The technology works with a 2cm square piece of glass that’s 2mm thick, and is etched in binary with a laser. There are four layers, which results in a density of 40MB per square inch. “That’s better than a CD (which tops out at 35MB per square inch), but not nearly as good as a standard hard disk, which can encode a terabyte in the same space,” writes Sam Grobart in Bloomberg. The company said it could also add more layers for more density.

Of course, the selling point is not how dense it is, but that it will, supposedly, last forever, without the bit rot that degrades magnetic storage and is leading some to fear a “digital dark ages” where we will lose access to large swathes of our history and culture because it’s being stored magnetically.

The technology was developed in 2009 and may be made available as a product by 2015, Hitachi said, according to Broadcast Engineering.

There’s more to the digital dark ages than simply preserving the media, however — there’s also the factor of having the hardware and software that enables people to read the data. Anyone who’s found a perfectly pristine 78-rpm record in their grandparents’ attic is familiar with that problem.

Hitachi says that won’t be a problem because all computers, ultimately, store data in binary, and the glass could be read using a microscope. But how it’s encoded in binary — the translation between the binary and turning it into music or movies or whatever — the company didn’t say. The microscope could read it, but how would it know what it meant?

As it is, the company still needs to develop readers for the glass pieces. (One envisions something like a a Kodak Carousel slide projector.)

The way it may work is to have organizations with a great deal of data to preserve, such as governments, museums and religious organizations, send their data to Hitachi to encode it, wrote Broadcast Engineering.

The quartz glass is said to be impervious to heat — the demonstration included being baked at 1000 degrees Celsius for two hours to simulate aging — as well as to water, radiation, radio waves and most chemicals, which is why many laboratory containers are made of glass.

On the other hand, the glass is vulnerable to breakage. And as anyone who’s used a microscope has probably experienced, imagine reading the data and then, trying to improve the focus, turning the microscope too far and watching in horror as centuries-old data gets crunched.

Last week it was Facebook’s Sub-Zero. This week it’s Amazon’s Glacier.

In both cases, the vendors are offering low-cost storage for long-term archiving in return for customers being willing to wait several hours to retrieve their data — though, in Facebook’s case, the customer appears to be primarily itself, at least for the time being.

“To keep costs low, Amazon Glacier is optimized for data that is infrequently accessed and for which retrieval times of several hours are suitable,” says Amazon. “With Amazon Glacier, customers can reliably store large or small amounts of data for as little as $0.01 per gigabyte per month.”

A penny per gigabyte equals $10 per terabyte (1,000 gigabytes) – compared with $79.99 for the cheapest 1-TB external drive from Amazon’s product search, while Dropbox’s 1-TB plan costs $795 annually, notes Law.com.

The service is intended not for the typical consumer, but for people who are already using Amazon’s Web Services (AWS) cloud service. Amazon describes typical use cases as offsite enterprise information archiving for regulatory purposes, archiving large volumes of data such as media or scientific data, digital preservation, or replacement of tape libraries.

“If you’re not an Iron Mountain customer, this product probably isn’t for you,” notes one online commenter who claimed to have worked on the product. “It wasn’t built to back up your family photos and music collection.”

The service isn’t intended to replace Amazon’s S3 storage service, but to supplement it, the company says. “Use Amazon S3 if you need low latency or frequent access to your data,” Amazon says. “Use Amazon Glacier if low storage cost is paramount, your data is rarely retrieved, and data retrieval times of several hours are acceptable.” In addition, Amazon S3 will introduce an option that will allow customers to move data between Amazon S3 and Amazon Glacier based on data lifecycle policies, the company says.

There is also some concern about the cost to retrieve data, particularly because the formula for calculating it is somewhat complicated.

While there is no limit to the total amount of data that can be stored in Amazon Glacier, individual archives are limited to a maximum size of 40 terabytes and up to 1000 “vaults” of data, Amazon says.

While it doesn’t deal with the issue of data for software that no longer exists, the Glacier service could help users circumvent the problem of the “digital dark ages” of data being stored in a format that is no longer readable, notes GigaOm.

Can similar services for other cloud products, such as Microsoft’s Azure, or for consumers, be far behind?

Mechner and his team had to deal with multiple possible problems:

• Finding a drive to read the disk
• Finding software to read the disk
• Dealing with whatever forms of copy protection the disk might have had
• Finding software to run the software on the disk
• Dealing with whatever damage the disk itself might have suffered during its 22 years in his dad’s garage
• Dealing with whatever “bit rot” the data might have suffered