Superficially, the logic behind the conjectures about cosmic machine intelligence appears pretty solid. Extrapolating the trajectory of our own current technological evolution suggests that with enough computational sophistication on hand, the capacity and capability of our biological minds and bodies could become less and less attractive. At a certain point we’d want to hop into new receptacles, custom-built to suit whatever takes our fancy. Similarly, that technological arc could take us to a place where we’ll create artificial intelligences that are either indifferent to us, or that will overtake and subsume (or simply squish) us.
Some of these extravagant ideas can be traced back to John von Neumann’s astonishing conjectures on self-replicating automata, which were compiled in his posthumous book, Theory of Self-Reproducing Automata (1966). That work helped cement the concept of machines building more machines, in an exponential and perhaps uncontained explosion that could simply swamp other life forms that get in the way. Von Neumann also considered how such machines could simulate some of the functions and actions of human neurons.
In the years since then, electronic connectivity certainly has had a huge impact on the way that many humans go about their daily lives, and even on the way in which we problem-solve and think about any new question or challenge. Who of us in the connected modern world hasn’t Googled a question before even trying to work through the answer, or before asking another human being? Part of our collective wisdom is now uploaded, placed in an omnipresent cloud of data. The relative importance of our individual breadth of knowledge might be declining. It might even be the case that the importance of individual expertise – specialisation – is lessening in the process.
To put that in a different context, our brains use energy at a rate of about 20 watts. If you wanted to upload yourself intact into a machine using current computing technology, you’d need a power supply roughly the same as that generated by the Three Gorges Dam hydroelectric plant in China, the biggest in the world. To take our species, all 7.3 billion living minds, to machine form would require an energy flow of at least 140,000 petawatts. That’s about 800 times the total solar power hitting the top of Earth’s atmosphere. Clearly human transcendence might be a way off.
One possible solution is to turn to so-called neuromorphic architectures, silicon designs that mimic aspects of real biological neurons and their connectivity. Researchers such as Jennifer Hasler at the Georgia Institute of Technology have suggested that, if done right, a neuromorphic system could reduce the energy requirements of a brain-like artificial system by at least four orders of magnitude. Unfortunately, that big leap would still leave a gaping hole in efficiency of a factor of 100,000 before reaching the level of a human brain.
Of course, the history of computer technology is replete with supposedly impenetrable barriers that collapse year by year, so optimism has not yet left the room. But the critical point is that none of this is a given. It might well be that, to capture the complexity, density and extraordinary efficiency of a modern human brain, silicon and its cousins are simply not the answer, no matter how they’re sculpted or stacked together.
Our current existence could sit in a cosmically brief gap between that first generation of machine intelligence and the next one. Any machine intelligence or transcendence elsewhere in the galaxy might be short-lived as an interstellar force; the last one might already be spent, and the next one might not yet have surfaced. It might not have had time to come visiting while modern humans have been here. It might already be dreaming of becoming biological again, returning to an islanded state in the great wash of interstellar space. Our own technological future might look like this – turning away from machine fantasies, back to a quieter but more efficient, organic existence.
There is no shame in admitting the highly speculative nature of these ideas, and there is something special about the questions that prompt them. We’re examining possible futures for ourselves. It is conceivable that the Universe is already telling us what those options really are. Such acts of self-examination are unlike any other human endeavour, and that alone is worth paying attention to.