Stephen Hawking

Explorer of Black Holes · Theoretical Physicist · 1942–2018

The physicist who proved that black holes radiate and evaporate, helped show the universe began in a singularity, and made cosmology comprehensible to the whole world — all while living with motor neurone disease.

Who was Stephen?

Stephen Hawking was diagnosed at twenty-one with a motor neurone disease expected to kill him within years; he lived more than fifty more, thinking through a speech synthesizer after he lost his voice. With Roger Penrose he proved that a universe obeying general relativity must begin in a singularity. Then, in his most celebrated result, he showed that quantum effects at a black hole's edge make it radiate — 'Hawking radiation' — so that black holes slowly evaporate. He held Newton's chair as Lucasian Professor at Cambridge, worked toward uniting gravity with quantum theory, and wrote 'A Brief History of Time', a global bestseller that brought the cosmos to ordinary readers. He undercut cosmic grandeur with a famous dry wit and refused to be defined by his body.

Major achievements

• Discovered Hawking radiation — that black holes emit particles and evaporate
• With Penrose, proved singularity theorems about the universe's origin
• Proposed, with Hartle, a 'no-boundary' model of the cosmos
• Wrote 'A Brief History of Time', which sold in the tens of millions
• Held the Lucasian Professorship of Mathematics at Cambridge

Life in brief

• 1942 — Born in Oxford: On the 300th anniversary of Galileo's death, he liked to note.
• 1963 — Diagnosed with ALS: At 21, and given only a few years to live.
• 1970 — Singularity theorems: With Penrose, on the origin of the universe.
• 1974 — Hawking radiation: Shows black holes are not entirely black.
• 1979 — Lucasian Professor: Takes Newton's chair at Cambridge.
• 1988 — A Brief History of Time: A worldwide bestseller.
• 2018 — Dies at 76: Interred near Newton and Darwin at Westminster Abbey.

Explore the life of Stephen — five chapters

1. The Lazy Undergraduate — Oxford, boredom, and a diagnosis at twenty-one
2. The Universe Had a Beginning — Singularity theorems with Roger Penrose
3. Black Holes Are Not Black — The calculation he expected to disprove
4. The Voice — A tracheostomy, a synthesiser, and a bestseller
5. Fifty-Five Years — Zero gravity, no boundaries, and Westminster Abbey

Read the five-chapter life of Stephen Hawking →

Where Stephen appears in your course

Stephen Hawking has a genuine claim on 3 lessons of the Pearson Edexcel International GCSE science course built into Incandio:

• The Doppler Effect — Physics: The effect on this page is the foundation of modern cosmology, and Hawking spent his career working on what follows from it. Almost every distant galaxy shows a red shift, and the more distant ones show more — which means space itself is expanding, and running that expansion backwards leads to a beginning. His own work with Roger Penrose showed that under general relativity such a beginning is unavoidable rather than optional, so the note an ambulance makes and the origin of the universe turn out to be the same piece of physics.
• The Life Cycle of Stars — Physics: A black hole is where the massive-star path ends on this page, and it is stated as a fact with no explanation of how anything can be dense enough that light cannot leave. Hawking spent his career on exactly that object, and his most surprising result was that a black hole is not entirely black: quantum effects at the boundary let it radiate very faintly, so it slowly loses mass and, over an unimaginable time, evaporates. He is also the right figure for the honest admission that the centre of a black hole is where the physics on this page stops working and nobody yet knows what replaces it.
• The Big Bang and its Evidence — Physics: This page is careful to say that the theory does not describe the very first instant, and Hawking spent much of his career on exactly that boundary. With Roger Penrose he proved that under general relativity the expansion must trace back to a point where the equations break down entirely, and he later argued that asking what came before it may be as meaningless as asking what lies north of the North Pole. He is the right figure to ask what a scientific theory is entitled to say about its own starting point, and what it means for a question to have no answer rather than an unknown one.

Begin

• Start a conversation with Stephen — a dramatised, historically grounded AI portrayal
• Read the Historical Brief
• Explore the life of Stephen — five chapters
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