Dr Kathy Sykes is a science communicator. Her background is in physics and she spends her time making science interesting for everyone either by giving talks and writing or by creating new exhibitions and science festivals.

So is there intelligent life out there?
What a great question. It fundamentally affects the way we see ourselves – yet we really don’t know the answer.

One way to tackle the issue is to break the problem down into manageable ideas. So you can start off with easier questions like: ‘what are the chances of there being stars like our sun?’ or ‘the chances of other planets being earth-like?’. That’s what the Drake equation, featured in the programme, does so elegantly.

For one aspect: ‘is there any life out there?' - I’m pretty sure answer must be 'yes'. ‘Life’ is so damned determined. Wherever there’s water on Earth – in liquid form, at a temperature within a reasonable range – life manages to eke out an existence; from bacteria discovered living underneath metres of Antarctic ice, to creatures that survive several kilometres below the sea’s surface. And just about as soon as life was feasible on Earth around three billion years ago – it began.

So all a planet probably needs is a bit of liquid water in places where there’s a reasonable range of temperatures. We’ve already managed to find over 60 other planets in our own galaxy. And then there are the billions of galaxies beyond ours. Surely some of those other planets have suitable conditions.

Another question I think matters is ‘what counts as intelligent’? The Drake equation looks at our chances of finding a civilisation that’s learned to use radio waves. But I’d be interested in finding other forms of intelligent beings too. Like the late Douglas Adams, I’d count dolphins as intelligent, splashing around having fun in the sea, rather than dashing around like the maniacs humans must seem. But dolphins left to their own devices may never end up developing radio astronomy. They may just find ways of having more fun swimming about. But if we were in a distant galaxy, how could we ever detect dolphins on Earth?

The idea that ‘if we haven’t found anything yet – there probably isn’t anything out there’ is also known as Fermi’s Paradox. Apparently, a load of physicists having coffee were discussing this very issue, and Fermi commented ‘So if they exist… where are they?’

But it may not be so surprising that we don’t see evidence of aliens, even if they do exist. The aliens probably have to choose to send out messages if we’re to have a hope of detecting them.

After all, we’re capable of sending messages, but do we actually choose to do it? So far, we’ve just sent out a single message – a radio wave – from the radio telescope Arecibo in 1974. It was directed to a particular part of the sky, the Hercules cluster. There was a big debate at the time about the wisdom of this. After all, we might be colonised, and from experience here on Earth, that never seems to end up being much fun. So, although more messages may have been planned, only one message was ever sent.

But if anything out there were able to detect this, what would they make of it? Would they be listening at the right time in the right part of the sky anyway? If so, could they translate it? And would they take it seriously? After all, a proper scientific approach needs reproducibility. Just imagine, a scientist here makes a one-off detection of aliens: we’d probably say they were barking.

Finally, if the signal we sent was recorded, interpreted and understood, what would these aliens think of us when we just sent out a single signal, then fell silent? After all, anyone intelligent trying to communicate would surely decide to do it, then try quite hard to do it well? So maybe they all know about us, but think we’re indecisive, not too sophisticated and probably not worth talking to anyway.

So - I think there probably is intelligent life out there. Whether it thinks we’re intelligent or not, is up for grabs.

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Content last updated: 02/04/2002

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