Convergence, Contingency, and Copernicus

In the summer of 1977 NASA launched the twin Voyager spacecraft, and following missions to the limits of the solar system, Voyager I entered interstellar space in 2012, followed in 2018 by Voyager II. Their departures from the heliosphere, the first by human-made objects, set those two ships on what Jonathan O’Callaghan describes as a “lonely, eons-long sojourns between the stars” (for a sense of scale, at 40,000 miles-per-hour, in 296,000 years Voyager II will pass 25 trillion miles from Sirius, the brightest star in the sky). As the Voyagers venture into the vastness of the galaxy, I cannot help but wonder what the future holds for humanity.

Given our dominance as a species, it is easy to forget that homo sapiens are a recent arrival in the 3.8 billion-year history of life on this planet, and with dominance, it is easy to ignore the convergence-contingency debate that asks if the appearance of intelligent life on earth resulted from strongly constrained forces or an enormous series of flukes. Most experts agree evolution is both convergent and contingent but disagree over which is dominant. On that I am drawn to Stephen Jay Gould and those who see us as an “accidental” and “fragile” consequence of natural selection; in fact if the “tape of life” were re-run, there is no guarantee we would be here.

More broadly, modern science has shown that humans do not occupy a special place in the cosmos (this is the Copernican Principle), and like all life forms we are finite. Will our probable extinction, whenever and however it arrives, be what Todd May calls a “tragedy,” or because of our devastating impact on the biosphere, something to be welcomed? By the time Voyager II passes Sirius in the vacuum of space the human race will presumably be gone, and to me, that would be sad but best.