[Allen]

Allen asked the Naked Scientists:
   
If human-kind were to be contacted by intelligence from another world, what are the odds that it will be a mechanical rather than biological?

What do you think?

[peppercorn]

If human-kind were to be contacted by intelligence from another world, what are the odds that it will be a mechanical rather than biological?

If by mechanical you mean non-biological, but still material (ie. metals, composites, silicon, etc) then I would hazard a guess that the odds are very low.

Any 'robotic' evolutionary step, would likely be short lived, if ever advantageous at all.  Although, some sections of a civilisation might choose to stay behind at 'meat' or 'machine' stage.

I think current developments in nano-technology & genetic-engineering would imply that our machines will become steadily more creature-like rather than visa versa.  So the reliance on steel & silicon will atrophy.

If the question is more meant in terms of the chance that machine-type creatures that have sprung up naturally & then come to visit us - I would say as good as zero.  Biology is unlikely to take a much different path in other parts of the universe.

There are a lot of science-fiction books premising the idea that intelligence in the universe will move quickly to some form of energy being.  I have always found this form of life an attractive concept, but I don't think current science has any current mechanisms that would support it.  However, if such a form of consciousness is possible I'd expect that most civilisations would move to it quickly (evolutionarily speaking).
Also, if no interstellar short-cut exists, then it may be the only form that the enormous distances could be crossed.

The other issue often not explored in formulas like the Drake_equation is 'Will more advanced civilisations be particularly bothered about finding their ET cousins?'.

[LeeE]

There are two separate aspects to this question: how likely are we to be contacted by intelligence from another world, and could that intelligence be 'mechanical?

First of all, the likely hood of being contacted by any type of intelligence from another world seem to be extremely slim due to the combination of the great distances involved and the lack of any means of circumventing the lightspeed limit.  These two factors mean that any distant communication i.e. by sending messages to each other, as opposed to an actual visit, will result in a gap of many years between prompt and response; if you were to ask a question it would quite likely be your descendants who got the answer.  This might qualify as communication at a societal level, but certainly not at an individual level.

Secondly, what do you mean by 'mechanical' life?  Strictly speaking, 'mechanical' precludes electricity, so you're really limited to gears, levers and slides to perform any action, with 'action' in this context including 'thought' or reasoning.  Well, we've managed to make some fairly complex and capable mechanical computing devices but they've been very limited in their capabilities and while there's no reason, in theory, why those devices couldn't be made much more complex, there are the factors of mechanical failure and driving power that would limit what could be achieved in practice.

However, if you're really thinking in terms of non-organic intelligence, as opposed to purely 'mechanical' intelligence, there's a bit more scope for intelligence to arise.  Even if it did though, it would still be limited by the distance and light speed constraints.

[peppercorn]

Strictly speaking, 'mechanical' precludes electricity, so you're really limited to gears, levers and slides to perform any action, with 'action' in this context including 'thought' or reasoning.

By what definition?
"Mechanics (Greek Μηχανική) is the branch of physics concerned with the behaviour of physical bodies when subjected to forces or displacements, and the subsequent effect of the bodies on their environment." - Wikipedia
- this kind of covers all of matter, doesn't it?

[ukmicky]

Their is also the lack of any evidence that their is life anywhere other than the earth.

[Don_1]

Allen asked the Naked Scientists:
   
....... what are the odds that it will be a mechanical rather than biological?

Presumeably, by mechanical, you mean an intelligence which is not a life form. In which case, I should say that there would have had to have been a life form to design and create the mechanical non-life intelligence in the first place. I can't see a situation where a robotic form can evolve naturally.

As ukmicky wrote, there is no evidence of life anywhere but on Earth, though I suspect it does exist somewhere. The problem is, as Lee pointed out, distance. We have been sending signals to other life forms for a long time now. One of them might be intercepted by a life form or remote station one day in the next century or three, or the next millenia or four.

Someone somewhere could have sent a signal to us, which might arrive in the next 1000 years or so. It could even arrive tomorrow, but don't hold your breath!

[demografx]

As ukmicky wrote, there is no evidence of life anywhere but on Earth, though I suspect it does exist somewhere.

Just curious, Don, what gives you that optimism?

[LeeE]

As ukmicky wrote, there is no evidence of life anywhere but on Earth, though I suspect it does exist somewhere.

Just curious, Don, what gives you that optimism?

It's simply a question of numbers; there are more stars in the visible universe than there are grains of sand on the Earth, so even though not every star will have a suitable planet upon which life could develop, unless there is a clear reason why life can have only occurred on Earth, it would be highly improbable that it hasn't occurred somewhere else.

[Don_1]

As ukmicky wrote, there is no evidence of life anywhere but on Earth, though I suspect it does exist somewhere.

Just curious, Don, what gives you that optimism?

It's simply a question of numbers; there are more stars in the visible universe than there are grains of sand on the Earth, so even though not every star will have a suitable planet upon which life could develop, unless there is a clear reason why life can have only occurred on Earth, it would be highly improbable that it hasn't occurred somewhere else.

Thanks, Lee, my way of thinking too.