Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

B A Long Time Ago in a Galaxy Far....

  1. Mar 6, 2017 #1
    The universe is said to be built for life. How many billions of years after the Big Bang when the first supernova spread the first ingredients of life and the first solar system with life possible? Is it 2 Billion years after Big Bang or even less or double that, estimate?
     
  2. jcsd
  3. Mar 6, 2017 #2

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    Who says that?
    Is the desert built for the cactus?

    We don't know how early life was possible - we don't even know the conditions where life can arise, apart from the one datapoint of "the conditions on Earth were fine".
     
  4. Mar 8, 2017 #3
    You mean there is a possibility only life exists on earth in the almost 200 billion galaxies now?

    I mean how many billion of years after the Big Bang when planets have already cooled and formed enough for life to flourish. Or maybe our solar system was one of the first solar systems that has formed and cooled after the Big Bang?
     
  5. Mar 8, 2017 #4
    Our solar system certainly isn't one of the first to form.
    https://en.wikipedia.org/wiki/Chronology_of_the_universe#Galaxies.2C_clusters_and_superclusters
    On July 11, 2007, using the 10-metre Keck II telescope on Mauna Kea, Richard Ellis of the California Institute of Technology at Pasadena and his team found six star forming galaxies about 13.2 billion light years away and therefore created when the universe was only 500 million years old.[32] Only about 10 of these extremely early objects are currently known.[33] More recent observations have shown these ages to be shorter than previously indicated. The most distant galaxy observed as of October 2013 has been reported to be 13.1 billion light years away.[34]

    But we don't know if life could form.
     
  6. Mar 8, 2017 #5
    It is a possibility since we don't yet have any indication of life elsewhere, and the conditions necessary for starting life are unknown.
     
  7. Mar 8, 2017 #6

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    I think it is unlikely, but it is certainly possible. The only way to rule it out is to find life elsewhere.
    Well, technically a few microbes from Earth are on various space probes in the solar system now, but I guess we don't count them.
     
  8. Mar 8, 2017 #7

    Grinkle

    User Avatar
    Gold Member

    I suspect the OP is referring to discussions like this.

    https://en.wikipedia.org/wiki/Fine-tuned_Universe

    Here is some discussion of that. It takes heavier elements, which take some stars exploding, so carbon at least did not exist in any planets orbiting the first generation of stars.

    http://www.space.com/17441-universe-heavy-metals-planet-formation.html

    Edit -

    It leads to more focused discussion, imo, to talk about 'live as we know it' rather than life in general. In my freshman astronomy class the TA used to say 'you speculate about rocks that think?' then he would snort derisively.
     
  9. Mar 8, 2017 #8
  10. Mar 8, 2017 #9

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    See the fine-tuned desert for the cactus. There is also good evidence that completely different laws of physics could lead to a very similar universe: The authors remove more than half of the known particles and get rid of the weak interaction completely, and still get a universe with similar chemistry, stars, planets and so on.
    DNA building blocks. Not DNA.
    Just random hydrocarbons, some of them with nitrogen or oxygen attached. All sorts of those molecules, not just the molecules used in DNA.
     
  11. Mar 8, 2017 #10
    No DNA has been found.
    DNA is chain of fairly small and simple carbon based molecules.
    It is those simple molecules that have been found.
    Lots of other simple organic molecules exist outside of Earth as well as those few which could combine to form DNA.

    If DNA had been found, that would be incontrovertible evidence of extraterrestrial life.
     
    Last edited: Mar 8, 2017
  12. Mar 8, 2017 #11

    Grinkle

    User Avatar
    Gold Member

    I get it. Douglas Adams (I think, apologies if I am giving credit to the wrong genius) talked about the water in the hole that was proclaiming itself the most fortunate water in the universe to have a hole that so perfectly matched its shape. Its easy to fall into that mode of reasoning.
     
  13. Mar 8, 2017 #12
    Do you guys know that biological processes are what give rise to oxygen in a planet. I read that if earth and mars both neighbors in the same solar system can give rise to oxygen in the atmosphere.. then it could be natural process in the thousands (if not millions) of exoplanets out there, is it not.
     
  14. Mar 8, 2017 #13
    The first life on Earth did not need atmospheric Oxygen or produce Oxygen.
    However when a life form evolved photosynthesis, (the first organism that could be called a plant), then Oxygen became a big deal.
    This was very bad luck for most of those earlier forms of life.
    https://en.wikipedia.org/wiki/Great_Oxygenation_Event
     
  15. Mar 8, 2017 #14
    So it's possible a planet doesn't necessarily need oxygen but methane or other chemicals coming from volcano vents and sentient creatures can exist that feed on methane. I once read a book by Nick called Oxygen about early life and the merger of the mitochrondria and another bacteria. Any good new book lately about this lately?

    Whatever. The universe is so big. If there are intelligent lives out there. Only the criminals or sick or deprived penal colony would come to earth. So in the future if they come. They should look sick with big insect like heads... lol...
     
  16. Mar 8, 2017 #15
    Photosynthesis allowed for a very big increase in the amount of energy available.
    It appears that after the first primitive plants, evolution went into a higher gear, and soon after there were multicelled organisms, and eventually animals.
    https://www.sciencedaily.com/releases/2013/01/130117084856.htm

    It is possible for life to exist without O2, but complex multi celled life?
     
    Last edited: Mar 8, 2017
  17. Mar 8, 2017 #16
    You left out the majority of evolution. Archaebacteria, eubacteria, single-celled eukaryotes. Plants are quite far along.
    I don't think there's a reason to expect alien life to follow anything similar to plants and animals.
     
  18. Mar 9, 2017 #17
    Those organisms living near underwater volcano vents are powered by others besides oxygen.. but do they really evolve separately from the surface organism? But how could we still share the same DNA with them.

    Is it possible they just moved from the surface to the underwater volcano vents? If not, then independent evolution like possibly in Europa?
     
  19. Mar 9, 2017 #18
    I agree, although photosynthesis was a major leap for evolution of life on Earth, probably the biggest leap of all time other than nucleic acids or their precursor.
    It seems likely therefore that any alien evolution would also hit on that very major advantage at some point.
    Not necesarilly would such life resemble the plants of Earth though.
     
  20. Mar 13, 2017 #19
    I've always seen the number eight billion years after the Big Bang before metals were common enough to produce the simplest life.

    Planets cooling has little to do with it, planets cool very quickly in astronomical time. What took time was the production of heavy elements. After the Big Bang there was only hydrogen, helium, and lithium (mostly) and big stars had to ignite, burn down their fuel, then explode. The first generation of stars would have to already exploded in order for any complex chemistry to happen.
     
  21. Mar 13, 2017 #20

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    That's not what the article says. The very first sentance says "NASA-funded researchers have evidence that some building blocks of DNA, the molecule that carries the genetic instructions for life, found in meteorites were likely created in space." Some building blocks. Not DNA.

    How do you expect people to take you seriously if you misrepresent your references?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: A Long Time Ago in a Galaxy Far....
Loading...