When we die, we leave behind information. This information can take many forms, from our genetics, replicated in future generations, to posts on the internet. We keep history trapped in photographs, videos, and stories written down into books. Sometimes, we take treasured artefacts, place them within a time capsule, and bury them underground.
Not all of this information will last, however: Elements conspire to erode our data as time passes. And that creates an urgent existential problem. There are myriad ways that the world as we know it could come crashing down, from nuclear war to rampant climate change. But somehow, if we’re to be remembered, our information must outlast these cataclysms.
What technology will allow us to do so? How will we guarantee that, in a million years, humanity—or intelligent non-humans—will be able to access this information and understand what the 21st century was like? The possibilities run the gamut from ceramic tiles to hard drives on the Moon, each more fantastical than the next.
Seth Shostak, a senior astronomer at the SETI Institute, quickly dismisses some of the more oft-suggested ideas. Deeply invested in the search for intelligent life across the universe, SETI is also concerned with how information is transmitted and understood across huge distances and over deep time.
Conventional time capsules are rubbish, as they can end up becoming decidedly soggy and ruined within decades. Any that do survive over the longer term are liable to get destroyed by the inexorable march of plate tectonics.
One drop of DNA could hypothetically store all of human history, the general idea being that, through the natural replication of this DNA, perhaps within a colony of bacteria, the data would automatically copy and preserve itself. Inconveniently, the bacteria would always need a food source, which we’d have to constantly provide. “Beyond that, it’s in the nature of DNA to mutate,” Shostak told Earther. “All the happy endings of these stories could become bad, you know?”
Hard drives are certainly durable, but powerful magnetic fields can render them inoperable. And if the distant future doesn’t have computer systems around to access the data, they’re also useless.
One privately-funded endeavour, the Memory of Mankind (MoM), is going back to basics. A small group of artists, historical archaeologists and researchers are engraving texts onto ceramic materials, which are then buried in the world’s oldest salt mine in Austria. Here, the expectation is they’ll remain intact for a million years. The idea is not too dissimilar to the cave carvings made by humans many millennia ago.
Martin Kunze, an artist and the founder of MoM, explained that these “ceramic data carriers” are resistant to extremely high temperatures, corrosive chemicals and powerful radiation. Kunze explains that it’s not meant to be a backup of all our knowledge, but a record of how we gained that knowledge. The group is particularly keen on receiving doctoral theses, which they have already started to gather.
MoM isn’t the only relatively low-tech communication tool available. Humans of the distant future might turn to trees to comprehend the past, much as we do today.
As a recent study on a New Zealand supervolcano highlighted, trees are constantly gathering data from the atmosphere and earth they sit on. Whether we look to their growth rings, or map out where different types of trees have grown on the planet, we can use them to determine major environmental changes that occurred.
That includes changes triggered by humans. Like much of the geological record, trees recorded a sudden uptick in radioactive materials during the early days of the Cold War.
Richard Holdaway, an adjunct professor of palaeobiology and isotope analysis at the University of Canterbury–and a co-author on that supervolcano study–said that a major problem here is that global catastrophes could simply wipe out these natural databases. “You might be hard pressed to find any tree rings to study,” he said. And of course, in order to document images and text, we still need something we can directly encode ourselves.
A more viable high-tech route might be something like Project Natick being developed by Microsoft. Currently in the testing phase, this project involves placing submarine-like data centres on the seafloors adjacent to coastal cities. These hubs would be cooled by the surrounding sea and powered by renewable sources, providing coastal communities with quick access to the internet. Although not designed for it, you can see how they could be viewed as catastrophe-proof time capsules, too.
Carlos Phoenix, a co-founder of educational non-profit Blueprint Earth, cyber strategist and data expert, said that the operational life expectancy of one of these hubs is currently around five years. However, if the system could be enhanced to use upcoming technologies such as quartz glass—already used to transmit electricity in regular, heartbeat-like fashion—quantum computing or even DNA storage, that could change things.
“We could create floating supercomputers with the ability to regenerate and store the planet’s data within its rig’s confines,” he said. Such data vaults could potentially have life spans on the order of centuries.
But storage on local devices is important, too. “The use of data centres and mass internet communications could be hampered if climate change goes up a few degrees and our internet backbone breaks down,” Phoenix said. “It wouldn’t be that far-fetched to image a world in 2065 that sees the Internet die as we know it,” for instance, as a result of sea level rise drowning fibre optic cables along Earth’s coastlines.
Fortunately, localised high-tech data storage is also being worked on.
Peter Kazansky, the head of optical physics at the University of Southampton’s Optoelectronic Research Centre, is part of a team that uses ultra-high-speed lasers to etch nanostructures into handheld quartz glass tablets. Kazansky said that the engravings alter how light passes through them, creating two additional dimensions in which data can be encoded. That’s why this tech is referred to as 5D data storage.
These proof-of-concept data chips can retain 360 terabytes each; roughly equivalent to 180 million high-resolution image files. They can also withstand extreme temperatures, and it’s estimated the information can kept intact at room temperature for the current lifetime of the universe. Already used to store several key texts, from the Magna Carta and the Universal Declaration of Human Rights, these disks could hypothetically outlast the Sun—and, if we play our cards right, any apocalypse that would ravage civilisation.
Regardless of what form we choose to store our data for the future in, from the low to the high-tech, if it’s kept on Earth it would need to be far from any sort of natural disasters or destructive geologic forces. You could, however, opt to not store it on Earth at all.
“In general, space is a good place to put stuff you don’t want to degrade too much, as long as you package it up,” Shostak said. Phoenix cautions that low orbital data centres are at risk from running out of fuel or smashing into other space debris. Extremely high orbits are the way to go here: even if they run out of fuel, their orbit won’t decay leading to an inadvertent atmospheric fireworks show.
In a 2008 episode of Doctor Who, the largest library in the universe is essentially an entire planet, and has an external hard drive built into its moon. The idea of using natural satellites as a backup system has appeared in the real world too: during the now-defunct Google Lunar X Prize, an Israeli-based initiative wanted to use one of the launches to send key religious and philosophical texts to the lunar surface.
Shostak pointed out that lunar hard drives wouldn’t be ideal, as they would be degraded by the radiation that reaches the Moon’s surface. If you wanted something to last, you’d have to bury it, a bit like the monoliths in 2001: A Space Odyssey.
“Regardless of the solution, I think a system that can rebuild and reconstruct itself using raw materials may be needed,” Phoenix said. Replicating DNA, as aforementioned, may prove problematic, but he suggests that an automated robotic system that keeps building new versions of itself using mined resources might not be such a bad idea.
Shostak suggested that the best option for truly long-term storage perhaps hearkens back to the beginnings of humanity. He mentioned chatting to astronomer Frank Drake as to why golden records were sent out on the two Voyager spacecraft launched in the 1970s, instead of digital data. Digital data can decay over time, Drake replied, but mechanical things last for what seems like eternity to humans. “Those records are like stone monuments,” Drake said, according to Shostak.
Figuring out how to send information into the far future is only half the challenge, though. The other half is ensuring it can be understood.
Civilizations can and do collapse, which often means their language and information gets wiped out or otherwise rendered difficult to comprehend. Historian of ancient science Mathieu Ossendrijver, of Humboldt University in Berlin, told Earther that there are multiple ancient writing systems that so far remain undeciphered, including the 5,000-year-old Proto-Elamite tablets from Iran.
Even if we are capable of translating extremely old texts, it’s not always certain that we’ll do a good job of it.
“Modern scholars always come with a ballast of modern conceptions that can distort the view on ancient texts,” Ossendrijver said. Sometimes, experts in medicine, mathematics or astronomy that attempt to translate ancient Babylonian texts, for example, don’t have the requisite historical or anthropological expertise, which can lead to accidental distortions.
And if the future beings doing the translating aren’t even human, that could make everything more complicated.
Common plot devices used to communicate information to aliens in fiction are limited. Mathematics is a good way to explain logical concepts, and musical tunes–a la Close Encounters–do convey information to an extent. Using these to explain complex social things, like governments, is more difficult to envision. And what about emotional states?
Shostak reckons that the most effective solution—whether we are hoping to talk to humans in the future or intelligent life—would be to bombard them with as much information as possible. If we stored the entire internet on a data drive built to last aeons, there would be enough redundant and repeated data on there (especially to do with cats) that the more complex stuff might gradually be translated by an intelligent society. We could even decide to store a colossal photographic dictionary.
So, perhaps a million years from now, intelligent beings won’t be looking to nanostructured quartz glass to uncover a chronological record of humanity’s past. Instead, they may be digging up stone carvings of every blog post and spam e-mail ever written in lava tubes on the Moon.