The Technology that Made the Internet Possible | Veritasium

The Gist

Fiber optic internet relies on high purity glass fibers invented by Corning researchers in 1970, which reduced signal loss below twenty decibels per kilometer to make global communication possible. Before this breakthrough, high signal loss in glass and copper made long distance optical communication seem impossible.

Quick Overview

Optical fiber communication became a reality in 1970 when Corning researchers Donald Keck, Peter Schultz, and Robert Maurer successfully manufactured a fiber optic strand with a signal loss under twenty decibels per kilometer. The documentary traces the historical hurdles of telecommunication, from copper wire capacity limits to the realization of Charles Kao and George Hockham that fused silica could theoretically work if impurities were removed. By using flame hydrolysis to create titanium and germanium doped fused silica cores, the team achieved an unprecedented breakthrough that powers the modern internet.

Key Points: In the 1960s, telecommunication companies faced a massive surge in daily telephone calls, doubling from 285 million to 576 million between 1960 and 1973 in the United States. Copper wires suffered from severe signal loss at high frequencies due to resistance and eddy currents, forcing engineers to install repeaters every few miles. In 1966, Charles Kao and George Hockham published a paper arguing that fiber optics could achieve low loss if impurities like metal ions were removed from fused silica. Early glass fibers suffered from a staggering loss of 1000 decibels per kilometer, making them completely impractical for long distance transmission. Corning scientist Robert Maurer realized that impurities like iron absorbed specific light wavelengths, which explained why commercial glass was so lossy. Donald Keck, Peter Schultz, and Robert Maurer at Corning Glass Works invented a technique called flame hydrolysis to produce ultra pure fused silica powder. By doping the fused silica core with titanium and later germanium to raise its refractive index, the team successfully trapped light inside the fiber. On July 22, 1970, the Corning team measured a signal loss of just 17 decibels per kilometer in a titanium doped silica fiber, crossing the threshold for practical commercial use.