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  1. Standard member sonhouse
    Fast and Curious
    28 Apr '15 16:32
    http://phys.org/news/2015-04-abundant-billion-years.html

    That may be an indication that life is rampant in the universe, eh.
  2. 06 May '15 17:28
    Originally posted by sonhouse
    http://phys.org/news/2015-04-abundant-billion-years.html

    That may be an indication that life is rampant in the universe, eh.
    But life is not made by water only. More elements are needed.
    And it is not a known fact that life couldn't use other liquids as solvents, perhaps ammonia.
  3. Standard member sonhouse
    Fast and Curious
    07 May '15 10:10
    Originally posted by FabianFnas
    But life is not made by water only. More elements are needed.
    And it is not a known fact that life couldn't use other liquids as solvents, perhaps ammonia.
    Look at the link I posted about pre-biotic molecules around stars.

    I suppose many fluids can lead to life but at the temperature of its liquid state. For instance, methane is a liquid on Titan, it could lead to some kind of life form there. The reactions would be very slow though, since the temperature is something like 200 degrees below zero F.
  4. 07 May '15 15:53
    Originally posted by sonhouse
    Look at the link I posted about pre-biotic molecules around stars.

    I suppose many fluids can lead to life but at the temperature of its liquid state. For instance, methane is a liquid on Titan, it could lead to some kind of life form there. The reactions would be very slow though, since the temperature is something like 200 degrees below zero F.
    Often people define 'life' as the kind we are. And that is with a reason.
    (1) We know what a earthly life works. Perhaps very rare.
    (2) We don't know of any other kind of life. But this unknown life is perhaps very abundant.

    So when we land of the soils of Titan, perhaps the life is there, been there for quite a while, but will be recognize it as life? I'm not so sure about that.

    Every life of our planet has DNA. Does life have to have DNA?
    Every life has to have an information carrier from generation to generation. What would it be if not DNA?

    Well, if we search for earthly life on other planets, we just not find it, even if we step on it.
  5. Standard member sonhouse
    Fast and Curious
    08 May '15 14:08
    Originally posted by FabianFnas
    Often people define 'life' as the kind we are. And that is with a reason.
    (1) We know what a earthly life works. Perhaps very rare.
    (2) We don't know of any other kind of life. But this unknown life is perhaps very abundant.

    So when we land of the soils of Titan, perhaps the life is there, been there for quite a while, but will be recognize it as lif ...[text shortened]... ell, if we search for earthly life on other planets, we just not find it, even if we step on it.
    I think there would be a lot of variation on what forms DNA would take. For instance, our kind of DNA is like two ladders intertwined. It seems to me another way would be a triplex or a quadroplex structure, they could even encode more information than our traditional DNA. Of course that is pure speculation. Maybe it could be just one long strand all curled up, who knows. It will be most interesting if life is found on the outer moons, Europa, Titan, etc. THEN we will see if our kind of DNA is endemic at least in the solar system.

    It's all speculation till probes out there show us one way or the other and that won't be happening any time soon. Maybe by 2070 or so, we will have the technology to cheaply send probes to Europa and such but right now it is extremely expensive for that particular game.

    I'm thinking in terms of developing some kind of fusion/Vasimr propulsion system that can give a sustained thrust of at least 1/20th of a g or maybe 1/10th of a g. That would be a significant development in space travel.

    For instance, 1/20th g constant acceleration to half way, then constant deceleration with the same 1/20th g gets you to a destination of 2 billion Km with zero relative velocity in about 46 days. Top speed at the halfway point: nearly 2000 km/SECOND. You turn the thruster around to bleed delta V to zero at the end of the journey.

    That seems to be within our projected technological capabilities within 50 odd years or so if there is political/scientific will to pursue such a system.

    The formula I worked out (which might be wrong) is T (time in seconds) = 2 times the square root of (distance in meters/acceleration in meters per second squared).

    Distance= 2 billion kilometers (which is 2E12 meters) divide by 0.49 m/sec^2 (1/20th g)
    =4.08E12 meters and the square root of that is about 2 million seconds, times 2 and we come out at about 4 million seconds or about 45 days.
  6. 10 May '15 20:51
    Originally posted by sonhouse
    I think there would be a lot of variation on what forms DNA would take. For instance, our kind of DNA is like two ladders intertwined. It seems to me another way would be a triplex or a quadroplex structure, they could even encode more information than our traditional DNA. Of course that is pure speculation. Maybe it could be just one long strand all curle ...[text shortened]... is about 2 million seconds, times 2 and we come out at about 4 million seconds or about 45 days.
    When we discuss about extraterrestrial life, a certain degree of speculation is inevitable by necessity.

    In our DNA there is four amino acids that build up the information, ACGT. But nothing prevent it to be exactly four? Two is enough. Six would be better. And two other amino acids have indeed being used in genetic experiments - and it works find! This mean that we could make artificial life, not dependent of the DNA we have in our cells but a super DNA with two extra amino acids! If we introduce this into living organisms, what boosting would this be in evolution? Normal DNA would soon be obsolete!

    So it is possible to think of another structure in storing of genetic information in other worlds. But it is of course nothing more than mere speculation.
  7. 10 May '15 21:01 / 1 edit
    Originally posted by FabianFnas
    In our DNA there is four amino acids...
    I think you meant "In our DNA there is four DNA bases". Amino acids are the building blocks of proteins, not DNA.
  8. Standard member sonhouse
    Fast and Curious
    10 May '15 21:10
    Originally posted by humy
    I think you meant "In our DNA there is four DNA bases". Amino acids are the building blocks of proteins, not DNA.
    I think we are going to be totally surprised by what we find in extraterrestrial life. Different structures, different chemicals, silicon base maybe, we will know in a couple hundred years for sure. ("we" being the human race in general)
  9. 10 May '15 21:30
    Originally posted by humy
    I think you meant "In our DNA there is four DNA bases". Amino acids are the building blocks of proteins, not DNA.
    Isn't Thymine, Adenine, Cytosine, and Guanine amino acids? No? Then I am wrong in this.

    I have thought so for ever. Until now. Thank you Humy for correcting me.
  10. 11 May '15 06:22
    Originally posted by FabianFnas
    Isn't Thymine, Adenine, Cytosine, and Guanine amino acids? No? Then I am wrong in this.

    I have thought so for ever. Until now. Thank you Humy for correcting me.
    your welcome. I myself have been corrected several times by people on this forum on misconceptions and things I misremembered that I previously had thought true for most of my life. I appreciated being corrected each time and learned something new each time.
  11. Standard member DeepThought
    Losing the Thread
    11 May '15 20:36
    Originally posted by sonhouse
    I think we are going to be totally surprised by what we find in extraterrestrial life. Different structures, different chemicals, silicon base maybe, we will know in a couple hundred years for sure. ("we" being the human race in general)
    I heard this discussed on a radio program donkey's years ago and as I remember it they were saying that silicon is unlikely as the bonds are too rigid compared with carbon.
  12. 12 May '15 05:30
    Originally posted by DeepThought
    I heard this discussed on a radio program donkey's years ago and as I remember it they were saying that silicon is unlikely as the bonds are too rigid compared with carbon.
    Rigid bonds means slower change. Given time it's still possible.

    As far as I know, the carbon bondings is just perfect for life ( as we know at the present. )

    Same goes for water. Water is the best solvent for life ( as we know at the present. )
  13. 12 May '15 09:48 / 1 edit
    Originally posted by FabianFnas
    Isn't Thymine, Adenine, Cytosine, and Guanine amino acids? No? Then I am wrong in this.

    I have thought so for ever. Until now. Thank you Humy for correcting me.
    What you thought was amino acids are in fact the nitrogenous bases of nucleic acids. It's a common misunderstanding. There are only three macromolecules of which all known life is made: polysaccharides, proteins and nucleic acids. Proteins consists only of amino acids, and the DNA is a nucleic acid whose base pairs are made of nitrogenous bases.
  14. 12 May '15 11:32
    I am always happy when people, who have the facts straight, correct me. This about amino acids made me dive into wiki and learn more.
    Fascinating subject! Thank you very much!
  15. Standard member sonhouse
    Fast and Curious
    25 May '15 15:29
    Originally posted by FabianFnas
    I am always happy when people, who have the facts straight, correct me. This about amino acids made me dive into wiki and learn more.
    Fascinating subject! Thank you very much!
    Meanwhile back on Europa, it looks like there are organics spewing out from an underwater ocean, the search for sodium chloride goes on:

    https://solarsystem.nasa.gov/europa/home.cfm