Australian scientists have paid tribute to physicist Stephen Hawking as a legendary inspiration and great scientific communicator following his death in England aged 76.
Professor Hawking was responsible for numerous advances in cosmology and physics and was one of the most well-known scientists of the past century.
The writer of A Brief History of Time was diagnosed with motor neurone disease in 1963 at the age of 21 and was only expected to live another two years.
But the disease progressed more slowly than anticipated, enabling him to continue his research.
Dr Brad Tucker, a research fellow and manager at Mount Stromlo Observatory at the Australian National University, said Prof Hawking was not only a leader in cosmology and astrophysics, but pushed fellow scientists to challenge themselves and the unknown.
"He leaves having inspired many of us and having helped us to tackle the big questions that humans have asked for centuries," Dr Tucker said in a statement on Wednesday.
Associate Professor Alan Duffy, a research fellow in the Centre for Astrophysics and Supercomputing and Lead Scientist of The Royal Institution of Australia, said Prof Hawking inspired him to become a scientist and a communicator of science.
"His work as a cosmologist and discoveries in black hole physics were legendary.
"His best-known prediction, named by the community as Hawking Radiation, transformed black holes from inescapable gravitational prisons into objects that instead shrink and fade away over time," Prof Duffy said.
"He was also wonderfully funny with a fantastic media savviness that propelled him into A-list celebrity stardom as few other scientists before."
Prof Duffy said Prof Hawking's illness made his achievements "near-superhuman".
"How he manipulated Einstein's equations in his mind when he could no longer hold a pen I can't even begin to imagine."
Paul Haese, president of the Astronomical Society of South Australia, said Prof Hawking had "a brilliant mind who gave so much both physically and conceptually".
"He will be missed amongst the amateur astronomical community."