His IQ: What He Said
When asked about his IQ, Stephen Hawking famously replied: "I have no idea. People who boast about their IQ are losers." He separately stated in interviews that his IQ was 160 — placing him in the same estimated range as Albert Einstein. See the IQ 160 profiles for context.
The 160 figure is a formal estimate rather than a documented test result. What can be assessed directly is his intellectual output: his work in general relativity, quantum mechanics, and their synthesis at the boundaries of black holes places him among the most formidable theoretical physicists of the 20th century.
Early Life and Before the Diagnosis
Hawking was born January 8, 1942 — exactly 300 years after the death of Galileo, a coincidence he found meaningful. He grew up in an intellectually active household; his father was a research biologist and his mother among the first women to study at Oxford. Hawking himself attended Oxford, studying physics, and later moved to Cambridge for his PhD under Dennis Sciama.
By his own account, he was not an exceptional student in the conventional sense. He was bright, but not the diligent studier that the term "genius" sometimes implies. He reportedly did very little work at Oxford, relying on a quick mind to get by, and later acknowledged that he only worked hard after his diagnosis forced a reckoning with how he wanted to spend his time.
How ALS Shaped His Physics
Paradoxically, the diagnosis may have focused Hawking's mind in ways that made his scientific career possible. He later said that before the diagnosis, he had seen no point in completing his PhD — his life felt aimless. Afterward, he became driven to accomplish something meaningful before he lost the physical ability to work.
His motor disease also forced him to do physics differently. As he lost the ability to write equations, he was forced to perform all calculations in his head — developing an extraordinary spatial and geometrical intuition for the topology of spacetime. Colleagues describe his ability to visualize complex solutions to equations he could not physically write as a kind of superpower, analogous to what Tesla described about his engineering visualization.
Hawking Radiation: His Greatest Discovery
In 1974, Hawking published what is widely considered the most important theoretical result in modern physics: black holes emit thermal radiation. This "Hawking radiation" arises from quantum effects near the event horizon, where virtual particle-antiparticle pairs can be separated by the black hole's gravity — one particle falls in, the other escapes as real radiation. Over astronomical timescales, this process causes black holes to slowly evaporate.
This result was the first major synthesis of quantum mechanics and general relativity — two theories that physicists have been trying to reconcile for a century. It implies that black holes are not truly eternal and not entirely black, and it raises profound questions about information preservation in physics (the "black hole information paradox").
Hawking radiation has not yet been directly observed (the effect is too tiny to detect with current technology for stellar-mass black holes), but it is accepted by the physics community as almost certainly correct and remains a crucial guide for developing a complete theory of quantum gravity.
A Brief History of Time
In 1988, Hawking published "A Brief History of Time: From the Big Bang to Black Holes." It became one of the most successful science books in history, spending 237 consecutive weeks on the Sunday Times best-seller list and selling over 10 million copies in 40 languages. The book made concepts like spacetime, black holes, the Big Bang, and the nature of time accessible to a general audience with almost no mathematics.
The book cemented Hawking's status as both the world's most famous scientist and as a symbol of the triumph of mind over physical adversity. His witty, clear prose and his willingness to engage with the biggest questions in science and philosophy — the existence of God, the nature of time, the origin of the universe — resonated with readers far beyond the physics community.
Esplora Hawking's full intellectual legacy at his profile on Geniuses.Club.