The "Superman Memory Crystal": How Glass Can Store Data for Billions of Years

Why we need better long-term storage

Hard drives typically last years, not decades. Magnetic tape, used by big data centres, is rated for a few decades with proper storage. Optical discs degrade, and formats become unreadable as players disappear. For records that must last centuries, such as history, science and culture, none of these is ideal.

How 5D storage works

A femtosecond laser (pulses lasting a millionth of a billionth of a second) focuses inside the glass and creates tiny nanostructures, without cracking it. Each structure, called a voxel, encodes data in:

• three spatial dimensions (its position across and through the disc), plus
• the orientation of the nanostructure, and
• its strength (how much it slows light, called retardance).

A microscope with polarised light reads the orientation and strength back, turning them into bits.

How much and how long?

The Southampton team has described a capacity of up to 360 terabytes on a disc about the size of a coin and estimated thermal stability up to around 1,000 °C. Their lifetime estimate at elevated temperatures runs into billions of years, which is where the "eternal" and "Superman memory crystal" nicknames come from (after the crystals in the Superman films).

What has been stored so far

• Documents such as the Universal Declaration of Human Rights and Newton's Opticks were written as early demonstrations.
• A crystal containing Isaac Asimov's Foundation trilogy travelled into space aboard the Tesla Roadster launched by SpaceX in 2018, via the Arch Mission Foundation.
• In 2024 the team announced they had stored a full human genome on a 5D crystal as a long-term archive.

Microsoft's Project Silica

Microsoft Research runs a related glass-storage project called Project Silica, aimed at cloud archives. It has demonstrated storing a full feature film on a small glass plate and designs robotic libraries that read plates on demand. The goal is cheap, durable "cold" storage for data that is rarely read but must never be lost.

Will you ever use it?

Probably indirectly. Writing is slow and the equipment is specialised, so glass storage suits archives run by cloud providers, libraries and governments. For your own files, the answer is still a good backup routine.

Read our free backup guide, and see how drives organise data in file systems explained.

Quick answers

Can I buy a 5D storage drive?

Not as a consumer product. The technology is in research and specialised commercial development.

Is glass storage rewritable?

No, it is designed as write-once storage, which is a feature for archives: data cannot be altered or encrypted by ransomware once written.