Quote:
Originally posted by Shrek@Dec 29 2005, 07:58 PM
CD ROM drives use lasers to read the data writen in the CD and CD Writers use lasers to burn info in to th media, so what's the diference between between a CD ROM and a CD Writer? It all lies at the "power of the laser", you'll need a stronger laser beam to burn a media.
Playing a CD over and over will cause the laser of the CD ROM drive to gradually contribute to the degradation of the CD track, and it all depends on the quality of the media and CD ROM drive ("cheap" CD Rom drives will probrably have "less" control quality at the laser mechanism, so there is a possibility that they can damage media more often).
|
That makes absolutely no sense when put in the context of how CDs and CD drives actually work. First of all, assuming that the laser did actually damage the media simply by reading it, what you're saying would only be true of (re)writable media. "Old-fashioned" CDs (manufactured read-onlys) have the data "bumps" actually fashioned into them during the manufacturing process whereas writable media works based upon heating and cooling special dyes.
It is because of this that two separate lasers must be used in a multipurpose (R/W/RW) drive. If the write laser (the more powerful of the two) was used for reading it would destroy any writable media immediately, not over time. The read laser, on the other hand, isn't powerful enough to alter the dye of writable media and thus wont cause any damage.
Now, there is a possibility that the dye itself might degrade in integrity over time, but that doesn't have anything to do with only reading the disc. Furthermore, rewritables cease to work after they've been rewritten enough times, but this also has nothing to do with simply reading.
As an aside,
none of this has anything to do with the surface of the media; damage to which is caused by other means.
Quote:
Originally posted by Yobor
Yeah, I saw a Myth Busters episode where they tried to detonate a CD by spinning really fast (Like as fast as the higher speed drives). It's true, they will shatter.
|
Actually, not at all "like the higher speed drives." The MythBusters actually attached CDs to a Dremel, iirc, and spun them up to 40k RPMs or so before the discs shattered. A retail 52x drive spins at 10k RPMs. Their final conclusion was that it was only
plausable for the CDs to shatter in a highspeed consumer drive if the disc was already damaged.
[Edit: fixed some numbers on drive speed]