Stephen Hawking warns "we should avoid aliens"
 

re: Stephen Hawking warns "we should avoid aliens"
 

I think Prof. Hawking has been watching 'V' :p

re: Stephen Hawking warns "we should avoid aliens"
 

Methinks his quotes have been misinterpreted - he said which, in previous discussions, was referring to the culture shock that happens when a more technically advanced people meet a more primitive one.

re: Stephen Hawking warns "we should avoid aliens"
 

Everyone seems to assume that any aliens would be carbon-based lifeforms dependent wholly on organic chemistry (i.e. Carbon, Hydrogen, Oxygen) like we are.

If an intelligent lifeform evolved completely separately from us in an entire galaxy, then why couldn't they be dependent on sulfur instead? Maybe in our biology where we need water, they'd need a liquid form of chlorine. Maybe our planet would be considered inhospitable and need to colonise Jupiter instead?

And if these lifeforms that are intelligent enough to build transport able to carry them safely whilst sustaining them across many lightyears, would the be reliant fossil fuels? Would need our human/animal carasses for food?

Given we are the only observable lifeforms (certainly within our nearest planets) our evolution is a basically a fluke. Given the size and diversity of the universe other flukes would occur, that's for certain. But would other evolutionary flukes exactly replicate our biology? Of course not - unless we shared a common ancestor that was spread in different directions at the start of the universe. And given that the observable universe appears to lack multicellular organisms, its extremely unlikely.

Professor Hawking is a genuis of course, but I find it odd he doesn't consider this. Noone seems to apart from the writers of Mars Attacks! NASA are obsessed with finding water and consider that to be the root of extra-terrestial lifeforms.

Seems a bit short-sighted to me.

---------- Post added at 15:42 ---------- Previous post was at 15:40 ----------

Well he does say: "He explained: "We only have to look at ourselves to see how intelligent life might develop into something we wouldn't want to meet."

But the prevailing consensus is that any lifeforms capable of such immense inter-steller travel would be highly evolved and therefore less hostile than us? Surely other aliens should avoid us instead?

re: Stephen Hawking warns "we should avoid aliens"
 

I was thinking same way as punky.

I would warn aliens to avoid us..we are the scary ones (or is that sick ones)

Sign on moon will say..beware of the humans :)

re: Stephen Hawking warns "we should avoid aliens"
 

Does that include illegal aliens.

re: Stephen Hawking warns "we should avoid aliens"
 

re: Stephen Hawking warns "we should avoid aliens"
 

Good post punky. it's refreshing to see an educated post in the forum :)

re: Stephen Hawking warns "we should avoid aliens"
 

We as carbon is the most common material, on would assume that other life forms would be carbon based.

Silicon based is another possibility.

re: Stephen Hawking warns "we should avoid aliens"
 

This, imho, explains the some of the options - fermiparadox

re: Stephen Hawking warns "we should avoid aliens"
 

Beware the extra terrestrial who arrives without the cab fare home...;)

re: Stephen Hawking warns "we should avoid aliens"
 

Every morning there's trail on my kitchen mat :erm: its either slugs or ectoplasm :mad: whatever they are they doesn't like washing up.

re: Stephen Hawking warns "we should avoid aliens"
 

We have evolved to suit our environment. Our atmosphere is air which is a mostly Nitrogen (~78%) and Oxygen (~20%). Nitrogen is pretty much inert and its hard to bond with and to isolate from compounds. So few organisms can use it baring some special types of bacteria that act on nitrates. Off the top of my head I can't remember anything (from A-Level Biology and Chemistry) that acts on N2 gas. So we use the next most prevalent gas which is a lot more reactive: Oxygen. Although its only 20% but its more than enough for us as we expel the vast majority of Oxygen we breath in (IIRC we use about less 10% we breath in). We breath out Carbon Dioxide which is handy as plants can use this to convert back to Oxygen. Hence we have a sustainable source of ambient Oxygen.

I have seen or heard of nothing that says organisms on a planet with a different atmosphere to ours can't adapt to whatever is available. Alien life forms don't have to be reliant on Oxygen and water. I'd be suprised if they did.

Given the near infinite amount of genetic mutations over billions of years, the chances of any complex life forms being even remote similar to us is infantessimal IMO. Professor Hawking acknowleges this by saying they might be yellow or lizard-like but why can't their internal chemistry be different as well as their appearance?

So given that they'll probably find out planet inhospitable, hostile and the fact they'd be hyper-intelligent and hyper-evolved and therefore more peace loving (look out peaceful we've become over a mere 2000 years), I don't think we'll be invaded and enslaved by aliens.

re: Stephen Hawking warns "we should avoid aliens"
 

As Captain Kirk discovered when he faced the Horta...

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re: Stephen Hawking warns "we should avoid aliens"
 

Evolution = peaceful?

They could be the dominant race after a bloody war, looking for planets to conquer or harvest for materials.

It would be interesting to postulate which other elements may be the basis for life, extrapolating from carbon, naturally our first thoughts turn to elements in the same group - silicon, germanium etc.