NASA News Conf: astrobiology finding that will impact search for evidence of extraterrestrial life
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NASA found some organisms, in fact they found some bacterium or something well change the define of organisms.
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They found bacteria that are based of arsenic, which is normally toxic to most/all life forms. Thus, the possibilities are even larger than what we would’ve expected as far as diversity goes.
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After taking a look at a periodic table, I can see how arsinic could be used in place of phosphorous. It is directly below it which means it has pretty similar properties. The same could also be said of the other elements making up a dna strand.
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LancerSolurus wrote:
After taking a look at a periodic table, I can see how arsinic could be used in place of phosphorous. It is directly below it which means it has pretty similar properties. The same could also be said of the other elements making up a dna strand.Right, it is the same idea as the Horta, which is based on silicon rather than carbon. It is yet another Star Trek prediction proven.
Dammit, Jim, I’m a doctor, not a bricklayer!
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Silicon was known to be a possibility for a while, arsenic is another matter entirely because while silicon is mostly inert, arsenic is some really nasty stuff.
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Not really FF. Funny how arsenic is mentioned just as this pops up in the news
http://www.bbc.co.uk/news/science-environment-11886943
Silicon has been talked about by scientists as well for years as a basis for life. We’ll never know until we meet someone/something, simple as that. Like the chick in Independance Day said,“I hope they bring back Elvis”
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FriendlyFire wrote:
arsenic is another matter entirely because while silicon is mostly inert, arsenic is some really nasty stuff.While arsenic might be a more potent toxin than silicon, both are toxic for similar reasons… they can replace elements that are required for life-supporting organic molecules, including DNA.
Both carbon and silicon are in Group 14, and have a valency of 4, which means that they will react with just about anything. Truly inert elements are in Group 18 with a valency of 8.
This is similar to Lancer’s point that arsenic and phosphorus are in Group 15. From a Periodic Table point of view, arsenic is to phosphorus as silicon is to carbon.
That is why I mentioned Hortas.
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I know that. The point is that Si is mostly found in compounds such as SiO2, which are perfectly inert, while As can be found more often as a pure element and that it and many of its compounds are very potent poisons.
It’s a lot easier to use an inert element for a building block of life than it is to use something that tends to wreck anything multicellular…
You might as well consider Germanium-based life forms, but again it’s just even tougher to use Ge than it is to use C or Si because it’s both far more rare than C or Si and it’s more toxic than C or Si.
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Bullwinkle wrote:
Dammit, Jim, I’m a doctor, not a bricklayer!
:lol: I used the same quote in a similar discussion on another forum. Maybe it is quoted a lot of times these days, on various fora discussing the NASA find.
Btw Bullwinkle: you never enlightened me whether or not your nick comes from the song in the Pulp Fiction soundtrack
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FriendlyFire wrote:
I know that.If you understand the chemistry, then what are you arguing about?
Or, if not really arguing then I misunderstood. Anyway, here is further explanation, just in case:Silicon and arsenic are poison to humans, but they might be a normal part of a Horta’s diet.
SiO2 is stable, on Earth, at STP, in absence of catalysts, but that does not mean that it is inert. The same could be said of C02. But it does not really matter to our previous discussion because these are molecules rather than elements.
Consider chlorine and sodium. They are both extremely reactive and toxic, but sodium chloride (table salt) is both stable and a required part of our diets. The molecules have very different properties than the elements themselves.
The reason that semiconductors work is because of the magic of valence-four elements. They react with just about anything except for Group 18 elements. While the reactivity of carbon and silicon is low, they are far from inert.
The NASA announcement proves that our previous notions of “life” are wrong. It was widely believed that life required carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur. Now we know, for certain, that other chemistries can also work.
This opens the door to the possibility of life in other temperatures, gravities, light, radiation, and atmospheric environments. The big deal here is that it means that universe could be teaming with life, although it might not be anything like terrestrial life.
In other words, what is “toxic” to you may not be toxic at all to a Horta… or to other alien life forms.
Le malheur des uns fait le bonheur des autres, non?
@Moohhead: Yes, the Horta analogy fits NASA’s announcement perfectly. As for my nickname, I answered, and gave you the entire story. You never responded. Check your PMs from several months ago.
