why fabric things go dark when wet?
In: 87
When water goes into the pores in cloth, the light now gets refracted instead of bouncing off the usual way, and now a bigger portion of light gets trapped in the cloth.
A little more advanced explanation:
some matte looking materials often don’t reflect light the same way as, lets say, mirros do. Instead, the light penetrates few very thin layers, and which each one, it gets bent and eventually it comes out at angles at which it can leave the material (basically just gets redirected more or less the same way it came into the material). Only some wavelengths of light are bent just enough to get redirected back, so this is why we see different colours of cloth (this is basically what dyes do, change which wavelengths get refracted).
With water into the mix, the refractive index changes, and the light loses more energy (not per photon, but the number of photones that get turned around is lower). Less energy in the light, without changing the frequency of it, means darker coulours.
When water goes into the pores in cloth, the light now gets refracted instead of bouncing off the usual way, and now a bigger portion of light gets trapped in the cloth.
A little more advanced explanation:
some matte looking materials often don’t reflect light the same way as, lets say, mirros do. Instead, the light penetrates few very thin layers, and which each one, it gets bent and eventually it comes out at angles at which it can leave the material (basically just gets redirected more or less the same way it came into the material). Only some wavelengths of light are bent just enough to get redirected back, so this is why we see different colours of cloth (this is basically what dyes do, change which wavelengths get refracted).
With water into the mix, the refractive index changes, and the light loses more energy (not per photon, but the number of photones that get turned around is lower). Less energy in the light, without changing the frequency of it, means darker coulours.
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