Sulfur Critters

[Dr. Dalek]

I recently read a book by David Grinspoon, who is a comparative planetologist for NASA. His book was titled "Lonely Planets" The Natural Philosophy of alien life. Using real scientific knowledge and the history of belief in extraterrestrials he presents a number of ideas and facts in order to educated readers and encourage them to speculate on the subject.

At one point in the book he states that the characteristic of carbon to form long polymers is necessary in life as we know it, then he goes on to say that this property of carbon is shared by sulfur.

Under certain conditions sulfer can form polymer compunds,

A noteworthy property is that the viscosity of molten sulfur, unlike most other liquids, increases with temperature due to the formation of polymer chains. However, after a certain temperature is reached, the viscosity is reduced because there is enough energy to break the chains.

molton sulfur is found in abundance on Io,

Polymeric sulfur nitride has metallic properties even though it does not contain any metal atoms. This compound also has unusual electrical and optical properties. This polymer can be made from tetrasulfur tetranitride S4N

 

and like some carbon compounds sulfur compounds can be broken down for energy.

Speculating of course, could sulfur be the basis of life on some other planet rather than carbon?

[reor]

But then again, sulfer is poisonous. No, serious, is that relevant? Would carbon be toxic to sulfur-based lifeforms?

[Kermit]

A noteworthy property is that the viscosity of molten sulfur, unlike most other liquids, increases with temperature due to the formation of polymer chains. However, after a certain temperature is reached, the viscosity is reduced because there is enough energy to break the chains.

 

Wouldn't they just cool down in a cooler atmosphere and be rendered solid? Thus I don't think they'd be able to leave their world, would they?

 

Someone verify this.

 

Also, they'd have to live in a narrow stretch of temperature range, since it says that the viscosity is reduced after a certain temperature.

[SkepticLance]

Sulfur based life forms would appear to be horribly unlikely, since sulfur does not have the versatility of carbon. Simply forming a few polymers is not enough. To begin with, some equivalent to DNA would be needed, and I do not believe any sulfur compound does this. Ditto a range of enzyme equivalents.

 

On the other hand, carbon is so versatile that alien life forms based on carbon could be found in a wide range of environments.

[alt_f13]

To begin with, some equivalent to DNA would be needed, and I do not believe any sulfur compound does this.

 

You're making assumptions.

Wouldn't they just cool down in a cooler atmosphere and be rendered solid? Thus I don't think they'd be able to leave their world' date=' would they?

Also, they'd have to live in a narrow stretch of temperature range, since it says that the viscosity is reduced after a certain temperature.[/quote']

You think humans are somehow exempt from either of these conditions?

[SkepticLance]

alt F13

If I am making false assumptions, please correct them.

 

As I see it, life MUST conform to certain characteristics.

 

1. It must be able to replicate its pattern, in a way similar to DNA.

2. It must be able to manufacture structural molecules in a manner analogous to proteins.

3. It must be able to vary in its set of instructions (genetic material) and have the poorer versions eliminated, permitting evolution.

4. In a sequel to condition 3, it must have the potential to form literally billions of different complex molecules, or else evolution has no base.

 

Carbon compounds can do all the above, but sulfur????????

[reor]

So, to sum it up, sulfur is just a poor excuse for carbon. Life as i see it is a rather unique constellation. That's why i don't totally exclude the possible existence of a god. I'd even go as far as saying there is no other life in this universe.

[alt_f13]

alt F13

If I am making false assumptions' date=' please correct them.

 

As I see it, life MUST conform to certain characteristics.

 

1. It must be able to replicate its pattern, in a way similar to DNA.

2. It must be able to manufacture structural molecules in a manner analogous to proteins.

3. It must be able to vary in its set of instructions (genetic material) and have the poorer versions eliminated, permitting evolution.

4. In a sequel to condition 3, it must have the potential to form literally billions of different complex molecules, or else evolution has no base.

 

Carbon compounds can do all the above, but sulfur????????[/quote']

 

You said DNA or an equivalent is a requirement of life, and I'd argue that it isn't neccessarily. You haven't said anything too unreasonable, but you're assuming ET life would somehow operate in a similar fashion to how we do.

 

David Grinspoon seems to have a bit of a fantastical view. From what I've read, he isn't talking about 'conventional' forms of life as you've laid out; he's suggesting that there might be some as yet unimagined forms of life.

 

I tend to agree, as DNA and protein synthesis would be pretty hard to invent, even for us now, so the chances of us coming up with a new system of life that reproduces, transforums energy, whatever, may be lower than the chances of use merely discovering new life. Who knows - it could go either way, but you get my point.

 

I haven't read about the sulphur idea, but it doesn't sound as if it resembles anything close to what we observe of life on earth.

[alt_f13]

So' date=' to sum it up, sulfur is just a poor excuse for carbon.

[/quote']No. Noone suggested that in any way. That statement doesn't even make sense.

Life as i see it is a rather unique constellation. That's why i don't totally exclude the possible existence of a god. I'd even go as far as saying there is no other life in this universe.

You wouldn't consider "a god" (whatever that means in context to this thread) an extra-terrestrial form of life? And how can you consider one completely invisible immeasurable concept over another completely invisible immeasurable concept? In one post!?!

 

As far as I'm concerned, gods and aliens are the same thing until we find evidence of either.

 

At the risk of sounding like a complete hypocrite... I'm all for religious and philisophical discussion, but I tried my damndest not to let my last post steer the thread away from the subject at hand, and I think it would be beneficial for you to consider thinking about this before posting.

 

Someone let me know if I'm out of line here... preferably not in this thread.

[Kermit]

Due to carbon's versatility, I think we'd have more of a chance finding organic compounds containing sulfur instead of something based entirely on sulfur, just like the concept of silicon. Maybe instead of being based only on sulfur, it'd just be a major part of the creature's body?

[AzurePhoenix]

But then again, sulfer is poisonous. No, serious, is that relevant? Would carbon be toxic to sulfur-based lifeforms?

Actually, in deep sea areas where the sun doesn't penetrate, chemo-autotrophic bacteria actually thrive off of sulfer and are the first link in a whole food chain of organisms able to at least tolerate it. They're all carbon-based of course.

[alt_f13]

Due to carbon's versatility, I think we'd have more of a chance finding organic compounds containing sulfur instead of something based entirely on sulfur, just like the concept of silicon. ?

 

I'm sure you meant "I think we'd have more of a chance finding organic compounds based on carbon and containing sulfur than of something based entirely on sulfur."

 

Well, we really don't have much to go on, so I wouldn't be counting my carbon-based chickens just yet. That would be akin to saying "there's no other life in the universe because Earth is the only living planet we've found."

 

Maybe instead of being based only on sulfur, it'd just be a major part of the creature's body?

I don't see any reason to speculate either way. Who knows, maybe David Grinspoon is just a crazy, and Sulfur based life is a stupid idea. I just like keeping my mind open to the possibilities.

[Dr. Dalek]

"I think we'd have more of a chance finding organic compounds based on carbon ......QUOTE]

That is a redundant statement, Organic molicules have carbon by definition

[alt_f13]

Yah, that was kindof stupid.

 

The statement following it still stands, though. One example doesn't form a very good pattern.