Science fiction has long imagined storing vast libraries in glass—think of Superman’s Fortress of Solitude or the data crystals in Star Trek. Now, Microsoft researchers are turning that vision into reality by storing nearly 2 terabytes of data—equivalent to hundreds of thousands of photos or hours of video—in small, coaster-sized plates of glass. Described in the journal Nature, the breakthrough offers a durable, low-cost solution for long-term data archiving, potentially preserving information for thousands of years. The technology, part of Microsoft’s Project Silica, uses common borosilicate glass—similar to that used in cookware and lab equipment—instead of the expensive, pure fused silica required in earlier attempts. This shift makes the process cheaper and more scalable. Unlike magnetic tapes or hard drives, which degrade within a decade and require constant maintenance, glass data storage needs no power to preserve data and can withstand extreme conditions like boiling, scratching, or baking. The method works by using a laser to alter the glass’s refractive index at microscopic levels. By rastering a laser across the glass and varying its focus depth, researchers can write data in hundreds of layers, each about 100 nanometers wide and 2 micrometers deep. Splitting the laser into four beams allows data to be written at 66 megabytes per second—though this is still slower than magnetic tape. The team believes they can improve speed by using 16 beams in parallel. Reading the data is equally innovative. A single optical microscope camera captures light passing through the glass, and a custom algorithm decodes the patterns, filtering out interference between closely spaced data points. The entire system has been automated, with robotic controls for lasers and microscopes, enabling fully integrated data archiving. Microsoft has already tested the system by storing Warner Brothers films and archiving music in a secure vault on Norway’s Svalbard archipelago. The results show that data remain intact even after harsh treatment, proving the technology’s resilience. While the storage density of this glass system is lower than earlier fused-silica prototypes—those achieved up to 100 terabytes per plate—the new approach is far simpler and more practical. Peter Kazansky, a pioneer in glass data storage from the University of Southampton, praises the innovation, noting that borosilicate glass, though lasting only about 10,000 years, is still more than sufficient for long-term archiving. He believes glass will become the ideal medium for preserving humanity’s digital legacy. The global demand for data storage is skyrocketing, with total capacity expected to grow tenfold by 2040, reaching over 250 zettabytes. Current solutions like magnetic tape and hard drives are fragile and costly to maintain. DNA storage offers high density but is expensive and slow to read. Glass, by contrast, is abundant, stable, and energy-free. Although Microsoft has not announced plans to commercialize the technology, experts like Kazansky believe glass storage will eventually become mainstream. “If you want to send messages to the future, there is nothing better than storing them in glass,” he says. With its durability, simplicity, and scalability, Microsoft’s glass data storage may be the key to preserving our digital past for generations to come.