Somewhere in your closet, you probably have a stack of VHS tapes or floppy disks. Dig deep enough and maybe you even have cassettes or 45s. Whatever's stored on these contraptions is useless, unless you can find somewhere to play them--and even if so, cross your fingers that they haven't been corrupted by moisture, dust, or time.
Now scientists have found a way to preserve data so that it will outlast us all. A team at the University of Southampton successfully encoded data into discs of glass that can last for billions of years. The team has already engraved the quarter-size discs with full copies of the King James Bible, the Magna Carta, and the Universal Declaration of Human Rights.
Data are recorded on the discs using lasers that create three layers of microscopic dots, known as nanogratings, separated by five micrometers. (One micrometer is one millionth of a meter.) Like the grooves on a record album or the indentations on a CD, the dots are arranged in different patterns to represent different information. Later, the data can be read using a microscope and a polarized lens.
For something so small, the discs can preserve huge amounts of information: One disc can hold 360 terabytes, or 3,000 times as much as a Blu-Ray disc. When retrieved, the data can be projected three-dimensionally, while also preserving the original orientation and strength of the light--and thus, scientists have taken to calling it "five-dimensional" storage.
And the reason the information can be preserved in a way it could not be on a CD or hard drive? It's located inside a layer of fused quartz. Even if stored at 374 degrees Fahrenheit, the discs will remain readable for a projected 13.8 billion years.
The lasers that encode the discs are still a long way away from being widely used. But the team suggested that the readers could be commercialized at some point the way that DVD players are today.
As the Southampton team demonstrated with its choice of files to save, the technology can ensure that the most important cultural, political, and religious documents are both safely preserved and easily accessible. Entire museums and libraries could be archived in a format resistant to the perils of time. "This technology can secure the last evidence of our civilisation," Southampton professor Peter Kazansky said, according to the university's website. "All we've learnt will not be forgotten."