Digital Storage To Survive a 25-Year Dirt Nap? 1044
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 I've thought of CDs, DVDs, a hard drive, or a thumb drive — but they all have drawbacks, not the least of which is outdated technology 25 years from now.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."
SATA, not IDE (Score:5, Insightful)
Re:SATA, not IDE (Score:5, Informative)
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,
Re:SATA, not IDE (Score:5, Insightful)
I'd be curious to know whether or not a laptop could survive 25 years underground. I know he said welded shut, but rust and corrosion could still be issues.
Maybe blueprints on how to build a computer to read said media should be included on paper? Then again even there, it's the same issue...
Of course do take some comfort in that media useable in 1983 (25 years ago) can still be accessible with hardware available today in the second hand market, or even new hardware; certainly no new giant tape reels are being manufactured, but I do occasinally spot big tape reel reading equipment available on Ebay or some such place. I also recently spotted a USB drive for 5.25" disks which were around as far back as 1970, so take heart.
Re: (Score:3, Interesting)
The ASUS EEE PC would probably fit the bill with a SD card as the storage media as well as a copy of the date on the EEE PC internal drive.
I would store it without the battery though as that will likely explode in that time frame.
Toss in A DVD drive and DVD copy for good measure.
DVDs and SD are both fairly popular formats and have already gone through iterations that have maintained backward compatibility.
Re:SATA, not IDE (Score:5, Informative)
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).
Re: (Score:3, Interesting)
Would storing the laptop in some type of inert gas (nitrogen) help? Hell, should the whole capsule be pumped full of nitrogen to reduce corrosion effects?
Re:SATA, not IDE (Score:5, Informative)
Would storing the laptop in some type of inert gas (nitrogen) help? Hell, should the whole capsule be pumped full of nitrogen to reduce corrosion effects?
The corrosion takes place inside the batteries and capacitors, so no.
Re:SATA, not IDE (Score:5, Insightful)
25 years is not all that long. My relatives still have 25 year old computers, and I've seen much older still in production use at companies. The main difference is the lack of power and regular use. Could a battery or a process be used to intermittently power a device every 6 months for 25 years? The traditional solution to bit rot (either flash or otherwise) is to refresh with new energy and new copying.
I assume that archival quality photo prints are too large for what you're attempting to store. What about writing each picture to a frame of a projection tape? Archival movie stock is pretty well understood at this point, and the size shouldn't be prohibitive.
For that matter, pay IBM to host an encrypted file of the pictures for 25 years. On a large slab of granite chisel the URL, searchable file name, and decryption code.
Re:SATA, not IDE (Score:4, Informative)
Re:SATA, not IDE (Score:5, Informative)
No, it doesn't, not since early mock ups.
Not the medium (Score:5, Funny)
I don't think it will be the medium that will be the problem, it will be the message. Imagine the shock of those viewing it to learn that our generation thought that there weren't WMD in Iraq or that Han Solo shot first. I'd limit the contents of this a few MP3's and photos of the Whitehouse, otherwise your time capsule will last all of 5 minutes after being unearthed before its whisked away to the Ministry of Subversive Materials.
Actually, better forget the MP3s, or you'll be tracked down by the RIAA and sued for 25years of lost song rental income.
Re:SATA, not IDE (Score:5, Insightful)
hehe, 25 years ago we used a Wang 10MB removable platter for storage. Good luck with reading that. I have never seen the drive come up on eBay and the shipping alone would be several hundred plus adding a 20 amp circuit to plug it into :) Only a handful of working systems in US including mine.
With the zillions of USB devices around they MAY make it that far. That Wang did make it 15+ years cause there were (relatively) alot of them installed. A SATA CD drive or HD might work. I also think the IDE drive is the least likely choice, it is only hanging on because of the CD/DVD drives :(
I imagine any of them would be available second hand however due to sheer numbers now. HAving one out of thousands is a ways from finding one of 100's of millions in 25 years. Toss both a CD and thumbdrive in there and call it a day. Hmm, on second thought will the media itself be readable at that age? CDR probably won't make it. No idea on thumbdrive lifespan. Maybe a HD afterall, should be able to dig up (oops, bad pun) something to run it somewhere. Will a modern HD even store data that long?
you have a WANG? (Score:5, Funny)
Only a handful of working systems in US including mine.
That's awesome! I have an old wang I would really like to get something from. Do you think I could take my wang out and put it in your system?
Re:SATA, not IDE (Score:5, Interesting)
Nither.
Audio tape and a player coupled with instructions on how to read it.
If you encode the file as a very basic encoding and then put it simple on an audio form computers 300 years from now will be able to read and then decode the images easily.
Building a SATA interface in 25 years will be harder than 1 hour of coding based on clear instructions in the box and reading in an audio signal.
Re:SATA, not IDE (Score:4, Insightful)
Just a thought...
Re:SATA, not IDE (Score:5, Insightful)
I'd be curious to know whether or not a laptop could survive 25 years underground. I know he said welded shut, but rust and corrosion could still be issues.
Silica gel is often used in new furniture or goods that are going to be stored for a long time, it soaks up moisture and prevents anything nasty growing inside. I expect that could quite easily be used, a significant amount and keeping as much moisture from getting into the container before it's sealed would solve that issue.
I'm more worried about knocks and magnets. If someone dug up a metal capsule in 25 years, would they know its contents were susceptible to shock or magnets?
(Talk about off-topic for something titled "Re:SATA, not IDE" xD)
Re:SATA, not IDE (Score:5, Funny)
Yes, but don't forget to label it "DO NOT EAT" in big letters so that some idiot doesn't find you and sue...
Re:SATA, not IDE (Score:4, Funny)
I suggest your write that "DO NOT EAT" in Chinese or French Canadian. So the people of the Future would understand...
Re:SATA, not IDE (Score:4, Funny)
Touche
Rust prevention / Paper printouts (Score:5, Interesting)
everything needs to be sealed well, however. double or triple on some water-tight somethingsomething to be safe,
Or maybe submerging it into mineral oil. Does anyone know if electronics can withstand 25 years submerged into oil ?
Everything will also need to be redundant :
- burned DVD-R/CD-R media may rot. Harddrive may refuse to spin because of chemical aging of the mechanical part, flash memory could fail, etc...
- as much spares as possible. 25 years from now, spare parts will probably be hard to find.
- a couple of SATA and USB drives/readers. Whatever the are the connection 25 years in the future, USB is currently so popular that in the future, we're bound to see adapters, just the we we currently see Serial-2-USB adapter even if serial connector have been phased out for quite some time.
---
Come to think of it, printouts of data compressed and printed out as 2D barcode may be the most durable technology.
- extensive experience shows that, under proper conditions, paper can be made survive for even longer than 25 years.
- reading and decoding a 2D barcode doesn't require any technology specific to the current generation of hardware.
- as long as the data is stored in a redundant manner and that it use open and well documented standard with source code available. It would still be accessible by computer 25 years later, even if it requires some programming and/or re-implementation of a long lost standard.
(as a bonus, include documentation of formats printed in clear on paper too)
- choose simpler standards. chance are none of the current open source library processing it will be available in 25 years. the kids will probably have to re-code a reader / decompressor using whatever will be the popular high-level language du jour ( Ruberlython#++ or something similar ). may make a fun science project for them.
Re:Rust prevention / Paper printouts (Score:5, Insightful)
-use something like paper disk [http://www.paperdisk.com/] to print the data on paper made with a plastic. or maybe laminate it ordinary paper.
-Write the decoding algorithm using a very basic language like c and leave a printout of the code along with the encoded data. Even a hundred years into the future, people will be able to find C manuals. Even if no one uses it they will be able to either write a new C compiler or translate it to their language of choice.
-Your biggest problem would probably be about the data itself. once the extract the bitstream how do they decode it to information. Hopefully people will still be able to decode jpegs, mp3s, and text documents. if not you will need to give them algorithms to those as well. (but for 25 years i think this should not be a problem)
Re:SATA, not IDE (Score:5, Funny)
Stone with the data chiseled in HEX.
Re:SATA, not IDE (Score:5, Interesting)
Re:SATA, not IDE (Score:5, Insightful)
At that rate it would make more sense to just print the photos.
Re:SATA, not IDE (Score:5, Informative)
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.
Pressed CD is the correct answer (Score:5, Interesting)
> and I know for a fact that CDRs deteriorate after about 10 years.
Some archival media is rated for 100 years. But forget that, just make a gold master and send it out to be commercially duplicated. It isn't THAT exensive, so have a small run of 100 copies made. Sell 90 of them in a fundraiser to recoup the expense of duplication and stick the other ten into a small stainless steel airtight container with an inert gas. Wrap that in some quality insulation to protect it againt the heat when the main capsule gets welded shut. I have heard lots of 25 year old audio compact discs and they sound just fine. But if there is enough bit rot to make recovering data dodgy, well you have nine more still shrinkwrapped copies to try reading any bad blocks from.
The only remaining question is whether equipment to read a Compact Disc will still be available in twenty five years. And the answer is almost certainly. It probably won't be nearly as popular as it is today but the LP is ten years in the grave and you can still buy a new turntable at Sears.
A pressed DVD might be even better because the recorded media is safely between two layers of substrate instead of only protected by the screenprinted label on the top. On the other hand we have enough history with the CD to know beyond any doubt that they survive in readable condition for the required time, even under typical consumer storage conditions.
Re:SATA, not IDE (Score:5, Funny)
I'd guess the best thing to use would be a laser time domain reflectometer
A "Laser Time Domain Reflectometer"? You made that up! Admit it!
Re:SATA, not IDE (Score:5, Interesting)
just stick it on a stack of cd's. And evacuate the vessel. Welding it shut might *not* be such a good idea because you will not be able to check if the heat affected your datastore after the welding.
The reason for a stack of cd's is that in a vacuum they should last a long long time and a whole bunch of them will allow you to do error recovery.
Re:SATA, not IDE (Score:4, Interesting)
I'd just swaddle the contents in a welding blanket, and design the vessel so the "welding shut" took place at a flange edge.
Better yet, just gasket the thing with a good automotive sealer and bolt together using anti-seize on the bolts. That way whoever digs it up doesn't have to cut it open and spew grinder sparks everywhere.
Hint: Build it like a hunk of pipeline. Flanges, bolts, all that stuff are common as dirt (and often buried therein for decades after assembly).
Re:SATA, not IDE (Score:5, Funny)
Just stick them on an Archival Gold CD, and in 25 years post this to Slashdot:
"I've been tasked with finding a way to read digitally stored photographs buried in a small underground time capsule 25 years ago. It looks like they used a steel vessel, welded closed..."
Re:SATA, not IDE (Score:5, Funny)
Re:SATA, not IDE (Score:5, Funny)
Re:SATA, not IDE (Score:5, Funny)
Well, shit, if he can count on /. still being here in 25 years...
Just post the whole of the data, tar'd and base64 encoded, in this thread. You can probably even con a few people into modding you up to +5.
Store the URL.
Bonus points: several other posters follow suit, and post huge, base64 encoded tars of goatse.
Re: (Score:3, Informative)
The CD's and DVDs
What's with everyone picking ONE format? (Score:5, Insightful)
Why is everyone suggest A format?
Why not store the data on a:
* DVD
* Pile of CDs
* USB drive
* SD card
* xD card
* Hard drive
And a choice few in hard copy.
Seriously... with the price of these things, and the timeframe, surely you can afford to store it on all of these things and put them all in? Plus it'll be fascinating in 25 years time to see how many are still readable... all? None? Some?
Print them (Score:5, Insightful)
Seriously, just print them. Unless we somehow evolve new sensory organs in the next 25 years, I suspect that photographs won't be rendered useless through obsolescence. They can always scan them into new digital files afterwards.
Re: (Score:3, Insightful)
Re:Print them (Score:5, Insightful)
Well, if data loss is an issue, then you shouldn't be burying it in the ground for 25 years. You should be keeping redundant backups and keeping the backups updated to the latest in archival technology every few years.
If you just want to make a time capsule, and a relatively short-term one at that, then even a modest printing should be perfectly adequate.
That said, I'd still recommend springing for some nice quality prints just because they are much nicer, and it'll be that much cooler when you open them.
It probably is a wise idea to investigate the inks used, though. Photographs seem to last a while, but I don't know how well printer ink lasts and whether it fades with age.
Re:Print them (Score:5, Informative)
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.
Re:CDs (Score:4, Informative)
Just curious - did you work for Sony or Philips? According to wikipedia [wikipedia.org] CDR were first spec'd in 1988, 20 years ago.
How about making actual photo prints .. (Score:4, Informative)
Re:Print them (Score:5, Funny)
Re: (Score:3, Insightful)
Seriously, just print them. Unless we somehow evolve new sensory organs in the next 25 years, I suspect that photographs won't be rendered useless through obsolescence. They can always scan them into new digital files afterwards.
"Just print them" shifts the nature of the question to "how do I make it last"
I wouldn't expect most photo printer paper to last 25 years.
Re:Print them (Score:5, Insightful)
Re:Print them (Score:5, Funny)
Ummm... I'm sure that most of us who are 25 years old or older have pictures of themselves that are stored in bad conditions and still look decent.
Now if only we could say the same for ourselves.
Re: (Score:3, Insightful)
Inks fade... (Score:3, Interesting)
Many consumer grade photo printers actually produce pictures with significantly shorter lifespans than their digitally stored copies. There was a great comparison a few months back of 6 different printers/papers/inks that varied greatly in their performance at only 6 months.
Now, if you really want to get long term with it, write the binary value of the image out on paper, or even punched in steal. 10101010101 etc... sure, it'll take a whole lot of time, money, and metal, but you could be sure that all that
Re:Print them (Score:5, Informative)
Don't Print Them - Use Microfilm (Score:4, Interesting)
Re: (Score:3, Insightful)
Even block based ciphers have problems. If your data has random bit errors every now and then, a block cipher will corrupt an entire block (often 16 bytes) for each one of those. A no-feedback (XOR based) stream cipher might work though.
Also, digital pictures are best stored in uncompressed formats. Preferably a raw bitmap with no headers even, together with a printed document describing the format (which can be done in a sentence or two). Fixed resolution 8bit/channel RGB data will degrade gracefully with
How about.... (Score:5, Insightful)
Re:How about.... (Score:5, Insightful)
... I'm sure they'll still have AA batteries 25 years from now.
Let's hope not?
Re: (Score:3, Insightful)
Why would such a common industrial form factor change? D cells, sure, you don't see them as much because people don't want the size and weight, but AA batteries fit in things that fit your hand nicely.
Re:How about.... (Score:5, Informative)
Flash memory works by trapping electrons on an insulated gate. Since there is no such thing as a perfect insulator, especially at high integration levels and taking into account quantum effects, those electrons will leech out over time. 25 years is probably more than enough to kill the data on a flash memory chip.
Re:How about.... (Score:5, Interesting)
Really, 25 years isn't all *that* long. 9 pin serial has been around longer than that, and USB and SD are much more broadly adopted than it ever was.
Re:How about.... (Score:4, Funny)
I'm sure they'll still have AA batteries 25 years from now.
As long as the enemy has aircraft, we will have anti-aircraft batteries.
Why not... (Score:4, Insightful)
just bury the entire PC. Surely AC power will still be around in 25 years.
Re:Why not... (Score:4, Insightful)
Won't work. The lead-free solder used in modern laptops will grow tin whiskers over that much time, and short out.
The way I see it, there actually isn't any available technology which will reliably store digital photos for 25 years.
Re: (Score:3, Informative)
A glass CD master should work fine. A brass CD stamper should, too. The issues then become how to turn those things into a stamped CD.
Multiple choice (Score:5, Interesting)
You can't guarantee that the data will be intact when they open the capsule. Nor can you guarantee that the gear you send will survive.
Seems to me that your best bet is three separate distribution mechanism.
1. CDs AND DVDs (two copies of everything), a small portable DVD player with multiple interfaces - component/composite/s-video out
2. NAS device with at least two disks (two copies of everything) and multiple interfaces - eSATA/SCSI/USB2/FireWire/ethernet(dhcp)/etc.
3. Digital picture frame and a handful of memory modules (two copies of everything)
Ensure that whatever device you send goes complete with power adapter and user manual. In at least two languages.
All there is to do when you're done, is cross your fingers and hope that video displays still operate in two dimensions :)
Re:Multiple choice (Score:5, Insightful)
I think of all those interfaces the most likely to still be used is Ethernet cabling. Get a NAS with ipv6 and dhcp enabled. Assuming we've adopted ipv6 in the next 25 years, this may be your best bet. Also consider wireless!
Re:Multiple choice (Score:5, Funny)
In fact, just bury a server with a power supply (or tie it right into the grid), and have it broadcast an open SSID. That way you don't even need to unbury the time capsule. If you're married to this "25 years" idea, you can always put on a cron job that won't turn on the wireless for 25 years. (Just make sure to fix any date rollover bugs first)
Of course, by then, you'll be old. And from my experience, old people love to force others to look at pictures of their family. So what you should do, when the time is right, is ssh into the machine, and configure it to take advantage of every single wireless exploit that exists at the time. If anyone walks by with a vulnerable wireless device, have your time capsule take it over, and force the device to do nothing but display your photos, all the while while your voice shouts "LOOK AT MY KIDS! SHE WAS SO CUTE THEN!" (with the occasional GET OFF MY LAWN)
Re: (Score:3, Interesting)
Hard drives store very poorly. No one uses them for "real" archiving for a reason.
Cheap CD-R media has a very low shelf life as well, but I believe that "100-year" CD-R media is available once more, for a few dollars per blank. Way cheaper than printing photos.
No one really knows how well modern flash memeory ages. Throw it in too (why not?) but don't count on it.
Professional archivists have worked out data format standards for pictures (jpeg-2000, I think, which is non-lossy, and a very large mvoie form
Re:Multiple choice (Score:5, Funny)
Technology finds a way (Score:5, Insightful)
Re: (Score:3, Funny)
It really doesn't matter. If you use any popular media the technology will still be around to use it. We live in a big world, and there always geeks who love to collect stuff like that.
Where can I find a Wang word processor?
Re:Technology finds a way (Score:5, Funny)
Re:Technology finds a way (Score:4, Funny)
They renamed it to get rid of that stupid joke. It's now called Genital word processor.
Re:Technology finds a way (Score:5, Funny)
Assuming the bits don't decide to align on the north-south axis!!
MOO!
USB Stick (Score:3, Interesting)
Re:USB Stick (Score:5, Insightful)
Floppy drives, $9 from Newegg.
You can still buy motherboards with serial and parallel ports, for God's sake.
25 years isn't that far in the future.
Re: (Score:3, Interesting)
The IDE interface has been around since 1986, and SCSI was standardised in the same year but implemented (with a proprietary brand name) since 1981. If you has a SCSI (or, rather, SASI) disk from 1983 then attaching it to a modern computer would be relatively painless. Since you wouldn't have an IDE drive, the most likely choices are ST-506 or ESDI. Both of these typically came with 8-bit ISA cards containing the controller (I used to have one where the drive was physically mounted on the end of a full-l
Include a playback device (Score:3, Informative)
Paper? (Score:5, Insightful)
Not that hard (Score:3, Insightful)
25 years is not THAT much, you make the problem sound much harder than it is.
Prints is an obvious solution as already mentioned.
Then, include a couple of CD copies. Forget about putting IDE drives in there. The CD format has been around for more than 25 years, I am sure we will keep using some sort of optical media that will be CD compatible for a few more years. Even if they don't make CD-R compatible drives in 25 years (which i doubt), it will be easy to find an older drive with the capability. Just make sure you use archival-quality media and don't stick any CD-label on it.
Then throw in a usb thumbdrive in case the USB (along with the thumbdrive) survive!
Microfilm (Score:3, Informative)
Screw digital. Get them printed to archival-grade microfilm and store them in a moisture-proof container. Microfilm is designed to last a minimum of 500 years when kept under the proper (and relatively easy to maintain) condition. All you need is a light source and a good lens to view it. Most of the world's better professional archives use a combo of microfilms and digital archiving to keep stuff around... the microfilm guarantees longevity while the digital copy is easy to search and access.
5.25" optical media probably the best choice (Score:5, Insightful)
The 5.25" optical disc format seems to be the most likely to survive, given that the CD doesn't seem to be getting replaced in a physical format anytime soon, and the follow-on products (DVD, HD-DVD, Blu-Ray) all use the same basic format and are backward-compatible due to the low cost of the lasers involved for the previous format(s). Given the preference in the mainstream to keep backward compatibility and the fact that even the fun new terabyte media are in a similar format, this is the best overall bet.
What a flood of garbage (Score:5, Funny)
Alternative title: "How many bullshit redundant replies can you fit in a Slashdot thread?"
Did you say redundant? (Score:3, Funny)
Welded Shut? (Score:4, Interesting)
If you use paper, SD card, USB memory stick, hard drive, or whatnot it would have to survive being welded into the box, as well as opening the box.
Re:Welded Shut? (Score:5, Informative)
Speaking as someone who welds bike frames, I don't think this is too much of an issue. I can reweld a cracked frame without burning the paint 3 cm away, if I'm using a TIG and doing short welds. Anything they put in there, wrapped in a layer of aluminum foil, should be fine.
Now if someone insists on using an oxyacetylene torch to weld it shut, you have more of a problem, but using a gas torch to weld up a time capsule in 2008 is like using punch tape to store your data in the capsule.
Paper copy (Score:5, Interesting)
It would be entirely possible to make a paper copy of binary data that could easily be read in with the correct software. Of course, the paper you would want to use would be acid-free.
One could simply encode the binary as forward slashes and backward slashes. Or as x's and o's.
But those would be really wasteful.
I've often thought that what would make a really good software contest would be to develop a format to back data up to a paper copy on a laser printer using the best compression possible but with enough error correction and detection to be able to read just about any paper put in that comes out in reasonable shape.
For example, one might use individual pixels on the paper. Or you might want to group several together and treat as a bit. Or use an innovative coding scheme that doesn't just map individual bits to spots on the paper.
I think that a scheme that spreads the information out over the entire paper might be interesting. In other words, the individual bits of a byte and any bits dealing with the error detection and correction would be located remotely from each other.
In such a contest, testing would be easy. Write images of several datasets to paper and then scan the images in after different stages of intentional damage to the paper. For example, you might read two data files back from the pristine paper without doing anything. Another two data sets might come from paper that has been crumpled up into a ball and then flattened. Two more might be from paper that has been moistened. Two more from paper with a tear across the middle. And, finally, make copies of two data sets on an everyday copier and then scan them in and decode.
Rank the results by the numbers of errors, possibly with factors to take in levels of difficulty based on the amount of damage to the paper, and select a winner.
Re:Paper copy (Score:4, Interesting)
Not going to survive (Score:3, Insightful)
The media may survive and be theoretically readable, but nobody will be able to read it. 25 years ago was 1983. The IBM PC was only 2 years old, the PC/XT had just been introduced. The IDE interface you hope will be around in 25 years? It didn't exist then. It didn't appear until 1986, and wasn't standardized (as ATA) until 1994. And it's at this point been all but replaced by SATA (I expect EIDE/ATAPI CD/DVD drives to be completely replaced by SATA ones by next year). The standard disk interfaces 25 years ago? ST-506, ESDI and SCSI. I don't expect changes in drive interfaces to slow down any, so expect in 25 years that even if you include the drive nobody's going to have a controller interface to plug it into. 9-track mag tape, 8" floppies, 5.25" floppies, punch cards, all those were standard digital media 25 years ago and you'd be hard-pressed to find equipment to read the media or computers that can interface with the equipment if you do find it.
For those suggesting he just print them out... (Score:3, Insightful)
First, a single CD will hold 500-1000 images, stored as reasonably high-quality JPEGs. A similar stack of printouts on photo-quality paper would measure up to a foot thick (1000 pictures on 12mil paper).
Second, and perhaps more important if volume doesn't matter, a sheet of paper will break down far faster than a polycarbonate disc when subjected to a moist environment.
Simple solution? Burn a dozen copies of a CD using something like PAR2 redundancy to allow complete recovery if even a tenth of the content remains readable on each CD. Include simple extraction instructions in a more durable form (a note sealed in an acrylic block? an etched nickel tablet? Something like that - Small and to the point). For the naysayers, this involves 25 years, not 2500. We'll still have CD reading drives available then, whether museum pieces or simple due to never-ending backward compatibility in newer optical drives.
I'd say go for a flash drive... (Score:3, Insightful)
...seriously, outdated? They will sell CD/DVD/Blu-Ray combo players for decades still, though my experience with CD-Rs has been strained in the longetivity department. And with USB1/2/3, you think that's going away? Hell, we still haven't been able to kill the keyboard/mouse PS/2 plug, and that one is extremely much less useful. Don't go with HDD interfaces, they could easily change. But the external connectors that people have tons of USB gadgets and CD records of? You got to be kidding me. If it's just readable, we'll have the readers.
Don't guess about the future-- look backwards 25 y (Score:4, Interesting)
what format was around 25 years ago, that is still available today?
now- what was around 50 years ago- that is still available today?
now-- for the hell of it, what's been around since 1844--- and still available today?
You're hosed for actives: Capacitors will fail. (Score:5, Interesting)
Electrolytic capacitors are used in the power supply filtering of essentially all circuitry currently in use. These components will be present in a number of places on the circuit boards of both disk drives and memory sticks.
The insulating layer between the plates in electrolytic capacitors is formed by electricity-driven chemical action. It gradually degrades over a period of several years. If the capacitor is operated occasionally the operating voltage across it will rebuild the insulating layer. But if it's left unused for too long the layer will degrade to the point that, when power is finally applied, the capacitor will short and (because most of them are hooked across a power supply) fail catastrophically. Like by blowing open and jetting chemical fumes, while shorting out the supply and damaging other components in the current path.
Mechanical moving parts may lose lubrication and spot-weld with time. This also makes storing entire drives problematic.
Recordible CDs usually record on a die layer that will degrade with time.
Some types of flash memory store data as stored charges, which will leak away with time.
So IMHO degradation of the medium itself is likely to be a killer problem. Much more than readability with future devices. (After only 25 years there should still be some working players available for currently widely-deployed standards, even if no new ones are being manufactured. Once you've go the bits read you can transfer them to new media.)
Things I'd consider:
- Integrated circuit memory devices using a technology like fusible link or a crystalline/amorphous transition. (Replace any electrolytic capacitors with ceramic types - which will greatly increase the size of the assembly.)
- CD masters involving actual removal of material - a material inert enough that it will not corrode away with time.
- If you want to store drives for removable media (and convert the caps), check with the manufacturers about what the bearings are like and talk with a mechanical engineer with applicable experience (like mil-spec or space-rated). I'd avoid sealed hard drives, especially those that don't lift the heads off the platters when parked.
Also: Use a coding scheme that has industrial-grade error correction. B-)
One downside to your task is that, with only a 25-year storage time, you'll probably still be alive to be blamed for failures when they open it. B-)
I would worry about the media more than the medium (Score:5, Informative)
Generally speaking, you can pull data from media formats (medium) that are 25 years old. If your capsule was to be opened in 50 or 100 years then you'd have a problem, but most media formats that are 25 years old are still readable today. How much effort it would take varies...
If you had a 160/180/320/360KB 5 1/4" floppy disk from 1983, you could even read it by buying an old 5 1/4" drive off eBay, connect it to the same floppy connector that's still in use today, and read the disk directly in Vista. Now, if instead you were trying to read an MFM/RLL hard drive, 8" floppy, magnetic tape, punch card, etc. from that era, then you'd have more of a problem--but it would still be doable.
Also, many companies make specialty products to connect old equipment to new PCs. While I've never seen one, there's probably a company that makes a USB 5 1/4" floppy drive. If push comes-to-shove, you can always buy old equipment to bridge the gap... If I had an MFM/RLL hard drive from 1983, I could always buy an XT or AT from ~1983-1991 (that has an MFM/RLL interface), connect it to a new PC by way of a serial port (well, the new PC will probably have a USB-to-Serial converter) or Ethernet and transfer the data.
Pick a technology that's very well used today and you should be fine reading it 25 years from now. Sure, it'll take some effort & creativity, but it should work. But if you pick a technology that's old by today's standards and you'll have even more trouble reading it in the future...
That being said, I would worry more about the media--whether it will withstand 25 years of isolation, heat expansion/contraction, humidity, etc.
Put it above ground (Score:5, Insightful)
There is no good reason to put time-capsules underground besides some strange belief that it should be done that way. You're much better putting the contents above-ground inside of a wall, behind a plaque, etc. This way, it is much less likely for there to be water or other sorts of damage that plagues underground storage, you also have a smaller chance of it being lost or forgotten. If secured properly, there should be very minimal risk of tampering.
Fuck it. (Score:4, Funny)
Let the people of the future figure it out, if they're so smart. If you really want to encourage them, just label everything "porn" and leave it at that.
Machine and spec. (Score:3, Insightful)
Consider an Inert Gas (Score:3, Interesting)
Considering filling the container with an inert gas [wikipedia.org] like nitrogen in order to reduce any wear and tear caused by corrosion. Just make sure that whatever inert gas you pick, unless it is helium or neon, is really inert with respect to the contents of your time capsule.
Get guaranteed discs... (Score:3)
Kodak guarantees their Gold CD and DVDs for 100 years. I don't know how they can, but that would be your best bet. I don't know what they'd do if they didn't hold up 25 years later, but at least that might make your boss happy. I'm sure you can find other discs from other manufacturers who make archival-quality discs.
Read this: http://www.kodak.com/global/en/service/faqs/faq1632.shtml [kodak.com]
PROM, EPROM, EEPROM (Score:3, Insightful)
The interface could be problematic, but somebody will have the means to read the data off of the EPROM into our quantum-tunneling diamond-substrate 100GHz personal computer interface devices. Or that dusty Pentium 2GHz non-DRM computer in the basement.
Learn from the past (Score:4, Informative)
Learn all you can from the (arguably) failure of the BBC Domesday Project [wikipedia.org] and build from there.
My advice for a time capsule is:
It's tough but it just might be doable. Again, the keywords are redundancy and simplicity. If the data is important, make two identical time capsules and store them in geographically different areas (different tectonic plates are safest but this is probably overkill :) ). It's important that the copies of the time capsule be identical so data lost from one can be restored from the other.
As others said, use SCSI if you use hard drives... (Score:4, Informative)
Re: (Score:3, Interesting)
Take black and white photographs of them and print on acid free fiber based paper. Then it will last for 100+ years.
Re: (Score:3, Informative)
mod parent up please...
he's spot on. Anybody that has ever welded anything at all will confirm that the inside of whatever you're welding tends to get a little warm, especially if it is a sealed container.
Cold rolling it shut would be a better option, evacuating it and using a simple seal would be even better, especially since that would stop the medium from being attacked by oxygen.
Re:Permanent storage through integrated circuits (Score:5, Informative)
At least Seiko produces serial EEPROMs with > 50yrs data retention, and are rated for high temperatures (125 degrees C).
Those max out at 64k, though.
You'd probably want to use some sort of EM shielding (Faraday cage or similar) in addition to ESD protection, and thermal shielding to keep the temperature on the surface of the die below 125C during welding, and also carefully choose your burying location.
But, yeah, storing thousands (the OP didn't actually say thousands of photos, did he?) of pictures would require thousands of 64k (k-bit, I believe!) of ICs. I can only imagine the programming effort involved; special jigs that house & power hundreds of PROMs per batch write...