clothes are wet it simply changes the way the light is absorbed by it and when its reflected back to us the color appears to have changed...

Answer 9

because wet surface reflects light rays not focused to a single point.so diverged rays make it look dark

Answer 10

because the water in the thing (cloths or whatever) absorbs more light rays than the thing by itself. just guessing.