Memory of Mankind¶
Memory of Mankind stores selected texts and images on ceramic tablets in an Austrian salt mine, designed for preservation over thousands of years. The tablets resist heat, water, and chemicals without requiring energy or maintenance; contributors include institutions, museums, and individuals selecting what matters enough to keep.
Memory of Mankind (MOM) is a long-term archive project started in 2012 by Martin Kunze, a trained ceramicist from Vienna. The archive stores text and images on ceramic tablets inside the salt mine above Hallstatt in Upper Austria, with the aim that they stay readable for thousands of years. As of the mid-2010s the collection held over 500 tiles, and it has kept growing tile by tile since.
Why the project exists¶
Kunze's argument, laid out in his TEDx Linz talk below, is that digital information is far more fragile than it feels. Storage media decay, formats become obsolete, and keeping data alive requires continuous energy and maintenance. He also points out a selection problem: less than 1% of ancient texts survived, yet they were durable enough to let us reconstruct the ancient world, while today's vastly larger output is mostly trivial and will likely be deleted in bulk — by algorithms, not by anyone deciding what matters. His conclusion is that we should deliberately select what gets kept, on a medium that needs no maintenance at all.
One concrete example he considers central to the archive: raw glacier-melt observation data, preserved so future generations can verify that climate change happened and to what extent.
The ceramic tablets¶
Ceramic is the oldest data carrier still readable today — fired clay tablets from Mesopotamia survive fine — and MOM's tablets are a modern version of the same idea. They resist heat (figures cited range from 1,200 to 1,500 °C), water, chemicals, radiation, magnetism, and pressure. All information is stored in analog form: text is letters, images are pictures. Nothing requires a machine or a format specification to read.
There are two kinds of tablet, both 20 × 20 cm:
- Colour tablets carry photographs and illustrations printed at 300 dpi using ceramic pigments. In news footage of the process (the report below), Kunze soaks a transfer sheet carrying the printed information, presses it onto the tile, then cures the tile in a kiln so the pigment fuses with the ceramic.
- Ceramic microfilm is for text and monochrome graphics. The digital file is laser-engraved directly onto the tablet at a density of five lines of text per millimetre — compressed, but still readable with a 10× magnifier. A single tablet holds up to 5 million characters, about five 400-page books. After engraving, a glaze resistant to alkalis, acids, and temperatures up to 1,300 °C is applied with a roller.
Kunze developed the printing process himself; a firing run in his home workshop takes hours to days per batch. Finished tablets go into ceramic boxes for storage in the mine.
The salt mine¶
The archive sits in the salt mine at Hallstatt, part of a UNESCO World Heritage region and, at roughly 7,000 years of continuous extraction, the oldest known salt mine in the world. Getting there involves a cable car up the mountain and a mining train several hundred metres into the rock.
This DW report follows Kunze on the trip in:
Salt rock was chosen for specific properties: it is dry, geologically stable, absorbs moisture, and — the notable part — it flows. Salt behaves plastically under pressure, so the chambers slowly close around whatever is inside, at roughly the speed fingernails grow. The archive seals itself, without anyone maintaining it, within a generation or two. That same property puts a deadline on the project: the chamber is expected to stay accessible for only about 40 more years of deposits. Under Austrian law the archive is classified as ownerless property.
The token¶
Sealing an archive inside a mountain creates an obvious retrieval problem, which the project answers with tokens: 6.5 cm ceramic discs given to every contributor. Each token shows an outline of Europe with Hallstatt marked, and the position of the mine entrance relative to the lake, encoding the location to within tens of metres. The intent is that thousands of scattered tokens make the archive findable without making it casually accessible — recovering it would take mining capability, which filters for a society with roughly our level of technology. A token-holder gathering is planned every 50 years, starting in 2070.
For future readers who may not share any current language, the archive includes a deciphering aid: thousands of photographs of objects and situations labelled with the corresponding words, alongside grammars and dictionaries of major languages.
What gets stored¶
Content falls into three categories:
- Common content, meant to give a broad picture of the present: daily newspaper editorials from many countries, monthly magazine issues, and randomly selected social media profiles. Conspiracy theories are included too, labelled as such.
- Specific content from institutions: museums, universities, literature and science awards. This includes documentation of nuclear waste repository locations — one of the few parts of the archive with a clearly practical audience.
- Individual content from anyone: life stories, wedding photos, recipes, theses. Submitting text is free; personalised tablets can be purchased, with pricing scaled to national income levels so participation is not limited to rich countries.
A separate campaign, "A Thousand Books for a Million Years", aims to select 1,000 significant books and store them on microfilm tablets.
Criticism¶
Archaeologist Jennifer Gates-Foster (UNC), interviewed in the news report embedded above, argues the archive is not necessary for future scholarship — archaeology already reconstructs societies from material remains and could do the same for the 21st century. She also calls the collection "a fairly disconnected, incoherent group of materials", lacking the context that makes artifacts interpretable. Kunze's response is that MOM is not a doomsday project but a gift to future generations.
My own read: the criticism about context has some weight for the individual contributions, but the deciphering aids and the systematic common content are a direct attempt to address it, and the nuclear waste documentation alone seems worth the effort.
Sources¶
The three videos embedded above, plus: