R = Q x δ
Astronomer Ivan Almar suggests the brief formula above might help scientists decide how to tell the world that we are not alone in the universe. It’s a mathematical way of saying that the risk (R) associated with a possible discovery of extraterrestrial life is a combination of the danger of the life if it does exist (Q, which itself is the sum of several other factors such as what sort of life it is and how far it is away) and how likely the claim of its existence is to be true (δ).
It’s not the first time Almar has tried to mathematically quantify the search for extraterrestrial life. He’s one of the authors of the so-called Rio Scale , a formula adopted by the International Academy of Astronautics to calculate the impact of publicly announcing that E. T. exists.
Almar presented his latest formula this week at the Royal Society in London as part of a 2-day conference  grandly entitled “The detection of extra-terrestrial life and the consequences for science and society”. But one audience member suggested such a calculation was a waste of time because the public likely wouldn’t accept that they needn’t worry about a claimed detection of alien life simply because a formula indicated a risk of only three out of 10.
Such debates mixing science and speculation dominated the unusual Royal Society event.
Topics ranged from the political (Vienna-based astrophysicict Mazlan Othman, who may have the best business card in the world as she is the director of the United Nations Office for Outer Space Affairs, discussed her duties and called for an international protocol on dealing with the possible detection of life in outer space) to the philosophical (theologian Ted Peters of University of California, Berkeley, discussed the significance of the discovery of extra-terrestrial life for the world’s religions) to the positively apocalyptic (astrophysicist Frank Drake, the original champion of the search for extra-terrestrial intelligence efforts, pondered whether a technologically advanced civilization would inevitably use its power to annihilate itself.).
Two of the most provocative speeches came from planetary scientist Christopher McKay of NASA Ames Research Center and physicist Paul Davies of Arizona State University. McKay suggested that the Viking Mars lander may have inadvertently oxidized any evidence of life it its samples of Martian soil, proposed an expedition to gather samples of water from the Saturn moon Enceladus, and offered a child-friendly analogy for how alien life might differ from life on Earth: “I could build a table out of Lincoln logs and you could build a table out of Legos: At the macroscopic scale they’d be the same—they’d both be tables; at the microscopic scale they’d be the same—they’d both be built from carbon atoms. In the middle, things would be different: one would be plastic and one would be wood. I think at the macroscopic scale any life we discover will have evolved by Darwinian evolution; at the microscopic scale it will be based on carbon chemistry. In the middle, at the level of biochemistry, I think there’s room for variation.”
Davies suggested that the “cosmic imperative,” the idea that, given favorable conditions, life would be bound to emerge, could be tested on Earth by looking for organisms unrelated to the currently known “tree of life.” He also speculated on how such a “shadow biosphere” might differ from ours and described efforts to find such organisms.
And the most entertaining? No contest. Paleobiologist Simon Conway Morris of the University of Cambridge in the United Kingdom began by suggesting that astrobiology might be considered “the study of that which does not exist.” He then went on to explain that survival in extreme circumstances can best be tested in dung heaps (“this may be why this field doesn’t attract many brilliant young scientists”) before suggesting that Darwinian evolution would inevitably favor organisms lacking altruism towards other species. His conclusion: “If the phone rings, whatever you do, do not pick it up!”