A research team at the University of Twente in the Netherlands claim they have designed and built a disk medium that is capable of reliably storing data for a million years, or even more. The team first needed a deep understanding of how information can become corrupt over time, and how to negate this process from happening. Technology Review breaks down the concept in which the research team based its design:

"This is based on the idea that data must be stored in an energy minimum that is separated from other minima by an energy barrier. So to corrupt data by converting a 0 to a 1, for example, requires enough energy to overcome this barrier... Some straightforward calculations reveal that to last a million years, the required energy barrier is 63 KBT or 70 KBT to last a billion years."

The team created a tungsten disk, struck with fine etched lines and coated in what is called silicon nitride (a chemical compound often used as an insulation or barrier in electronics circuits), that they claim has achieved this.

According to Arrhenius law, a disk capable of maintaing information for a million years would need to be able to withstand a temperature of 445 Kelvin for around one hour. So after putting the drive to the test, the team figured out that it was able to handle that temperature without any problems at all. In fact, it was able to withstand temperatures double that, but it did begin experiencing data loss at that point.

While theoretically the research does provide us with a plausible method of storing data for millennia, there are several caveats, such as serious natural disasters, that the technology obviously will not withstand.