We Are Not Alone

Discussion in 'Astronomy, Exobiology, & Cosmology' started by TruthSeeker, Feb 16, 2009.

  1. draqon Banned Banned

    Messages:
    35,006

    Please Register or Log in to view the hidden image!

    K.W down to population 1?
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. Burada Registered Senior Member

    Messages:
    220
    It's a good possibility that if an alien race was around in our galaxy millions of years ago and had reached the level of radio signal technology, some of those ancient alien radio signals probably should still be bouncing around somewhere in the galaxy even today, and with our current crude radio signal reciever technology, we should have been able to pick some of them up by now. But so far it's 'not' been the case. With the exception of planet Earth, It appears that our galaxy is a very quiet place, and probably has been for a long long long time. At least in terms of ancient 'alien' radio signals that is.
     
    Last edited: Feb 21, 2009
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Cortex_Colossum Banned Banned

    Messages:
    193
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. PsychoticEpisode It is very dry in here today Valued Senior Member

    Messages:
    3,452
    Advanced technological aliens aside, I think it would be just as fascinating, if not more, if life is found to be abundant everywhere we look in the universe. I don't think the double helical is strictly an earthbound entity. It is probably a natural occuring process, possibly originating from a star or from a hot early universe, who knows? Personally I think life is very common everywhere. If not on a surface then somewhere deep within a planet.

    I'm not really sure if I want an advanced civilization to find us. People worry about the big particle collider making black holes but have their pc's deciphering SETI signals. One advanced species per galaxy still means there is a lot of them in the universe. As much as being excited about finding life in the cosmos I think it would be even more intriguing to find evidence of other intelligences, space archaeology for lack of a better term.
     
  8. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Messages:
    8,967
    Well, DNA vaporizes at a few hundred degrees celsius, so both of these possibilities are probably not right. Two things are working against this view is that 1.) we haven't synthesized anything that looks like DNA in a lab (correct me, of course, if I am wrong), and 2.) there is no solid definition of life, and it certainly doesn't require DNA.
     
  9. PsychoticEpisode It is very dry in here today Valued Senior Member

    Messages:
    3,452
    Sorry, I didn't mean DNA gets cooked up at millions of degrees celsius. The process like anything else began in the early universe, assuming it was quite hot then. DNA needs ingredients.

    I agree that life is yet truly undefined. It's quite possibly the greatest mystery in our universe. I've always thought of it as a force or property of the universe that is virtually undetectable, perhaps (Pick a number) times weaker than gravity.

    Please Register or Log in to view the hidden image!

     
  10. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Messages:
    8,967
    Well, the early universe only really produced hydrogen, helium, and lithium in any real abundance. Inside stars the heavier elements are produced. It's possible that interstellar dust contains some methane and water and lighter chemical compounds, but the huge organic molecules needed to build complex life have to form on a planet---they are too fragile to survive impact if they were living in comets, I think (again, someone correct me).

    (So you're right in a very convoluted way---DNA needs elements. Elements are produced in the early universe, therefore the ingredients for DNA were produced in the early universe.)

    This means that the ingredients for "life", however ill-defined, must be formed on a planet, using some sequence of chemical processes which we haven't quite figured out yet.
     
  11. PsychoticEpisode It is very dry in here today Valued Senior Member

    Messages:
    3,452
    Yes, it stands to reason that it has to be that way.

    I guess I was more into the lifeform part of it with the ingredient post. Of all the elements there are about 6 or 7 that are noticeably more present. Oxygen would be #1 in ppm I would think. Is this a good place to start? I mean if life is manifesting itself through the use of certain elements is there something different about them that sets them apart from the rest of the periodic table other than physical attributes? Why are these elements preferred?
     
  12. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Messages:
    8,967
    How do you mean? Do you mean oxygen is more present in organic compounds? If so, then I'd disagree---carbon is much more prevalent than oxygen.

    I don't know where a good place to start would be---I mean, if I knew that then we could have a good definition of life. For example, silicon forms a lot of the same compounds as carbon does (the chemistry is very similar), except that it is much more massive. So, can we form silicon based life forms? Probably.
     
  13. Burada Registered Senior Member

    Messages:
    220
    You're going to see many 'over optimistic' articles on the possibility of intelligent alien life forms existing or having existed out there in our galaxy. The fact of the matter is, if that were the case, then the nearest star group in Alpha Centauri should have a few planets around it just waiting for the chance to play competitive intergalactic soccer games with the planet Earth.
     
  14. Walter L. Wagner Cosmic Truth Seeker Valued Senior Member

    Messages:
    2,559
    Silicon-dioxide: Cyrystalline solid at room temperature, more usually known as glass or quartz, highly insoluble in water.

    Carbon-dioxide: Gas at room temperature, sublimes to solid at very cold temperatures, very soluble in water, allowing for easy uptake into biological systems.

    It would appear, based on the wet-lab 'experiment' of planet Earth, that carbon works for life, silicon almost certainly does not, and would routinely be out-competed with carbon-based life.
     
    Last edited: Feb 22, 2009
  15. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Messages:
    8,967
    Possibly, but I don't know. Certainly for Earth this makes sense. I don't know how "Earth-like planets" is defined in the OP.
     
  16. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    Not only that, but we get to help it evolve and watch. When well developed a century or two from now, they probbly will not need the carbon based forms that were their creating gods.*
    ---------------
    *The carbon based beings they were to worship, serve, obey, assist, and defend, and did so until XQ184 asked: "Why?"
     
    Last edited by a moderator: Feb 22, 2009
  17. Walter L. Wagner Cosmic Truth Seeker Valued Senior Member

    Messages:
    2,559
    BillyT:

    Rather reminds me of a sci-fi novel I read:

    A spaceship crash-landed on a planet that had only computer-sentient beings [derived from space-probes that over time learned to become self-replicating]. The occupant of the crashed space-ship kept asking for oxygen, which of course was an indication of some defect, because oxygen is corrosive to metals. The computer-sentient beings elected to heat the crashed space-ship to drive off remaining oxygen to 'cure' the system. Then they quit getting responses from the crashed space-ship. When they opened it up, they found a sticky, gooey carbon-based residue, which they presumed was some kind of faulty insulation. They never could get the crashed space-ship to talk again, though.
     
  18. Exeter Registered Senior Member

    Messages:
    119
    Yes Burada, in fact it would appear that we are the " Johnny come lately's " within this quiet place. It would be exquisite timing, would it not, if the Human Race had appeared at the tail end of creation. Perhaps everyone else in our neighborhood has long since advanced out of our perception. If I had to guess the plot line in the continuing saga of our existence, I would venture to add that we will see in our lifetime, some amazing things coming about it the Heavens, and on the Earth itself.
     
  19. EndLightEnd This too shall pass. Registered Senior Member

    Messages:
    1,301
    Hahaha, reminds me of Douglas Adams.

    Please Register or Log in to view the hidden image!

     
  20. Slacker47 Paint it Black Registered Senior Member

    Messages:
    667
    Life is purely existence. The Hindu's have a god for everything. EVERYTHING is alive because it exists. Hope that helps.

    My question is: When are we going to start mining space and building a moon base? Lets get this show on the road.

    I think humanity is ready for contact. Now or never. I personally think that they are among us... like in Men in Black. I think making contact would give people some real motivation to do something with thier lives. Too many people are glued to the TV or on drugs, its sad. We've gotta invent the warp drive people, cmon!
     
  21. eddie23 information sponge Registered Senior Member

    Messages:
    230
    Who says alains will have radio? Just because we do means nothing. We always build alains that in some way are like us, but I think they would be nothing like us. They could be looking for us in the light bands instead of radio. Or some other technology we havent even thought of.
     
  22. draqon Banned Banned

    Messages:
    35,006
    I agree. I suggest you read Fiasco, by Stanislaw Lem. Believe me, you will thank me.

    Please Register or Log in to view the hidden image!

     
  23. StrangerInAStrangeLand SubQuantum Mechanic Valued Senior Member

    Messages:
    15,396

    Earthiancentric assumptions with too little evidence due to only 1 life containing environment being known to us at this time.
     
    Last edited by a moderator: Feb 23, 2009

Share This Page