Two established technologies
The medium needs to preserve readable information without depending on power, software or a particular digital system. It also needs to remain usable if today's languages and institutions no longer exist.
We are evaluating both materials below.
5D Optical Quartz
- Fused Silica
Leading candidate
- Writing
- Femtosecond laser pulses form nanoscale structures inside the body of the glass. A separate human-readable layer of micro-text and images is etched near the surface and read with a standard optical microscope no dependence on a file format, operating system, or software.
- Durability
- Fused silica is among the most chemically inert materials known. It does not oxidize or tarnish, and it resists water, acids, and alkalis under normal terrestrial conditions. Its softening point sits near 1,650°C, well above the temperature of an ordinary fire.
- Limit
- Quartz is hard but brittle. A thick solid disc resists crushing far better than a thin sheet, but a direct blow can still shatter it. This is why the casing and burial environment matter as much as the medium.
Nickel
Micro-Engraving
Backup medium
- Writing
- Text and images reduced to microscopic scale and written into the nickel archival medium, read with an optical microscope. Also fully analog no power, no software, no file format to depend on.
- Precedent
- This candidate uses an analog format that does not depend on power, software or a file format. Its suitability for the archive will be assessed as part of the final preservation design.
- Limit
- Nickel resists corrosion through a passive oxide layer, but over long spans it is not immune. Acidic soils, salt water, and some microbial environments can pit the surface, and the fine detail that makes the text legible degrades before the metal itself fails. Its long-term performance depends strongly on fabrication, surface condition, and burial environment we are treating those as part of the preservation design rather than assigning a lifetime to the medium alone.
A lens, and nothing else.
Whatever medium is chosen, the requirement is the same: a person holding the object and a simple magnifier can reach the writing. It does not depend on a file format, a device or a particular institution.
A plain surface with a faint mark at the centre. Nothing legible.
Ordered rows resolve out of the surface. Structure is obvious; meaning is not yet.
Characters and figures become legible. A person with a microscope can read the record directly.
Why fused silica is currently ahead.
On the properties that decide survival chemical inertness, heat tolerance, and resistance to water and soil chemistry fused silica currently appears the stronger candidate.
Fused silica currently appears the stronger candidate on the properties that matter for long-term preservation. Whether the archive uses one medium or more than one will be determined through specialist review and the final preservation design.