Methane-Based Life Possible On Titan 69
Randym writes: With the simultaneous announcement of a possible nitrogen-based, cell-like structure allowing life outside the "liquid water zone" (but within a methane atmosphere) announced by researchers at Cornell (academic paper) and the mystery of fluctuating methane levels on Mars raising the possibility of methane-respiring life, there now exists the possibility of a whole new branch of the tree of life that does not rely on either carbon or oxygen for respiration. We may find evidence of such life here on Earth down in the mantle where "traditional" life cannot survive, but where bacteria has evolved to live off hydrocarbons like methane and benzene.
membrane (Score:4, Interesting)
Making a shell is nice, but that's hardly the most fundamental aspect of life.
Re:membrane (Score:4, Insightful)
Sure it is. That's how you concentrate things. Probably wasn't the first thing life did - replication has to happen first, but it was an early (and energetically favorable) change.
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Making a bag is much simpler than making a self-replicator. I don't know about you, but when I try to figure out if something is possible, I start with the hardest part.
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Way back in 1990, I worked for about six months informally on the theoretical design of assemblers based loosely on Eric Drexlers design plans.
For them the 'bag' or shell definitely looked like one of the hardest parts. The design required that the 'bag' be a rigid crystalline shell, and that it had to be structurally strong enough to support the internal mechanisms. It also had to survive temperatures from around liquid nitrogen or cooler - the assemblers functional working temperature, - all the way up to
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I never really got to the level of detail of looking at heat dissipation in assemblers themselves.
I did look at heat dissipation in a computer that was assembler constructed. The machines design was for a flat grid of roughly 1 million CPUs connected in a 4D hypercube array, designed as a flat plate of 10 mm x 10mm x 0.2 mm - mounted in a much larger support structure. At its peak power it would consume an estimate of about 40KW of power and put out 40 KW of heat. My sketch solution to cooling was to hav
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making a micelle was the very first step in creating life
http://en.wikipedia.org/wiki/P... [wikipedia.org]
the next step was the chemicals concentrated in the micelle being able to control it
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making a micelle was the very first step in creating life
What was making the micelle ?
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go pour a little soap/oil in some water and shake it
congratulations, you've "made" micelles
micelles are self organizing. you don't "make" sea foam, it's a simple product of natural wind and wave with sufficient chained carbon compounds
micelles occurred naturally in the early earth out of non organic processes that produced simple hydrocarbons
then the rudmientary self-replicating processes also occuring naturally in that time period, and sputtering out, uncontained, joined up with micelles and sustained. bec
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then the rudmientary self-replicating processes also occuring naturally in that time period
Sounds like you have two very firsts steps then, the formation of a self-replicator, and the formation of these micelles, in arbitrary order. And it seems to me that the earliest replicators would benefit more from free interaction with the medium they're in, rather than being locked up in a sealed bubble.
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when you're working, can you do it in the middle of a concert hall? the middle of an interstate highway? in between a screaming fighting couple?
or do you benefit from having a private room/ cubicle?
same principle
the wide world is full of nasty chemical interactions and potent free radicals ready to destroy anything they touch. rooms help immensely
not only do they protect, they isolate. a self-replicating process can sputter out if not restricted to it's own products
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when you're working, can you do it in the middle of a concert hall? ... or do you benefit from having a private room/ cubicle?
Depends on whether I'm a concert musician or a programmer, I guess.
a self-replicating process can sputter out if not restricted to it's own products
I also sputters out if it can't get rid of waste products, or does not get enough energy/building materials. These require a properly controlled transport mechanism through the cell wall.
If you just start with naked replicators, they can evolve to use a cell wall, and they can evolve to develop a transport mechanism. It limits the amount of things that need to spontaneously form, so it makes it more likely to happen.
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And it seems to me that the earliest replicators would benefit more from free interaction with the medium they're in, rather than being locked up in a sealed bubble.
What if the early replicators or proto-replicators benefited from the differences between the outside of the bubble, and the inside of the bubble?
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What's the difference?
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Well, it eats, excretes, and reproduces, all that's missing is some form of self-organization.
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It's worse than that. He's dead, Jim!
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I wonder how religious groups would rationalize something like this?
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What is life? Maybe active homeostasis? Maybe any system where continuing active homeostasis is required to maintain the system and for continuing on-going functionality. Where the failure of active homeostasis leads to irreversible 'death' where the system cannot be restarted... of course that still doesn't cover hibernation.
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Why aren't you feeding the poor instead of posting on Slashdot? Isn't that the most important thing? You could have given some well deserved, undernourished child one of your twinkies. Oh wait, the child lives in some stinking desert without a functioning water well in five miles.
Or maybe we could use some of the earth sensing satellites (created by those self same hair-brains) to map out artesian flows and show people on the ground where an inexpensive well could be dug. Or we could give the kid a vacc
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"We are the only life forms. Get over it"
You make an assertion without a shred of proof.
The earth formed life over 3.7 billion years ago, and you are saying no other rocky planet in the universe has had similar conditions at any time in the last 13.8 billion years? That's unreasonable.
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Harebrained.
Brains don't have hairs, but hares have brains....
Re:based vs inhaling vs exhaling (Score:5, Informative)
Slashdot summaries are confused, when not outright inaccurate - news at 11. If you actually want to know details, you're pretty much required to RTFA.
As for your question, humans (/mammals/animals/multicellular organisms) are a recent addition, not typical of Earth-based life.
Earth life is water-based (well, suspended anyway), with lipid(hydrocarbon)-based cell walls to keep vital chemistry sufficiently concentrated to continue. Eventually blue-green algae evolved their ability to photosynthesize and poisoned the planet with toxic oxygen byproducts, which some of the survivors later managed to harness as a fuel. But that's really an incidental development so far as life itself is concerned. Before that life was all chemovores - likely consuming complex organic molecules from either hydrothermal vents and/or their fellows for both nutrients and energy.
In this case researchers have found some other hydrocarbons that can form "cell walls" with properties very similar to those in our own cells, except that they operate in a liquid methane suspension instead of water, at temperatures that would render our own cell walls solid. One of those hydrocarbons is acrylonitrile, a compound found in Titan's atmosphere, so the building blocks for cell walls at least are already present there.
Who wants to bet they shit crude oil? (Score:2, Funny)
Once this get out, we won't have Any problems with funding for NASA. :)
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Classic joke, but it obscures the fact that an actual solution to these jokes exists.
Uranus's Roman name is Caelus [wikipedia.org] and since all the other planets use Roman rather than Greek deity names in English, there is no reason this name could not be adopted for the 7th planet.
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Apart from Pluto.
[gets popcorn; retires to a safe distance]
Oxygen-based life possible on Earth (Score:5, Insightful)
Although the third planet from the Sun suffers from crippling gravity and heat, scientists long held that the corrosive atmosphere of oxygen and water vapor is what forbids life as we know it.
If we didn't melt instantly from the heat or collapse from the gravity, the oxygen would burn us up in a flash! Scientists have been unable to explain how so much uncombined oxygen could exist in the atmosphere of such a hot planet, but new data suggests life *is* possible with a carbon-based shell of special molecules called lipids and proteins.
etc... etc.. etc...
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I've seen their VHF transmissions about their god "Hank Hill"! If those fiery demons ever come to our Titan, they would drill wells for water, contaminating other methane and ethane we breathe.
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Although the third planet from the Sun suffers from crippling gravity and heat, scientists long held that the corrosive atmosphere of oxygen and water vapor is what forbids life as we know it.
Discussed on Stack Exchange:
http://worldbuilding.stackexch... [stackexchange.com]
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Uh... clue, OP: methane and benzene are organic molecules based on carbon.
Doesn't rely on carbon or oxygen? (Score:4, Insightful)
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That said, the idea of using a different base for respiration doesn't really require much imagination. We use oxygen because that's the environment we evolved in; any life evolving in an atmosphere without oxyg
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Methane is CH4. The C is for carbon. Come on people!
You left out the last part: "...does not rely on either carbon or oxygen for respiration". I'm no chemist nor am I an expert in exobiology so somebody who is may feel free to educate me if I' wrong here. Having said that, the way I understand it a hypothetical methane based life form on Titan would use complex hydrocarbons as an energy source by reacting them with hydrogen like for example reducing ethane and acetylene to methane and it would consume i.e. respire (inhale) hydrogen for that purpose. So the s
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And unicorns *may* suddenly leap out of my bum, but without some form of supporting evidence for that claim I'm not going to take it seriously. All life we know of depends on cell walls to maintain a sufficient density of organic chemistry, and now we know that cell walls functionally much like our own could exist on Titan, using compounds we already know exist in the atmosphere. That's a big boost for the argument that there might be life on Titan.
As for porous materials - life might well start there, bu
Exclusive: pix of Titan ancient civilizations (Score:3)
According to a news flash I just made up, NASA sent a probe to titan and not only found definitive proof of life there but they were able to take pictures of ancient civilizations of methane based life on titan... According to a new hypothesis formulated by the lead scientist on the mission, "This must be some very old fart" :p
Titan is a most beautiful moon (Score:3)
Titan is gorgeous.
https://upload.wikimedia.org/w... [wikimedia.org]
http://www.astrobio.net/wp-con... [astrobio.net]
True color: https://upload.wikimedia.org/w... [wikimedia.org]
It's also the setting of the first chapter in the brilliant hard sci-fi novel Fiasco [wikipedia.org] by Stanislaw Lem.
I can't wait for new probes [wikipedia.org] to report from there.
I'd love this to be true, but... (Score:2)
Does the surf on Titan's methane sea foam? (Score:2)
If these materials that act as surfactants for liquid methane at cryogenic temperatures occur naturally on Titan the obvious evidence for their presence would be foam. The next probe to follow Huygens should be an autonomous boat to study the shores.
Already exists on earth ... (Score:2)
... down in the Earth's mantle. Where do you think all our "fossil" fuel deposits came/come from [Deep Hot Biosphere] [wikipedia.org]?