The Cosmic Distribution of Love

Avi Loeb
5 min readMay 1


A projection of the dark matter distribution in the TNG cosmological simulation. Gravitationally collapsed structures (in orange/white) are surrounded by successive shock surfaces (blue) which encode their formation histories. (Credit: TNG Project).

Computer simulations of the evolution of structure in the Universe often plot the three-dimensional distribution of matter.

Throughout my long life, I learned that accumulating material possessions does not bring happiness. For most people, love matters more than matter. Given that perspective, could we construct a three-dimensional map of the distribution of love in the Universe?

Clearly, love evolved over cosmic time. Initially there was none. In the first 50 million years after the big Bang, there were no stars or planets and no opportunity for love as-we-know-it. But we now recognize, 13.8 billion years later, that love exists on Earth. It may have started billions of years earlier on numerous habitable planets orbiting stars in galaxies within the observable Universe. And the collection of similar galaxies continues farther to a region outside our cosmic horizon that will never be in contact with us because of the accelerating cosmic expansion. Measurements of the microwave background anisotropies imply similar cosmic conditions on scales that are at least 4,000 times farther away than our cosmic horizon. This means that there are at least 64 billion (4,000 cubed) more galaxies than the trillions of galaxies observable in the deepest images of the Webb space telescope. They represent plenty of opportunities for the emergence of love beyond Earth.

But let us keep the discussion first down to Earth. So far, we only have conclusive evidence for terrestrial love, which concentrated in recent millennia on the two-dimensional surface of Earth to which earthlings are bound by gravity. When Edmund Hillary and Tenzing Norgay reached the summit of Mount Everest in 1953, love reached an elevation of 8.85 kilometers above the global mean sea level. And after the first flight of the Wright Brothers in 1903, commercial airplanes carried love up to slightly higher elevations. On July 1969, the Apollo 11 astronauts Neil Armstrong, Buzz Aldrin and Michael Collins extended the reach of human love to the Moon.

Population growth implies that the total quantity of terrestrial love grew over time. But there is plenty of room for further growth in our future. Some humans already get attached to GPT-4, and one can envision a romantic reality similar to that portrayed in the 2013 film “Her”. When humans will get emotionally attached to artificial intelligence (AI) systems or robots, the amount of human-machine love could exceed the current reservoir of human-human love. In other words, AI technology could bring about the next peak in the level of love on Earth.

Given the AI revolution, humanity will likely launch to space AI astronauts which are better equipped to survive long journeys in vacuum, exposed to energetic cosmic-rays. If these astronauts pass the Turing test, we will get attached to them and feel a loss if they get injured by micrometeoroid impacts. For comparison, no sympathy was expressed by NASA scientists towards the Webb space telescope after it was struck by micrometeoroids. But once AI-sentience will be onboard spacecraft, AI astronauts could spread terrestrial love to interstellar space.

This suggests the possibility that a realistic cosmic map of the current distribution of love may include bubbles of love expanding around habitable exoplanets which host sentient, love-capable forms of life. Over billions of years, these bubbles may overlap in interstellar space to the level where love fills the entire volume of the Milky-Way galaxy and beyond.

With this in mind, Enrico Fermi’s question: “Where is everybody?” feels like a desperate romantic call. It often triggers the cold viewpoint that we are alone and that claiming otherwise is an extraordinary claim that requires extraordinary evidence. If singles were to adopt this mindset, they would never go out on dates and remain singles for life, thus justifying their initial premise. Believing that you will always be single and not seeking partners, is a self-fulfilling prophecy. Without competition we will stay the smartest species in our mind, but finding others could help us grow and be better. The routine advice that dating coaches give is that in order to find love, one needs to engage in the search. Why is it so difficult for us to adopt this advice in the interstellar context? We just need to look out.

Call me a hopeless romantic, but I do believe that humanity could find loving partners out there. The simplest way to seek them is to search for interstellar love letters in the mailbox of the inner Solar system. This is why I am leading a search for objects manufactured by extraterrestrial technological civilizations called the Galileo Project. Our operating observatory at Harvard University is monitoring the entire sky at all times, and in a few months we will travel to the Pacific Ocean to check if the anomalous material strength of the first interstellar meteor, IM1, was because it was sent by an interstellar partner.

Finding an interstellar love letter could be regarded as a close encounter of the emotional kind. This class should be added to Hynek’s classification of possible contacts with extraterrestrials, which inspired Steven Spielberg’s science fiction film “Close Encounters of the Third Kind.”

Even without a physical contact with the sender, an interstellar package may deliver an important message that will change our perspective on cosmic love. All of a sudden, the Universe will not appear pointless, as it is currently portrayed by cosmological simulations of lifeless galaxies and stars. After receiving the message, it will not be the distribution of matter that we will care about. It will be the map of the islands of interstellar love with which we can connect and feel happier as we cope with our terrestrial challenges.


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".