Oh, and I should mention. Parity files. Use par2 or dvdisaster. This allows you to lose some bits of data without losing the information completely. By adding some additional information during the archival process, you can lose up to a certian percentage of data and be able to 'resurrect' it.

This is an absolute necessity. In the last year I have begun to do things this way with my consumer grade stuff; it's better to set aside 10% of your DVD space for parity than lose your data forever. Well, at least you have an increased chance of avoiding the latter. I'm an insurance guy... why wouldn't this be a logical move?

/tongue in cheek
@jefro: We're drifting dangerously close to religion pondering the significance of the Mayan calendar.

In fact, no reasonable discussion of the possible reasons for a time capsule can take place fully without discussing the end (Including religious aspects). But let's pretend you (or your kid) survived an event that knocked us back so far we lost all the progress of recent centuries. Without batteries, petrol, or generated power. Today's consumer goods and archive material would be shiny useless junk. Somebody would have to wind a generator onto a watermill, and get close enough to your power supply before anything could be recovered. Even then any PC sent forward in time would fail because of the capacitors.It would be much more likely your cds would be used as frisbees until they smashed off some rock.

Do so many people really believe the world will end in 2012 just because it's a significant date on some old calendar?!?

What do you mean "discharge"? Flash memory is not like RAM with a built-in capacitor.

It's not, but they do discharge after a long time, at least that's what the wiki says. I think it's possible, although I've never tested it myself, they usually break before then anyway.

Hi,

The problem is that everyone misinterpret that the calendar ends in 2012. Loads of people misread into that as a end of the world as we know it. FUD!Not a significant date with modern day man unless a conspirator or doomsday believer. The Mayan calendar presented after the final date as winter solstice on the Mayan calendar. Therefore a new beginning after that date by their rituals.

Look at the calendar.
Cell degradation over time is a problem with modern flash and can be attributed to frequency of writes along with the level. A problem if not managed properly. Throw away device;
Flash is improving but there is a 'life' for retention. The referenced paper is rather dry reading but valid.

So each bit in a flash memory chip is like a little capacitor, and will drain over time?

Flash (usb pocket type) can be stated to act like a bunch of caps that would slowly diminish unless powered and that is different and you'd need to supply power until the unit is found and used. It has no physical change that secures it.

I doubt that the Mayan calender has any other interest than hype. Just a statistical oddity. More like the YTK deal. It is a number based worry with no real facts behind it. However you get enough nuts together and one should worry.

My concern is that we did survive the Cuban missile crisis. One hopes that and I believe that any number of humans would survive the predicted effects of any number of issues. I suspect the world would survive corneal flairs that reached and affected the earth. I believe that some power lines would be damaged in the year 2012 but the earth is a big place.

I suggested pressed cd's as they would seem to me to have features that protect against EMF/RFI.

Hi,

Simplistic but the general idea. Gate of the cell is the weak point when power is removed. Longer term without power & previous use of the flash cell will determine retention because of leakage through out the cell at the gate layer;
Simple definition but easily understandable.
HTH!

Parity... that certainly makes a lot of sense in a long-term storage situation like this. Question: Are there any actual /file systems/ that automatically store parity data? (With provided file-system recovery tools?) Quick googling said ext3 could be modified to store parity, but that is all I saw.

On a separate, but related note: With a compact digital storage device in the capsule, we could also store some paper-based material documenting the format of the digital data or any other pertinent details that might aid in future recovery.

Simpler is usually better. The less complex you make it, the more likely the chance of recovery. Sure, parity files aren't as transparent, but really, if you're going to insurance over ease of use, go separate parity files than a filesystem based one.

But if you want to store information, I still think etching into precious metals is the best (though expensive). I would also avoid using a file system (not necessary). A CD burned, with the ISO9660 specification printed or documented with it.


By the way, I don't believe the world will end in 2012. The worst that will happen, is that the Mayan version of Linux will suffer a Y2K like bug. I think there is a patch for that.

2012 is BS, just like Y2K. Probably hyped by the media to take eyes off of other things.

That's probably the only way, to copy the data to be saved over and over again, eternally, making sure that each copy survives long enough to be copied again. Any "static" storage will disintegrate in some way sooner or later, and 'later' doesn't usually mean more than a few hundred to a few thousand years. Small bits of information, such as "this skeleton apparently had two legs" can survive for millions of years if the conditions are good, but even then there is a significant amount of destruction that has already happened. In case of information, as in storing photographs or code or longer texts or such, even a slight data loss may corrupt a lot. Lots of data loss, due to disintegration of the medium it's stored on, means usually that only bits and pieces can be revived, which is not sufficient if lots of information is supposed to be stored. The destruction is due to how things work: natural processes such as chemical reactions and radioactive decay (which not only changes the original medium, but may change other media as well due to energy that is emitted in the reactions) will wreck any static media over time. Not to mention volcanoes, earthquakes, freezing and heating and such. The only way to go for a really long period would be to turn everything needed into information, and then copy that information around to (try to) keep it safe. This is a process that goes against the natural thermodynamic routes, meaning that it tries to preserve order, and therefore it requires energy. This means that when energy is not pumped into the system anymore (for example when people cease to exist and nobody is burning coal or running a nuclear power plant anymore), this method stops working and the information is (after some time) lost, again.

Quite on the same lines. But even though gold is a "precious metal [and so] it doesn't corrode", it doesn't mean it stays like that forever. The processes are simply slower with it, but will happen (due to all real systems having a finite probability of transferring from one state to another, for example at the atomic level). Gold too will be subject to the same "ravages of entropy" as the rest of things, it just lasts a bit longer than some "weaker" subjects. And it's still a game of luck: even though you can find gold pieces (jewellery, so you know it's more or less human made) that has survived for thousands of years, you must understand that not all such things have survived. Some of it has surely been lost, one way or another, and that means you can't rely on gold, or anything else for that matter, in the end. The only thing you can rely on is having a copy available always when one is lost, which again means you'll have to supervise the thing all the time somehow, and keep it fuelled.

Whatever the method, practically the storage place affects the result too. One would have to stick to a place that is stable (i.e. no earthquakes or molten lava flows or such), mostly non-radiative for the period of storage time, dry (moisture typically does bad things), cool (high temperature allows transfer of energy which may modify the surroundings), and so on. But how would you know if it stays like that for thousands or millions of years? The things we've found that are very old have been spared more or less accidentally, not intentionally. The biggest problem might not be the medium, after all, but the place of storage.

No offence, but:

So it's "one joke & you're out" atmoshphere nowadays? Where's the sense of humour? I get it when people are warned for saying they're gonna [...] up everyone, but not if something completely harmless is posted. If every post should be "constructive", we could also say every post should be constructive enough (for example "more constructive than not constructive at all" and then "a bit more constructive than that, please"), which means that some people would get kicked out just because they weren't helpful enough. Pointing out, for example, that a time capsule should only last a couple of years if the world is going to end next year is quite constructive in my opinion, because you couldn't possibly prove that the end of the world is not going to happen next year. If you could, you could see the future, which is rather bizarre.

No offence, but:

Do not forget to look at both sides of the mirror. I agree a little humor keeps an interest in a thread but from the other side too much could ruin a thread or be miss taken and offend.

I'm sure there are other ways, but beyond our technical abilities.

One way could be to invent a time machine. You can SEND the information to whenever you like.

The tragedy of what happened at the library of Alexandria shows that you can't put all your eggs in one basket. Copy, copy, copy.
DNA breaks down fairly quickly, but there are genes circulating millions of year old, because of copies made. A self replicating system, like a cell or nano bot containing a DNA like sequence of the information could do.

But to store information today, I think what I've suggested is perhaps the best for digital. But information as a shelf life. I'd like to keep my photos for as long as possible, but they only need to last long enough to ensure that I can make a copy to pass to kids. I dont need them to last 1 million years, what are they going to do with it?

There probably is a lot of lost information from pre-history, but was it of any use? Probably only a curiosity, nothing more.

Our entire civilisation, given enough time, just wont be important. There will come a time when no one, or nothing will care.