Re: [OT] How long is a DVD supposed to last, anyway? - Linux

This is a discussion on Re: [OT] How long is a DVD supposed to last, anyway? - Linux ; [H]omer wrote: > Like light bulbs, I seem to be replacing DVD discs nearly every day, and > I'm getting really sick and tired of it. > > Given that the discs themselves appear to be virtually pristine AFAICT, > ...

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Thread: Re: [OT] How long is a DVD supposed to last, anyway?

  1. Re: [OT] How long is a DVD supposed to last, anyway?

    [H]omer wrote:

    > Like light bulbs, I seem to be replacing DVD discs nearly every day, and
    > I'm getting really sick and tired of it.
    >
    > Given that the discs themselves appear to be virtually pristine AFAICT,
    > and that I have ... lemme count ... *47* DVD players (mostly PC drives),
    > it makes me wonder exactly what the Hell is going on with these discs.
    >
    > The latest victim is Blade Runner (the original DVD release, not the
    > REDUX). There's some barely perceptible wear at the outer edge, but
    > nothing serious. It just won't play, at all, in *any* of my drives.
    >
    > Another case of "disc rot" perhaps?
    >
    > That's it. From now on I'm ripping *every* disc I get to an ISO file on
    > the server. Just think, the UK government are considering making ripping
    > *illegal* (like that DMCA nonsense in the US). I wonder what they have
    > to say about the need to constantly replace discs? Do they even care?
    >


    I heard someone claim they'd last 100 years under normal circumstances.

    B.S. I have a theory if you're interested... the laser diode that does the
    writing is the same one that does the erasing.... You get it? While you use
    your cd/dvd media, it slowly gets erased... makes sense.


    --

    Jerry McBride (jmcbride@mail-on.us)

  2. Re: How long is a DVD supposed to last, anyway?

    On Jan 10, 3:22 pm, Jerry McBride wrote:
    > [H]omer wrote:
    > > Like light bulbs, I seem to be replacing DVD discs nearly every day, and
    > > I'm getting really sick and tired of it.

    >
    > > Given that the discs themselves appear to be virtually pristine AFAICT,
    > > and that I have ... lemme count ... *47* DVD players (mostly PC drives),
    > > it makes me wonder exactly what the Hell is going on with these discs.

    >
    > > The latest victim is Blade Runner (the original DVD release, not the
    > > REDUX). There's some barely perceptible wear at the outer edge, but
    > > nothing serious. It just won't play, at all, in *any* of my drives.

    >
    > > Another case of "disc rot" perhaps?

    >
    > > That's it. From now on I'm ripping *every* disc I get to an ISO file on
    > > the server. Just think, the UK government are considering making ripping
    > > *illegal* (like that DMCA nonsense in the US). I wonder what they have
    > > to say about the need to constantly replace discs? Do they even care?

    >
    > I heard someone claim they'd last 100 years under normal circumstances.


    They know that because they've tested them for 100 years under normal
    circumstances.


  3. Re: [OT] How long is a DVD supposed to last, anyway?

    In article ,
    Jerry McBride wrote:
    > B.S. I have a theory if you're interested... the laser diode that does the
    > writing is the same one that does the erasing.... You get it? While you use
    > your cd/dvd media, it slowly gets erased... makes sense.


    Actually, that doesn't make sense. DVD+RW and DVD-RW use a phase change
    metal allow that has an amorphous state and a crystal state, and can be
    changed between states by carefully controlled heating with a laser.
    The different states have different reflectivity. The information is
    recorded in the pattern of amorphous and crystal regions. These have
    different reflectivity, so they can be detected by a laser.

    Read-only DVDs, such as those used to distribute movies (which is what
    the original poster is talking about) have a plastic substrate that has
    little bumps, and a reflective coating. Shine a laser on it, and you
    can tell from the reflection whether it is aimed at a pit or not. The
    pattern of pits and non-pits encodes the data. (For a dual layer disc,
    there are two layers of pits, and the laser is focused on the layer you
    are trying to read).

    For completeness, write-once media, such as CD-R, has a reflective
    layer, and in front of that has an organic dye that is originally
    transparent to the laser frequency. To write, the dye is hit with a
    more powerful laser, which darkens the dye. The pattern of darkened and
    nondarkened dye encodes the data.

    Anyway, reading a pressed DVD is not going to "erase" it. First,
    reading is done with a lower power laser than that used for writing
    discs. Second, and more importantly, the disc is just plastic with
    bumps in it, and an aluminum (I think that's what they use) coating over
    the bumps, encased in plastic. To "erase" part of it, you'd have to hit
    it with enough power to damage the aluminum coating, or melt the
    plastic. That's not going to happen in your consumer players or drives.

    --
    --Tim Smith

  4. Re: [OT] How long is a DVD supposed to last, anyway?

    Jerry McBride writes:

    > [H]omer wrote:
    >
    >> Like light bulbs, I seem to be replacing DVD discs nearly every day, and
    >> I'm getting really sick and tired of it.
    >>
    >> Given that the discs themselves appear to be virtually pristine AFAICT,
    >> and that I have ... lemme count ... *47* DVD players (mostly PC drives),
    >> it makes me wonder exactly what the Hell is going on with these discs.
    >>
    >> The latest victim is Blade Runner (the original DVD release, not the
    >> REDUX). There's some barely perceptible wear at the outer edge, but
    >> nothing serious. It just won't play, at all, in *any* of my drives.
    >>
    >> Another case of "disc rot" perhaps?
    >>
    >> That's it. From now on I'm ripping *every* disc I get to an ISO file on
    >> the server. Just think, the UK government are considering making ripping
    >> *illegal* (like that DMCA nonsense in the US). I wonder what they have
    >> to say about the need to constantly replace discs? Do they even care?
    >>

    >
    > I heard someone claim they'd last 100 years under normal circumstances.
    >
    > B.S. I have a theory if you're interested... the laser diode that does the
    > writing is the same one that does the erasing.... You get it? While you use
    > your cd/dvd media, it slowly gets erased... makes sense.


    You need to re-read the Dilbert Principle and start getting promoted. It
    is scary that you think you have even half a clue. I know you are joking
    so it's half ok though.....

  5. Re: [OT] How long is a DVD supposed to last, anyway?

    * Tim Smith fired off this tart reply:

    > Anyway, reading a pressed DVD is not going to "erase" it. First,
    > reading is done with a lower power laser than that used for writing
    > discs. Second, and more importantly, the disc is just plastic with
    > bumps in it, and an aluminum (I think that's what they use) coating over
    > the bumps, encased in plastic. To "erase" part of it, you'd have to hit
    > it with enough power to damage the aluminum coating, or melt the
    > plastic. That's not going to happen in your consumer players or drives.


    Try leaving the DVD out in the sun instead.

    --
    The increasing percentage of Vista isn't growth -- it's molting.

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