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San Francisco, 10:51 PM
Sun Nov 29
11 posts in the last 24 hours
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08/18/09
08/18/09
08/18/09
Yup. But not on a solid body. There's clouds of carbon compounds floating in interstellar space (Can you say CHON? Did I read Gateway last week?) and spectrographic analysis shows radiation will make the molecules link up. And it's not hard to get some of the molecular rings (2-ring Vinyls) to open up and attract side chains, creating amino acids. There was an article in Scientific American about pre-biotic amino acid synthesis a few years ago.
08/18/09
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08/19/09
-Kle.
08/18/09
Proteins can do stuff, which calls for a specific sequence of amino acids, and for a mechanism to push the protein into a functional shape.
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07/30/09
But in writing that this study "offers evidence that our ancestors were, indeed, extraterrestrial," the writer here falls into a logical fallacy that characterizes exogenesis and a lot of other bad science- the creation of an exciting, tempting hypothesis, and the subsequent attempts to pigeonhole data to support that theory, without the logic to support that. Even at face value, the claim that comets within our solar system may have been capable of supporting life makes no connection between that theoretical life and the actual life existing in our planet. It is still infinitely more likely that life arose on this planet, even if it also arose independently many other places.
The summary sentence that concludes this piece is far more accurate than that in the lead. This result is not inconsistent with a theory of panspermia, but neither does it provide any evidence to support that theory.
07/30/09
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07/30/09
If you're referring to what I think the popular interpretation of the "star dust" theory is, then you're a little off base. It's already clear that the heavy elements required for life - as in the ones that make up our bodies and pretty much everything around us - are formed at the end of stellar lifetimes when fusion reactions run rampant as stars start dissipating gas and desperately trying to fuse helium to stay alive. That part's pretty well proven, while not unquestionable of course.
07/30/09
But to go in the other direction, while we know what elements are required for life as we know it thus far, does that extend to knowing what is required for life in any possible form? When scientists speculate about life being possible because of the presence of water, do they just mean earth-like life, or do they know that water is an absolute requirement?
07/30/09
To that end though - you're absolutely right; I think that there's a lot of great hypothesis based on "what's required for life" as far as mixing the right things together and applying the right conditions, but there's simply still no explanation for what happens once those ingredients and conditions are met, which is what I think you mean.
And about water - I think the understanding is that water is required for life "as we know it," or life that we would be able to identify. :)
07/30/09
And water was probably a bad example. It seems like we are always ready to get excited over the idea of conditions similar to those on earth when, say, oxygen isn't even a requirement much of the life we know about, outside of water. We should be more creative!
07/30/09
My first thought on reading this was to wonder if you were obscurely referring to alien-sex. My second thought was to wonder what it says about me that this was the first thing I thought.
So, is that what you were referring to?
07/30/09
But hey, I got no problems with a little alien sex as long as all parties are willing participants.
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07/30/09
Of course, that says nothing about how they got/formed in space, or the whole re-entry process. Which is where I think you really nailed it in your last sentence.
07/30/09
And technically life developing on earth would have to deal with several of the problems you listed; no oxygen until oxygen-producers evolved and high exposure to radiation due to this, as well as extreme temperatures.
07/30/09
"Ok, so, how the heck did life on Earth develop? I mean, molecules growing slowly more complex in a chemical soup somewhere? People seem to have enough issues with evolution as it is."
"I know- maybe the life came to earth on comets! From space!"
"... ooooo-k. That's simpler?"
"Yeah, cuz it didn't have to develop here, it just had to ride in on a space rock or something! From space!"
"Soooo... on some other planet, or a gas cloud or something, molecules grew slowly more complex in a chemical soup until the first basic life was created... and then a volcano or meteorite impact or something else happened to send it flying in our direction, it randomly hit the infinitesimally small grain of dust in the galaxy that is our planet, survived re-entry, found the local conditions liveable, and then proceeded to develop into complex life on our planet."
"Uhhuh! A planet or gas cloud... in space!"
"So why is that any simpler?"
"... did I mention it came from space!?"
It adds complexity instead of removing it. Its sort of like responding to the question "well, if God created the universe, who created God?" with the answer "God's dad!"
That's not saying it didn't happen that way, but the simplest answer is usually the correct one, and in this case, the simplest answer is "groups of complex organic molecules naturally tend to create more complex and ultimately self-replicating forms over time, thus beginning life", and thus occured independently on our planet, rather than it being very rare in the universe and we were just luckily enough to be hit by one of those miniscule and rare bits of space debris that can actually store it in a useful form for long periods.