Skip to main content

The Great Silence – Milan Cirkovic ****

The great 20th century physicist Enrico Fermi didn’t say a lot about extraterrestrial life, but his one utterance on the subject has gone down in legend. He said ‘Where is everybody?’ Given the enormous size and age of the universe, and the basic Copernican principle that there’s nothing special about planet Earth, space should be teeming with aliens. Yet we see no evidence of them. That, in a nutshell, is Fermi’s paradox.

Not everyone agrees that Fermi’s paradox is a paradox. To some people, it’s far from obvious that ‘space should be teeming with aliens’, while UFO believers would scoff at the suggestion that ‘we see no evidence of them’. Even people who accept that both statements are true – including  a lot of professional scientists – don’t always lose sleep over Fermi’s paradox. That’s something that makes Milan Cirkovic see red, because he takes it very seriously indeed. In his own words, ‘it is the most complex multidisciplinary problem in contemporary science’.

He points out that the paradox is far more acute now than it was when Fermi formulated it, back in 1950. Based on a better understanding of galactic evolution, we know something no one suspected in those days – that most habitable planets are going to be billions of years older than the Earth. We’ve also discovered that life began to develop on Earth almost as soon as the planet reached the right temperature to support it. So there are stronger reasons than ever for supposing that ‘space should be teeming with aliens’. Yet, even with high-tech astronomical methods that were undreamed of in 1950, we still haven’t found a scrap of evidence for extraterrestrial civilisations.

After defining the problem, the bulk of the book is devoted to a detailed review of the many hypotheses that have been put forward to explain Fermi’s paradox. Some of them are fairly hackneyed, such as the ‘zoo hypothesis’ popular in science fiction, and various takes on the ‘rare Earth hypothesis’ – that there’s something intrinsically unique about our planet and/or our species (including, of course, the Bible-style ‘special creation hypothesis’). More thought-provoking are the ‘transcension hypothesis’ – that intelligent species evolve towards an energy-efficient post-biological form that is impossible for us to detect – and the ‘simulation hypothesis’, that the physical universe is an illusion, and we’re actually living in a computer simulation (amusingly illustrated in the book with a Dilbert cartoon).

But that’s just the tip of the iceberg – Cirkovic’s list goes on and on. I can’t help mentioning a few more (without even trying to explain them) just because I love the names he gives them: ‘Interstellar Containment’, ‘Thoughtfood Exhaustion’, ‘The Gigayear of Living Dangerously’, ‘Introvert Big Brother’ and ‘The Paranoid Style in Galactic Politics’ (if I was a sci-fi writer, those titles would keep me in business for several years). To bring some order to the chaos he follows the discussion with a (highly subjective) scorecard – giving his highest rating, A minus, to a variant of the rare-Earth hypothesis called ‘Gaia Window’ (for what it’s worth, this reviewer’s favourite, the transcension hypothesis, gets a respectable B minus).

There’s one little fact I’ve been holding back to the end. Cirkovic is a professional philosopher of science, and like all philosophers he’s extremely precise and meticulous in the way he uses language (a less charitable person would say he’s pedantic). That means it’s not the lightest of reads – although it’s not overly academic, either, as you can see from the phrases quoted in the previous paragraph. If you’ve already read a few books about the search for extraterrestrial intelligence, and you’re looking for something a little deeper, then this would be a great book for you. On the other hand, if you’re new to the subject, there are probably better places to start, such as The Aliens are Coming.

Hardback:  


Review by Andrew May

Comments

Popular posts from this blog

Quantum Space: Jim Baggott *****

There's no doubt that Jim Baggott is one of the best popular science writers currently active. He specialises in taking really difficult topics and giving a more in-depth look at them than most of his peers. The majority of the time he achieves with a fluid writing style that remains easily readable, though inevitably there are some aspects that are difficult for the readers to get their heads around - and this is certainly true of his latest title Quantum Space, which takes on loop quantum gravity.

As Baggott points out, you could easily think that string theory was the only game in town when it comes to the ultimate challenge in physics, finding a way to unify the currently incompatible general theory of relativity and quantum theory. Between them, these two behemoths of twentieth century physics underlie the vast bulk of physics very well - but they simply can't be put together. String theory (and its big brother M-theory, which as Baggott points out, is not actually a the…

Beyond Weird - Philip Ball *****

It would be easy to think 'Surely we don't need another book on quantum physics.' There are loads of them. Anyone should be happy with The Quantum Age on applications and the basics, Cracking Quantum Physics for an illustrated introduction or In Search of Schrödinger's Cat for classic history of science coverage. Don't be fooled, though - because in Beyond Weird, Philip Ball has done something rare in my experience until Quantum Sense and Nonsense came along. It makes an attempt not to describe quantum physics, but to explain why it is the way it is.

Historically this has rarely happened. It's true that physicists have come up with various interpretations of quantum physics, but these are designed as technical mechanisms to bridge the gap between theory and the world as we see it, rather than explanations that would make sense to the ordinary reader.

Ball does not ignore the interpretations, though he clearly isn't happy with any of them. He seems to come clo…

Everything You Know About Planet Earth is Wrong - Matt Brown ****

This is the latest of a series of 'Everything You Know About... is Wrong' books from Matt Brown. Although I always feel slightly hard done by as a result of the assertion in the title, as there are certainly things here I know that aren't wrong (I mean, come on, the first corrected piece of 'knowledge' is that 'The Earth is only 6,000 years old' and I can't imagine many readers will 'know' that), it's a handy format to provide what are often surprisingly little snippets of information that are very handy for 'did you know' conversations down the pub (or showing up your parents if you're a younger reader).

Some of the incorrect statements that head each article are well-covered, if often still believed (for example, people thought that world was flat before Columbus), some are a little tricksy in the wording (such as seas have to wash up against land) and some are just pleasantly surprising (countering the idea that gold is a rar…