1884: Greenwich becomes the world's prime meridian

On 13 October 1884, the International Meridian Conference in Washington, D.C., formally adopted the meridian running through the Royal Observatory at Greenwich as the world's prime meridian. Twenty-two nations voted in favour, establishing both a universal zero of longitude and the basis for the global system of time zones still used today.

The decision solved a centuries-old practical crisis. Accurate navigation at sea demanded a single agreed reference line and reliable clocks; without them, even the best astronomical tables produced dangerous errors. The same hunger for error-free calculation had already driven Charles Babbage to design his Difference Engine and Analytical Engine earlier in the century—machines intended to automate the production of navigational and astronomical tables that human computers so often got wrong.

Once a common meridian and time standard existed, the great telegraph networks of the late nineteenth century could coordinate messages across continents with unprecedented precision. Those networks were the first global information systems. They evolved into telephone switching systems, then into packet-switched computer networks, and finally into the high-bandwidth fabrics that link modern data centres.

Today's large-scale artificial intelligence rests directly on this inheritance. Training a frontier model requires thousands of processors scattered across the planet to operate in near-perfect synchrony. Their clocks are kept aligned to within microseconds by protocols that ultimately depend on the universal time framework fixed on that October day in 1884. A quiet diplomatic vote about ships and stars became part of the invisible infrastructure that makes contemporary AI possible.