Naked Science Forum
General Science => General Science => Topic started by: christianchick on 18/03/2004 14:13:51
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OK if my cd gets a scratch on it and i put toothpaste to fill it and then clean it off, my CD will stop skipping, why does this work, does anyone know?[?]
God Bless You
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HELLO?
God Bless You
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Don't know why it works for CDs, but it also works well for cleaning jewelry.
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Are you sure its the toothpaste working miracles? The cd's probably working because you cleaned it- my guess is that it would have worked equally well/better after cleaning with washing up liquid!
"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe
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The laser in your cd player is developing cavities and picks up the toothpaste from the CD repairing the cavity damange.
Ah seriously though no idea my guess is that qpan is right with the cleaning of the cd
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OK, a real answer: Think of your CD as a record and the laser as the needle (just to ake it esaier to viualize). The information stored in the place where the CD was scratched is lost forever. However it is a miniscule amount of information. The problem is, when the "needle" hits that place it gets "stuck" in it. If its a small scratch it finds its way out if its a big scratch, it REALLY gets stuck (as I'm sure you know). When you put tooth paste on you are filling in the hole. Obviously the toothpaste does not replace the information that was lost (music etc.). But it does allow the "needle" to pass smoothly over it. Chances are the amount of data lost os so small that when you are listening to it, you can't tell anything is missing.
Yar, the flies be everywhere maty....save yerselves!!!
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Toothpaste is also good for teeth !![:D]....Some high-end cd players can play discs that are atrocious in condition, that would not even be recognized on lesser players. Toothpaste is an excellent cleaner though some can be quite abrasive and this is the last thing you want on your circle of musical delight. The laser mechanism is fundamental to your listening pleasure and depending on the degree of accuracy implemented by the laser mechanism is relative to how much information a laser can read off a disc. I think the toothpaste has cleaned and filled in the odd pot hole in your cd Christianchick in this case. However, it's also a good idea to periodically clean the laser itself with a reasonable lens cleaner.... It looks just like a cd, with little brushes on it. the same can be said for DVD players too. Clean it after every 10 hours of use.Dust that can build up can(without maintenance) permanently soil the laser lens itself. A good lens cleaner here in the Uk cost about £10-£15. It's quite possible that with a clean lens you may not have experienced any skipping at all, however, it can be a symptom of a misalligned lens, but in your case, I reckon it was just a dirty disc. Also, it's worth noting that when you clean a cd, you DON'T do it like a record, you move in straight lines out from the hole to the edge. It's just the way the data is stored and the construction of the cd that this method of cleaning is recommended.
'Men are the same as women...just inside out !'
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Mayoflyfarmer- your analogy is quite a good one - except, how does a laser get stuck in a scratch? [:p]
"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe
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The data on a CD is written in a certain format (ISO 9600) and contains quite a bit of redundancy that is used to correct errors due to noise in the reader or missing data. The data retrieval mechanism is constantly reading everything off the disc and checking the consistency to make the final output error free. When too much data is lost, there is a "gap" in the output stream that you may hear as a pop (or may not if it is small). If the tracking data is lost, the CD player can lose it's ability to find the next frame of data and then you get a skip of maybe several seconds worth of music or an error message.
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John - The Eternal Pessimist.