London - Sir Fred Hoyle, the astronomer who coined the term "Big Bang" but never accepted that theory for the origin of the universe, has died at age 86.
Hoyle died on Monday in Bournemouth, said his family. The cause of death was not announced.
He became Britain's best-known astronomer in 1950 with his broadcast lectures on The Nature of the Universe, and he recalled using "Big Bang" for the first time in the last of those talks.
But over time, his belief in a "steady state" universe was shared by fewer and fewer scientists because of new discoveries.
Hoyle continued to robustly defend his view, and last year published A Different Approach to Cosmology, co-authored by Geoffrey Burbidge and Jayant V Narlikar.
He graduated from Cambridge University, and was professor of astronomy there from 1958 to 1972.
He was a staff member of the Mount Wilson and Palomar Observatories in 1957-62, visiting professors at California Institute of Technology in 1953 and 1954, and professor of astronomy at Cornell University in 1972-78.
Working with Hermann Bondi and Thomas Gold, Hoyle proposed the steady state theory in the 1940s, arguing that the universe developed in a process of continuous growth. "Every cluster of galaxies, every star, every atom had a beginning, but the universe itself did not," Hoyle contended.
Observations by radio astronomy in the 1950s demonstrated that the universe was expanding faster than Hoyle's theory predicted, giving credence to the view that the universe began in an explosion of incredibly dense matter - the theory Hoyle called the "big bang".
"He coined that phrase in fact as a denigration for the conventional wisdom," said Hoyle's associate, Professor Chandra Wickramasinghe of University College, Wales.
"And it was his belief, and it is also my belief, that the standard 'Big Bang' theory which says that everything began at a definite moment in time and that there was nothing before that, this has to be essentially wrong, and that the universe has an infinite age and an infinite extent in space," said Wickramasinghe on Wednesday on British Broadcasting radio.
In the 1950s, Hoyle worked with Fulbright scholar William Fowler and Geoffrey and Margaret Burbidge to demonstrate that chemical elements heavier than helium were the product of nuclear reactions inside stars.
They published Synthesis of the Elements in Stars in 1957.
To Hoyle's annoyance, Fowler, then at California Institute of Technology, shared the Nobel Prize for physics in 1983 with Subrahmanyan Chandrasekhar of the University of Chicago for their work on the creation of chemical elements.
Fowler, in his autobiography for the prize, credited Hoyle as one of the great influences in his life.
Hoyle's contribution to that work was honoured in 1997, when he shared the Crafoord Prize of the Royal Swedish Academy of Sciences with Edwin Salpetre of Cornell Univeristy.
With Wickramasinghe, Hoyle promoted the theory that life - and some diseases including Aids - reached earth from space.
Their publications included Diseases from Space (1979), and Space Travellers: The Origins of Life (1980).
Hoyle also wrote science fiction, including The Black Cloud (1957) about an intelligent cloud around the sun which caused an ice age, and A for Andromeda (1962) about aliens instructing human on building a destructive machine.
He is survived by his wife, a son and a daughter.
Funeral arrangements were not immediately announced.
- Sapa-AP