For many years our place in the universe was the subject of theologians and philosophers - not scientists.
But in 1960 one man changed all that. Dr Frank Drake was one of the leading lights in the new science of Radio Astronomy when he did something that was not only revolutionary but could have cost him his career. Working at the National Radio Astronomy Observatory in Greenback in Virginia he pointed one of their brand new 2 5metre radio telescopes at a star called Tau Ceti 12 light years from earth.
His mission? To listen for signs of extra terrestrial intelligence – quite literally listening for ET talking.
Although project Ozma, as he called it, resulted in silence, it did result in one of the most seminal equations in the history of science - the Drake Equation.
Examining seven key elements necessary for extra terrestrial intelligence to exist from the formation of stars to the likely length a given intelligent civilisation may survive. When Frank and his colleagues entered the figures, the equation suggested there were a staggering 50,000 civilisations capable of communicating across the galaxy at this very moment.
But, in the 50 years of listening that has followed, not one single bleep has been heard from ET. So were Drake and his followers wrong? Is there no life form out there capable of communicating? No one is really sure as the search itself is so difficult. Drake's own calculations are that we’d have to scan the entire radio spectrum of 1,0000,000 stars to be sure of contact.
But what the equation and the search for life has done is focus science on some of the other questions about life in the universe – specifically biogenesis, the development of multi-cellular life and the development of intelligence itself.
The answers to those questions are increasingly suggesting that, far from being a one off, life may not only be common in the universe but, once started, will lead inevitably towards intelligent life.
To find out how the Drakes Equation has influenced scientists around the world, Bang Goes The Theory’s Dallas Campbell goes on a worldwide journey to meet the men and women who have dedicated their lives to focusing on different aspects of the equation – finding out, as he travels, just how the equation has changed our view of life the universe and our place within it.
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In this series of articles originally published in July 2001 to coincide with Truth Will Out, our panel of experts discuss their views on the... Read more : OU on the BBC: Truth Will Out - There is intelligent life elsewhere in the universe
ET, life and the universe
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Is there intelligent life out there? Professor Russell Stannard examines various possibilities, and our chances of ever finding out about them. Read more : ET, life and the universe
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WHY NOT SEARCH FOR ET CLOSER TO HOME?
After 50 years searching for life as a "needle in a haystack" across the universe with no results, why not search closer to home in our own Solar System? This would be the equivalent of searching for the "elephant in the room". Radio SETI would not be required, as optical, UV, IR, visible and radar technologies are more than sufficient to scan the planets and moons of the Solar System to search for extra terrestrial artifacts. This is Planetary SETI. See http://spsr.utsi.edu/ 14
There are many enigmatic anomalous features on the Moon and Mars. We need to do the research and the science. Shame there was no mention in the BBC programme by Dallas! Dare you to do another programme covering planetary SETI.
Also see Discovery article 'SETI to scour the Moon', quoting Paul Davies of Arizona State Uni who was featured several times in the BBC programme.
http://news.discovery.com/space/seti-to-scour-the-moon-for-alien-tech-11...
The Drake Equation - Why the silence?
If the emergence of intelligent life was somehow synchronised across the universe then the only intelligent life with the capacity to communicate with us would have been doing so for only the last fifty years or so (age of SETI). Since the speed of radio waves like all electromagnetic waves is approximately 180,000 mps, we would only be able to listen to extra-terrestrial civilisations who live within a radius of approx 50 light years. As our human civilisation is possibly one of the oldest cosmologically we may be the first or very nearly the first to attempt communication with extra-terrestrials. We know that our sun is a star which has been reborn from fragments of other stars which have provided the heavy elements essential for the emergence of intelligent life. Maybe we should rewrite the Drake equation with this in mind?
The Drake Equation - Time
With L at 10,000 years, by the time we received any signal, the intelligent life sending the signal would not exist. As the diameter of the Milky Way is 100,000 light years, and N for the Milky Way is 10, each planet with intelligent life must be at least 10,000 light years apart. By the time we received any signal the life form would have drastically altered, even if L was a billion. Assuming intelligent life is still about, where will it be in 10,000 years, a million, or even a billion. Think big.
In the short term the best I can envisage is hearing a history from another life form of the processes it is going through, so we might profit from the knowledge. There's hope.