Distinguishing Ourselves from Nature

Avi Loeb
5 min readMar 4, 2023
Credit: Christian Darkin (Nature).

We should not accept nature as fate, especially when dealing with the extinction of the human species. If our Artificial intelligence (AI) astronauts will venture into interstellar space, they will serve as monuments that humanity distinguished its destiny from the death prescribed to it by nature. Our natural endpoint involves the evolution of the Sun that will boil off all terrestrial water and sterilize Earth’s surface from life-as-we-know-it within a billion years. Most sun-like stars formed billions of years before the Sun and have already sterilized the surfaces of their formerly habitable Earths. We were not around billions of years ago to listen to the numerous cries for help from distressed civilizations on these planets. If these civilizations were indistinguishable from nature like the dinosaurs were 66 million years ago when the Chicxulub impactor killed them, then the ruins of these civilizations must lie on the surface of their burnt-up planets. Our AI astronauts might find these relics. But we could find the relics of the more intelligent species that ventured into interstellar space and avoided their natural doom to arrive at our doorstep near Earth.

Distinguishing ourselves by overcoming our natural destiny is what makes us human. I was supposed to play it safe and stay at home after noticing this morning the pileup of five inches of snow outdoors. Instead, I chose to maintain my morning jog at sunrise. When nature offers me a challenge, I enjoy facing it and marveling at its beauty. Life is worth living, particularly when we make possible what seems impossible at first sight.

Sometimes, nature brings to the `wrestling stage’ a force majeure that is far greater than we can cope with. But I say: “let it be known that we gave up after a good fight.” Obviously, we cannot cut out our umbilical cord to the nutrients provided by our natural environment. Matter flows in and out of our body but the organization of this matter to a persistent form defines our identity. Also, the laws of physics apply to anything we do. On the one hand, we are constrained by our natural circumstances. But on the other hand, our scientific knowledge allows us to distinguish ourselves from nature by designing technological objects that would have never been made at random.

This realization sets the search for extraterrestrial technological objects — as described in my forthcoming book “Interstellar, apart from the search for microbial life — as described in the textbook that I wrote with my former postdoc Manasvi Lingam, “Life in the Cosmos”.

Based on the early emergence of microbes relative to technological life on Earth, it is reasonable to argue that microbes are much more common on other astrophysical objects. However, bio-signatures could be much more subtle relative to techno-signatures. It might be far easier to identify a technological device passing near Earth as a sign of intelligent life than to identify the molecular composition of an exo-planet’s atmosphere as a flag for microbial life. In order to maximize our chances for success, we must engage in both searches within the mainstream of astronomy.

Even though humanity already launched five interstellar probes in half a century, the scientific search for probes from other civilizations near Earth — which defines the Galileo Project– is outside the mainstream of astronomical research. Changing its status to be as central as the search for microbial life and allocating similar resources to both endeavors, will also echo the broad interests of taxpayers and governments. This was implied by a new scientific paper, still under review, about Unidentified Aerial Phenomena (UAP) that I wrote with Dr. Sean Kirkpatrick who serves as the director of the All-domain Anomaly Resolution Office which was established by the National Defense Authorization Act for fiscal year 2022 at the Pentagon in July 2022, in coordination with the Director of National Intelligence.

While searching for extraterrestrial technological signatures, we should keep in mind the caveat that humans are not reliable scientific detectors. This is evident from conflicting reports by eyewitnesses of car accidents or fans of sport events. Well-calibrated scientific instruments could guide us towards a sober view of reality without wishful thinking about what we want it to be. Steven Spielberg’s wonder about UAP in his recent conversation with Stephen Colbert, should trigger scientific curiosity but not dictate the outcome beyond science-fiction scripts in Hollywood.

Here’s hoping that humanity will be intelligent enough to distinguish science from fiction. By fiction I also mean the arrogant notion that we are the smartest in our cosmic neighborhood, which is prevalent among my fellow astronomers. To shift their paradigm, the Galileo Project is seeking indisputable evidence for extraterrestrial technological objects near Earth. Such evidence should not invoke new physics to explain incomplete data. Instead, we must stand up to the standard requirements of scientific rigor, collect as much evidence as possible, and only contemplate extraterrestrial technologies or new physics if we have no other choice. This is a tall order, but as I found during my morning jog — nature is under no obligation to make our life easy.


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”, is scheduled for publication in August 2023.



Avi Loeb

Avi Loeb is the Baird Professor of Science and Institute director at Harvard University and the bestselling author of “Extraterrestrial” and "Interstellar".