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Digital Storage To Survive a 25-Year Dirt Nap?
AlHunt writes "I've been tasked with finding a way to bury digitally stored photographs in a small underground time capsule to be opened in 25 years. It looks like we'll be using a steel vessel, welded closed. I've thought of CDs, DVDs, a hard drive, or a thumb drive — but they all have drawbacks, not the least of which is outdated technology 25 years from now. Maybe I'll put a CD and a CD-ROM drive in the capsule and hope that the IDE interface is still around in 25 years? Ideas and feedback will be appreciated."
I agree completely. Current digital technology is not designed to last for long periods of time untouched. Storage methods evolve, things move around, old hardware fails and new hardware shows up, and data is in a continuous flux. If you shove data into one device and leave it untouched for many years, chances are it will be gone one way or another, since normal storage devices just aren't meant for that kind of use. Flash memory gets erased, hard drives have bearings which stick and die, CDs and DVDs have dyes that can break down over time and aluminum that can oxidize, etc. The proper way of using current storage technology to store data for long amounts of time is to do what we've been doing all along: use normal methods of redundancy (offsite backups, etc), keep the data online, check up on it periodically, and move it over to new storage systems as the old ones become obsolete or break.
If you just want to stick some data in a box for 25 years, printing it out is bound to get you a much higher chance of getting it back. Other means exist of storing data for long periods of time, but consumer digital technology isn't it. Things like laser engraving, coupled with a good reference manual that describes the encoding could work, but these kinds of things are highly specialized and probably not available for a reasonable amount of money. Printing is.
he can add in a small laptop with a power adapter and a media reader (usb ports, card reader, optical drive, whatever he needs).
that way all he *needs* later is electricity, and id be surprised if the US (or whatever country he is from) has phased out the currently used electrical outlets in 25 years, and even if he did, some electrical tinkerer could power it up anyway.
as for getting them off that device later...thats his problem :)
everything needs to be sealed well, however. double or triple on some water-tight somethingsomething to be safe,
By and large, language is a tool for concealing the truth. -- George Carlin
I will tell you in all honesty, from experience; that if you want your grandchildren and great grandchildren to know what you and your family looked like, you should have all your digital photos transferred to the highest quality black-and-white (silver halide) print stock that you can afford. Three years ago when my mother passed away at the age of eighty-four, we found pictures that my grandfather had taken of her and my uncle, together, when they were two and four years old respectively. The pictures were eighty-two years old and were as clear as the day they were taken. Stored correctly -oxygen-free, dry, and don't use a steel enclosure unless it's about 4 inches thick and if you weld it shut you'll probably burn up everything inside- they could last for hundreds of years.
Sig this!
The problem is that solid state drives suffer from bit rot as others have described here. Flash stores data as an electric charge, but no insulator is perfect. The high density flash is probably even worse.
Also, after 25 years it is doubtful that any PC or laptop will work. The CMOS battery will likely leak all over the place, and the electrolytic capacitors will not work very well after 25 years (electrolytic capacitors also do poorly when they are unused for long periods of time).
This post is encrypted twice with ROT-13. Documenting or attempting to crack this encryption is illegal.
You joke, but I think the best solution would be a macro scale physical recording medium. I wouldn't trust magnetism over 25 years, I wouldn't trust microscopic silicon SRAM for 25 years, and I know for a fact that CDRs deteriorate after about 10 years.
I think the best would be a large stainless steel disk. On the disk, at certain intervals, would be impressions. Each impression would be one of 4 depths of a relatively large difference in height, maybe 2mm. Each depth would represent an octet. Each height difference would be a square milimeter or so. The disk should store about 1000kb for each meter of disk size with both sides used.
Stamped on the middle of the disk would be instructions for reading the disk: What height represents what octet, which way the disk rotates, whether the disk starts at the front or the back. I'd guess the best thing to use would be a laser time domain reflectometer to acquire the data, which could be read one-bit at a time into whatever sort of PC exists in the future. There would be information detailing how to determine the beginning and end of the disk, and at least a reference to whatever graphics standards you use to save the image.
The disk should sit in a vacuum-filled glass case. The glass case should have rubber legs, and the disk itself, being relatively massive, should have rubber legs too. If there's room, a reference telling how to program a reader for the disk and a reader for the graphics standards you've used would be best too.
The pictures should be saved as one massive image on each side of the disk, and that's all that should be on the disk. There shouldn't be a table of contents, only a header and a footer. This will reduce complexity and ensure the person retrieving the data doesn't have to find a 50 year old copy of MS-DOS to run the 25 year old disk.
Doing all this would prevent rust from degenerating the data, it would prevent magnetic fields from disrupting the data, it would prevent subtle chemical changes in the disk from disrupting the data, it would prevent particulate matter from disrupting the data, it would prevent complicated and antiquated drive mechanisms from preventing easy retrieval of the data, it would prevent incompatible future operating systems from causing the data to be unretrievable, it would prevent unknown file formats from causing the data to be unretrievable.
I figure the only thing that could cause real trouble would be if someone made a serious effort to destroy the data surface. Dust could cake the data, but it should be cleanable. As long as there's someone capable of building a reader aparatus (you could include one, but don't depend on it interfacing with anything anybody understands -- let alone working after 25 years), there shouldn't be any hardware issues.
I'm a bit worried about the data density, but that's just the way she goes. A milimeter is a nice macro scale so you don't have to worry about quantum effects damaging the disk, and stainless steel wouldn't rust, but there's a chance of read errors if someone scrapes the disk. Parity mechanisms could be used, but that'd cut the size of the disk substantially in order to provide error correction.
It's been a long time.
No, it doesn't, not since early mock ups.