OT: Extrasolar planets discovered directly

[Strategia_In_Ultima]

HUH what are you talking about? This is a discussion about extrasolar life forms.....

oh but if your e-mail server is giving you problems you can open a Hotmail account temporarily and change your email adress in your profile to that adress until your original email account is back. That is, if you're talking about your account here..... otherwise, you could also open the hotmail account anyway and forward all the mails you want to keep, contacts etc. there.

[Renegade 13]

I believe he's talking about a beta test spot, if he gets one. The email notification would bounce.

[Hunpecked]

Fyron,

Thanks for the link. I thought your post was about silica structures secreted by certain prokaryote cells, but I see that the link actually refers to Dr. Tom Gold's (so far unconfirmed) speculations on the existence of true silicon-based organisms on Earth. Dr. Gold's book was indeed published in 1999; I found a review here:

http://www.findarticles.com/p/articl...80/ai_56022636

Unfortunately, none of the reviews I read mentions any discussion of silicon-based life. The focus of the book is Dr. Gold's theory of a deep underground biosphere supported by an abundance of hydrocarbons (oil and gas) left over from the formation of the Earth (i.e. of non-biological origin). Of relevance to our forum discussion is his suggestion to look for extraterrestrial life BELOW the surface of such bodies as the moon, Mars, and Saturn's moon Titan.

[Hunpecked]

We've already discovered organisms that live and breed in acid pools (something like that anyway)

So the theory that all life must be Earth life (ie. oxygen & water) has already been proved false

Well, even the creatures that exist under (for us) extreme conditions on Earth are still based on carbon, water, nucleic acids, etc. In other words, they're variations on a theme, but not a new theme.

There is no doubt in my mind that life can exist out there, its just a case of whether sentient life has yet to develop out there that I wont make up my mind until its proven either way

As long as even a little corner of the universe remains unexplored, the existence of alien life/sentience can't be disproven. So despite the skepticism of some, an enthusiast for ET's can only be proven right, never wrong.

[Hunpecked]

Also, who is to that the universe itself is not, or is a life form?

I recall a line from Carl Sagan's "Cosmos" series on PBS many years ago: "We are a way for the universe to know itself." Since we (and possibly other intelligent species) are part of the universe, then in a sense the universe itself is alive and sentient.

Or maybe just alive...

[DeadZone]

Renegade 13 said:
I believe he's talking about a beta test spot, if he gets one. The email notification would bounce.

Yea, it posted into the wrong bloody thread, forum plays up for me sometimes

[Hunpecked]

Perhaps silicon beings don't have such complex and long polymer chains and therefore are simpler, but this does not mean that they cannot be alive.

Well, "simpler" is a complex concept when it comes to alien life. If silicon-based life is unable to mimic carbon's complicated polymers, the required chemical "workarounds" might be extraordinarily complex. As a layman I can't even begin to think about the chemical gymnastics required...I think I'm getting a headache.

but I think that to support life the building blocks don't need to posess similar properties as carbon.

Which would render useless just about all of our current knowledge of life. To imagine non-carbon life we'd have to start from first principles, e.g. what chemical structures could/would our chosen element(s) form to reproduce, react to stimuli, evolve...? (My head hurts more.)

For all we know, there might be iron-based life forms out there debating whether or not carbon-based life is possible.

See below.

Plants breathe carbon dioxide, yet are still considered Terran life.

Green plants also consume oxygen, just like we do, though they're net oxygen producers. BTW, one gets a real sense of our place in the universe by remembering that we survive only by breathing plant excrement.

What are the similarities between, say, a stag deer and a clump of moss?

Strangely enough, I understand that the genetic differences are smaller than one might think. Note also that they're similar enough chemically that they both survive in the same overall environment (a North American woodland, say) and the deer can even eat the moss.

Returning to iron and silicon as building blocks of alien life, I'm actually kicking myself here for overlooking popular scifi "silicon-based" lifeforms that actually seem quite plausible: mechanoids (droids, robots, automata...). So far our own efforts in the areas of AI and self-directing automata are fairly primitive, but we're far enough along to envision far more sophisticated forms worthy of the adjective "alive". Although it's hard to imagine how mechanical "life" could develop on its own, we already know of one carbon-based lifeform that may some day give rise to such "iron-based" life.