Pun Salad

I picked this book up on impulse from the Portsmouth Public Library. A decent read, sometimes mind-blowing, marred somewhat by the author's politics.

The concept is pretty simple: we're here, we're (somewhat) intelligent, there's nothing to say we're particularly special in the universe, therefore it's easy to conclude there's almost certainly other intelligent life out there. OK, not on Mars or Venus (sorry, 1940s SF fans). But on other stars' planets. So let's use the tools at our disposal to look for it.

Fine. Some people go a lot further than that: the language they use betrays their fervent hope/belief that there must be ETIs Out There. Is that a proper scientific mindset? I don't think so.

The author, Keith Cooper, starts at an unexpected place with a chapter on "altruism." Which turns out to be kind of a shorthand. If we assume ETIs, can we also assume the ETI's motivations and attitudes toward (say) us would be benevolent, and willing to share? Intelligence aside, is whatever evolutionary path they followed likely to have resulted in a psychology that would be similar to ours?

And (for that matter) let's not put intelligence aside. Say that some alien evolutionary process produces living beings capable of complex responses to the environment. Would that result in an "intelligence" we'd even recognize, let alone communicate with?

Well, you get the idea: evaluating the likelihood of ETI involves looking hard at "how we got here". This takes Cooper down some unexpected paths, for example, plate tectonics. Which (many believe) caused upwellings of trace elements into the oceans, driving the proliferation of species.

How rare are planets with plate tectonics? We don't know.

And then there's the Moon: it's huge. Because it's huge, it stabilizes Earth's axial tilt, which gives us a relatively stable climate, giving species precious time to adapt and thrive. And yet, it was (probably) caused by a freak collision between Earth and some Mars-sized early planet.

How likely is that to happen elsewhere? We don't know that either.

Then there's the possibility that "intelligent" species have a finite lifetime. That would explain why they're not obviously knocking on our door: they're dead. Cooper goes into (you might find this depressing) detail about various ways our species could bite the dust, either by suicide (climate change, nukes, aieee!) or natural catastrophe (e.g., asteroids, nearby supernovae or gamma ray bursts).

These musings are only a small part of the book. Cooper delves into the details of the history and current status of searches for ETIs. Radio? (What frequencies, Kenneth?) Maybe the ETIs are using lasers? Masers? Infrared? Neutrinos? Maybe we should be looking for Dyson (RIP) Spheres?

And another issue: should we be proactively sending out signals to other systems, hoping for a response? This is surprisingly controversial. My old college classmate David Brin is mentioned here about being pretty freaked out about efforts in that area. Who exactly should bear responsibility for "talking" to ETIs? How should "we" decide the content of such messages? Do we hold a democratic vote? I say: just let Brin decide.