Use radio waves to read a CD conventional CDs would probably work. It wouldn't matter how scratched they were because the radio waves would go right through the plastic. The only problem might be less storage space.-- skybw, Dec 17 2007 light is a radio wave. But this wouldn't work. Inless I'm unaware of a way to focus a radio wave on a microscopic pit in plastic and detect the presence of aluminum, this won't work.-- evilpenguin, Dec 17 2007 //I'm unaware of a way to focus a radio wave on a microscopic pit in plastic and detect the presence of aluminum//
MASER ?-- FlyingToaster, Dec 17 2007 Radio waves are much too long for this to work. For example, even a 1GHz radio wave is about 30cm (or a foot) long.
The optical laser used in a CD player has a wavelength of 780nm, or about 1/385,000 as large! --- csea, Dec 17 2007 Fishbone for bad physics. Light is an EM wave, but as [csea] states radio waves refer to a band from about 30cm to several kilometers.-- MisterQED, Dec 17 2007 Simple - just scale up the CD accordingly. Of course, then you'd have to just call it a D...-- lostdog, Dec 17 2007 Ooh ooh ooh! How about an oil- immersion CD player? The whole thing runs in a bath of light mineral oil. The refractive index will be closely matched to that of the plastic outer layer of the CD, and so scratches will be effectively invisible.-- MaxwellBuchanan, Dec 17 2007 What about turbulence created by the rotation of the disc ?-- 8th of 7, Dec 17 2007 //What about turbulence// Shouldn't be a problem optically if the oil is homogeneous. Of course you'd need a beefier motor to spin the CD, and probably to move the head.-- MaxwellBuchanan, Dec 17 2007 ...and a way to keep the disc from floating around...-- phoenix, Dec 18 2007 This thing would be a monstrosity of a Disk. maybe it should be calle an MD instead. Oh, and people could live in the pits, which would need to be dug with shovels. Maybe that's what that move "Holes" was really about. Certainly it wouldn't (or would) be far fetched to have the disk reader be in orbit around the disk and have the disk stand still, with the pits on the outer edge of the disk.-- quantum_flux, Dec 18 2007 //oil- immersion CD player? //
Much better idea for the stated purpose, albeit a bit messy! [MB], can you find an appropriate oil?
Given the popularity of Drivesavers, etc for HD media, I suspect this could be a good business in the not-very-far-off-future (20x0s?) for reading "old" CDs.-- csea, Dec 18 2007 What about using a Mexican wave? Or would that make everything sound like a mariachi band?-- Murdoch, Dec 18 2007 It is called oversampling, or Nyquist-Shannon Sampling. It erradicates noise, possibly introduced by scratches (in the case of optical media), or other noise. Harry Nyquist is not to be confused with Harry Renquist (an affible character portrayed by, the now, Governor of California).-- 4whom, Dec 18 2007 radio waves destroy CDs, ever try putting a CD in a microwave? fun.-- krigre55, Dec 19 2007 Appologies for any flippancy, but interleaving and oversampling work hand in glove to reduce reading/writing errors and associated noise. Although this is not oversampling's *priority* job. Oversampling's job, as I understand it, is to parse analog signals to digital bits. Its efficiency led to its use as a filter:
//The second method of output reconstruction deals with an oversampling digital filter prior to the DAC// ~ Dr. KM Buckley.
However, I stand for correction, as my investigation of this particular matter was a long time ago, with only a recent, rather truncated, revisit.
I object to be called a *complete* arse, many will attest to the fact that I am only an arse-part.-- 4whom, Dec 24 2007 random, halfbakery