Is there really life on other planets?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by pluto2, Mar 13, 2009.

  1. D H Some other guy Valued Senior Member

    OK. Miscellaneous free thoughts moved to [thread=94481]this thread[/thread]. Continue with the discussion on life elsewhere in the universe in this thread.
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  3. rcscwc Registered Senior Member

    Ya. Till yesterday, we did not know how to travel faster than sound. In fact, fluid mechanics makes it very HARD to do, what with sound waves getting piled up as a barrier. Though that barrier was yet to breached, already fluid mechanics theories predicted the scenerios post that breach.

    In case of speed of light barrier, such a math is simply not there at all.

    Correct. Presently we do not know how to do it.
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  5. TheHandyman Registered Member

    Yes. Life exists.

    Here's my theory behind faster than light travel, teleportation, whatever you feel apt a name:
    Enter a singularity (with technology capable of it)
    Once inside infinity, leave infinity.
    Exit an entirely different singularity.
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  7. sifreak21 Valued Senior Member

    if there is a billlion trillion trillion stars in the univers which there probably is and there is life on 1 of the planets of every 75 trillion there is still billions of different life forms.. if we are a freak of nature im positive there are other freaks of nature out there to

    1. i will disagree with you on this as its been pretty well debunked
    2. possible

    heres what i think i think of the ant in the rain forest. most ants have never seen a human or there are ant colonies that have never been seen by humans but i gaurentee they are out there.. just because we havent seen them doesnt mean they arnt there. or maybe they have seen us but we havent seen them

    if we are just a "freak of nature" there are other "freaks of nature" out there but they may not be the same as us or even breathe oxygen
  8. RAW2000 suburban Registered Senior Member

    Last edited: Aug 14, 2010
  9. Kajalamorth The Doctor Registered Senior Member

    I find that belief laughable. Man was not created in gods image... its the other way around.

    What is your view of life? I hope you don't think it has to be like ours. We are composed of Carbon. Perhaps we will find lifeforms are composed of calcium or Silicon. It all depends on the conditions. Earth can be seen uninhabitable by another alien. Water is only needed for life on earth. Heck maybe we will find life forms that drink liquid nitrogen.

    Also mars probably doesn't have life. There is proof that it had more water and from what modern science knows is that you need pressure for water to be on a planet or sublimation will happen. So maybe Venus has tons of water? But its too hot so it will be a gas.

    Maybe Earth is the only planet with life like ours? Evolution is random and people need to get that idea in there head. If we can create the clone of earth and the sun in the same exact conditions it will probably be different. No matter what. That's why I like Stephen Hawking's view on life on other planets.
  10. Parmenides Registered Senior Member


    This question contains a mix of scientific, philosophical and theological questions. I will address them seperately.

    1. From the standpoint of science, we don't know as yet whether life exists on other planets. It is now clearly known by science that other planets besides the ones in our solar system exist, and detecting them is now fairly routine (the observatory I volunteer at has detected one of about five Jupiter masses using microlensing techniques). However, few of these planets seem suitable habitats for life as many have the mass of Jupiter or are larger and orbit very closely to their parent star, sometimes much closer than Mercury's distance from the Sun.

    There are promising missions coming up which should help us narrow down the potential range of planets which might have life. It is likely of the planets detected and we will detect, only a fairly small percentage will be suitable for life. It is fairly easy though to extrapolate from the known numbers of statistics that it is certainly possible there are millions of planets and their moons in the galaxy which might be habitable, and billions or trillions of such habitable planets might exist in the universe.

    As life has arisen on Earth through evolution, from a scientific point of view, there is nothing (at least as far as is known) that should prevent life arising elsewhere in the cosmos. However, we don't know at this point in time whether life has only ever arisen on Earth. There is a lot of evidence which suggests the precursors of life, like organic molecules (which are often found in dust clouds), water, suitable planets, etc are fairly common in the universe. But complex life is fragile and easily destroyed, and the evolution of intelligent life especially seems highly improbable and frought with many risks. It seems on Earth in all the 4.6 billion years of the planet's history, sentient life capable of using technology has only arisen just once (maybe a few times if you include tool use among animal species). This in itself suggests intelligent beings, if any exist besides us, are rare.

    I think life is likely to exist elsewhere in the universe. I think the discovery of extrasolar planets in such numbers strongly improves the chances of life arising elsewhere in the universe. But I think there are compelling scientific reasons, given in good books on the subject, which suggest intelligent life is rare because its evolution depends on many contigent factors 'working' together in a fortunate way to allow intelligence to emerge.

    2. Philosophically speaking, I don't see any reason why intelligent life should not exist. The universe does not seem to have an inbuilt teleology towards or against life, but there does seem to be a set of pathways which allow complex systems to emerge from simple precursors (DNA and RNA) based on fairly straightforward chemistry. It seems as though life is a 'natural' development from the laws of physics, chemistry, and time. But there are also many contingent factors which indicate life cannot exist unless certain pre-conditions are met, some of them relating to the strength of certain forces, the values of certain constants, and so on. Some have argued this indicates there is 'intelligent design' or 'fine-tuning' in the universe, perhaps either at the hands of an intelligent creator who wants to instantiate a universe which allows for the possibility of sentient, free beings to exist (as theists like Keith Ward argue), or maybe our universe is just a 'lucky' pick out of an infinite number of different worlds which exist (multiverse theory), or it is just brute, random fact and there is nothing more to it.

    Philosophically speaking, I don't see anything repugnant about accepting there is life elsewhere in the universe. On Earth we co-exist with millions of species of creature who are just as 'alien' as anything we could meet elsewhere. Why could we not accept evolution can do the same on other planets elsewhere in the universe, when the evidence indicates the laws of nature apply universally through the universe at all times and places?

    3. Theologically speaking, I don't see an issue with aliens. The Bible does only mention two orders of beings besides God, humans and angels. However even classical theists like Augustine and Aquinas accepted that God could have made other worlds, including worlds better than this one, if he had so chosen. Only Leibniz seemed to argue God could only create this universe, as it was the 'best of all possible worlds' and most fitting with divine justice and wisdom. The doctrine of the incarnation relates to the notion of mankind needing redemption from original sin, which is achieved by Christ's atoning and sacrificial death on the cross. When the merits of this act are appropriated by faith in humans, they become justified in the sight of God and also adopted heirs of God's kingdom. But Aquinas argued quite interestingly God could have redeemed humanity without needing the incarnation or the death of Christ. Classical theism leaves plenty of room, thanks to God's omnipotence, to permit God to choose any kind of world he chooses to make (so long as logical contradiction is not involved). God could also achieve redemption of other beings by other methods, perhaps unknown and unknowable to us.

    The main problem with the theological view is God seems very concerned over human beings, who are really tiny, petty creatures in the cosmic scheme of things. Blaise Pascal rightly felt fear before the universe, which seems infinite on the micro-scale and infinite on the macro-scale, and pins human beings between two gigantic abysses in a lonely and perhaps meaningless universe where the divine does not seem to be evident. The view of humans in the Bible seems very narrow and anthropocentric and does not do justice to the immense range of living creatures on Earth (30 million species) as well as the immensity of the wider universe, unless perhaps somehow the incarnation involves and redeems them as well. Why should God be so concerned over human beings, and not say, bacteria, gibbons, monkeys and chickens? Why should an infinite, omnipotent and omniescent being, powerful enough to make an entire universe, worry about tiny, petty creatures like humans, any more than we worry about mites, fleas and bacteria? I think this is quite a challenging question to consider, if you are a theologian or believer.

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