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Are we alone in the universe or is there life out there waiting to be discovered?
NASA is getting ready to launch the Kepler telescope on an ambitious, first-of-its-kind mission: to search for Earth-size planets in our galaxy, orbiting stars at the right distances to have water on their surface.
It takes a great deal of arrogance and denial to believe that we are alone in the universe. The utter immensity of it guarantees that there is a lot of life out there.
It also takes a great deal of arrogance to believe that we are an intelligent race, and would be peers to any that might discover our existence. I suspect they would view us much as a kid views ants on a sidewalk on a sunny day.
It takes a great deal of arrogance and denial to believe that we are alone in the universe. The utter immensity of it guarantees that there is a lot of life out there.
It also takes a great deal of arrogance to believe that we are an intelligent race, and would be peers to any that might discover our existence. I suspect they would view us much as a kid views ants on a sidewalk on a sunny day.
If the aliens view us like ants, no doubt some rowdy alien may decide to start turning people into cinders using a magnifying glass aimed at the sun. LOL!
While there may indeed be life teeming throughtout the universe, even intelligent life, we have yet to find any real evidence that there is indeed life elsewhere. What we know is that there is life on our planet. But so far, there's no "guarantee" there's life anywhere else. However, that's all we know.
The question of life elsewhere in the universe is one reason why we're looking at Mars. It's still possible some kind of micro-organisms might live there, maybe beneath the surface.
Any suggestions that the vast size of the universe "guarantees" there's a lot of life in it, is based on speculation and theory - not on observed facts. Nothing wrong with that though because speculation and ideas are what help us imagine possibilities and make new discoveries. We are still at the very beginning of understanding the nature of the universe.
In my opinion, if there is intelligent life within our galaxy, I don't think there's too much to worry about in the way of visitations or alien invasions. The distance just to the nearest neighboring star is mind-boggling. Travel between galaxies is even more unlikely considering the distance to the nearest major galaxy is around 2 million light years away.
That's not to say there is no life elsewhere. It's just that we don't know if there's any life anywhere else. It'll be interesting to see what the Kepler telescope shows in the way of any Earth-sized planets in the so-called Goldilocks Zone of their host star. Seems to me it could take 3 or so years before discovering any such planets though. Even then, we won't really see much apart from it transiting in front of their star. From what I understand, Kepler is only a first step to discovering exoplanets that are smaller than the usual gas or rocky giants that have already been discovered.
Last edited by NightBazaar; 03-06-2009 at 08:12 PM..
Reason: Spelling correction
I use to think that intelligent life was fairly commonplace. Now, I think it is likely extremely rare.
The sun had to be the right class of star, in the right band of the galaxy, Jupiter or an analog had to exit within certain parameters, the Earth had to be roughly a particular size, it had to get hit hard to create a just-the-right-size moon that acted as a shield and stirrer, the core had to be magnetic to act as a shield, there had to be lots of water and carbon, life itself had to develop, and then there had to be catastrophes large enough to have three mass extinctions without totally killing off all life, and then there had to be a subtle genetic shift to twist the brain into a more developed form.
All totaled, if one star out of 1,000,000,000,000 had the possibility of a planet with intelligent life, then we would have to consider how long intelligent life capable of communicating on an extra-planetary system scale would exist. Intelligence is not an automatic answer to problems of diseases and natural disasters, especially if those disasters are on any large scale. Whales could be commonplace compared to smart humanoids, but whales have no need or ability to communicate on an extra-planetary system scale. Although we might not be alone in the universe, I suspect we are close enough to it, given the huge distances involved, that we might as well figure that we are.
The real issue is that there are very few pockets in the universe where radiation is minimal enough, elements are plentiful enough and in the correct proportions, and temperatures are in the correct range all for a long enough period of time to allow life, and later intelligent life, to form.
All totaled, if one star out of 1,000,000,000,000 had the possibility of a planet with intelligent life, then we would have to consider how long intelligent life capable of communicating on an extra-planetary system scale would exist.
Thus assuming carbon based life, and we have found life on our own planet that lives it an environment that is very toxic to most life on the planet.
But OK, if 1 in 10^12 stars might have a planet computable with carbon based life forms, and there are an estimated 10^24 stars in the universe. Thus there is the possibility of 10^12 planets (or 1,000,000,000,000) that could support life as we view it as oxygen breathing carbon based life.
And what about sulfur based life, or silicon, or methane, or ammonia , and anything that might allow life to develop.
But there will always be those that deny anything they can't see, or even what they can see when it is in conflict with religious doctrine.
The real issue is that there are very few pockets in the universe where radiation is minimal enough, elements are plentiful enough and in the correct proportions, and temperatures are in the correct range all for a long enough period of time to allow life, and later intelligent life, to form.
Yeah, and even then, in order to be advanced technologically, an intelligent species likely be hamstrung by the lack of useful elements that would help him build tools to explore and to better enhance their lives.
Thus assuming carbon based life, and we have found life on our own planet that lives it an environment that is very toxic to most life on the planet.
But OK, if 1 in 10^12 stars might have a planet computable with carbon based life forms, and there are an estimated 10^24 stars in the universe. Thus there is the possibility of 10^12 planets (or 1,000,000,000,000) that could support life as we view it as oxygen breathing carbon based life.
And what about sulfur based life, or silicon, or methane, or ammonia , and anything that might allow life to develop.
But there will always be those that deny anything they can't see, or even what they can see when it is in conflict with religious doctrine.
Brian, you seem to be on a crusade, rather than thinking it through. Methane is CH4 (CARBON and hydrogen). Ammonia is likewise not an element and is too highly highly reactive anyway. Silicone just doesn't have the energy depth required unless very pure and doped with rare earth elements. If you are trying to consider other life forms, you would be better off considering the old Fred Hoyle macguffin of an intelligent interstellar cloud of dust. The physics of that are at least unknown enough to make it plausible.
My point is not religious, I think the likelihood of life elsewhere is somewhat possible. My point is that after factoring all of the fine tuning that is needed to force the growth of a lifeform that can attempt to communicate on an interstellar basis, "intelligent" life is extremely rare, to the point that we can just about rule out ever contacting one.
I remember reading that scientist found 3 earthlike planets in another galaxy, but with the technology we have today and the distance to that galaxy would take more than a life time.
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