(German translation published in DIE WELT on October 15, 2025)
ROLF: If you find an extraterrestrial piece of equipment and it has a button on it, would you press it?
AVI: No, I want to first understand what the function of this button is — by taking it to the laboratory. It’s sort of like with humans: you don’t want to press any buttons of a human before you come to know that human.
ROLF: And then what?
AVI: Most likely it will teach us something we don’t know. Because our science and technology are extremely premature. Quantum mechanics was discovered a century ago. We still don’t fully understand it, and it’s a fundamental facet of our reality. We don’t have a theory that unifies quantum mechanics and gravity. We know very little.
ROLF: Your quest is to look for extraterrestrial civilizations by searching for artifacts from those civilizations. Why has nobody come up with this idea before?
AVI: I don’t know. To me, it sounds like common sense. But common sense is not common. For 70 years we have been searching for radio signals and other electromagnetic signals. And that is just like waiting for a phone call at home. If nobody is transmitting a signal that will arrive to you when you are listening, you will not hear anything. You need the counterpart to be active. Whereas in the case of packages that land in our cosmic backyard, they could have been sent millions of years ago and the senders could be dead by now.
ROLF: What makes you so optimistic that you will find anything?
AVI: Over the past 50 years we have sent five packages to the interstellar medium: the spacecraft Voyager 1 and Voyager 2, Pioneer 10, Pioneer 11 and New Horizons. They will reach the outskirts of our solar system in 10,000 years. By then they will not be functional anymore. They will be space trash. It’s possible that other civilizations existed billions of years before us because most stars formed billions of years before our sun. And it takes less than a billion years for the kind of spacecraft that we launched to cross the Milky Way galaxy from one side to the other. So, a lot of packages could have arrived from far away corners of the galaxy to us. All we need to do is search. And that sounds to me like common sense. Only over the past decade have we started to detect the first objects from outside the solar system. The first one was a meteor that collided with Earth on January 8, 2014. Half a meter in size. It was spotted by U.S. government satellites. The second one was an object about the size of a football field that was detected by a telescope in Hawaii in 2017. Both of them had properties that do not resemble the kind of rocks we know about in the solar system. And the third one was a comet. It is called Borisov, discovered by amateur astronomer Gennadiy Borisov in 2019. This opens a new frontier. The fact that the first two were highly unusual raises the possibility that they were manufactured technologically. We need to figure it out by collecting evidence. That’s the way science makes progress.
ROLF: What surprises me is that we spend billions of dollars creating Hollywood movies about extraterrestrials. But very little money into actually searching for extraterrestrials.
AVI: Well, it reflects the fact that there is a huge interest in this subject in the general public. So, the entertainment industry makes a profit out of it. What is missing is the scientific community taking advantage of the public’s interest. Instead, you find the mainstream of science rejecting the idea of studying extraterrestrial artifacts by saying that it’s too risky, too controversial. And very often funding allocation committees would argue we shouldn’t take risks because we would waste taxpayers’ money. But when they say that, they never ask the taxpayers what they’re really interested in. And my point is: If they were to ask the taxpayers, the message would be loud and clear. The question “are we alone in the universe?” is one that people want to fund.
ROLF: You are anything but a mainstream scientist.
AVI: I just see myself as a curious boy that was born on a farm in Israel. You know, I’m connected to nature and I don’t feel superior to any other human being. I just want to figure out, out of curiosity, what the reality that we live in is. Being a scientist is not a status symbol for me. Harvard is not a status symbol. It’s just that I have a great privilege: to pursue my curiosity and be paid for it. But even if I were not be paid for it, I would do it anyway.
ROLF: Don’t you need your Harvard salary to put food on the table?
AVI: Well, I was born on the farm, so I can easily collect my food from the ground. Actually, my father was born in Germany. And when he came at age 11 to the village in Israel, he eventually became a farmer. He always said he never had resentment towards the history of Germany because he never witnessed the Second World War. He always listened to Strauss music. And we always had a Volkswagen. It was very much a German upbringing.
ROLF: In which year did your father flee Germany?
AVI: 1935. The history is quite interesting because my grandfather fought for the Germans in Verdun against the French. He fought in the mud for two years. 700,000 people died in that front. And the border between France and Germany hardly moved an inch. People just died for nothing. So, he was one of the survivors of Verdun. He then came back from that war being a German patriot, of course, and was awarded a medal. In his honor, a street was named after him, the “Albert-Loeb-Weg”, at his village Netze in Waldeck near Frankfurt. Then Hitler came to power. Around 1933 there was a gathering in the village near Frankfurt, and one of the members of the Nazi Party stood up and said that the Jews are using up resources from society. And my grandfather stood up and said, “How dare you say that! You dodged the draft during the War, and I fought for Germany.” And then the speaker said: “I’m not talking about you, Mr. Loeb. We all know about you. I’m talking about the other Jews.” And at that point, my grandfather was determined to leave Germany. All of the rest of the family stayed in Germany. They said they would leave in the last train out. But that last train led to the concentration camps. No other branch of the family survived. It’s all thanks to my grandfather, who was courageous to leave everything behind and moved to a farm in what was then called Palestine. And that’s where my father, at age 11, started working. So, he was a farmer. And that was also my plan — to become a farmer.
ROLF: And now you are a Harvard professor.
AVI: When I came to Harvard, I was told that the chances of promotion to tenure are very small. But I was never worried about it because I had Plan B: I could always go back to the farm. So, even if I didn’t get a salary for my research, I could put enough food on the table.
ROLF: Quite a triumph, from a farm boy to head of the astronomy department of the world’s most prestigious university.
AVI: Well, if you call that a triumph. I’m not sure, because life in the company of nature is far more satisfying than in academia, where ego is celebrated and where sometimes fights over credit are more appreciated than the truth. So, I’m not sure I would have been less happy on a farm.
ROLF: What attracted you to science?
Avi: From a young age on I was always interested in the big philosophical questions about our existence. I read philosophy a lot. But then I had to serve in the Israeli military. It’s obligatory, and the closest thing to thinking abstractly was physics and mathematics, which I was good at. So, I was recruited to a special program that allowed me to finish my Ph.D. at age 24 and then do research that was useful for the defense of Israel. I became a captain in the military, and then I started working on President Reagan’s “Star Wars Initiative” or “Strategic Defense Initiative” as it was officially called. Israel was the first international partner in that program. That’s when U.S. General Abrahamson came to Israel and brought me to Washington. The Americans gave us a few million dollars a year for the project. Later, Princeton’s Institute for Advanced Study offered me a five-year fellowship under one condition: that I switched to astrophysics. So that was a surprise because I didn’t know anything about astrophysics. I had to learn everything from scratch. Like the Baron von Münchhausen, I had to pull myself out of my ignorance in astrophysics. Eventually I came to Harvard. So, I would say it was an arranged marriage with astrophysics.
ROLF: You are currently the most famous astrophysicist in the world, but also the most attacked astrophysicist in the world. How do you deal with this emotionally?
AVI: First of all, I don’t subscribe to social media because I enjoy the company of nature and I enjoy following the scientific method, which is based on evidence, not on opinions. I’m fully aware of the history where people get attacked just by becoming prominent. It’s true for singers, entertainers, it’s true for creators of all types, also for scientists. I take it that it comes with the territory. And the approach I take is, first of all, not engaging in any mud wrestling because that’s what gets you dirty. The metaphor that I enjoy is that of the eagle, which often has a crow sitting on its back and the crow is trying to peck at the neck of the eagle. But the eagle never fights the crow back. The eagle just rises to greater heights where the oxygen level is low, and then the crow drops off the back of the eagle. And for me, going to the greatest heights is doing science as it should be done by collecting evidence, analyzing it, and then writing a scientific paper to the highest possible level. And my hope is that those crows that peck on my neck would drop off.
ROLF: You just led an expedition to the Pacific Ocean to collect pieces from an object that came outside from our solar system. It could be a rock or it could be trash from a far-away civilization. You collected so-called “spherules”, sub-millimeter tiny balls. Five of those are really exceptional.
AVI: We brought back 700 spherules from the likely path of the 2014-meteor that come from outside the solar system. We were able to localize them near Papua New Guinea. We found them using a magnetic sled on the ocean floor. And now we are studying their composition using the mass spectrometer in the laboratory of my colleague Stein Jacobsen at Harvard, who is a highly respected geochemist. I gave him the task because he is very solid, and he will tell me whatever he finds without any bias whatsoever. And he indeed came back to me and said that we found some spherules that were never seen in the scientific literature in terms of composition. So, these were the five that you alluded to.
ROLF: But it’s still not clear if this is material from an extraterrestrial civilization or just some rock from a far-away solar system.
AVI: Right. So in the scientific paper, we consider a natural origin: a planet with a magma ocean. But of course, the alternative would be that it’s of technological origin, because of the unique composition. So maybe these elements were combined for a technological purpose. But there is a simple way to figure it out, which is to find a big piece of the object. Then you can easily tell the difference between a rock and a technological gadget. And that’s what we plan to do in the next expedition.
ROLF: A major documentary about your research is in the works.
AVI: There were 50 filmmakers and producers that wanted to be with me on my last expedition. On average, five filmmakers and producers contact me every week with requests that I have to decline because I already have a contract.
ROLF: Let’s get to some of the big philosophical questions. What is the meaning of life? The meaning of our existence? The meaning of the universe? The meaning of it all?
AVI: We are unable to answer this for now, because we are still very ignorant. We came late to the cosmic play — just at the end, i.e. over the past few million years. That’s one part in 10,000 of the age of the universe. And we are not at the center of the stage. So obviously, if you arrive late to the play and you are not at the center of the stage, the play is not about you. So, you better find other actors who tell you what the play is about. You better ask civilizations who have been around for much longer.
ROLF: What is your conception of God?
AVI: A very advanced technological civilization is an approximation to God. Just to give you an example from the Old Testament: Moses witnessed a burning bush. And the bush was never consumed. If I had infrared cameras with me next to Moses, I could measure the temperature of the bush, the amount of energy emitted. And I could advise Moses whether this bush was created by a superhuman entity. And if the answer is yes, it would have enhanced the sense of religious awe that Moses had. So that’s an example of encountering something that is beyond you and which is, in a sense, what religion advocates. But this something could be just a more advanced technological civilization. You can imagine nowadays easily making a bush that appears to be burning unlike a natural bush. We can do it now. But in the future, you can imagine a technological civilization that could create life in the laboratory, that could even create a baby universe in the lab.
ROLF: Creating a baby universe in the lab. Theoretically possible through a quantum process. Let’s assume we are a few thousand years into the future and you know how to pull this off: How many universes would you create?
AVI: Oh, I would create more than one.
ROLF: So, God is a guy in a white lab coat.
ROLF: What is death for you?
AVI: I think that death is just like pulling the cord out of the electrical outlet for a computer. Basically, it shuts off. It’s a physical thing. I don’t think there is anything beyond that. I don’t think there is a soul that survives that process.
ROLF: Does it interest you what happens after you are dead?
AVI: I once heard a colleague say: “I plan my life so that people will say good things about me after I die.” And I thought to myself, what a hopeless hope. Because when you are dead, who cares? I do not care what people think about me when I’m dead. I only care if I’m doing something good while I’m alive. Once I’m dead, the game is over. Of course, we get all kinds of promises about what happens after death, just to make us feel better. But then actually, you know what Epicurus said: we should not be afraid of death, because when death is around, we are not around. When we are around, death is not around. So, we never meet death. Why should we be afraid of something we never encounter? Which I think is very good advice: Live life to the fullest and make the world better while you are alive.
ROLF: Do you think we will ever come to a point where we know everything?
AVI: No. Science is a never-ending process. That is good news because it means there will be something to do forever.
ROLF: Why are you so sure about it?
AVI: Because there is always a question to be asked about what you already know. The more you know, the more questions you can ask.
ROLF: What’s your hope?
AVI: My true hope is that we will get a letter from a smarter civilization that will alert us to our risks here on Earth. And it’s not just about the letter. It’s also about the fact that we will be open-minded enough to read it, because it’s possible that people would just ignore it and move on.
ABOUT THE DIALOGUE PARTICIPANTS
Rolf Dobelli is the Founder of WORLD.MINDS, a community of some of the world’s most famous, distinguished thinkers, scientists, artists and entrepreneurs, including Nobel prize winner Joe Stiglitz, Paul Romer, Matt Ridley (The Rational Optimist), Henry Kissinger, General David Petraeus, historian Niall Ferguson, investors Bill Ackman, Charlie Munger and Henry Kravis, philosophers Daniel Dennett, Peter Singer, and many others. Dobelli is best known as the author of The Art of Thinking Clearly, a million-copy bestseller with translations in 47 languages. He earned his Ph.D. in philosophy from the University of St.Gallen in Switzerland.
Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s — Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University (2011–2020). He chairs the advisory board for the Breakthrough Starshot project, and is a former member of the President’s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos”, both published in 2021. His new book, titled “Interstellar”, was published in August 2023.