3 ms·

If it reflects at the walls it looses energy and isnt UVC anymore …maybe uvb …. Thats the reason we can see uv floruelenc … 300nm( UVA) radiation that gets redu

If it reflects at the walls it looses energy and isnt UVC anymore …maybe uvb …. Thats the reason we can see uv floruelenc … 300nm( UVA) radiation that gets reduced to something like 350nm(blue light)

323 5y ago
If true that would be terrible. Because higher wavelength UV is very dangerous. And are you sure about this? When visible light gets reflected by a wall it doesn't seem to change wavelength significantly (color basically remains the same).
- bratwurst3000 5y ago
  Okey i wasnt clear. The wall has to interact with the radiation. Thats why you see colours. https://wonderopolis.org/wonder/why-does-a-black-light-make-things-glow https://wonderopolis.org/wonder/why-does-a-black-light-make-...
nkmnz 5y ago
That’s not at all how reflection or fluorescence work. Reflection does not change the wavelength. Fluorescence is a three-step-process of absorption, internal conversion (energy-loss) and re-emittance of light with a higher wavelength. Fluorescence-efficiency is usually very low, and highly specific to the absorbance of a certain wavelength, so unless you have bad luck with the color of your wall, fluorescence should not be of high concern.
- Tagbert 5y ago
  “re-emittance of light with a higher wavelength” I would say that the re-emitted light has a “longer” wavelength. Fluorescence always produces a longer wavelength. UVC becomes UVB, UVB becomes UVA, UVA becomes blue, etc. Though different materials increase the wavelengths to different degrees. That is why “black lights” can produce different fluorescent colors.
- bratwurst3000 5y ago
  Hmmm light is a package of photons and when it reflects and the object is blue it looses the blue spectrum(photons) in the package. This package can be disected with furier and should have a different wavelength then befor……. Are you sure thats not how it works?? I would love to be proven wrong. Had not enough physics to fully grasp that concept :) And did you ever use a blacklight in a dark room? Many things are shining. For example teeth. So smilling could get 220nm to a dangerous zone and kill the one that is smiled at? … hehe little joke.

323 5y ago

If true that would be terrible. Because higher wavelength UV is very dangerous. And are you sure about this? When visible light gets reflected by a wall it doesn't seem to change wavelength significantly (color basically remains the same).

bratwurst3000 5y ago
Okey i wasnt clear. The wall has to interact with the radiation. Thats why you see colours. https://wonderopolis.org/wonder/why-does-a-black-light-make-things-glow https://wonderopolis.org/wonder/why-does-a-black-light-make-...

nkmnz 5y ago

That’s not at all how reflection or fluorescence work. Reflection does not change the wavelength. Fluorescence is a three-step-process of absorption, internal conversion (energy-loss) and re-emittance of light with a higher wavelength. Fluorescence-efficiency is usually very low, and highly specific to the absorbance of a certain wavelength, so unless you have bad luck with the color of your wall, fluorescence should not be of high concern.

Tagbert 5y ago
“re-emittance of light with a higher wavelength” I would say that the re-emitted light has a “longer” wavelength. Fluorescence always produces a longer wavelength. UVC becomes UVB, UVB becomes UVA, UVA becomes blue, etc. Though different materials increase the wavelengths to different degrees. That is why “black lights” can produce different fluorescent colors.
bratwurst3000 5y ago
Hmmm light is a package of photons and when it reflects and the object is blue it looses the blue spectrum(photons) in the package. This package can be disected with furier and should have a different wavelength then befor……. Are you sure thats not how it works?? I would love to be proven wrong. Had not enough physics to fully grasp that concept :) And did you ever use a blacklight in a dark room? Many things are shining. For example teeth. So smilling could get 220nm to a dangerous zone and kill the one that is smiled at? … hehe little joke.