Astrobiology is the study of evidence for life on other planets. Caleb Scharf is the director of astrobiology at Columbia University, a position rather like being the mayor of a ghost town. No such evidence has been discovered. Universities thrive on educating students and raising money for research. Neither students nor money are attracted to fields in which nothing happens. As a result, each year more people titter at Scharf’s title and his position becomes less and less comfortable.
Consider his recent contribution to Nautilus, “Is Physical Law an Alien Intelligence?” Scharf is committed to the existence of alien civilizations but despairs of detecting their signals in the near future. These civilizations, Scharf speculates, might be hidden in the “[v]ast halos of dark matter [that] seem to lurk around galaxies.”1 Dark matter is believed to occupy about a quarter of the mass of the universe, while the matter we know about represents only a twentieth of the total. Scharf conjectures that life on earth may have been created by intelligent dark-matter beings five billion years ago, at a time when our universe was expanding rapidly. They may yet be among us, though we would not be sophisticated enough to detect them:
Although dark-matter life is a pretty exotic idea, it’s still conceivable that we might recognize what it is, even capturing it in our labs one day (or being captured by it). We can take a tumble down a different rabbit hole by considering that we don’t recognize advanced life because it forms an integral and unsuspicious part of what we’ve considered to be the natural world.2
Five billion years ago, there were doubtlessly many planets on which life would have been possible. Who wills the ends, wills the means. If we had the power, would we endeavor to plant life on a dark matter-planet? Why suppose the reverse is true? In any event, I find it difficult to understand why dark-matter beings would have singled out the earth. If it was only the earth that received their favors, Scharf’s hypothesis is useless. If they did so for many planets, we should have heard from some of them by now.
No news is good news, I suppose.
Scharf writes:
Life’s desire to avoid trouble points to some options. If it has a choice, life always looks for ways to lower its existential risk. You don’t build your nest on the weakest branch or produce trillions of single-celled clones unless you build in some variation and backup.3
The idea here confuses me. I do not build nests anywhere, nor do I produce clones, so I may be unqualified to comment. But whoever these remarks are intended to describe bears no relation to human beings, who in their single-minded exuberance often do precisely the equivalent of building on the weakest branch, and never ever think of consequences a billion years ahead.
Scharf’s wording gives me doubts as to how seriously he takes his essay. What he refers to as life, and which, he suggests, planted life on earth, sounds to me like a naïve deist notion of God. After referring to Stanisław Lem and Carl Sagan, Scharf concludes with the dictum “life might not just be in the equations. It might be the equations.”4 I can see no argument for this dictum, no detail as to what it means, nor how it might be observed.
The same issue of Nautilus contains an article on the discovery of gravitational waves, by Jonah Kanner and Alan Weinstein.5 Working in a small team, Kanner and Weinstein injected spurious signals to the gravitational-wave detectors in order to test whether researchers could reliably distinguish between real and spurious signals. Scharf might do well to organize a similar scheme for signals from faraway planets. Although Scharf’s title refers to astrobiology, there is precious little biology in his essay. He might consider attempting to understand how fundamental organic molecules, such as DNA or RNA, were formed in a world without organic material. We know that nucleotides are linked together forming a chain. In the presence of loose nucleotides, one chain can become two. When a separation between linked chains occurs, the separated chains can re-bond to lose nucleons and push old connections between those chains apart. The pair becomes two chain pairs, each identical to the original, reproducing itself. In a soup of nucleotides, many incompatible chains will form, and will fight with one another to grow at that other’s expense. Scharf might consider making a soup of nucleotides and watching what happens under various conditions. It does seem that reproduction of chains by splitting is a very natural phenomenon, when not blocked by competition.
Who knows what Scharf will find?
