Stonehenge is a prehistoric monument and UNESCO World Heritage site located in Wiltshire, southern England. Archaeologists believe it was built in three stages anywhere between 3000 BC to 2000 BC. The monument is constructed of Bluestone, Sarsen, Welsh Sandstone which stand in a ring. It is not known why or how Stonehenge was constructed - some believe it was a place of healing while others claim it is a burial place. It attracts millions of visitors each year.
HK's date with top scientist
A scientist whose dating technique is offering researchers a better understanding of the evolution of life on Earth, is to give a series of lectures in Hong Kong.
Professor Derek York, a geophysicist from the University of Toronto, has in the past decade pioneered the development of a precision technique for dating rocks.
Now he is helping researchers put together pieces of the puzzle on how the world began with the help of a laser-based technique.
His accomplishments include dating rocks - including those from the moon - to re-dating some of the oldest human fossils discovered on Earth.
Professor York's scientific curiosity and versatility have won him recognition in areas including statistical research.
He was awarded the Bancroft Award of the Royal Society of Canada in 1986 for making science accessible to the average reader through more than 60 articles.
A joint publication by his laboratory in Toronto and the University of California in Berkeley, on the discovery and dating of a 2.33 million- year-old jaw unearthed in Ethiopia, was ranked among the top 10 science stories of 1996 by the Time magazine.
Professor York was the brains behind a documentary titled Chaos, Science and the Unexpected , produced by the Canadian Broadcasting Corporation with the use of computer- generated fractal images.
The film won him an award for creativity in 1992 at the International Science and Technology Film and Video Festival in Tokyo.
Professor York has summarised his reflections on various mysteries of the universe in his book, Lost Time.
Its simple, witty and humorous style makes it a great read for all ages.
Professor York will give lectures based on his book every Wednesday for the next three weeks at the University of Hong Kong.
The lectures will cover everything from our oldest known ancestors to dinosaurs and meteorites.
Professor York told Young Post that his fascination with time and its scale inspired him to explore man's survival-driven ingenuity to measure time as far as 5,000 years ago.
'For over a third of a century my life has been spent on lost time,' he said.
'In 1957 the head of the Department of Geology at Oxford invited me to join scientists setting up radioactive dating techniques in his laboratory.
'Having just graduated in physics, this seemed like a huge step into the unknown.
'I accepted his invitation and have since been in pursuit of thousands of millions of years,' he said.
His book takes the reader on a time odyssey from the pyramids of Egypt through Stonehenge and the North China plain to the Ethiopian desert.