Who was Stephen Hawking
Stephen William Hawking (Oxford, 8 January 1942–Cambridge, 14 March 2018) was a British theoretical physicist and author. [28] He investigated gravitation, quantum mechanics and cosmology, contributing to research on singularities, black holes and the early universe. His popular writing brought these questions to readers around the world. [29]
Education at Oxford and Cambridge
He attended St Albans School and entered University College, Oxford, in 1959, studying physics and earning a first-class degree. In 1962 he began doctoral work in cosmology at Cambridge under Dennis Sciama. [8]
His 1966 thesis, Properties of expanding universes, examined problems arising from cosmic expansion. Cambridge made it openly available in 2017, giving readers access to the research that began his career. The document records the mathematical construction of his arguments and distinguishes that early research from his later popular books. [9]
Positions and work at Cambridge
He became Reader in Gravitational Physics in 1975 and Professor of Gravitational Physics in 1977, holding the Lucasian Chair of Mathematics from 1979 to 2009. [10] He subsequently continued as Director of Research in Applied Mathematics and Theoretical Physics, associated with the Centre for Theoretical Cosmology until his death. [1]
Singularity theorems
With Roger Penrose, he published a theorem in 1970 generalising results on spacetime singularities. Under specified energy, causality and gravitational conditions, some trajectories cannot be extended indefinitely. The result identifies limits of Einstein’s classical description in gravitational collapse and cosmology, with validity tied to its mathematical assumptions. [12]
Black holes, horizons and radiation
His classical work examined black-hole geometry and event horizons, the boundary of the region from which signals cannot escape. Under the conditions considered, a horizon’s area cannot decrease. He connected this result with limits on the energy that could be extracted from a black hole. [13]
Hawking radiation emerged when quantum effects were included. His 1975 paper showed that a black hole should emit particles with a thermal spectrum and slowly lose mass. For a nonrotating, uncharged black hole, temperature rises as mass decreases. The result transformed the picture of black holes as perfect absorbers. [14]
Entropy and thermodynamics
The 1974 prediction gave black holes a physical temperature, consolidating their relationship with thermodynamics. Horizon entropy connects their surface area with a central quantity in statistical physics. This field brings relativity, quantum theory and thermal concepts together to investigate objects once thought outside ordinary thermodynamic description. [15]
With Don Page, he studied black holes in anti-de Sitter space in 1983, using a negative cosmological constant. They identified conditions under which large black holes can remain in stable equilibrium with thermal radiation. Comparing thermodynamic behaviour across spacetimes expanded the tools for investigating gravity and temperature. [17]
The information paradox
In 1976 he argued that gravitational collapse could fundamentally limit prediction of a final state from an initial one. Possible information loss conflicted with ordinary quantum evolution, becoming a central question for theories seeking to reconcile gravitation and quantum mechanics. [16]
In 2016 he returned to the problem with Malcolm Perry and Andrew Strominger. They proposed that black holes carry zero-energy quantum modes, called soft hair, associated with symmetries and conservation laws. Their theoretical study explored information recorded at the horizon and its relationship to evaporation products. [20]
Quantum cosmology and the early universe
With James Hartle, he proposed a wave-function description of the universe’s quantum state in 1983. Known as the no-boundary proposal, it uses a sum over geometries and simplified models to investigate cosmological conditions, opening an approach to the universe’s origin through quantum tools. [18]
In a late collaboration with Thomas Hertog, he investigated an exit from eternal inflation. Released as a preprint in 2017 and published in 2018, the paper used theoretical models to propose a finite, relatively smooth outcome rather than an infinite fractal multiverse. The authors explicitly framed it as a conjecture. [21]
The chronology protection conjecture
His 1992 paper examined whether physical laws would prevent closed trajectories allowing travel into the past. He argued that quantum effects could disturb spacetime before such trajectories formed. Chronology protection was a conjecture supported by calculations, rather than an experimental demonstration involving a time machine. [19]
Books and science communication
A Brief History of Time, published in 1988, introduced general readers to the universe’s beginning and fate, black holes and the direction of time. Later editions incorporated developments and new chapters. It brought theoretical-physics debates into public conversation without asking readers to work through the mathematical proofs. [22]
The illustrated The Universe in a Nutshell appeared in 2001. [23] With Leonard Mlodinow, he wrote A Briefer History of Time and The Grand Design, the latter published in 2010. [24] He also collaborated with Lucy Hawking on George’s Secret Key to the Universe, combining adventure with science for younger readers. [25]
Disability and communication
He was diagnosed with motor neurone disease in 1963. After a tracheotomy in 1985, he lost his voice and used speech synthesis. [8] In 1997 Intel presented an adapted computer providing internet access and remote controls, part of a technological collaboration that continued for years. [26]
His contribution to the artificial-intelligence debate
At the opening of Cambridge’s Leverhulme Centre for the Future of Intelligence on 19 October 2016, he advocated research into both AI’s benefits and risks. His speech addressed economic disruption, concentrated power and autonomous weapons, calling for study of the technology’s consequences and control. [3]
Scientific recognition
The Royal Society elected him on 21 March 1974 and awarded him its Hughes Medal in 1976 and Copley Medal in 2006. He became a CBE in 1982 and Companion of Honour in 1989. These honours accompanied a career addressing fundamental problems through mathematical and theoretical research. [11]
Archives and public legacy
Transferred to Cambridge in 2021, his archive was catalogued and opened for research in 2024. It includes scientific papers, correspondence, A Brief History of Time drafts and television material, including scripts from The Simpsons. It enables study of his research, editorial decisions and distinctive public presence together. [27]
His ashes were interred in Westminster Abbey on 15 June 2018, near Isaac Newton and Charles Darwin. His family and representatives of the scientific community attended the ceremony. [28]
Work adaptation and communication technology
In 2014 Intel presented a system developed over three years with Hawking’s continuing participation. His feedback guided successive design revisions.[5] ACAT combined computer access, text prediction and speech synthesis through an interface adapted to his motor capabilities.[6]
Hawking also publicly advocated inclusion in employment. In his foreword to the WHO and World Bank’s 2011 World Report on Disability, he described how an accessible workplace, assistants and adapted communication supported his work. He called for the removal of physical, financial and attitudinal barriers excluding others from employment opportunities.[7]
For ergonomics, his collaboration with developers illustrates user participation in workplace adaptation: checking whether someone can write, correct a selection, use applications and communicate during actual tasks. This is the specific occupational-health connection: accessibility and adaptation of professional activity.
