Some people, notably Graham Hancock, believe that there was a human civilization here on Earth long before our current epoch. Our current records go back 5,000 years or so and current prevailing theory is there wasn't any civilization to speak of before then. The lost civilization theory is that there was an advanced civilization here on Earth sometime before 10,000 years ago and that it was destroyed by some natural cataclysm. One theory is that the Northern hemisphere was covered by a much larger and thicker ice sheet than we have now, something more along the lines of the ice sheet that covers the South Pole, which is a couple of miles thick. An meteor, or a comet, struck this ice sheet and the energy released by this impact caused this ice sheet to melt, which released a large quantity of water which flowed into the oceans and raised the worldwide sea level by about 400 feet.
This biggest argument against there having been a previous civilization is the lack of written records. There's also the problem that most anything that they would have built was most likely along the coastline which is now 3 or 400 feet underwater.
This makes me think we should be constructing some kind of archive that could survive a similar calamity. Now we have server farms which contain much of our data, and as long as our civilization is viable these are probably fine. But what happens if there is a real disaster, one that kills a sizable fraction of our population, or possibly even a majority? Those server farms are dependent on a vast computer industry that is continually producing new digital data processing and storage equipment because that stuff doesn't last forever. In cold storage it might last for a while, but in operating I think the most you can expect is about ten years. Should disaster strike those server farms are going to start failing.
The only way you can be sure an archive remains intact is by checking it, and that basically means someone needs to be reading it. It's all very well for computers to read the data and run check-sums to see that everything is correct, but that doesn't tell you whether the people who are there can access it, read it and understand it. So maybe what we need is a paper archive along with a printing press and paper and ink production facilities. With this equipment a small group of people could maintain a sizable archive for hundreds of years. Printing presses wear out eventually, but that is mostly a function of how much printing they do.
Something like that would still require some kind of society to maintain it, and if things get really bad that might not be possible. So then you are going to want some kind of vault.The problem here is what kind of vault could you make that could survive 10,000 years? Volcanoes, floods, earthquakes or war could destroy any kind of physical device you could construct. You could make multiple copies and place them in diverse geographic locations.
Since we have conceived of this idea, it's reasonable to assume that the same idea would have occurred to any previous civilization. If it did, then where are these archives? Or perhaps they were struck down before they got around to building them.
Or maybe they did, but they have archived the data in a place that would never be destroyed as long as there was life on this planet: in our DNA.
Recently some brainiacs have managed to record some binary data in DNA and then retrieve it. It's only a lab curiosity now, but given the data storage industries quest for ever greater storage capacity, I don't expect it will be too long before you can buy a packet of seeds at Wal-Mart that will contain all of the Facebook posts ever posted.
So if we can come up with this idea, it's possible that a previous civilization might have also done it, and we are in fact carrying their archives around with us in our own DNA.
Problem now is, if it is actually there, how to decode it. We can store all kinds of data in binary form, but you have to know what that form is, and there is virtually no limit to the ways data can be encoded. If you don't have some kind of clue, trying to figure out what message is contained in a binary string might very well be hopeless.
7 hours ago