The Universe in a Wheelchair

Stephen Hawking was born in Oxford on January 8, 1942, exactly 300 years after Galileo died. He liked to point that out. He also shared a birthday with Elvis Presley, though he was less proud of that one. Hawking had a sense of humor about the universe, which was fortunate, because the universe gave him plenty of material.

He was diagnosed with ALS at 21 while studying cosmology at Cambridge. Doctors gave him two years. He lived for 55 more. The disease gradually paralyzed him -- walking, writing, speaking, all taken. By his 40s he communicated through a speech synthesizer controlled by his cheek. The flat, robotic voice became one of the most recognizable in science.

His greatest work came from black holes. In the 1970s, most physicists believed nothing escaped them. Hawking realized quantum mechanics complicated the picture. At a black hole's edge, particle pairs could spontaneously form -- one falls in, the other escapes. The black hole appears to radiate. Over billions of years, it could evaporate. This connected gravity, quantum mechanics, and thermodynamics in a way no one had done before.

stephen hawking delivering a public lecture at the hebrew university of jerusalem, december 2006. source: wikimedia commons

A Brief History of Time spent 237 weeks on the bestseller list. Millions bought it; far fewer finished it. But Hawking made cosmology feel urgent and personal. He appeared on Star Trek, The Simpsons, took zero-gravity flights. Just as Isaac Asimov made robots feel moral, Hawking made the cosmos feel comprehensible.

He died on March 14, 2018 -- Pi Day, Einstein's birthday. His ashes were interred in Westminster Abbey, between Newton and Darwin. He showed that a single human mind, however constrained, could reach across billions of light years and glimpse the structure of reality.