All humans, plants, animals and the Earth itself are built from the ashes left behind after the death of stars. We are fashioned from the nuclear waste that remains after massive stellar explosions, according to the UK's astronomer royal.
Prof Sir Martin Rees also suggested that, although very small compared to the rest of the universe, the Earth may be very important in cosmological terms as the place where sentient life originated before being dispersed to other planets.
One of Britain's most prominent researchers and cosmologists, Sir Martin yesterday gave a compelling talk on some of the great philosophical questions on the origins of life, time and the future of the universe, themes explored in his new book, Our Cosmic Habitat. He was delivering the inaugural McCrea lecture at the Royal Irish Academy in Dublin entitled "Understanding the beginning and the end".
"Every atom we are made of has an origin that can be traced back to before the solar system was formed," he said to a full house at the academy's headquarters on Dawson Street. "We are literally the ashes of dead stars or the nuclear waste left behind."
Sir Martin discussed the beginning of time after the Big Bang and the origins of the sun, our nearest star. It formed 4.5 billion years ago and will live as it is for another five or six billion years, he said. While we are familiar with the time-spans in Darwinian evolution, cosmological evolution is a much more protracted affair.
"The thing we learn from astronomy is we shouldn't think of a culmination," he said. "The universe may have an infinite life ahead of it."
To help his audience he equated the lifetime of the sun to a walk from New York City across the US to California. In this case each step would take 2,000 years. All recorded human history would represent just four or five steps of the total so far and these would have been taken while crossing Kansas, "not the high point of the journey". Earlier yesterday Sir Martin met the President, Mrs McAleese, at Áras an Uachtaráin.
