Scenario:
The world is ending, a giant wave of plasma from the sun is hurtling towards us, about to burn us to a crisp.
Luckily we have some warning.
The world gets together and quickly jams all human knowledge into automatic computers with automatic teaching programs (complete with language teaching thingies) so that some part of Western civilisation can survive.
The idea is that the remains of humanity finds them and learns once more everything we knew.
How long (assuming good conditions) would the computers last before degrading?
Aside from acid-free paper (too space constricted) what is the best way to preserve information?
Modern commercial computers are designed to last maybe 7 years on average. Industrial grade computers are a bit more rugged and might double that. Your best bet would probably be some of the space certified stuff.
A lot of the things that are done to make computers faster these days also seriously limit their long term longevity. They run hot, and they have really tiny transistors and gates inside of them. Space certified processors have larger gates in them (so that each gate isn’t so easily corrupted by radiation) which would make them last longer.
Long term data storage is definitely going to be a problem. Magnetic media is good for maybe 7 to 10 years. CDs and DVDs also go bad over time. One thing you can do is dramatically over-size your storage and store multiple copies, along with error checking. In order to prevent data decay you can keep copying the data back and forth from one storage unit to another so that the data gets refreshed. As storage units die, you’ll end up with fewer and fewer extra copies of everything, but with enough storage units you’ll end up with a few oddballs that survive much longer than the average.
The dead sea scrolls survived for something like 2000 years on parchment and papyrus, and stone & clay tablets can last easily as long - all given a decent environment.
A working electronic computer is highly unlikely to last as long as that. Generally, I wouldn’t expect any common computer to last longer than 3 decades. A hardened, simple and slow machine may work longer - see the kind of stuff in the voyager space probe as an example - but I’m still doubting a lifetime of over a hundred years. Even microfilm is probably much easier to guarantee a longer lifetime.
In any case, I don’t think space is the biggest concern. Cut the stuff in stone. The only real issue is the amount of time to prepare the documents.
Addendum: the best way to preserve information is to have some civilization interested and advanced enough that they can make copies. IIRC we know most of the interesting classical Greek science only because the Arab Muslims were making copies.
It’s not hard: ink and parchment are relatively easy to make. It just takes time (meaning you need some bunch of people with enough time and education to write the stuff down).
Why does the computer need to be kept turned on? Assuming that the OP’s scenario is plausible (a big plasma blast with anyone at all surviving isn’t but a less severe scenario is), why assume our decendants are too stupid to turn on a switch?
I agree that writing stuff down is going to be more reliable than hoping a computer survives and is usable (since it has specific power and other requirements). You might use something like the Rosetta Disk concept of the Long Now Foundation. It’s a small metal disk with something like 13,000 pages of text etched on it in a size that ranges from readable with the human eye down to needing a microscope to read the text. They’ve got language information on the one they created, but you could make additional ones with any sort of textual information on them.
Dust build up, mice nests, insect nests causing shorts when powered on.
Mice and insects chewing on the components.
Earthquake, floods, forest fires, or weather activity that damages components.
Simple age seems to cause man made items to loose their properties over time. (They become more brittle, less heat tolerant, the small metal parts in become used to being bent, and are harder to move, etc.)
There’s a light bulb that is said to be burning for a century, and it’s considered a much simpler device.
An off-the-shelf PC isn’t gonna last long. Your teaching machine is going to have to be custom made with longevity in mind, and even then I suspect that there are going to be things that the designers failed to consider, or made incorrect assumptions.
The copying thing is very useful. Getting all the data on computers, and teaching them to use only so many at a time and transcribing everything to paper would probably work.
Throw in teaching them how to make more computers, and the data can last forever.
But I still wonder why so many people seem to assume digital information is more permanent. IT relies on people continuing to create digital devices.
Most of the current “long term” storage media require regular use if not regular copying to stay reliable for their projected life time. And that’s just the storage material. Sure you can switch off a computer, but you just won’t know if it’ll work when you switch it back on. For my money, I’d bet a Commodore 64 that’s been put in a closet for the last 20 years has a higher chance of working than a late 1990s PC that’s been in storage for 10 years.
Addendum 2: The Rosetta Disc Dewey Finn pointed to is probably one of the best currently feasable media. The only real objection is that the makers pitch it as a “unique” item. Uniqueness is bad for reliability. Those things should be ubiquitous.
As mentioned above, the current media is not meant to last longer than maybe 10-20 years. (See note below.)
However, some computers are meant to take a beating, like the Panasonic Toughbook series. I would expect those computers to last much longer than other computers, possibly surviving conditions that would cause other computers to break or corrode.
Personally, I would say not to use any type of electronic media because of the layers of equipment necessary. You need the computer, you need the OS, you need the right language, right keyboard/mouse, drivers, disk drive, etc. etc. etc. Deconstructing and reconstructing each thing might be impossible.
For any other type of media, language is going to be a problem. Who knows if the future people will know English? Remember how hard it was to decipher Egyptian until the discovery of the Rosetta stone.
Note: Home-burned CD’s are usable because there is a reflective paint applied to the CD. The home computer burner etches into the paint, not the plastic. These are only meant to last maybe 3-5 years. Store-bought CD’s, with the data etched directly into the plastic, supposedly last a lot longer. Last I checked, it was comparable to magnetic media.
That being said, I think optical media is the best choice to paper or stone because of the sheer volume of human knowledge. There are risks involved, but I would prefer if there is something physically etched into something else.
There are archival digital storage systems. Ideas like gold on glass CDs. Very stable, and the information is likely to survive millenia.
Computer electronics are much more limited.
All the current electroncis we use are very much designed to a price. This means that almost no heed is paid to ageing effects. A lot of issues eventually will kill your normal electronics. Many materials that we assume are stable solids turn out not to be over time. Metals can migrate, form whiskers, alloys degrate. Inside semiconductors dopants can continue to diffuse. You can be assured that no computer from the early 60’s built from point contact germanium semiconductors will work. Many insulating materials will degrade, and don’t even think about electrolytic capacitors.
Space hardened electronics is a good example of the sort of thing that has to be done. The effects of radiation, thermal cycling, age, handing heat, and stuff that fails after time in a vaccum all have related issues with age.
If you are to preserve human knowlegde the only trick is teaching the end user to read. After that all you need are books. If you assume that the end user is a human, no less inteligent than current, and curious, with language, it should not be a massive task to try to workout a pictorial tutorial that gets them to the point where they can be bootstrapped into learning to read. So your teaching computer is the wetware in the human. The trick is the software, and preserving that.
I would be pretty uncomfortable trying to design any computer that could work after 200 years, even with an open ended materials budget. But readable booklike things that could survive millenia, that is feasable. The biggest risk is that at some point the remaining humans decide that the books are either - blasphemous and to be destroyed - or made of far too valuable/useful materials and are to be melted down to make weapons or jewelry. Hence the need cited above for many many copies.