Book Review: “Extraterrestrial” by Avi Loeb

Extraterrestrial by Avi Loeb

This is a really cool topic, and Professor Loeb has some really interesting things to say about ʻOumuamua.

The object zinged through our solar system from way out—at the time, the first known interstellar object observed.  (Now we have looked and found others.)

It is also weird with a capital ‘W’.   I had read some of the weirdness, but I didn’t know about the initial velocity and change in direction near the sun (with no visible outgassing).

That is very suspicious behavior, indeed, for a natural object.

Loeb reviews a lot more of the evidence and argues that what we know is consistent with… a light sail—i.e., a starship or interstellar buoy.

Wow!

If so, it’s the biggest discovery in the history of everything.

One thing I noticed is that Loeb seems to subscribe to Hansen’s answer to the Fermi Paradox (“Where is everybody?”):  we see little evidence of extraterrestial civilizations because of the ‘Great Filter’.  When a civilization just reaches the first ability to travel and signal into space, it also has just reached the ability to destroy its planet with technology.  Perhaps most civilizations wipe themselves out, as we seem to be trying to do.

Of course, there are actually a range of possible answers to Fermi (e.g., see this and [2, 3]). I’m pretty sure Prof. Loeb is aware of these ideas, and, frankly, they seem to be right in keeping with his enterprise.  Open minded and rational evaluation of many possibilities.  So I’m not sure why he skirts this fascinating topic.

Fortunately, this partial omission matters little to his main points.  However rare, and for whatever reasons we haven’t seen positive evidence of extraterrestrials, ʻOumuamua could be that evidence, and should be taken seriously as such.

By the way, Loeb’s coverage of ‘where to look’ for life is kind of sketchy.  He is just listing what he thinks are the most likely targets to focus on first.  But there are a ton of other possibilities besides his list.

Much of this book is autobiographical, and much of it is beefing about hide-bound, conservative scientific culture.  The former is more than I needed, and the latter is neither news nor interesting.  But he has a point:  I’m sure that Prof. L. might well say that we haven’t found evidence of extraterrestrial civilizations because the powers that be have refused to let people seriously look for them.

(Even he sees irony of a tenured professor at Harvard complaining that he can’t get support for his research.  Think what it is like for those of us in less privileged positions.)

For myself, I would have been happy with just the cool science, please.  Hold the mundane science politics and family history to a few pages.

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1. Avi Loeb, Extraterrestrial: The First Sign of Intelligent Life Beyond Earth, Boston, Houghton Mifflin Harcourt, 2021.
2. Stephen Webb, If the Universe Is Teeming with Aliens … WHERE IS EVERYBODY? Fifty Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life, New York, Copernicus Books In Association With Praxis Pub, 2002.
3. Stephen Webb, If the Universe Is Teeming with Aliens … WHERE IS EVERYBODY? Seventy-Five Solutions to the Fermi Paradox and the Problem of Extraterrestrial Life, New York, Springer, 2015.

 

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