Talk About Aliens With Harvard’s Chairman of the Department of Astronomy

Image courtesy of Clive Grainger/CfA Public Affairs

If aliens were to ever travel millions of light years and land their spaceships here on Earth, the first thing Abraham “Avi” Loeb’s wife wants the Harvard professor to do is ask them kindly to keep off of her lawn.

“My wife actually jokes that, when I talk about this, if they ever come to our home and ask me to join them, then it’s OK with her if I want to—I’m most welcome to join them—but I must make sure that they leave the car keys with her, and not to ruin the lawn in our backyard when they blast off,” he said.

On Tuesday, besides discussing what he would say if he ever made contact with aliens from another planet, Loeb, Harvard’s chairman of the department of astronomy, and the director of the Institute for Theory and Computation, will delve into the age-old question about whether the universe is teeming with life, and how experts can utilize special equipment and technology to explore both primordial and developed forms of existence floating in the vast darkness, during a special lecture titled “New Search Methods for Primitive and Intelligent Life Far from Earth.”

We talked with Loeb about the event, which takes place at the Harvard Science Center in Cambridge, as well as his research, and how he feels about space invaders.

So you’ll be talking about the speculation of life forms?

Not so much speculation as the methods that would allow us to conduct the search for either primitive or intelligent life in the future that we have not used in the past. I think it’s an exciting time because one of the most important questions that science can answer is are we alone, or is the universe teeming with life?

Are we alone?

I think it’s likely that [the universe] is full of primitive forms of life. With respect to intelligent life? I’m completely agnostic. I don’t know. But I think we have to search. The biggest mistake we can make is to assume that we know the answer. It’s very common for people to know the answer before they test it, and that’s a mistake because such a blunder would stifle progress. I think we should—in cases where we don’t have a good sense of what the answer is—explore and search. We should be open-minded. It’s worth a try. If we don’t try, the chance of finding anything is zero. There are more planets in the livable universe than there are grain sands on all of the beaches on Earth, so even if the likelihood of getting life as we know it is small, there is plenty of room for having it in many places.

What are the methods for doing these searches?

One method is when a planet goes in front of a star, some of the starlight goes through the atmosphere of the planet, and by measuring the spectrum of this light, you can measure the fingerprints and the composition of the atmosphere, and the fingerprints of the atoms and molecules that make up the atmosphere. [There are] methods for detecting oxygen in the atmosphere of habitable planets, like the earth. There is another layer of interesting work that can be done; for example, if there is industrial pollution in the atmosphere of a planet.

Are there other methods?

The search for primitive life is currently one of the major themes with NASA, and there will be instruments built in the coming decades that I think will advance this frontier. We will be able to examine the atmospheres—and the conditions of the atmospheres—of exo-planets using these telescopes coming online, and instruments being designed and constructed now. That will lead to some interesting results.

What type of primitive life do you think is out there?

It would be similar to what we had on Earth for a long time. It could be single-cell organisms, or algae, or rather simple things. With respect to what allowed complex life to emerge on Earth, there are many conditions that need to be satisfied, and it could be that the probability for that could be small. People are searching for evidence of life in the solar system, but they haven’t really checked if there are objects producing their own light. For example, a city like Tokyo, if you place it at the edge of the solar system, it can still be observed with the biggest telescopes we have, and people don’t check if objects far away are producing their own light. The underlying assumption is that all of the objects in the solar system must simply be reflecting sunlight. But it would be possible to do a search for that. So as I mentioned, you can search for intelligent life based on industrial pollution, or the traditional way, by eavesdropping on radio signals. But not much has been detected so far. But these searches are ongoing.

What about intelligent life?

The search for intelligent life is not funded by NASA, and I think it should be ongoing as well, entirely. It’s an exciting time. We have the technology that would allow us to address these questions that people have wondered about for decades, and maybe hundreds of years, or even centuries. I think it’s a fascinating time to be in, because if a discovery is made it will have a huge impact on society and culture, and change people’s perceptions about our place in the universe. Also, if you look at the history of humans, emperors were proud of conquering a small piece of land on earth, but it’s no more admirable of an achievement than thinking about it as an ant hugging a grain of sand on a huge beach. As I mentioned, there is so many planets out there—more than grains of sand on all the beaches on Earth—so focusing on Earth is a ridiculously limited point of view in the grand scheme of things. One of the things astronomy teaches us is modesty. If you look up [at the sky], you have no choice but to be modest, because in the big scheme of things, what we often worry about is really insignificant.

If you could put a timeframe on when you think we could make a discovery of life on other planets, what would it be?

I don’t know. I think we should definitely search. If it exists, at some point we might find it. Hopefully it will be in my lifetime, and it’s not ruled out. I think we should do it in the coming years. We should not assume we know the answer. The other very important thing that I’ll mention is, when did life start in the universe? We usually think that we are special, that it formed on earth, and we are at the center of the biological universe…But we are not at the center of the solar system…and we might not be at the center of the biological universe. People think as the universe as full of lifeless objects, but all the galaxies we may be looking at may be full of life. We might not be the center. Maybe life started much earlier. The universe was not constructed for us to exist in it. We might be late-comers…there is no reason to assume that we are the only ones.

What would you think aliens would look like?

If it exists, they are more likely to be much more advanced than we are, because we developed our technology only over the past hundred years or so. They have had billions of years, so think about how much more we could develop over the next billion years. For them, what we are doing is extremely primitive. We could ask hem questions like, ‘what’s the dark matter?’ or ‘what is the dark energy?,’ and questions we don’t have answers to, but that would be like cheating in an exam.

So that’s what you would ask them?

My wife actually jokes that, when I talk about this, if they ever come to our home and ask me to join them, then it’s ok with her if I want to—I’m most welcome to join them—but I must make sure that they leave the car keys with her, and not to ruin the lawn in our backyard when they blast off. That’s all she asked me to tell them. She assumes that I would have plenty of time [to ask about dark matter] later.

Don’t ruin the lawn.

And leave the car keys.

“New Search Methods for Primitive and Intelligent Life Far from Earth,” September 23, at 7 p.m. Science Center Hall B, 1 Oxford St., Cambridge.