Professor Stephen Hawking and his wife Elaine pose for photos before his 60th Birthday Symposium on January 11 at the University of Cambridge

THEY arrived armed with stories about a man and theories about the universe. They talked of a genius and friendship. And they celebrated a 60th birthday that some called "a miracle."

During a week of parties and lectures, Cambridge University cosmologist Stephen Hawking was complimented by colleagues as an original thinker, cherished friend, and a strong-willed survivor who has lived for decades after being diagnosed with amyotrophic lateral sclerosis, known as Lou Gehrig's Disease. The disease is generally terminal within a few years.

The birthday week celebration ended last Friday with cheers, laughter and a stirring rendition of "Happy Birthday" as 400 friends and colleagues, many from labs and college campuses around the world, gathered for one last set of lectures on "the future of theoretical physics and cosmology," topped off by a speech from Hawking.

Wearing a red rose on his collar, grabbing a control to manoeuvre his wheelchair and speaking with a computer-generated voice, Hawking tried to sum up his career in a speech entitled "60 Years in a Nutshell."

It turns out he almost didn't make it to the festivities surrounding his 60th birthday, which was last Tuesday.

On December 28, Hawking was speeding down a Cambridge lane to meet his wife, Elaine, at an optician's office when he crashed his wheelchair into a wall and fell to the ground, breaking his right leg. Hawking was taken to a local hospital where his leg was pinned and plated to stabilize the area and reduce the pain, his wife said.

He was bruised and broken, but apparently his humour was still intact.

"It was nearly 59.97 years in a nutshell," Hawking said. "I had an argument with a wall a few days after Christmas, and the wall won."

In his speech, he talked of his career, of arriving at Cambridge in 1962 to work with esteemed astronomer Fred Hoyle — only to discover the scientist was booked up. He was assigned to work with another equally compelling teacher, Dennis Sciama.

At Cambridge, Hawking embarked on a life of grappling with the basic laws of the universe, making ground-breaking discoveries on black holes and trying to determine the origin of the universe.

Only later in his career did Hawking reach a wider audience with the publication of the bestselling book, "A Brief History of Time."

"It has been a glorious time to be alive and doing research in theoretical physics," he said. "Our picture of the universe has changed a great deal in the last 40 years, and I'm happy if I have made a small contribution. I want to share my excitement and enthusiasm."

Hawking's life is a tale of genius and fortitude. It was 38 years ago that he was diagnosed with a motor neurone disease and, as he noted on Friday, he was "given to expect I didn't have long enough to finish my PhD.

"Then suddenly, toward the end of my second year of research, things picked up. My disease wasn't progressing much, and my work all fell into place, and I began to get somewhere."

Turning 60 seemed to be reaching a summit for Hawking, who has two sons and a daughter.

"He has been very excited about it," said Hawking's younger son, Tim, 22, who is studying French and Spanish at Exeter University. "Sixty years — he has done a good job."