Can we preserve knowledge … forever?

What It Covers

TED Radio Hour explores three approaches to preserving human knowledge permanently: Brewster Kahle's Internet Archive has saved over 866 billion web pages since 1996; molecular biologist Dina Zelensky demonstrates DNA as a data storage medium; and archaeologist Chris Fisher uses lidar scanning to create a digital record of a rapidly changing Earth.

Key Questions Answered

• •Web Archiving Participation: The Internet Archive's "Save Page Now" feature at archive.org allows anyone to permanently archive any URL and is used approximately 80 times per second. Individual users can directly contribute to preserving the web by submitting links — obituaries, news articles, or any page at risk of deletion — before content disappears within its average 100-day lifespan.
• •DNA Data Encoding: Digital data converts to DNA using a two-bit-per-letter encoding scheme: 00=A, 01=C, 10=G, 11=T. The resulting text file is sent to a synthesis company, which returns a dried powder within days. Stored frozen in silica glass beads, DNA remains stable for thousands of years, as demonstrated by ETH Zurich researchers who successfully recovered data after simulated millennium-scale storage conditions.
• •Digital Ownership Risk: Publishers license rather than sell ebooks, meaning files on Kindle or similar devices can be altered or deleted without user consent at any time. The Internet Archive's legal battle with four major publishers — over its practice of buying physical books, scanning them, and lending digital copies — has already resulted in restricted access to 500,000 titles, signaling a structural threat to digital preservation efforts.
• •Lidar Scanning Efficiency: Airborne lidar technology, which fires hundreds of thousands of infrared pulses per second to generate full 3D terrain maps, compressed 20 years of conventional archaeological fieldwork at Mexico's Angamuco site into 45 minutes of flight time. The Earth Archive project uses this method to prioritize scanning regions most threatened by climate change, deforestation, and rising sea levels before those landscapes are permanently altered.
• •Baseline Data Strategy: Effective climate change mitigation requires a high-resolution "before" dataset of Earth's surface, which currently does not exist for most of the planet. The Earth Archive addresses this by scanning vegetation, topography, hydrology, and archaeological features simultaneously in a single lidar pass, creating layered records that future scientists can analyze using techniques not yet invented, including for questions not yet conceived.