Machina Dynamica New Dark Matter CD and Blu Ray tray treatment?
mapman15,742 posts04-04-2019 8:48pmHere’s another pop quiz. a) Given the speed of light and the small quarters inside a CD player compartment, what difference does it make if the light, regardless of wavelength is scattered or not ? The sensor detects the light at the same time whether scattered, reflected or direct. >>>>You’re no fun, Moops. You just answered your own question. |
moopman b) Also black matter being black only means it absorbs the light we can see, just like other black things. That alone provides no evidence that either IR or UV wavelengths are absorbed. Even if it was proven to absorb IR, and other black things not, it would not seem to matter given point a). >>>>You said it was black, not me. |
moopman BTW, anyone know the actual EM frequency range that sensors used in CD players actually detect? That would be a good start to know what will be most effective in absorbing the light, not that it is likely to matter... >>>>Yes. I do. Now, see if you can guess what frequency range the CD laser operates at. |
Moops, did you forget to take your smart pill today? If the scattered light is always in the background then it can get into the photodetector at times when there is supposed to be no light detected, i.e., when the laser beam is over a “pit.” When the laser beam is over a “land” the full reflected signal is registered by the photodetector for that short period of time. Obviously, you don’t want any scattered light to get into the photodetector during periods when there should be no reflected signal. Follow? |
