SETI. Yet again I've found myself in recent days trying to answer questions about whether or not there's intelligent life elsewhere in the universe. Yet again I find myself in the role of sourpuss, or is that sceptic? One item that actually helped focus this for me was another question on how aliens might show up brandishing their weapons and licking their lip-like-features, before squishing humanity.
Let's just go through this. Do I think there's life - recognizably familiar, reproducing, information carrying arrangements of molecules - elsewhere in the universe? I think there's an awfully good chance. Do I think any of it's 'intelligent', like wot we are? Well, I think the odds are far worse, but given the size of the universe then sure, it just may be tucked away somewhere we'll never, ever, know about. So, on the face of it this kind of kills the notion of the mother-ship arriving over suburbia and hordes of iPhone wielding creatures texting us into submission. Except...well, except that there's another way to look at things.
I'll start by saying that I know this is not an original idea. Let's take the history of life on Earth. Intelligence - in the form of machine creating, modeling, mathematically fixated organisms - has not played a big role over the past 4 billion years. Dinosaurs were fabulously successful as a type of life, a hundred million years of romping (plus all the chickens running around today), extraordinary adaptations and variations...but not a wheel, differential equation, or moon shot in sight. Humans, by really all measures, are freakish - an extraordinary and wonderful oddity. This doesn't even begin to address the issue of the microbes, ancient and incredible terraformers and survivors, but no intelligence in the way we define it.
Given all of that, I think in-the-incredibly-unlikely-event that aliens show up on our doorstep they will be no smarter than your average jellyfish. They will not have built spaceships, at least not the way we think about spaceships, with flush toilets. They might have built some kind of structure to carry them through space, much in the same way that ants build a nest, or hermit crabs snag a nice shell, but they won't be doing this as an outcome of design review, they'll be doing it instinctively. These will be organisms that have evolved to treat space much like we treat the oceans. Sailing, drifting, or zooming, when they find a useful resource (if they need such things) they make planetfall and set to work, maybe like locusts, or maybe less destructively.
Is this crazy? Maybe, but less so than the other options. There are still significant physics problems. Assuming any such life originated on a planet, then climbing out of that gravity well is always going to be tough. Perhaps this filters out all but the tiniest organisms, lofted up to the exosphere, evaporated out into space. Or perhaps it filters out all but the oddities....
Obviously I should stop drinking the water.