The good news: the Milky Way could be abundant in intelligent life forms. The bad news: we may never hear from them.
At last week's meeting of the American Association for the Advancement of Science (AAAS) in San Diego, California's top SETI scientists were asked how long it will be before we receive an interstellar greeting from an extraterrestrial civilization. Their estimates range from "minus 10 years" (it should have happened by now!) to 250 years into the future.
The most balanced guess in my opinion came from Seth Shostak: 25 years. This is based on the fact that the number of stars being reached in SETI optical and radio searches is growing exponentially with improved telescopes, signal processing, and detection strategies. This means that within the next two years as many stars will have been surveyed as have been in the past 50 years since the birth of modern SETI observations.
The SETI exponential slope can't steeply rise indefinitely. Statistically, your chances for success happen near the top of the slope, when it begins to flatten out. "If we don't have a detection by the year 2035 then something is wrong with our fundamental assumptions," says Shostak.
The Rare Earth hypothesis proponents say we'll never hear anything because the emergence of intelligence is an evolutionary crap shoot. We are likely to be the only sentient life in the galaxy.
If you find intelligent life once, it's a miracle; twice, and it's a statistic. There is accumulating evidence that intelligent life has appeared twice on the Earth. At the same AAAS meeting the case was made that dolphins, whales and other cetaceans are so intelligent, they should be legally safeguarded as "persons" too.
Physiologically, dolphins have a brain architecture and brain mass-to-body mass ratio that is closer to that of humans than for any other species on Earth. Many years of experiments on captive dolphins show that they are self-aware, have a sense of self-identity, do detailed problem solving, interpret symbolic language, and exhibit empathy. Dolphins form complex societies with groups segregated by sex and age, alliances, and conduct long-term nurturing of the young.
Unlike apes, cetaceans are far removed from humans in evolutionary time. Therefore human and dolphin brains have emerged independently and evolved very differently. Human and cetacean species have completely different cognitive abilities: one fine-tuned for surface dwelling, the other for life in the water.
If we accept the premise that two intelligent species arose independently on Earth, the inescapable conclusion is that evolution has tried, minimally, two pathways to intelligent life. This would argue that self-aware beings are a common evolutionary watershed on planets capable of sustaining multi-celled lifeforms for hundreds of millions of years.
Last week's tragic death of an Orlando Sea World veteran trainer by a killer whale underscores that we shouldn't subjugate the other intelligent creatures we share this planet with. The killer whale was captured in the wild, taken from its family pod, and housed in an enclosure as claustrophobic as putting a goldfish in a shot glass.
True, most dolphins and whales are bred in captivity and have contributed to our knowledge in a number of behavior experiments. But the price is premature death, self-mutilation, self-destructive habits, neurotic repetitive movements and aggression.
What is not compelling is the argument forwarded by Jack Hanna, Director Emeritus of the Columbus Zoo, in a recent CNN interview. He said that tens of millions of people are "educated" about sea life by watching dolphins and whales jump through hoops in the multi-billion dollar sea park and aquarium industry. If you want your kids to have a true appreciation of these creatures, then go on a whale-watching expedition in Vancouver Sound, and not to a pricey amusement park.
We have the hubris that because we can make guns, cars and refrigerators we are the superior species on Earth. But the reality might be that tool-making societies are inherently unstable and destroy themselves in a tiny fraction of geologic time.
Non-technological beings simply do not have a mastery of matter and energy to engage in the global destruction of their habitat. They cannot tip the checks and balances in a biosphere but instead live in harmony, as romanticized in the blockbuster sci-fi film Avatar.