That fact that physicist Stephen Hawking is an icon of our era was made plain during the production of La Damnation de Faust that my wife and I saw at the Paris Opera in 2015. A dancer trundled silently about the stage playing the role of the wheelchair-bound physicist as Faust made his pact with the devil and ended up in Hell (which was apparently Mars). The opera preposterously concluded with the apotheosis of Hawking standing unsupported as a Mars rover cruises across the stage. The singing was superb, but the staging was, well, unfortunate.
Among Hawking's distinctive contributions to physics and cosmology is his work on black holes. Black holes are celestial objects with a gravitational field so strong that light cannot escape them; they are believed to be created by the collapse of very massive stars. Sagitarrius A, a black hole with more than 4.1 million times the mass of the Sun, is at the center of the Milky Way. Among other things, Hawking figured out that black holes do emit particles and therefore would "evaporate" over time. Hawking declared that he'd like the formula for this Hawking radiation engraved on his tombstone:
Hawking was diagnosed with a motor-neuron disease at age 21. It eventually confined him to a powered wheel chair. When he lost the power of speech in 1985, he famously turned to a text-to-speech system that produced his, well, iconic "robot" voice. His 1988 book, A Brief History of Time, brought his thinking on cosmology to the wider public, eventually selling more than 10 million copies. In the words of his friend Martin Rees, "the concept of an imprisoned mind roaming the cosmos" grabbed people's imagination.
Clearly brilliant, and ferociously brave in overcoming the physical limitations inflicted by his illness, Hawking did sometimes endorse some fashionable apocalyptic views. While acknowledging that "the potential benefits of creating intelligence are huge," Hawking was worried artificial intelligence could turn out to be "the worst thing ever to happen to humanity." In addition, he thought that humanity should avoid contact with extraterrestrial civilizations because they could be "rapacious marauders roaming the cosmos in search of resources to plunder, and planets to conquer and colonize." Cooler heads are less concerned about alien invasions.
In any case, the world was a better place because Stephen Hawking was in it. He will be missed.