Extraterrestrial: The First Sign of Intelligent Life Beyond Earth

My review and reflections on the book EXTRATERRESTRIAL – The First Sign of Intelligent Life Beyond Earth, by Avi Loeb


When its publication was announced some months ago, I was eagerly anticipating this book. When I read it, my expectations were not disappointed. My impressions, as a Ph.D. astrophysicist, are very positive for a series of reasons that I want to briefly discuss.

The author, a top astrophysicist, professor and director at Harvard, discusses the case of Oumuamua, a highly anomalous celestial object that was serendipitously discovered and monitored during a limited period using several types of telescopes. Orbital calculations showed that this object was of interstellar origin. Its characteristics of exceptionally high luminosity and periodic variability, the lack of a comet-like tail, and its non-gravitational acceleration induced some astronomers – in particular Loeb – to suggest that this object might be of artificial origin, presumably the relic of a probe sent from an exoplanetary civilization. The only way to justify its very elongated shape is to guess it is a very thin sail seen almost edge-on pushed by the radiation pressure of the Sun. The author discusses the meticulous calculations that he and his collaborators did in order to reach this preliminary conclusion before the object inexorably went away from the solar system.

According to Loeb, all of these findings do not really require acrobatics to fit them in the accepted beliefs of astronomy, but rather an iron organization and preparation in the case that similar objects cross the solar system again. And the soon operational Large Synoptic Survey Telescope might furnish us with crucial new discoveries in this sense.

I particularly appreciated when he said that research on Oumuamua-like objects should be considered much more mainstream than research on topics such as dark matter, superstrings, and multiverse, for which there is no factual evidence to confront with mathematical models. And this is shockingly evident.

Sadly enough, research is concentrated on what is perceived as fashionable at the time ie: dark matter etc. This is a very limited approach, in my humble opinion. But – if a shared will existed –  we might discover reality is more simple and fully measurable: through classical physics, statistics, good astronomical observations and calculations. There is nothing really exotic in thinking that a possible alien probe crossed our solar system.

The book is an excellent source for those who really want to know and understand how an astronomer works and reasons in real life, and how a hypothesis is always born from rigorous calculations that are carried out directly on the observed data. Professor Loeb shows how and why the extraterrestrial hypothesis in order to explain the nature of Oumuamua was favored against more natural explanations (comet or asteroid with peculiar characteristics) that some of his colleagues proposed in alternative to his one, maybe with the intent to avoid exotic ones, which would have not been conveniently accepted by the standard academia.

In reality, the astrophysical discussions that Loeb does in this intellectually stimulating book range over many other aspects of astrophysics and cosmology, which correspond to what he effectively did during his very prolific career as a researcher and professor, including the Starshot Breakthrough initiative aimed at sending Laser-powered light sails to the system of Proxima Centauri (same concept as Oumuamua if it were really of extraterrestrial origin). The way in which he presents all this is methodologically very useful to people – especially young students, but also attentive nonprofessionals – who want to approach seriously physical science. Loeb is very able to show how mathematical and logical rigor coupled with the sense of exploration can bring to real scientific discoveries, which should never be limited to mere mathematic gymnastics but rather strongly attained by the observed facts of Nature and at the same time propelled by a strong dose of rational imagination, and passion for the matter.

In few words, Loeb shows outright to everyone that a real scientist is supposed to be an investigator that is constantly and humbly able to communicate with Nature (in the spirit of Galileo, Newton and Einstein, for instance) before pleasing that ivory tower that wholly the academic world still represents. Science is a human endeavor involving all humanity, which has the right to be constantly informed on the recent findings, even without false modesty when true anomalies are encountered. Revolutionary discoveries are born from a balanced coupling of mathematical and experimental rigor, healthy skepticism and well-grounded open mind and imagination.

The author uses very often astounding analogies in order to explain his concepts, regarding Oumuamua specifically and astrophysics in general, showing that he cares that they are fully understood. All this shows very clearly how being able to communicate science is the aptitude of people who understand problems in their realistic light before solving them.

This book caught me very much because it reminded me of my own experience when I was doing astrophysical research after I obtained my Ph.D. All of a sudden, my boss wanted to interrupt my research on FU Orionis nova-like protostars, because he thought that our group could have done a larger number of publications on XY UMa variable stars. In the first case, a lot of exploration was still necessary at that time, in the second case (where we know substantially almost everything) only mathematical refinement was demanded. At that point, I was not motivated anymore. After all, do we carry out astrophysical research only with the goal in mind of accumulating tons of papers for our careers (inside our ivory tower) or with the one of studying in depth better what we do not know yet and that could have really a revolutionary impact if we are tenacious enough to go ahead like panzers?

I then changed observatory and – in parallel with extrasolar planets, SETI and still my beloved FU Orionis stars – I concentrated my attention on the observational investigation of highly anomalous plasma-like atmospheric luminous phenomena. Of course I didn’t have a lot of support from my colleagues, most of whom still think that such phenomena do not exist or, at most, that they are “just a curiosity”. However, I enjoyed doing this research (on which I published a lot), which is still going on, because I felt that trying to understand the confinement mechanism of a plasma (natural or not) can potentially open doors to several aspects of fundamental physics and maybe to something else too. I was and I am passionate in this kind of research (and not only in this one, which was just an example of my interests) only because I feel I am dialoguing directly with Nature in order to search for the hidden key of a coffer, and not because I have to account for it to the temple of the priests of Academia, who keep on thinking that humbleness in science means kneeing inside that temple.

I believe that scientists in general should imagine living in a home whose ceiling is represented by the starry vault and not the one of a church-like building. Even if in some cases I do appreciate mathematical “toy models” as I think this is the language in which Nature is written. I believe that our rational thinking must be put in practice mostly on what we are able to observe, namely on experimental data regarding things that we do not yet understand well enough. Of course, all this was only a digression, just to show how Loeb’s book reminded me of my own research experience.

I saw that his book had already many and fully deserved positive feedbacks, but frankly, I do not understand the reasons of some negative comments. I have often the impression that on one side too many people do not understand science in the making, which is not made of “revelations” but rather of mechanisms, processes, ideas, calculations and sometimes confutations, and that on the other side too many among scientists do not understand the importance of making analogies or metaphors (this reminds me much David Bohm) in order to let the others understand the problems to be solved or the importance of drawing philosophical considerations following certain scientific discoveries.

In addition, yes, science cannot only be mathematical gymnastics in order to build up a career  following the easiest and most convenient path, which favors talented guys but not true explorers. It must have a meaning, which can be shown to everyone. Science should not be a “Pickwick Circle” but rather the spearhead of human ingenuity, to which everyone has the right to participate. Because shining a light into the darkness is the biggest source of happiness for humanity.

In spite of a mere chronicle of Loeb’s findings on Oumuamua, his writing deals with how Science is supposed to be: exploration – and not contemplation – of the unknown.

Due to all these reasons, I strongly recommend this book, especially to young people, who represent the science of the short-term future.