Imagine this: Ten thousand years from  now, an explorer wanders a forgotten land,   searching for traces of a lost civilization.

They begin to dig among some  odd, unsettling-looking ruins. And as they dig, they unearth a mysterious,  granite disk, not quite two hands wide.

Covered in unnatural markings. It’s the find of the century. At least until the explorer starts getting sick,  and so does everyone else who decided it was worth   setting up a permanent dig site to learn more  about the people who left that plate behind.

The land, it turns out, was  cursed by that lost civilization. And the plate was their attempt at a  warning for future generations to stay away. If only their message had been understood.

That scenario might seem theatrical,  but it isn’t just fiction. Because right now, in the  southeast corner of New Mexico,   the United States is burying  decades of nuclear waste. The site will remain deadly for millennia.

So scientists are trying to figure out how  to keep people from disturbing the area,   long, long after we’re gone. [♪ INTRO] If you drive about 40 minutes  east of Carlsbad, New Mexico,   you’ll find yourself at the Waste  Isolation Pilot Plant, or WIPP. And the waste it’s isolating is nuclear. It isn’t made up of glowing green barrels, though.

It’s much less dangerous looking stuff: clothes,   tools, rags, debris, residues, and  other non-liquid disposable items. But they’re all contaminated with  radioactive elements like plutonium. And many versions of these elements  have really long half-lives,   meaning that they take forever to decay.

According to one estimate, the waste being stored  at the WIPP will remain lethal for 300,000 years! Which is way longer than the goal of crafting  a message that will last 10,000 years. But that’s a hard enough challenge as it is.

Because 10,000 years is plenty of time for Earth’s   civilizations and cultures to  become utterly unrecognizable. Just take a look at where we are now. If you could travel that far back in time,  you’d find yourself in the Late Stone Age.

Humans were still figuring  out agriculture and animal   domestication, and hadn’t yet developed writing. So the WIPP team’s crafting of the ultimate  “Keep Out!” sign has been in-progress for   decades, bringing together material  scientists, archeologists, linguists,   anthropologists…even science fiction writers! The messages they’re working on are called  passive institutional controls, or PICs.

And there are several hurdles to overcome. First, you have to consider the limitations  of whatever you'll store your message on. Stone erodes, wood and paper can burn and rot,   metals could get scrapped and reused for  “more important” projects.

And so on. Meanwhile, you can basically forget  about electronic media altogether. Your average solid state drive only has  a lifespan of about ten years these days.

And when those fail, the data  on them is essentially gone. Even the most durable compact discs only  last a century before they start to fail. One medium you may not have thought of,   but archaeologists know can last  more than 10,000 years, is bone.

Discovered in 1950, in what’s now  the Democratic Republic of Congo,   the Ishango bone dates back to the Upper  Paleolithic Era, about 20,000 years ago. It’s a simple bone tool, perhaps from a baboon,  covered in columns of grouped tally marks. But exactly what those marks mean, no one knows.

Researchers have proposed a bunch of  ideas for what this bone was used for,   from some kind of calculator to a calendar. We’ll be getting back to the problem of  interpretation later, but the WIPP doesn’t   have to rely on a bunch of bones, or anything  similarly old-school, to get its message across. Researchers are working on new  methods of long-term storage.

For example, one team based at MIT has been  working to store digital information in DNA. They’ve tested the technique by  encoding the Emancipation Proclamation,   the MIT logo, and even the  Jurassic Park theme song. And while DNA molecules do degrade over time,   this research team has developed a  method to store them in a special   block of silica, taking inspiration from the  millenia-long preservation of DNA in amber.

Of course, DNA has the same  problems as CDs and Betamax tapes:   future civilizations will also have to  know how to decode a string of 1s and 0s,   or DNA nucleobases, into the message  we’re actually trying to send them. But this hasn’t stopped us from recording such  encoded messages for our distant descendants. Back in 2007, NASA’s Phoenix Lander was sent to  Mars with a miniature DVD made of etched silica.

And an even more extreme version  of this project, featuring an   etched diamond wafer, was planned  for the Cassini mission to Saturn. The messages on that diamond were  meant to last billions of years,   up until the Sun turns into a red  giant, and may or may not eat the Earth. Unfortunately, the plan fell through  because the project’s funder, Fuji-Xerox,   wanted the company’s logo to  be included on the diamond.

But fun fact: some of the researchers involved  in that project were involved with both the   Phoenix time capsule, and the WIPP! According to the Department of Energy,   the WIPP’s current plans call not  for a diamond wafer, or a silica DVD,   but a batch of 23 centimeter-wide disks  made from granite, aluminum oxide,   or fired clay…just in case one material  winds up standing the test of time better. The disks will be scattered around the site,  and buried at just the right depth so they’ll   stay put for millennia, but can still be  dug up by people who need the warning.

There are also plans to construct  whole archive buildings,   as well as separate monuments, all out of granite. That hopefully solves the longevity problem,   and they’re choosing to evade  that pesky decoding problem. But there’s still the issue of how future humans   are going to understand the  warning that’s written down.

But before I tell you how they  plan to solve that, a quick ad. Thank you to McLaren Stanley, Charlie Stanley,  and TJ Steyn for your continued support of   trustworthy stuff that inspires curiosity  and lowers barriers to knowledge building. These incredible patrons help us keep  SciShow totally free for everybody else.

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Consider how hard English teachers have it getting  students to understand what Shakespeare wrote. Shakespeare died in 1616, four centuries ago. That’s only 4% of the 10,000 years  the WIPP team is planning for.

And he was writing in Early Modern English! Actual Old English sounds like this: “Hƿæt! ƿē Gār-Dena in ġeār-dagum…gefrūnon” Did you catch that? I didn’t.

It’s from the opening of Beowulf, an  epic poem written around 1200 years ago. It translates to: “Lo, we have heard  of Spear-Danes in the days of yore.” Which some of you will argue  is still not modern English. Some languages do shift more slowly than others.

Like Icelandic, Lithuanian, or Tamil. But even those languages will change  significantly over 10,000 years. Linguists only know of one language that  dates back 10,000 years: Proto-Afroasiatic.

This language is the ancestor of  modern day languages like Arabic,   Hausa, and Somali, and is estimated to  be anywhere from 10 to 20,000 years old. But unfortunately, we can’t  understand it very well. It hasn’t been reconstructed to the  same degree as other ancient languages,   and many scholars still disagree  over basic things about it.

But they are working on it. Which means  that it’s possible scholars 10 millennia   from now could understand one of our  languages if they put the effort in. The WIPP warnings will be written in seven  different languages to hedge their bets: English,   French, Spanish, Arabic, Russian, Chinese…and  because it’s in the American Southwest…Navajo.

But what should we write in all of those  languages? How much detail should we include? In 1993, a group from Sandia National Laboratories   in New Mexico put together a report  dividing messages into four levels,   which could be used to warn visitors  with increasing levels of complexity.

After all, messages with more detail  are more difficult to understand,   but messages with lower levels of detail and  nuance might not convey enough information. But together, they would convey a unified message: “This is not a place of honor. No highly  esteemed deed is commemorated here.

Nothing valued is here…What is here  is dangerous and repulsive to us… The danger is still present, in  your time, as it was in ours… This place is best shunned and left uninhabited.” For Level I, the WIPP team plans  on using hostile architecture   just to make it obvious that the  site is not completely natural. Humans were here and did…something. That, hopefully, will get our distant descendants  to stop and pay attention long enough to see the   other messages, carved either into the disks or  a much larger information archive buried on-site.

Then the Level II messages kick in, simply to   tell people that there’s something  dangerous buried below the surface. At the moment, the plan is to  use both text and pictographs,   like symbols showing a human  face recoiling in horror. The Level III messages will expand on that,   telling people that the danger is radioactive  and that they shouldn’t dig or drill.

Basic “who what when where why” stuff. They’ll also include a map of the site,  and charts of the stars showing both   the time when the site was sealed,  and when it should be safe again. Because we can’t assume they’ll be familiar  with our calendar system that far in the future.

And we, right now, can predict  where the stars will be in the   sky 10,000 years from now, pretty easy. And they’ll instruct people to add their own  translations in the empty space provided,   to make it easier for people in the even more  distant future to understand the warning. Finally, Level IV messages  will have the most detail.

Like, full blown essays that talk about stuff  like cancer being the primary thing you have   to worry about, and why we chose to bury all  this nuclear waste in this particular spot. This level will also include a map of the  world with markers for the locations of   other nuclear waste disposal sites, so  that future scholars could go and make   sure that the warning messages  there are intact and readable. It’s a lot to think about.

But you might also be wondering why  we’re bothering with language at all. Can’t we just draw symbols  to get our point across? Well, the WIPP team has thought of that.

They might not be as vague as tally marks,   but symbols aren’t universal  across cultures and times, either. Take the skull and crossbones. While we interpret that to mean  “danger”, pirate or otherwise,   in the Middle Ages it was used to  represent Adam’s skull and Christ’s cross.

That said, there are other ways  to convey meaning through time. Our society is full of ideas that  descend from oral history and tradition,   going far back enough that  we’ve forgotten the meaning. One particularly out-there idea,   proposed by a consultant back in the  80s, includes starting a new religion.

Or as he referred to it, an “Atomic Priesthood”. Even if it died out, its myths might remain. Then again, he also pointed out that  the threat of “curses” didn’t exactly   prevent grave-robbing in Egypt, so it  might not be the best plan to enact.

Still, oral history is a legitimate technique   that’s been used by humans to pass  knowledge down across millennia. We even have examples of Australian  aboriginal stories recounting a rise   in sea level that happened over 7000 years ago. Some stories might be as old as 13,000 years,   which is beyond the timeline  the WIPP is planning for!

So humans have a lot of options to  communicate with the distant future,   each with their own complications. That might explain why planning these  nuclear waste PICs has taken decades. Back in 2004, researchers said that they wanted  to have the WIPP’s messages finalized by 2033,   but it’s been difficult to find  any official updates after 2007.

The WIPP site itself was supposed to be  sealed in 2020, but that hasn’t happened yet. It’s been plagued with setbacks, like  a radiation leak in 2014 that may have   affected some staff and caused  the site to close for 3 years. But eventually, the WIPP site will close.

And hopefully, 10,000 years from now, that  explorer will figure out the land isn’t   actually cursed…but they should still  hold off on setting up that dig site. [♪ OUTRO]