What Makes Us Human?

Avi Loeb
5 min readNov 14, 2022


The athlete Zion Clark, who was born without legs.

When Stephen Hawking visited my home for a Passover dinner in April 2016, he could barely move his cheek muscles. Yet, he delivered an inspiring speech about the importance of reaching the stars instead of just staring at them from a distance. It was a privilege to host him and I committed to pursue this goal through my leadership of the Starshot Project.

Fast forward six and a half years. After delivering a public lecture on extraterrestrial intelligence at the Palm Desert Summit yesterday, I met Zion Clark, who was born without legs and set the Guinness World Record for running the 20 meter on his hands in 4.78 seconds. Zion told me that he loved my lecture and was inspired by the associated research program. It was my honor to shake his hand, and I promised to pursue the related research through my leadership of the Galileo Project.

Both experiences underscored for me the simple truth that what makes us human is our forward-looking spirit, which can overcome all physical barriers. It is our aspirations that propel us beyond the prescribed context of the physical reality. Any physical beauty deteriorates over time — like the Venus de Milo sculpture which lost its arms. But the beauty of the human spirit remains intact because it is abstract, like musical notes.

The Venus de Milo, or Aphrodite of Milos (Credit: Bradley N Weber/Wikimedia Commons).

Cosmologists imagine a lifeless Universe shaped by the predictable interactions of physical objects. But the spirit of humans and their extraterrestrial counterparts can change all of that. As we identify the nature of dark matter and dark energy, we might realize that there is something else out there, defying our expectations from a purely physical world. Whereas our computer simulations can reproduce the formation of galaxies out of the initial conditions of the early universe, they will never be able to reconstruct cosmic engineering projects initiated by free spirits.

Consider Earth as an example. Gravity keeps humans bound to Earth but the human spirit launched spacecraft. The escaping rockets from Earth were never explained by a planetary scientist, since there is nothing in the physical properties of the Earth that would imply the ejection of objects made of stainless steel into interstellar space at a high speed.

The news about us breaking expectations can extend to the vast space outside the Solar system once our spacecrafts become interstellar, especially if they collide with a habitable exo-planet and deliver the package into the mailbox of an advanced civilization. At that time, the package will change its interpretation from an “interstellar object” to a monument of the human spirit.

Plenary lecture on Extraterrestrial Intelligence at the Palm Desert Summit (November 12, 2022).

In reciprocity, perhaps we can infer that an extraterrestrial spirit was responsible for some anomalous interstellar objects without meeting their senders. This is the rationale for the ocean expedition planned by the Galileo Project to scoop the ocean floor near Papua New Guinea for the fragments of the first interstellar meteor, IM1, which appeared tougher than all space rocks seen so far. Was it made of stainless steel?

At the Summit dinner, I met the accomplished actor Adrian Grenier, who told me that he is organizing an ocean expedition in search of a lonely whale who is believed to have a communication problem with the remaining whale population. I reasoned that humanity is a lonely whale in the vast ocean of interstellar space. Here’s hoping that someone is searching for us.

The following morning, I had breakfast with the amazing engineer and social entrepreneur, SoHa Zadeh, who invited me to record a video message to the many women of Iran who are aware of my research on extraterrestrials. In the video, I said that the protests of the women of Iran are an inspiration to the world. The life of Gina Amini was stolen but we must ask in return for a better life of others in the name of her spirit. Last week, I was invited to speak in front of 800 women on the question: “Are we alone?”, in the 2022 World Leadership Conference of the International Women’s Forum — dedicated to advancing women’s leadership and championing equality. And I can tell you: you are not alone. We are not alone.

Leaders lose their power once they lose their humanity. The horrors of human history are shaped by groups of people feeling superior relative to other people. One reason I seek intelligence in space is because it is not common on Earth. My hope is that once we find the Amini spirit of a more advanced extraterrestrial civilization, we will learn our lesson and treat each other as equal members of the human species.


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 June 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".