

No? Let us see …

The Copernican Principle, that Earth is not an unusual planet, is asserted as everyday science even when it anchors unlikely speculation. New Scientist informed us in 2008 that

There’s nothing special about the Sun that makes it more likely than other stars to host life, a new study shows. The finding adds weight to the idea that alien life should be common throughout the universe.

Are doubts “anti-science”? Certainly, faith is urged on us as a duty. We read, “Finding planets outside our solar system that can sustain life should be made a top priority, say Australian astronomers,” because “Life, by managing its own environment, makes a planet habitable. It has produced adaptive features as a result of Darwinian evolution to live in colder and warmer environments.”

And the essentially religious character of the quest is unmistakable. When astronomers located a small rocky planet outside our solar system (Kepler 10b), a planet that probably could not harbor life due to its orbit, the discovery was hailed by Berkeley’s Geoffrey Marcy as “among the most profound in human history.” Why? Natalie Batalha, a San Jose State University professor of astrophysics, explains,

We want to know if we’re alone in the galaxy, simply put — and this is one link in the chain toward getting to that objective.

Actually, Batalha does not want to know if we are alone. She wants to receive and offer assurance that we are not.

In 1961, astronomer Frank Drake proposed the Drake Equation to estimate the probability of life on other planets, with a view to finding intelligent life and advanced civilizations. With few hard numbers to plug in, the user can assign preferred values to estimate the probabilities. His colleague, astronomy popularizer Carl Sagan (1934-1996), who likewise believed that we live in a crowded universe, riffed off the Copernican Principle in his sci-fi bestseller and 1997 extraterrestrials movie, Contact.

NASA was interested in ETs in the 1970s, especially after SETI (Search for Extraterrestrial Intelligence) found the contested 1972 Wow! Signal. But the space agency lost interest in the 1990s. Aliens were just not returning our calls.

Absent evidence, speculations clash. Paleontologist Simon Conway Morris argues that aliens, if they exist, must be a lot like us. On the contrary, say others, they needn’t be like us at all. In any event, we may not be able to communicate with them. Fred Hoyle advanced the idea, in a novel, that they could be a black cloud of gas, floating through space.1 The Copernican principle rises above all such trivia by responding: They just must be out there. For example, Discover science writer Ian O’Neill urges the question,

There’s at least 50 billion worlds, which have fostered the development of basic lifeforms? How many have allowed advanced civilizations to evolve?

Hard to say, with none in sight. As a curious aside, astronomers didn’t always welcome contact with aliens; quite the opposite. In 1967, when Cambridge astronomers thought they had heard an intelligent signal from another galaxy, Martin Ryle, Britain’s future astronomer royal, told them that if so, they should dismantle their new telescope immediately and tell no one, in case the aliens were hostile. Now, however, bureaucrats are developing a protocol in case they do contact us.

Meanwhile, there is no shortage of explanations as to why they have not. They are said to be hiding from us in order to survive. Maybe the space aliens are hiding on Earth, in junk DNA, as famous astrophysicist Paul Davies has suggested. Former nanotechnology watchdog Mike Treder theorizes that the aliens have run into “a cosmic roadblock that either destroys them or prevents their expansion beyond a small radius.” Or, some mathematicians suggest, maybe ET is just avoiding us. Another researcher warns that the aliens may destroy us because of our greenhouse gas emissions.

Or there is not enough time for Darwinian evolution to cause them to evolve. One thread winding through the new cosmic story is Darwinian evolution. It is not incidental; as biology’s contribution to the Copernican Principle, it is integral.

In this wilderness of unknowns, how do we decide what’s modern science and what’s modern folklore? Does ET vs. Bigfoot come down merely to the number and type of letters after one’s name?

In other science news, the Mars Rover still hasn’t detected methane (a possible indicator of life). This year NASA did discover a new microbe … in its own clean room, used for building spacecraft. The (earthly) bacterium adapts to a “harsh, nutrient-poor environment,” and had thus gone unnoticed in the countless throng a bucket of soil provides. Life is found everywhere we look on Earth but so far nowhere else. Meanwhile, the University of Georgia offers a course, “Extraterrestrial Intelligence: Where Are They,” to equip the student to “act as a main intellectual figure in any future ET dialogues they may have in the future.”

As always, the will to believe drives conjury. What happens when doubt sets in? Ah now, that would be telling …

Notes:

(1) Fred Hoyle, The Black Cloud (London: Heinemann, 1957).

Image: Sunlit Side of the Planet Mercury; NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.