"We succeeded in taking that picture [from deep space], and, if you look at it, you see a dot. That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there on a mote of dust, suspended in a sunbeam.
The earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and in triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of the dot on scarcely distinguishable inhabitants of some other corner of the dot. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light.
Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity -- in all this vastness -- there is no hint that help will come from elsewhere to save us from ourselves. It is up to us. It's been said that astronomy is a humbling, and I might add, a character-building experience. To my mind, there is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly and compassionately with one another and to preserve and cherish that pale blue dot, the only home we've ever known."
When you see things like these you have to think that we are not the only life in the entire existence and it is highly doubtful we are the only 'intelligent' life in existence just by probability alone.
It's a shame we'll probably never come across intelligent life, unless some incredible developments are made in traveling space.
The Drake Equation ( http://en.wikipedia.org/wiki/Drake_equation ) estimates between 1 and 10 intelligent life forms in our galaxy. The unmanned probe Voyager 1 is the furthest Earth born object that we have radio contact with (probably without, as well) and was launched in late 1977. It has traveled less than 2 thousandths of a light year. The nearest star (other than the sun) is over 4 light years away, and our galaxy is something crazy like 100,000 light years across. The nearest similar galaxy is the Andromeda galaxy which is 25,000,000 light years away.
In other news, I just recently finished an astronomy course.
Well, you never know. If the universe really is holographic and we can find a way to move within that, then locality might come to seem like a quaint concept. I had a near-death experience some years back which left me with the gut feeling that our space is embedded within 5 dimension. It was pretty strange, but that's another story. For about 5 minutes after I came round I could see around things. If you think that sounds weird, you shoulda seen it from my side.
The Drake Equation is missing something. If humans were to go extinct in, say, 100,000 years (arbitrary), the earth still has plenty of time left to evolve another intelligent species. That cycle could repeat itself dozens of times over the course of a planet's lifetime. The Drake Equation doesn't model this concept of "multiple windows of opportunity".
right, now ok, if it takes 25 million light years, and and in 40 years that voyager apparently only travelled 1 thousands light year away. How on earth,do they know how far it is? Can the telescope travel extend our sense faster than the light can travel? Because if not, then surely it would take 25 million years for us to find out how far it is? And if you will be lazy and ask me to wikipedia it, ave got an exam tomorrow :P. But it seems quite puzzling to me, puzzling enough to perhaps disregard the numbers.
As for how big I feel? Ohh gigantic, bigger than the sun, I contain so many cells, and these cells contain so many cells and they probably contain so many cells, I am a giant universe so giant that I have within me so many universes.
Be that as it may, that's still an irrational reaction. We don't know what the odds of intelligent life are, and there's no guarantee that they are not comparable to the size of the universe... or even a long shot despite the size of the universe.
For all the stars in all the solar systems in all the universe across all time, for as large as that number may be, you start stacking together independent requirements for life (galaxy with available stable orbits, water planet, habitable zone, mineral abundance, perhaps big moon, and this is the tip of the tip of the iceberg for feasible potential requirements) and the odds against can go up fast, too.
As an example, it is hypothesized that only a spiral galaxy can support life, since only a spiral galaxy will have orbits that are not too close to the galactic center at some point. (Recently, there have been some suggestions that it may also be important not to be too far from it, either.) Right off the top, this eliminates a gigantic number of galaxies from contention. Certainly it leaves roughly an equal number still in contention (couldn't find precise frequency counts but 50% is close enough here), but even the mighty size of the Universe can't sustain an indefinite exponential culling.
We still don't know. Just because there's a really big number on one side of the question that's visibly obvious, doesn't mean that a much more subtle but equally large number doesn't lie on the other side.
(To save time, I've assumed "life as we know it". Feel free to substitute some other definition, though personally I'm yet to see a very convincing argument in favor of non-carbon, non-water intelligent life. YMMV.)
Please be clear: I am not advocating the "we're alone" position. I'm advocating the "we truly don't know" position. There's a difference.
(It may seem trite and old now, but I still think the Fermi Paradox is one of the most important questions of our time. The silliness of the Drake equation sort of got in the way, but it can be boiled down to: If intelligent life is easy and there's no terribly compelling reason why intelligent life can't at least populate the galaxy, why hasn't it? Note that "populate the galaxy" may and probably does take the form of some form of machine life, but I've seen no compelling reason to believe that's impossible yet.)
I'm down with that. For a really well rounded and thoroughly informed view, I recommend Ernst Mayr (http://en.wikipedia.org/wiki/Ernst_Mayr). A Biologist and Philosopher, he really understood the foundations of "life as we know it" and what implications this has on our view of the universe.
For instance he wrote some wonderfully insightful essays on the probability of intelligent life (maybe even just "l.a.w.k.i") on the grounds that most people misinterpret the products of strict evolutionary theory. He claimed that for il/lawki to have evolved one must posit the happenings of not just the simian evolutionary line, but all life and it's corresponding physical environment. If we take this literally, then we can say that for il/lawki, an unbroken line of events 13 billion years long are invested in the simple phrase "intelligent life" or "life as we know it"... and we need not restrict ourselves to any time period as it's a continuum, so we start to get an infinite on this side of the equation that divides the infinity of the universe into a simple and undeniable unity - us. To posit anything further than this is beyond the realms of scientific integrity.
I remember reading A Short History Of Nearly Everything by Bill Bryson and one particular rambling that stuck with me was that the Earth had been through something like 7 extinction periods where 99% of all life had been eliminated. It was after all these extinction periods that life evolved to what it is today.
That gives you another perspective--one that shows the possibility of life outside earth is pretty small.
But I wonder if there is some probability that can take both of these factors into consideration.
The most interesting part of it, IMHO, is time, not so much the distance and probability. We are new at being an intelligent species with organised science. Other intelligent life in the universe that we might hope to interact with, aren't less developed than us, but they might easily have 50.000 years or more on us.
How do we know that there aren't already "aliens" that know about us?
The time aspect also suggests that we have nothing to fear from aliens. If they've survived themselves for thousands of generations from where we are today, it's impossible that they don't have a viable and sustainable way of life, that doesn't require them to go "harvest" us :)
No doubt, the only reason there was any question about it in the past(before technology), was due to the fact that we are in the middle of nowhere(by galactic standards), and can only see a handful of other stars.
A FASCINATING point that runs contrary to this whole awe-yourself-in-front-of-the-omniverse-bullshit is the curious mathematical abstraction that a single human brain contains more _potential_ structural architecture than there are atoms in the universe. This always felt like a big "fuck you" to that "humbling" sense of insignificance the universe seems intent on drilling into my skull....
I believe that there are other people living somewhere in the space, very very very far from here...
View the distance, I see like it's impossible to reach them, but if we just create a high precision telescope that can capture photos from these places... I'll create a program that automatically capture them and try to detect an aslike earth photo and we'll may be see those other people
![Yup, We're All Pretty Small [Photo]](http://img19.imageshack.us/img19/2706/spaceb.jpg){kind=link}
The earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and in triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of the dot on scarcely distinguishable inhabitants of some other corner of the dot. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light.
Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity -- in all this vastness -- there is no hint that help will come from elsewhere to save us from ourselves. It is up to us. It's been said that astronomy is a humbling, and I might add, a character-building experience. To my mind, there is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly and compassionately with one another and to preserve and cherish that pale blue dot, the only home we've ever known."
--Carl Sagan