Since childhood, I have hated funerals. They mark the end of learning, an unfair verdict to a kid with unlimited curiosity about the world. The adults in the room accepted the end as a fact of life, and some even argued that it offers benefits in coloring life with a purpose and opening space for the birth of others. In an interview for the “Mission Daily” podcast yesterday, Stephanie Postles asked me which fact of life bothers me the most, and I replied: “Death. In particular, I wonder whether we could leave a memorable mark on life beyond Earth?”
Traditionally, people are commemorated after death by a tombstone on their grave. Their life is summarized in a few words engraved on a stone. In the rare case of the physicist Ludwig Boltzmann, the tombstone summary also includes his famous equation for entropy. Is that the best we can hope for?
There are two problems with this tradition. First, its information content is static. Second, it carries very limited data about the person it represents. Alas, maximizing information was not a priority in burial services, as some traditions burned dead bodies. Turning biological entities into ashes destroys their genetic information content. This devastating tradition was extended by NASA to space when the New Horizons spacecraft to Pluto carried a box with ashes of Clyde Tombaugh, Pluto’s discoverer. If extraterrestrials were to recover that box, they would wonder about our barbaric act of removing any trace of DNA from Tombaugh’s body in the ashes. After all, a single hair would have carried more information about Tombaugh than NASA’s box of ash.
So far, we have not done much to preserve essential information about the 117 billion humans who lived on Earth over the past 10 million years. We can attempt to do better for the next 117 billion people. Of course, there are common partial solutions to the challenge, like writing a book or having children that would outlive us. But modern technology offers another way.
Imagine replacing tombstones in graveyards with digital screens. Each screen will be linked to an artificial intelligence (AI) avatar that was trained on all electronic records of the person it represents, including text, voice, and image data. The avatar would be trained while a person is alive and learn how to interact with living people after the person is gone. Instead of staring at a tombstone in a graveyard, one could engage in fresh conversations with AI avatars, who follow the characteristics of the person they emulate.
Having a conversation with Ludwig Boltzmann in his original voice could reveal new thoughts of Boltzmann’s avatar about all aspects of life and not just present a static celebration of his equation. After all, digital tablets are much richer in information than stony tablets. It would have been far easier for Moses to convey the Ten Commandments on a digital tablet.
A single state-of-the-art AI system could simultaneously serve numerous digital screens and interact in all languages on Earth.
This approach could be extended to space. Instead of encoding 115 images and a variety of sounds or music on the Golden Record of Voyager and carrying a box with Tombaugh’s ashes on New Horizons, a future spacecraft could carry an AI system that represents all humans on Earth.
An AI avatar could commemorate humanity in interstellar space long after the Sun boils off all oceans and extinguishes all lifeforms on Earth’s surface. It would be far more economical to send a single AI system than to put the humans it represents on a spaceship in the spirit of Noah’s Ark.
If we can imagine sending an AI monument to space, perhaps other technological civilizations already did that in the past, because their star was born billions of years before the Sun. Their AI records might show up in the form of interstellar devices. Just like tombstones, the main purpose of these devices would be to commemorate the senders. Finding them would not pose any existential threat to us, but rather offer an opportunity to appreciate the knowledge of our long-lost cosmic neighbors.
This knowledge could bring scientific benefits. When viewing an image of the Universe from billions of years ago, astrophysicists would be able to constrain the nature of dark matter and dark energy far better than possible today.
Through its search for interstellar artifacts, the Galileo Project may hopefully discover AI records from other stars. They would encode far more information about our neighbors than interstellar asteroids or comets.
Studying AI records from other civilizations would constitute a new branch of astrophysical archaeology, the study of cosmic civilizations that predated us by billions of years. Learning what they went through could offer tips on how to avoid catastrophes in our future.
Today, I am heading to the CURIOUS 2024 Conference near the birthplace of my grandfather in Germany, where I will echo my childhood sentiments and give a keynote lecture about the search for technological interstellar objects. Finding extraterrestrial monuments could convey the recipe we need for leaving our own mark on life beyond Earth.
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 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.