My short piece on the number of civilizations that may exist in the universe (January Astronomy, p. 9) continues to provoke a virtual flood of responses, mostly by email. I thank each and every one of you for sharing your thoughts with me, and I have read them all. I continue to be amazed at the superb thoughtfulness and clarity with which you have expressed your thoughts and feelings. Here are some more samples:

Some of you have pretty straightforward ideas. “I think if there’s life out there, we will never know it,” says Doug Secker. “I believe there’s nothing wrong with the possibility that we’re the only intelligent life in the universe.”

According to Rodrigo Kaiser, “I’m sure there are no planets in the universe with life except ours, let alone intelligent life. Civilizations? Just ours.”

Darin Bartosch takes the opposite view. “I believe life exists on many of the planets we are rapidly discovering,” he says. But he thinks most life out there will be primitive. “I believe we will discover primitive life before finding intelligent civilizations. The search is certainly worthwhile. Maybe, if my most heartfelt desires are met, I will one day read about the newly discovered extraterrestrial life in Astronomy magazine.”

Similarly, Mel Mohr feels “the odds are just too overwhelming to prohibit civilizations out there. Is there an Earth-like planet in the right zone for development around each star? Probably not even close to one in 1,000, or more likely 10,000. That reduces the numbers to 5 billion billion stars with a solar system like ours. Given the time our civilization took to form, the odds are further reduced to find a civilization in the same state of development as ours. There may have been many civilizations that are now long gone. Maybe there are 650 million stars in the cosmos with a civilization about like ours!”

John Lonergan says “I’m certain that beings are out there asking the same questions we are. It’s like two lonely people on Earth asking themselves, ‘Is there someone out there for me?’ Yet they may never have the chance to meet one another, but destiny somehow matches them with the one they’re supposed to be with. I believe this is a lot like the human story and other civilizations in the cosmos — we are destined to come together, and the only real questions are how, when, and where.”

The story from Don Cruikshank is, “I do not believe our planet Earth is unique in the universe and that we’re the only place where intelligent life has evolved. There is most certainly organic life out there, and the odds are that intelligent life resides in other places in the cosmos. And by intelligent life I mean beings with the ability to think, to understand, to have an awareness of themselves, to communicate and reason with one another, to learn and remember, and to plan and solve problems.”

I’ll continue sharing more of these over the next few days.