waters relationship to life

[lucaspa]

Is it just me or is there anything that doesn't need water to live? why is life so attracted to water?

 

It's not that life is attracted to water, but rather that water has unique properties as a liquid that are conducive to life. I suggest getting hold of a biochemistry textbook. They all have several pages devoted to the role water plays in living organisms.

 

The only other liquid that has comparable properties to water would be liquid ammonia. Unfortunately, ammonia is only a liquid at < -33°C, which is too cold for the reactions that are life to proceed quickly enough.

[Moontanman]

Higher pressure broadens the range that NH3 is liquid

 

At 60 atm, for example, which is below the pressures available on Jupiter or Venus, ammonia boils at 98°C instead of -33°C, giving a liquidity range of 175°C. Ammonia-based life need not necessarily be low-temperature life!

 

http://www.daviddarling.info/encyclopedia/A/ammonialife.html

 

Boron based life might be more conducive to Ammonia as a solvent.

 

http://www.daviddarling.info/encyclopedia/B/boron-based_life.html

[Mr Skeptic]

Water is a fairly nice chemical; a very polar good solvent, has a good liquid range, a high heat capacity, can be used and produced in hydrolysis and condensation reactions (used extensively by life as we know it), transparent to visible light. I don't know whether some form of life could use a different solvent, or even no solvent at all.

[lucaspa]

Higher pressure broadens the range that NH3 is liquid

http://www.daviddarling.info/encyclopedia/A/ammonialife.html

 

Good point Thank you for the information.

 

Boron based life might be more conducive to Ammonia as a solvent.

 

http://www.daviddarling.info/encyclopedia/B/boron-based_life.html

 

However, as the author notes, boron has other problems: "One of the biggest drawbacks to boron as a basis for life it is [sic] scarcity. On Earth, its abundance in the continental crust is only about 10 parts per million, so that any biology would seem to depend on their being present some mechanism for bringing about greater local concentrations of the element."

 

Another drawback is that boron apparently doesn't make polymers. It's difficult to imagine life without polymers to act as catalysts or hereditary material.

 

So, while boron might work well with ammonia as a solvent, the other drawbacks would seem to limit its utility as a basis for life.

[Moontanman]

Truth be told if I had to bet I would bet that all life in the universe is based on water and carbon. there may be some extremely rare exceptions but all things being equal carbon and water have a big advantage. Having said that it's important to note that we only have one data point, for all we know the galaxy crawls with boron or silicon or silicone life, or nitrogen or phosphorus or something we have no idea of yet. Very small statistical fluctuations could, in some limited locality, bring about a solar system with huge amounts of boron or some other chemicals that are even more conductive to life than carbon and or water. That life might get along great without the things we think life has to have and maybe these other chemicals react in ways we are unaware of that makes life much easier with that chemical. Until we put some more data points on our curve we simply will not know. All we can do is speculate and use the life we know as a template.

[Mr Skeptic]

Well, I could consider a sufficiently advanced robot to be life. However, I think that robots would have to be intelligently designed, so they'd also need some chemical-based life to make them.

[Moontanman]

I would also have to acknowledge a AI as alive but not in the biological sense. Possibly intelligence is what many people think of as life but if an artificial intelligence is considered alive would not even the simplest robot have to be considered alive as well? As a bacterium is alive to us a simple computer controlled machine would appear alive to an AI? possibly the galaxy is being occupied by machine intelligence that knows not it's origin in biological life and ponders the connection. Possibly they know of us and are studying us to find out how they came into being? maybe that is why they do not contact us for fear of spoiling the data and ruining their chance to know their origins, then again maybe frogs wouldn't bust their ass when they jump if they had wings

[lucaspa]

Very small statistical fluctuations could, in some limited locality, bring about a solar system with huge amounts of boron or some other chemicals that are even more conductive to life than carbon and or water.

 

I think those would be at the far end of the bell-shaped curve. We can get an idea of the relative abundance of elements in a solar system by analyzing the spectrum of the star. After all, both the star and its planets formed from the same nebular cloud. So, do you know of any stars that have an abundance of boron?

 

That life might get along great without the things we think life has to have and maybe these other chemicals react in ways we are unaware of that makes life much easier with that chemical.

 

That presumes we have a huge gap in our knowledge of chemistry! The evidence suggests we don't have a large gap. After all, chemists have been trying out possible combinations of chemicals for over 300 years, using more and more exotic conditions. So, the odds are that, if boron polymers are easily made, we would have made some before now.

 

I agree we only have one data point about life, but we have many data points about chemistry. And life is, essentially, chemistry.

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Well, I could consider a sufficiently advanced robot to be life. However, I think that robots would have to be intelligently designed, so they'd also need some chemical-based life to make them.

 

1. A sufficiently advance robot would be considered sapient, but not necessarily "alive". It probably would not have internal mechanisms either for growth or reproduction.

 

2. I don't see any natural process in the universe that could produce an AI. If nothing else, there is no natural process to refine the metals that go into the body of the robot and the semiconductors or chips. So yes, ultimately robots are artifacts manufactured by a chemically-based lifeform.

[Mr Skeptic]

1. A sufficiently advance robot would be considered sapient, but not necessarily "alive". It probably would not have internal mechanisms either for growth or reproduction.

 

A simple matter of scale. The robots would have to reproduce or they would die out. If you take a robot city or factory, that would have inside it the necessary capabilities to grow and reproduce.

 

2. I don't see any natural process in the universe that could produce an AI. If nothing else, there is no natural process to refine the metals that go into the body of the robot and the semiconductors or chips. So yes, ultimately robots are artifacts manufactured by a chemically-based lifeform.

 

I agree. But some chemical life could make the robots and then the robots wipe out their creators. A life form that couldn't evolve on its own, if you agree that it is a life form. I could, however, see limiting "life" to chemical processes only. I mostly mentioned them as they could satisfy the criteria for life, but clearly don't need water. In fact, they could be very flexible in their material design.

[Mokele]

1. A sufficiently advance robot would be considered sapient, but not necessarily "alive". It probably would not have internal mechanisms either for growth or reproduction.

 

Not to delve too far into science fiction, but while I'd agree for Terminators, I'm not so sure for Cylons. Given a LOT of time, and a lot of technological advances, it may be possible to create a robot that operates at such a fine scale that its operating units are much like cells, and it has similar capabilities.

 

Alternatively, could non-growing, non-reproducing robots produced by an automated factory be considered 'life' in much the same way as a bee hive, functioning as a sort of 'superorganism'?

 

However, I do agree that it's moot, since such machines would need a non-mechanical race to create them in the first place.

[lucaspa]

Not to delve too far into science fiction, but while I'd agree for Terminators, I'm not so sure for Cylons. Given a LOT of time, and a lot of technological advances, it may be possible to create a robot that operates at such a fine scale that its operating units are much like cells, and it has similar capabilities.

 

There was always a question whether the 12 were machines or biological organisms. Since BSG had a Cylon and an H. sapiens having a fully fertile offspring, that would make those Cylons and H. sapiens the same species! It also meant that they were no longer robots but were using biological chemicals, i.e. DNA instead of circuits.

 

Alternatively, could non-growing, non-reproducing robots produced by an automated factory be considered 'life' in much the same way as a bee hive, functioning as a sort of 'superorganism'?

 

Good question. But notice "factory" Bees are still reproducing by processes within (at least a specialized) bee. Not a separate factory.

 

However, I do agree that it's moot, since such machines would need a non-mechanical race to create them in the first place.

 

Yeah. Still no natural process to manufacture the first one.

 

What I think would happen is that the definition of "alive" would end up changing (despite Mr. Skeptic's attempt in Politics to have a definition frozen) to include anything that was sapient. Star Trek explored that idea both with Mr. Data in TNG and the Doctor in Voyager.

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A simple matter of scale. The robots would have to reproduce or they would die out.

 

Not necessarily. Remember, individual parts can be replaced so that a robot would, for practical purposes, be immortal.

 

 

But our current definition of "alive" means the individual has within itself the means to grow and reproduce. A factory is not within the individual.

 

But some chemical life could make the robots and then the robots wipe out their creators.

 

That doesn't change the fact that robots ultimately are a manufactured entity -- no process in the environment could produce a robot. Chemistry can produce a biological organism.

 

I could, however, see limiting "life" to chemical processes only.

 

From your posting in Politics, to be internally consistent about definitions you personally would have to.

 

I mostly mentioned them as they could satisfy the criteria for life, but clearly don't need water.

 

That's the problem. They don't satisfy the criteria for life. We would have to change the definition before they could qualify.

[Mr Skeptic]

But our current definition of "alive" means the individual has within itself the means to grow and reproduce. A factory is not within the individual.

 

I meant that the factory itself (not the individual) would satisfy the criteria to be alive. Alternately, a robot might contain a factory within itself. However it does seem doubtful that it could be shrunk to the extent that we have. Not only are we alive as organisms, but we are made of living cells.

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That doesn't change the fact that robots ultimately are a manufactured entity -- no process in the environment could produce a robot. Chemistry can produce a biological organism.

 

Isn't evolution an environmental process? Evolution --> Chemical life --> robotic life --> now you could find robotic life in places inhabitable by chemical life.

[lucaspa]

I meant that the factory itself (not the individual) would satisfy the criteria to be alive.

 

The factory would not. That would be separate from the individual robot and the factory would not have the sapient features you are attributing to the robot. It would be an automated assembly line.

 

Alternately, a robot might contain a factory within itself. However it does seem doubtful that it could be shrunk to the extent that we have.

 

It's that "shrinkage" that would be the problem. Remember, the robot is refined metal, plastics, doped semiconductor chips, etc. It's extremely unlikely that you are going to get a steel mill and oil refinery contained within the robot.

 

Isn't evolution an environmental process? Evolution --> Chemical life --> robotic life --> now you could find robotic life in places inhabitable by chemical life.

 

I think you are confusing natural selection with evolution. It's a common confusion. Evolution is "descent with modification". This is not so much an "environmental process" as a process that will happen when the following conditions are met:

" Many kinds of systems are evolutionary ... In all such systems there are populations, or groups, of entities; there is variation in one or more characteristics among the members of the population; there is HEREDITARY SIMILARITY between parent and offspring entities; and over the course of generations there may be changes in the proportions of individuals with different characteristics within populations. " Douglas Futuyma, Evolutionary Biology, (1999) pg 4.

 

Robotic life would have to satisfy the conditions to undergo evolution.