Explore the challenges and advancements in long-term digital data preservation in this USENIX ATC '20 conference talk. Delve into the evolving techniques for archival storage, including DNA and glass-based technologies, and their implications for preserving information for future generations. Examine the physical and semantic obstacles in maintaining digital data integrity over extended periods, ranging from decades to millennia. Gain insights into the importance of protecting not just bits, but also the ability to interpret data in the future. Learn about media reliability, data integrity, and the economics of archival storage from Professor Ethan L. Miller, an expert in storage systems research. Discover ongoing archival storage projects and the complexities of managing and searching vast amounts of preserved information. Consider the potential threats to our society's knowledge continuity and be inspired to contribute to solving these critical data preservation challenges.