The government of a rich country decides that it's time to create a time capsule to store our scientific knowledge so that in the case of a global disaster (meteor impact, nuclear apocalypse, etc.) the knowledge can be recovered and decrypted even millions of years in the future (they want to protect against even dinosaur extinction scale events).

At least some of the data should be encoded to be decodable with low tech. Maybe an instruction how to build a reader to harvest the rest of the data.

Obviously, cultural hardcoding, like using the English and Latin alphabet, is not recommended.

How can they do that?

Please use only our current technology to design the artifact.

  • 1
    $\begingroup$ This is very close, possibly a duplicate of How might modern humans leave a message for 50,000 years? The timescale is even larger, but the basic premise of having a timecapsule and preserving a message over a very, very long time are the same. $\endgroup$
    – Secespitus
    Jul 5 '18 at 10:55
  • $\begingroup$ What do you want to know about? How to preserve how much data exactly for millions of years? How to make it obvious how to read that data for any intelligent life form? Something else? $\endgroup$
    – Raditz_35
    Jul 5 '18 at 11:04
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    $\begingroup$ When you say "decodable with low tech," how low do you mean? $\endgroup$ Jul 5 '18 at 20:55
  • $\begingroup$ Normie do you mind if I pimp up your formatting a bit? $\endgroup$
    – P.Lord
    Jul 6 '18 at 23:21

It can be done -meaning that you can build a multilayered time capsule that could resist the erosion. Wouldn't place it underground, or it would simply be lost until it is accidentally discovered.

So we need to buy a capsule for the capsule, a visible structure made of...gold! Yes gold encapsulated in diamond encapsulated in titanium encapsulated in plastics, etc. The ultimate artifact made to last, assault afer assault from the big outdoors.

You also need to place it in the middle of a plains, with a reasonable hope that geological movements will not cover it, so...the Death Valley, Central Australia, any place where as of currently, even without the anthropic factor, there will be no chance for greenery explosion for a while.

Capsule must be smooth, flawless, TALL, a new shiny pyramid, no even taller than that, so that it must look artificial even when covered by moss and vegetation.

L.Dutch's answer covers it for the rest^^

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    $\begingroup$ Good luck leaving something as gold or titanium out in the open and having it not broken by thieves or scavengers in the last days of homo sapiens... $\endgroup$
    – L.Dutch
    Jul 5 '18 at 12:12
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    $\begingroup$ you might be right that a large artificial structure (pyramid?) is a good message to the future. Today's Central Australia might be covered in the ocean in few millions of years. But maybe even with todays knowledge we are able to predict the tectonic movements and which places will remain safe. I would also scatter some clues throughout the globe pointing to the structure location. $\endgroup$
    – normiesc
    Jul 5 '18 at 18:54
  • $\begingroup$ How are you planning on making a HUGE diamond with today's tech? $\endgroup$
    – P.Lord
    Jul 6 '18 at 23:20

The Pioneer plaques carry some information but most informations are about humans' shape/body and how to find us, they aren't actually source of that much knowledge because the next intelligente specie will find them on hearth (so location info are useless) and humans are already extinct. Moreover they are not designed to last on hearth but in space. Aluminium/gold is a quite good material but the shape and thickness are not optimal except for the weight (wich is really important only if you have to launch them into space).

I totally agree with Valerio Pastore's answer, beside the fact that you can pretty much place the capsule wherever you want since after a Chicxulub-scale cataclism and after millions of years you can't really know which place will be fine. On a second thought, since the capsule is designed to last millions of years but it doesn't mean that the next specie arrive after millions of years (maybe they will arrive after only a thousand years, who knows), a safe place now is a better choice. Mas que nada...

Our languages would have been forgotten, but people that study how to create messages that should be understandable for ages (100K year) already exist, their goal is to warn people about radioactive scories storages: Documentary film. Contrary to the pioneer plates or the Voyager golden record we don't have to care about the weight, therefore some more space is available. Knowledge is not well defined and i'm not sure about what you really want to preserve.

Do you want to preserve our history or our science?

If you want to preserve history you could create the new rosetta stone but i guess that after such a cataclism history as we know it is gone, in the best case scenario it will be possible to find some kind of especially rare "fossils" (compared to our fossils) but certainly nothing comparable to our museums or the pyramids or the coliseum (thousands of years are quite different from millions of years).

If space/weight is not an issue then history should be recorded, otherwise i'd go with science. Languages are gone but some huge science milestones could be engraved as images. For instance: periodic table, atom structure, Darwin evolution theory, the wheel (please note that's not obvious, some evolved civilizations didn't develop wheels), crop rotation, our solar system (the new specie could still be hearth native as us), metal casting, Archimede's and Leonardo's designs, Pitagora's theorem, classical mechanics... This list could be very long and it will be much more useful since the physics laws won't change in millions of years. :)



But how? You ask


Use images.

Take Lego as an example. A child who is deaf can still easily make Lego as the instructions are incredibly simple and follow a logical order.

They will speak a different language, may read differently, may have a completely different biology. However they will still use sight, show images of how stuff works e.g.

  • Show a stick figure with some parts.
  • Show him building something using said parts.
  • Show an amazing outcome.
  • Repeat for every device.


  • Make the images by overlaying panels of Gold on Platinum (this will be extremely expensive if many copies are made)
  • To avoid decay:
    • Keep in an inert gas in a sealed container with 2-3 inch thick bulletproof lead glass exposing the pictures to visible light but avoiding radiation decay.
    • For the rest of the container used 1 inch of lead buried in a concrete monolith.
  • This will limit temperature, chemical, radioactive and biological decay. And should survive a nuclear apocalypse or two.

A couple should be made where the gold is painted black in case they use infrared to see.


Your very same question has been already asked (and answered) by a group of scientists busy with the launch of Pioneer 10, 11 and Voyager.

The Pioneer plaques are a pair of gold-anodized aluminum plaques which were placed on board the 1972 Pioneer 10 and 1973 Pioneer 11 spacecraft, featuring a pictorial message, in case either Pioneer 10 or 11 is intercepted by extraterrestrial life. The plaques show the nude figures of a human male and female along with several symbols that are designed to provide information about the origin of the spacecraft

At the top left of the plate is a schematic representation of the hyperfine transition of hydrogen, which is the most abundant element in the universe. The spin-flip transition of a hydrogen atom’s electron has a frequency of about 1420.405 MHz, which corresponds to a period of 0.704 ns. Light at this frequency has a vacuum wavelength of 21.106 cm (which is also the distance the light travels in that time period). Below the symbol, the small vertical line—representing the binary digit 1—specifies a unit of length (21 cm) as well as a unit of time (0.7 ns). Both units are used as measurements in the other symbols.

As you might notice, the message is biased to be understandable only by civilization with at least our same level of knowledge (Galileo or Lavoisier wouldn't have known of Hydrogen hyperfine transition).

Other than this, you can include any info which can be easily expressed with figures: images of building, a cartography of the world, maybe with the transliteration of those items into some language, in order to create the equivalent of a Rosetta stone to be used if other remains are found.

I think it is pretty hard to convey detailed knowledge without using a language but only images.

An additional challenge is given by the long time you are asking. For that I would bet on large numbers: engrave several plates and store them all around the world. Some of them might survive long enough to be found, more or less like fossils do.

  • $\begingroup$ Yes, all the above, except - bury them on the moon, with a visible-from-earth marker... $\endgroup$
    – Joe
    Jul 5 '18 at 15:15
  • $\begingroup$ @Joe, how do you make clear that a feature on the moon, which it has been visible for as long as memory goes, is artificial and not natural? $\endgroup$
    – L.Dutch
    Jul 5 '18 at 15:19
  • $\begingroup$ @Dutch Many ways, paint or colorants would fade quickly, shiny objects become obscured by dust over time...I'd use robotic bulldozers to carve 'roadways' into the regolith that simply enumerate such as : I II III IIII or use combinations : I III IIII - math should be a universal language, much as the Voyager plaques were designed. On the Moon, no tectonics, or man made disaster will interfere- maybe for hundreds of millions of years. This is the Basis underlying Dr. Clarke's "The Sentinal" and the more Familiar "2001: A Space Oddessey" $\endgroup$
    – Joe
    Jul 5 '18 at 20:06

Carve many images on hard rock like granite/basalt/etc and bury them in many different places on Earth. Hard rock is cheap, last long time, not need special care, not need high technology for future see images, can use rock images for decorate structures too.


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