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Aliens are here?

  1. Feb 22, 2004 #1
    Do we need to prove Aliens exist?
    Some people are pretty much convinced that there’s life out there, and I mean just do the math, what proof do we really need that we’re not alone? Maybe I should say that lack of evidence doesn’t mean we’re alone.

    I’m guessing from the math, that intelligent civilizations originating from other planets, have existed for millions of years, if not billions of years. I think those figures can be calculated if you take some things into consideration, for instance the rate of suitable planetary formation.

    In the sense that I’m talking about, life in the Universe would start off quite slowly and I guess in the phase of the Universe we’re at now, would begin to explode with life.

    I won’t be surprised if I get attacked for this theory, but I would appreciate any constructive criticism.
     
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  3. Feb 22, 2004 #2

    LURCH

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    One problem with this idea is the lack of alien encounters here on Earth. The one civilised species we know of (ourselves) colonises wherever it goes. If other technological civilisations exist, and have existed for millions of years, and if one of these civilisations is within the Milky Way gallaxy, then every habitable planet shouild already be entirely populated by them. A gallaxy-wide supercivilisation should be in place and readily apparent. It is for this very reason that scifi stories like Star Trek came up with the "Prime Directive", not because it makes any sort of sense or is the least bit believable, but because without it one can't reasonably speak of other civilisations existing without our knowledge of them.
     
  4. Feb 22, 2004 #3

    Ivan Seeking

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    Re: Re: Aliens are here?

    I think this assumes way too much. What motivates an ET? What are his limitations? Why would he colonize given the technical burden of doing so? Finally, there is evidence that ET has been here; just not proof beyond doubt.

    Try another angle. The math indicates that many, many ETs are almost certainly out there. We can already imagine potential methods for escaping the SOL limitation on travel. There should be some ET's that are between thousands to millions of years more advanced than us. Whether or not ET can, will, or did visit requires assumptions about future technology for which we have no frame of reference. The fact is, we don't know what's possible for a highly advanced race of ETs.
     
  5. Feb 22, 2004 #4

    selfAdjoint

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    The math indicates that many, many ETs are almost certainly out there

    No it doesn't. You can make any kind of assumptions and plug them into the Drake equation and get any number oout that you want. GIGO.

    Actually stars like the sun - just on the edge of dwarfdom but not quite over it - are fairly rare, I think there's only about one other in our 100 ly sphere (except double stars like alpha Kent.). And they say not all the galaxy but just a band of it has gas clouds with the heavy elements we need. And so on. You can keep plugging in worst case values and make Drake say we're alone in the galaxy.
     
  6. Feb 22, 2004 #5

    Ivan Seeking

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    and with billions of galaxies...

    Also, with the recent discovery of many planets, the worst case Drake numbers just got larger.

    There is no reason to think that our solar system or planet is unique.
     
    Last edited: Feb 22, 2004
  7. Feb 22, 2004 #6

    Ivan Seeking

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    I recently heard a NASA scientist talking about the Hubble. She said that at some point when they focused the Hubble on a dark spot in space, a place where nothing can be seen in our galaxy, a spot "the size of a grain of sand held at arm's length", they saw over two thousand galaxies. The point being just how vast a place the universe really is. If we humans are a one in a billion by chance, then there are, or were, or will be billions and billions like us.
     
  8. Feb 23, 2004 #7

    russ_watters

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    Hubble Deep Field Stay tuned for the sequel due out this month: Hubble Deep Field 2.

    While I am of the opinion that there is probably life out there, I also agree that the Drake equation, while interesting, doesn't really tell us anything right now.

    Also, the first post and the title of the thread don't seem connected...
    The laws of physics provide a frame of reference for such predictions. They make it highly unlikely any have or ever will visit us.
     
  9. Feb 23, 2004 #8

    Ivan Seeking

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    It does address the magnitude of the numbers involved.

    They [the laws of physics] make it appear unlikely based on our understanding of physics at this time. Since physics is by no means complete, or at least it is not recognized as such, we can’t know the physics of the year 500,000 A.D.; that is we have no valid frame of reference from which to divine the future. We can’t extrapolate physics like a trend line.
     
  10. Feb 23, 2004 #9
    The title of the thread is essentially trying to include “detection or visitation” into the math. Although I’m not sure what evidence there is, we have been visited which Ivan Seeking was referring to, I can pretty much say that our priority is to detect other intelligent civilizations. For the reason we have SETI, the same reason ET would have to look for life elsewhere in the Universe.

    Once it did find life, the question then becomes, what stage of evolution would that life be at? If a more advanced civilization detected ours, say at a time when we we’re still primitive apes, communication wouldn’t really work, but instead they would simply observe our evolution.
    They could probably extrapolate that in another few million years our evolution would reach what it is today, and simply let things take its own coarse. I don’t think ET would have any reason to alter another species evolution, it simply wouldn’t need to, but this is just my impression. I like 2001 A Space Odyssey for this reason.

    Also I’m more inclined to believe that traveling throughout the Universe isn’t limited by the speed of light.

    SelfAdjoint made an important point that the heavier elements needed seem to only occur in certain locations around the galaxy. As I understand it, the heavier elements that are created from supernovae, should already be widely distributed. These heavier elements come from much younger stars, those existing in the earlier Universe. Our Sun is about 5 billion years old, but stars in the earlier Universe may have lived shorter lives going be recent observations.

    This of course determines how rare those Earth like planets are, which is why I think it is ever more probable that they are likely to occur.
     
  11. Feb 23, 2004 #10

    russ_watters

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    It gives us a theoretical association between arbitrary numbers: ie, very little of real value. We don't have nearly enough info to pin down most numbers in it to the nearest order of magnitude (should we go over each one?) and as a result, the values we get from it can't be pinned down to within a good 5 orders of magnitude. So while its interesting to maniuplate, it doesn't give us much of scientific value.
    The first sentence is correct, after that, ehhh...

    Our understanding of science is for the most part hyperbolic and you can fit it to a curve. That is, if you take a scientific observation (the speed of light for example) and graph the accuracy with respect to time (year the measurement was taken), the result is roughly hyperbolic.

    As a result, the possible error in the postulate of the constancy of the speed of light has continually decreased and is now extrordinarily small. In 10,000 years, scientists will not suddenly discover that C is 600,000 km/s. Its quite simply not possible.

    You can fit other observations (oribital mechanics calculations for example) to similar curves. The bottom line, however, is that what is unknown about how the universe works is getting pretty small. Whether we stumble upon a GUT tomorrow (some physicists used to think we were pretty close) or we just keep getting closer and closer without hitting it doesn't matter: C is roughly 300,000km/s, no object with mass will ever exceed that, and no ammount of research will change that.
    Why? That is: on what do you base that belief?
    IIRC, the sun is thought to be third or fourth generation.
    But until we find one outside our own solar system, we are just speculating. That's my point to I.S. There really isn't any firm basis for that particular term in the equation.

    I certainly hope NASA isn't so burdened by Bush's boondoggle that they have to cancel or cut the Origins Program, because it has a real possibility of being able to pin some of those terms down and possibly even hit the jackpot of finding another earth.
     
  12. Feb 23, 2004 #11

    Phobos

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    For now, I think we can say the odds are good (based on math, bio, etc.)...but we have a lot more research to do before we can prove it's reality.
     
  13. Feb 23, 2004 #12

    jimmy p

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    Aliens according to Star Trek...Strap a cornish pastie or sausage roll to an extra's head and voila, we have new race. Maybe the size of the savoury on their head is how fearsome the race is. And they NEVER meet any NICE aliens.
     
  14. Feb 23, 2004 #13

    Ivan Seeking

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    I was talking about the size of the universe and the number of galaxies and stars that exist.


    You are talking about simple measurement error and precision. I am talking about great leaps in understanding as with Galileo, Newton, Heisenberg, Schrödinger, and those forced by discoveries that cannot be anticipated. In physics we must think in terms of centuries, not decades.

    Prove it. This assumes that we know how much we don't know; clearly a fallacy. In fact we only recently realized that we observe only about 5-10% of the universe. We now realize that 90% of the universe - dark matter, or whatever we call it today - is unknown. Of course, Michio Kaku thinks that the gravity from the alleged dark matter may really be the gravity from another universe leaking into ours. Oh yes, can you please explain the mechanism for entaglement. How exactly is the information "communicated"? I don't think we're done yet.

    This assumes travel in the sense that we know it now. Just one concept like space folding, warp bubbles [where Star Trek got its idea], controlled worm holes as proposed by Cal Tech in 1987, or certain spin offs from the Casimir effect could make this limit a moot point. Presently it seems that the energy requirements are the biggest limitation. For a preliminary update of the facts please see The Future of Spacetime by Hawking, Thorne, Novikov, Ferris, Lightman, and Price. c2002.
     
    Last edited: Feb 23, 2004
  15. Feb 24, 2004 #14
    I'm not trying to say we can violate the laws of nature, but its not very clear as yet what the laws of nature permit us to do. For now traveling in the Universe seems very inefficient if its kept under the SOL.
     
  16. Feb 25, 2004 #15
    Physicists said the same thing about the sound barrier. It can't be broken.
     
  17. Feb 25, 2004 #16

    Phobos

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    That was believed to be a technical (engineering) problem, not a violation of the laws of physics like breaking the speed of light.
     
  18. Feb 25, 2004 #17
    Hey Phobos, are your eyes brown?
    People often whistle another tune when they are proven wrong, but then there are some that just keep whistling creating deception after deception. Time to debunk the deceivers.

    There is no limit to how fast we can go. We just need a faster engine.
     
  19. Feb 25, 2004 #18

    Ivan Seeking

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    There is a difference between engineering limits and fundamental limits. According to our best understanding of the laws of physics, faster engines will not beat the speed of light barrier...EVER!

    There are a range of potential solutions that seek to bypass this limit [not to beat it], however none of these approaches are presently possible due to engineering and energy limits. None may ever be possible...even if in principle they might work. For example, in some approaches exotic materials are required that may not even exist. Other solutions require the energy of a thousand suns, or the infinite (?) mass density of a black hole. In other cases we require perfect superconductors which likely will never be possible to make. Any hopes to beat the SOL barrier are just that and only that for now - hopes. There is a chance; we can say no more.
     
  20. Feb 25, 2004 #19
    wow, we just never think outside the box eh? faster engine? tsk tsk.. anyway..

    aliens yes or no? of course just look at all those movies, lol :wink:

    ah i don't believe so.. i mean the distances and times are just so huge, and even if those were conquered what would be the point of coming here? to earth? if there are other ppls out there, you think they would come to earth?! lol, no no, well mb if we are a tv show.

    god i love south park. http://www.southpark.dsl.pipex.com/scripts/scr704.shtml

    yeah you wont' read the whole script basically says earth is a tv show.
     
  21. Feb 25, 2004 #20
    Well if the human race were important in one respect or another for some reason then there might be a reason that ET may be watching us. As it is written in the bible, “we are a spectacle to them that watch from the heavens”.

    Go figure, maybe it is our TV shows.
     
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