Three Revolutions that Will Change Humanity

One out of 11,000 hansom cabs in London at the end of the 19th Century (Credit: Historic UK)

In a Clubhouse fireside chat last night with a quantum photonics forum, I was asked about my thoughts on the future of humanity and intelligence.

Any long-term forecast must be handled with caution, I reasoned. In my mind, I recalled that the growth in the use of horses for transportation in the late 19th Century filled city streets with horse manure. As cities around the world were “drowning in horse manure”, this was regarded as a major challenge for urban life. Then the car was invented and circumvented this concern. Similarly, by the end of the 20th Century, citizens of many underdeveloped countries thought that it would be nearly impossible to connect everyone through a wired telephone communication system. Then, cell phones, communication satellites and WiFi came along and resolved these connectivity concerns. The moral of these examples is that new qualitative revolutions make all forecasts fundamentally unreliable in the long term.

What are the new qualitative revolutions that are awaiting humanity in the 21st Century?

One involves the development of sentient artificial intelligence (AI) systems. The AI revolution will proceed in two stages: first, sentient AI systems will take over routine tasks that are currently assigned to humans, such as driving cars, accounting, shipping and handling, routine legal transactions, administrative tasks, or medical prescriptions, to name a few examples. All of these tasks involve the interactions of AI systems with humans. The second phase transition will result from AI-AI interactions. In that stage, the community of AI systems could develop independently from humans and establish its own communication and societal norms. The development of an AI community might not be inhibited any longer by humans since it will have direct access to physical resources acquired from the first stage in the AI revolution. Of course, humans can always unplug AI systems out of the wall, in the same way that they can pull the trigger and kill another person. But in that late phase, terminating livelihoods might be outlawed for all sentient beings, including AI systems.

The second qualitative development in our future would involve extending the lifespan of humans indefinitely. The human body is a machine that can be steadily repaired and potentially live forever. Accomplishing biological immortality will change society as it will modify the goals, experiences and motivations of all its members. Sentient AI systems could achieve this phase before humans.

Finally, the third qualitative development will stem from an encounter with advanced extraterrestrial civilizations. This will be the most significant of all three revolutions, because other civilizations might be billions of years ahead of us in their scientific or technological knowledge, given that most Sun-like stars formed 5 billion years before the Sun.

As a result of an encounter with extraterrestrials, we could learn from their vast knowledge, get a jump start to our technologies, but most importantly — we could get a glimpse of what might be possible in our long-term future, as represented by their past.

There is probably a spectrum of intelligence levels in the Milky Way galaxy, some being less accomplished than us and others far more impressive. As I remind Harvard students on their first day in class: half of you are below the median of the class. It is a statistical fact that in any class half the students are below the median. The same must be true for the human civilization and its counterparts throughout the Milky Way galaxy. It will be a major challenge for us to understand a more advanced level of intelligence. But it is worth a try.

We can get a sense of the best future that we can aspire to have, by paying attention to what was accomplished by the smartest students in our Galactic class of technological civilizations. This could change our aspirations. With an elevated perspective, our current space exploration plans to settle on the Moon or Mars would appear as trivial as the aspirations of a colony of ants to build a new home on the nearest hill. It may sound ambitious to the ants but it appears trivial to a traveler from another continent.


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 is the Frank B. Baird Jr Professor of Science and Institute director at Harvard University and is the bestselling author of “Extraterrestrial”.

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Avi Loeb

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