Avi Loeb suggests that alien probes may use synthetic biology

Astrophysicist Avi Loeb proposed that advanced extraterrestrial civilizations may develop forms of intelligence based on synthetic biology, rather than necessarily relying on silicon-based computers like today’s human artificial intelligence.

The reflection was presented in response to a question from a university student in France about the so-called Von Neumann probe paradox — autonomous machines capable of self-replication, self-repair, and interstellar travel. According to the argument, even probes traveling at only 1% of the speed of light could, in theory, spread throughout the Milky Way within a few hundred thousand years, a relatively short period on the cosmic timescale.

The student questioned why there is no observable evidence of such machines or large-scale galactic engineering projects, raising the possibility that no technologically advanced civilization beyond humanity exists or has ever existed in the galaxy.

In his response, Loeb stated that human beings themselves can be considered intelligent probes capable of self-replication and self-repair. In his view, the question of whether humanity’s existence on Earth may have any connection to a possible extraterrestrial visitation remains an open one.

The researcher noted that current artificial intelligence depends on silicon chips, a material derived mainly from quartz and silica found in Earth’s crust. Despite technological advances, modern AI systems consume large amounts of energy to perform cognitive tasks that the human brain carries out using approximately 20 watts.

With a more advanced understanding of biology in the future, Loeb argues that it would be possible to create artificial brains based on synthetic biology within bodies capable of obtaining energy from nutrients available in natural environments. These entities could be more energy-efficient and more adaptable than robots powered by silicon-based artificial intelligence.

According to the astrophysicist, future versions of these biological machines could have enlarged brains, greater intellectual capacity, and self-repair systems capable of ensuring extremely long lifespans. They could become ideal candidates for interstellar missions as Von Neumann probes sent to potentially habitable exoplanets.

As most stars in the Milky Way formed billions of years before the Sun, Loeb argues that older extraterrestrial civilizations could have reached this technological stage long before humanity.

He then raises the hypothesis that human beings may ultimately be intelligent probes of extraterrestrial origin created through advanced synthetic biology technology. The idea remains speculative and has no confirmed scientific evidence.

Loeb also stated that he hopes research related to unidentified anomalous phenomena may help determine whether Earth is being visited by non-human intelligences and, if so, understand the nature of that possible intelligence.