A Review of "Extraterrestrial" by Avi Loeb
2021 September 01

I’ve been listening to “Extraterrestrial” by Avi Loeb published in January 2021. It is a decent book with some flaws in it’s presentation and dialogue. It’s about what is believed to be the first extra solar object found called “Oumuamua” and how it’s weird properties might indicate that was made by intelligent extraterrestrial life. It also covers a fair bit of the author’s academic career which seem to be very successful based on how many committees he’s on, and some of the issues he sees with the academic community and how funding is allocated.

He draws a lot of attention to how odd “Oumuamua” is as an asteroid. It has a very strange ratio in it’s dimensional ratios. He says that most objects in our solar system are cube like, while this object is very long. He also talks about how weird the tumble is and it had a weird trajectory. The weird trajectory was where the object sped up when it has getting close to the Sun in a way that couldn’t be explained by off gassing as like a comet does. The author thinks that radiation pressure from the sun might be to blame for that acceleration, which he uses to jump into the concept of “Solar Sails.”

I think the coolest topic that he covers is the “StarShot” initiative which is how we could launch a probe to the nearest star, Alpha Centauri, that would arrive within 30 years using a light sail. He talks about how this is the quickest and most feasible solution because it uses powerful lasers to accelerate the probe instead of a chemical rocket which would have to be incredibly large, while a laser can be powered from the ground. I think this is one of the coolest concepts of all time, as who doesn’t like the sailing metaphor.

He then talks about how SETI did the wrong thing on focusing on radio signals as a sign of Extraterrestrial intelligence instead of other markers like industrial chemicals or varying brightness from planets cross a star or other biological signs indicated by spectroscopy. I personally would argue that they picked out the best indicator with their knowledge, understanding and political climate. I do agree with author that radio signals are a poor indicator because they will only exist for a brief time as a powerful source and it is very hard to differentiate between random noise and a valid signal.

Even now our radio signals are reducing power and becoming more directional than in the past, and that’s just 90 or so years of improvements on techniques. So there’s a small window on a cosmic time scale where that might be visible to other people. My other point is that most signals in the modern day are encrypted, and encrypted messages are generally hidden. They try to look as much as random noise as possible. Finally, would it even be possible for us to decode an alien message as their thought process is likely to be totally different from ours? These are my personal thoughts on it, and I wish that he had covered some of these challenges before dismissing what SETI has tried. It really is a shame that they don’t get that much funding, but it is a very hard topic and I think our funders just see more potential in other academic work at this point.

The final point I want to cover is how he attacks various fields, and goes on how things should be. He believes that more high risk research should be funded, which is perfectly fine, but provides no criteria to help separate the woo from the potentially fruitful paths. He also attacks a lot the string theory and multiverse stuff. I don’t fully understand his arguments for why there’s not much proof for them, but he mentions that just because a model is elegant does not make it right. He also talks about how people are most creative when they are young and how it’s a shame they aren’t given more power to go down different paths in research. It goes into how there’s a lot of group-think in academia. However he provides no solutions for avoiding or reducing it. I realize that organizations are not his field of study, but I’m sure he has ideas on how to fix it which are not shared.

Overall, I found the book to be pretty interesting, but it has some structural issues with tangents on the authors life and other ideas rather than focusing on the actual proof given by “Oumuamua.” He talks more about his personal views on philosphy and his path into science. He does provide a lot of good insight into the search on how things could be more fruitful. So this book was a 3.9 out of 5 for me.

*****
Written by Henry J Schmale on 2021 September 01