Is aluminum foil (I think plain kitchen foil) not longer lived than paper? Punching it at a 10 holes per mm (fairly dense but surely doable using things we have at hand like lasers, PLL-ed rotating mirrors etc.) will store >100 megabytes on an A4 sheet... Hopefully the morlocks will be smart enough to read that though.
Unfortunately books printed on modern papers will deteriorate in a century or two due to the pH of current papers. Why would the paper tape last any longer ?
Unless modern books are scanned and the scanned copies are copied to modern media every 10 years (how many paper tape and 1/2 inch mag tape readers are operational these days, what is the true life expectance for a burned CD), most current literature is lost in a century.
I have a lot of the old papertapes around here. They are almost 50 years old, now. And in mint (perfect) shape. I'm looking at one right now. There is NO QUESTION in my mind that they will last many, many more groups of 50 years to come. (And I'm not counting the mylar.) These tapes are 4 mils thick. Almost cardstock. And oiled. Not fanfold, but coiled, and in their plastic holders. Otherwise, they were kept in attics, garages, sheds, and so on. Quite a range of humidities and temperatures. Looks flawless to the eye.
Other than that, I've no idea. But if I cared about 1000 years from now, I would NOT use a DVD or a CD unless there were a process to copy them over and over. I'd use paper (or stone.)
Yup. Libraries around the world have been studying long term storage issues. No DVD, even kept in optimal situations, appears certain to last more than 100 years or so according to two different studies I read a couple of years back.
Anyway, it's all kind of interesting in an odd way.
Doesn't flex. I've used the paper tapes I have a lot. They look mint, after a decade of occasional use and three more decades of simple storage.
Foil may certainly serve some service in long term storage. But we already have LONG experience with paper, what works, what doesn't, and what kinds can actually survive a millennia because we actually still have surviving bits here and there despite many attempts to destroy (church seeking to destroy heretical materials) or repurpose the paper (monks reusing old documents to write new ones by scraping them first.)
I would be worried about foils, more so that I would about paper. But to be honest, this isn't my field and I don't really know one way or another except what I have for personal experiences with using paper tape. Seems remarkable to me.
I don't want to even think about the problems using foil.
In any case, that's not fun for me. This is about a hobby idea, not solving the world's millennia long storage of data problems. Others are better at such problems than I am. I just like paper tape. Good stuff.
dp wrote in news: snipped-for-privacy@8g2000yqp.googlegroups.com:
Unfortunately the only durable metal foils are of precious metals and your epic is likely to be recycled for jewlery or coinage long before the next civilisation develops an interest in archeology.
I'd look at PTFE impregnated glassfibre cloth tape. have some non-adhesive ones on up to 30 meter rolls.
To print on it you would need a custom ink with platinum black pigment in a PTFE binder, which would be thermally fused into the surface.
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Just keep that foil away from any acidic or basic solutions!
If you want real archival storage, go back to the basics. Have your solenoids indent some good quality clay. Glaze and fire. You could also get colored patterns for optical sensing by filling the indentations with colored glaze before firing.
A well-fired ceramic will outlast your paper tape---especially if you don't live in a desert area. To make sure it gets passed on from generation to generation, fashion your codex in the shape of a number of beer coasters! Nothing like continued utility to make sure something gets passed on to the kids!
If you want to pass on your spoken word, how about an Edison phonograph with fired ceramic cylinders instead of wax?
For real duration broadcast your data into space. Observatories are still looking at echoes of the big bang back 12Billion or so years, much long than any material will last unchanged.
I'm surprised nobody has mentioned it -- although it may be up-thread somewhere in the drifting topics -- but the 10,000-year clock project is a real effort to pass information forward a few millennia.
Hmmm, true of course. Gold foil will last but we will have to do better with the pyramids to store it in than the Egyptians did, otherwise the morlocks will always get only fragments and thus CRC errors - at best.
Well Teflon should be long lived indeed but we can only extrapolate on its longevity, too new. I wonder if there are people who really want to do something in the data longevity field who have already made CDs with some highly durable plastic (or plain glass?), gold plated (there we go, pyramids again). Likely so, come to think of it.
Yes, that would make the pyramids unnecessary. But then who knows, those future beasts may use the things as jewelry or toilet paper, we should never underestimate their inventiveness.
Walters idea to beam the data into space and let those who capture it worry about it is probably best, long-term speaking.
I wonder whether ants are interested in parsecs the way we seem to be interested in millenia, universe age etc. :D .
Hmm. New 3D printer --- melts rock fed into a hopper and extrudes it.... might work.
A few things may. Some very old fossils have been found. I don't know of any carved stone that has survived anywhere near that long. Of course, I don't think there have been the technical concepts for making carved stone for long enough to know, either. hehe. Still, it's an open question. Some fossils, I gather, (not many) have actually survived an overturning into heated situations near and perhaps through liquified magma. Rare, if I remember reading. But some minerals that substitute for bone may withstand higher heat than the surrounding rock.
Hmm. Sapphire melts at over 2000C. Iridium at over 2400C. Both not entirely cheap, a sapphire boule cost me about $5000 last time I bought one. Iridium is very expensive (never bought any, though it is used to make the crucibles that are sometimes used to make sapphire.) But it might be usable in smaller quantities for communication over eons and tectonic effects. ;)
Or, getting back to the 3D printer head, I just need to make the extruder out of sapphire or iridium -- most magma is lower temperature when liquid, I think. So technically doable that way, perhaps.
Now there is a business opportunity if I ever saw one. :)
Yesterday I thought of something I thought I might add to my reply, in case you are still reading this thread.
In C there are certain types, e.g. "int", but there is no law that says how an int is stored in memory. It may be 16 bits or 32 or whatever (the compiler chooses this). There are however also types that specify exactly how wide they are, these are in the header file inttypes.h. Then you can choose things like uint16_t or int32_t. Especially in embedded systems these are very handy but to be honest, I use them in every C program I write nowadays.
You may not find this "type of types" mentioned in for example the book I recommended, in practice they are more of an embedded / low level stuff thing but like I said, I always use them and I thought it wouldn't be a bad thing to explicitely mention them to you.
Agreed those are wonderful types for situations where they make sense, but they are actually in stdint.h, not inttypes.h. inttypes.h contains various related goop like the PRI/SCN macros and other bits and pieces.
Not really. You can use the spare bit to indicate a different packing.
I hope that, when the galactic discovery is underway that would make this amount of code points necessary, software engineering will have evolved beyond the point of humans worrying about bit widths and encodings.
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Hm, I had noticed myself that in a certain source file in which these types were used I had not included inttypes.h and it still worked. But I thought that probably it was included through some other included file. Obviously my assumption was wrong, my apologies for spreading this incorrect information and thanks to Chris for correcting it.
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