#### Stephen Hawking (University of Cambridge Professor) – Remarks at Cambridge Union (Mar 2018)

#### Chapters

#### Abstract

Stephen Hawking: The Journey from Birth to Cosmic Legacies

The Early Years and Foundations of Genius

Stephen Hawking, born on January 8, 1942, in Oxford, England, began his life under extraordinary circumstances. During World War II, his parents chose Oxford as his birthplace due to a strategic decision between Germany and Britain to protect the city from bombing. Hawking’s early education at Byron House School marked the beginning of his intellectual journey, where he excelled in science and engaged in deep conversations about the universe with his peers. His family’s move to St. Albans exposed young Hawking to an environment that nurtured his burgeoning interests.

The Cambridge Chapter and a Turn of Fate

Hawking initially pursued natural sciences at Oxford due to the absence of a mathematics fellowship. The laid-back academic culture he initially embraced changed dramatically following his diagnosis with a severe motor neuron disease. This turning point brought a newfound appreciation for life and a fierce determination to pursue his goals. During his travels to Iran, Hawking experienced an earthquake, further fueling his resolve to make the most of life. Overcoming illness, Hawking returned to Cambridge to begin his groundbreaking work.

A Cosmic Odyssey: Black Holes and the Universe

Hawking’s arrival at Cambridge in 1962 marked the beginning of his contributions to cosmology and black hole physics. Initially focused on the bouncing universe theory, he challenged existing ideas and paved the way for later breakthroughs. His discovery of the area theorem for black holes and contributions to the no-hair theorems were monumental, reshaping our understanding of these cosmic phenomena. Hawking’s exploration of the black hole information paradox further solidified his status as a luminary in theoretical physics. His collaboration with Malcolm Perry and Andy Strominger focused on understanding how information exits black holes, utilizing the concept of super rotation charges to explain information retrieval.__Black Holes, Hawking Radiation, and the Information Paradox__

Hawking applied similar arguments to the universe’s expansion, proving that it had a beginning, contradicting Lifshitz and Kaladnikov’s theories. Hawking’s Eureka moment came in 1970 when he realized the area theorem: the event horizon’s surface area always increases with additional matter or radiation entering a black hole. The area theorem and no-hair theorems were later confirmed by LIGO’s gravitational wave detections of black hole mergers.

Hawking’s next goal was to combine general relativity with quantum theory, but the singularity problem seemed insurmountable. As a warm-up, he investigated particle and field behavior near black holes, leading to his discovery of Hawking radiation. His calculations surprisingly showed that black holes emitted radiation, with the emission rate proportional to the horizon’s area. This led to the famous formula expressing black hole entropy in terms of the horizon’s area and fundamental constants.

Hawking eventually proposed that information is not lost in black holes but is not returned in a useful way, similar to burning an encyclopedia. However, this resolution was not without controversy, and Hawking himself admitted that initially believing information was destroyed in black holes was his biggest blunder in science.

Pioneering Contributions and Lasting Legacy

Hawking’s journey in cosmology and black hole information further solidified his status as a luminary in theoretical physics. His collaboration with Malcolm Perry and Andy Strominger on super rotation charges to understand how information exits black holes represented his relentless pursuit of knowledge. His shift towards inflationary cosmology in the 1970s, particularly his ideas on the origin of cosmic structures arising from quantum effects during inflation, demonstrated his versatility and foresight. Hawking’s emphasis on scientific communication and public engagement, most notably through his book “A Brief History of Time,” highlighted his dedication to making complex scientific ideas accessible.__Hawking’s Life and Work in Cosmology__

Hawking’s interest in cosmology resurged due to suggestions of an early universe inflationary expansion period with exponentially increasing size. In 1982, he proposed that quantum effects during inflation could create seeds for structures in our universe, similar to radiation from a black hole horizon. The 1982 Cambridge workshop he organized established the foundation for the current understanding of inflation, including density fluctuations leading to galaxy formation.

Hawking and Hartle developed the Euclidean approach to cosmology, where the universe’s quantum wave function is expressed as a Feynman sum over imaginary-time histories. They proposed the no boundary condition, where the universe has no boundary, avoiding the issue of time’s beginning by treating it as a spatial dimension. The universe spontaneously emerges from nothing, starting smooth with tiny departures predicted by inflation, leading to the observed structures.

Hawking’s popular science book “A Brief History of Time” and his advocacy for public engagement in science earned him widespread recognition. He encouraged public interest in space exploration for the future of humanity.

Planned experiments will map billions of galaxies and enhance our understanding of the universe using supercomputers like Cosmos. Gravitational waves may offer a glimpse into the Big Bang’s core. Hawking reflects on the progress made in understanding the universe and encourages curiosity, perseverance, and looking beyond our immediate surroundings.

Conclusion

Stephen Hawking’s life, marked by extraordinary challenges and unparalleled achievements, leaves a legacy that transcends the fields of science. His journey from a curious child in Oxford to a renowned physicist who revolutionized our understanding of the universe serves as a testament to the power of human perseverance and the endless pursuit of knowledge. His message of curiosity and exploration continues to inspire future generations, cementing his place as one of the most influential scientists in history.

Notes by: MythicNeutron