# why would cd-roms (even not used) lose photos **URL:** \ **Category:** Factual Questions\ **Created:** [May 2, 2003, 2:44pm UTC](https://boards.straightdope.com/t/why-would-cd-roms-even-not-used-lose-photos/172629 "2003-05-02T14:44:20Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![drhess](https://avatars.discourse-cdn.com/v4/letter/d/94ad74/32.png) [@drhess](https://boards.straightdope.com/u/drhess)\ **Post date:** [May 2, 2003, 2:44pm UTC](https://boards.straightdope.com/t/why-would-cd-roms-even-not-used-lose-photos/172629/1 "2003-05-02T14:44:20Z")
I’ve heard that CD-roms that you write photos to will lose them in about 7 years. How is this possible? Will music CDs lose their music? I’ve never noticed that. What happens that CDs go bad? I don’t think they meant the technology would become obsolete, although that is a storage issue, and I don’t think they meant wear and tear. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [May 2, 2003, 2:54pm UTC](https://boards.straightdope.com/t/why-would-cd-roms-even-not-used-lose-photos/172629/2 "2003-05-02T14:54:37Z")
It’s not that they _lose_ data, but with normal use wear-and-tear, exposure to light, and other envirnmental factors, eventually the disk will simply become unreadable due to scratches, abrasions, or clouding of the polycarbonate coating. ---
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [May 2, 2003, 2:55pm UTC](https://boards.straightdope.com/t/why-would-cd-roms-even-not-used-lose-photos/172629/3 "2003-05-02T14:55:47Z")
They won’t “lose” the photos, per se (like paper photos fading or something), but there’s a very real possibility that CDs (home-burned CDRs, esp.) will one day physically degrade and therefore the data will be destroyed. Many think that the dye used as the recording base in CDRs will break down over time, IIRC, and there is some concern that various inks (or sharpie marker inks, if hand-applied) used to print pictures/song titles/etc. on music CDs may one day eat through the plastic of the disc, eventually exposing the aluminum recording base to corrosion, etc. IIRC. ---
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [May 2, 2003, 3:01pm UTC](https://boards.straightdope.com/t/why-would-cd-roms-even-not-used-lose-photos/172629/4 "2003-05-02T15:01:47Z")
[http://www.athensmusician.net/archive/2001-10-17\_cdr01.php](http://www.athensmusician.net/archive/2001-10-17_cdr01.php) > [@](#): > > CD-Rs do not have pits and valleys. They use a photo sensitive dye to emulate the physical characteristics of a real CD so they act the similar to a CD when hit by a laser. Since the dye on a CD-R is photo sensitive it can be damaged by sunlight or even the laser used to read it. So if you leave a CD and CD-R face up in the back of your car all afternoon, chances are your CD-R will have been wiped clean while your CD will still play–provided neither of them melted in the hot sun, that is. > > CDs may also last longer than CD-Rs, though the technology hasn’t been around long enough for anyone to prove it for sure. Rapid aging of CD-R’s have shown that. CD-R dyes can decompose over time, or oxidize. The life span varies with your treatment of the disk. Keep it scratch free, dry, and out of the sun and some say a CD-R can live from 70 to 200 years. While CDs can last longer. Wow. ---
**Author:** ![drhess](https://avatars.discourse-cdn.com/v4/letter/d/94ad74/32.png) [@drhess](https://boards.straightdope.com/u/drhess)\ **Post date:** [May 2, 2003, 3:06pm UTC](https://boards.straightdope.com/t/why-would-cd-roms-even-not-used-lose-photos/172629/5 "2003-05-02T15:06:27Z")
So there is not a home-based way of making a CD as opposed to a CD-R? I don’t get how a CD is made if it didn’t start as a CD-R… ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [May 2, 2003, 3:12pm UTC](https://boards.straightdope.com/t/why-would-cd-roms-even-not-used-lose-photos/172629/6 "2003-05-02T15:12:51Z")
CD’s are mechanically stamped from a thin disk of aluminum foil using a master die that was created using a laser, then encased in polycarbonate. No, really. It’s aluminum foil. ---
**Author:** ![dwc1970](https://avatars.discourse-cdn.com/v4/letter/d/a183cd/32.png) [@dwc1970](https://boards.straightdope.com/u/dwc1970)\ **Post date:** [May 2, 2003, 3:28pm UTC](https://boards.straightdope.com/t/why-would-cd-roms-even-not-used-lose-photos/172629/7 "2003-05-02T15:28:12Z")
Look up [How Stuff Works](http://entertainment.howstuffworks.com/cd.htm) for more information on how CDs work and what the differences are between a pre-recorded CD and a CD-R made on a home computer.