Dr. Andrew Siemion is director of the Berkeley SETI Research Institute at the University of California in Berkeley and a leader in the new Breakthrough Listen initiative. SETI is the "Search for Extraterrestrial Intelligence" and Breakthrough Listen searches by scanning the skies for evidence of alien technology.

Siemion was in Huntsville this week to speak to the Tennessee Valley Interstellar Workshop and give a "Pass The Torch" lecture at the U.S. Space & Rocket Center. What follows is a condensed transcript of the audience Q&A at the space center.

The conversation begins with a question about the "Drake Equation" - a calculation of how many intelligent civilizations might exist in our Milky Way galaxy. That number is defined in the equation as "N."

Q: Will you tell us your personal estimate of 'N'?

A: That's the hardest question we ever get asked. N's actually not a completely accurate way of thinking about this because, remember, it depends on how many civilizations exist right now. I think that number is, maybe, a few 10's.

But I'm an optimist. We really have no idea. That's why we do the experiment. The answer might be zero, it might be a thousand, it might be a million. We know that there's lots of opportunity for life to arise, but we also know the probability for life to emerge is small. We don't see any life on any other bodies in our own solar system. We don't see ancient forests on Mars, any kind of microbial life anywhere. So life is relatively rare.

Q: Here on Earth, when a more advanced civilization discovers another civilization, it's usually followed by conquest, sometimes complete destruction. Would we be better off if we did not try to attract other life from other planets?

A: That's a great question. This is a very controversial topic. There's actually an entire field that's related to SETI called METI, or Messaging to Extraterrrestrial Intelligence. There are people on both sides of that debate. Some people think that we should try to contact other civilizations, some think we should not.

It's probably important I should point out, again, in case it was not completely clear, that what we do in our group is simply listen. We don't speak.

I'm not ready to say it's a good idea for someone to unilaterally (reach out to make contact). But it's also true that we're already leaking quite a lot of radiation off from this planet, and a civilization maybe only a few thousand years advanced from ours, if they go the way we did in terms of our tech progression, could very easily detect those signals.

So, in some sense, if you wanted to talk to a distant civilization, you just have to pick up your Ham radio or call in to your local AM radio show and say what you want to say, and eventually they'll get it - at the speed of light.

Q: Where do you get your funding? Do you feel pretty set to finish what you're trying to accomplish?

A: SETI has been around since about 1960. Up until about 1993, it received increasing government support from NASA. NASA had a SETI program that was growing to about $10M a year. In 1993 the funding was terminated by an act of Congress. Since then, it's received quite a lot of support from the private sector.

Q: What can a regular person do to help the search for SETI?

A: There are many things. One of the things we're trying to do is open up the search to anyone, go to our website, social media, asking us a question, engaging in the work.

Q: (Assume) advanced societies would create some form of computational system that is going to replace them, then those technological entities are going to enjoy much longer longevity than biological life forms and will also require probably a lot of energy. Are you aiming at high-energy objects, specifically, like the center of a galaxy or quasars, where a lot of energy might be found?

Q: That's actually my personal favorite idea about what to look for. The searches we do are agnostic to the form of life we're looking at. So, we could detect biological life that produced technology or some kind of silicon-based, artificially intelligent life just the same, as long as they're using some kind of communication technology that we would be sensitive to.

Q: Suppose in your search you find what you're looking for, unmistakable signs of a technological civilization on the nearest possible candidate star. What happens now in society and your organization?

A: Well, I've been promised unlimited funding (laughter). That would be the first thing. Usually, my answer to this question is our most important responsibility is to confirm the signal. Assuming that it has been confirmed, I think we would look for more. The only thing stranger than there being just one example of intelligent life in the universe would be that there would be only two. (We would) build larger telescopes to learn more about the signal.

As far as what happens with society, that's hard to say. Seth Shostak is another very well-known person in this field, and he's fond of saying, and I'm fond of repeating, that something like 50 percent of people already believe that intelligent aliens are visiting the Earth, so maybe it wouldn't be that much of a surprise to a lot of people. In any event, it will take some time for that to completely sink in.

Q: Do you have a protocol in place, if you get an unambiguous, say, binary representation of pi repeated from out in space, for the release of that information?

A: There is such a program, and there's actually a group tasked with post-detection. It hasn't had a lot of activity in the last decade or so, and I sometimes joke that I don't have their number. And I don't. Our most important responsibility as scientists doing the search is to confirm the signal and make sure that it's bonafide, that we're not being fooled. And that whole process would take some time. We're committed to transparency. We would release as much information as we have at the time.

(Siemion said his organization would immediately contact large telescopes in the hemisphere where the signal was received and ask them to scan for more signals. Information could leak, he said).

Q: What do you think discovery of any type of life in our solar system would do to the search for intelligent life? Help or hurt?

A: I think it would absolutely would help. I'm a huge fan of all searches for life. The search for life has been characterized as a three-way horse rate between the (on site) investigations, the exoplanet atmospheres, and what we do in SETI. I think if I were to place my bets on one of those horses, it would be on searches within our own solar system. I think Europa and Enceladus are both incredibly exciting places to look for life, And I think it would be a huge scientific discovery. Maybe not as big as intelligent life? But it would be certainly the biggest discovery that had ever been made in the history of science. I would love to see that in my lifetime.