Is humanity alone? No. Period. As Douglas Adams says, the universe is a really big place. The question is, why haven't we had contact? Well, you know, I actually don't think that's a hard question. First, how long have we been looking? 50 years, max? Second, how could aliens find us, out here on the edge of the galaxy, until we waved at them, which we've only been doing for about 100 years, a mere tick of the clock, using a method so primitive that even creatures with our minimal intelligence can employ it (i.e., radio)? Third, and most important, how have we been looking? We've been using telescopes, a ridiculous method, and lately, with SETI, some few radio frequencies. Not unreasonable, given that aliens are like us... but why should that be true?
Let's put this in perspective. Suppose that dogs were trying to signal another species of dog. How would they do it? By barking or howling, right? Would we notice that, as a signal of that type? Would we care? How much smarter, given some theoretical maximal potential for intelligence, are we than dogs? Infinitesimally, I would say. Our brains must fit, badly, inside our heads, folded up, in order to have expanded to the amount they have, which is about all our bodies will take, both in volume and metabolically.
Suppose we found out how to increase head size, or produce more efficient folding, or better, connect ourselves to our computers? Where would our intelligence go then? In the latter case, the practical limits would be... well, I certainly can't even begin to envision it. Now, given that we could be, let us conservatively say, 100 times more intelligent than now, how would we signal... what indeed would our picture of the universe be, our physics, our electronics? We are not now 100 times smarter than dogs. How would our physics compare with our present idea of physics? Etc. You see my point? To aliens, if they notice us at all, we are, until we can consciously increase our intelligence, merely another species of animal on this planet. So why should they want to contact us, any more than we would want to contact those dogs? And how would we notice or understand it, if they did, any more than dogs could conceive, build, and use a radio set?
That's one of my theories, I think the most likely one. The next most likely one is this: look at the way computers are going. What if we are able to "scan" our brains totally, convert our neural dynamics into another form, and embody ourselves within a computer (a very large one, of course, and a radically different type from present digital computers, but those are — for the purpose of this discussion — quibbles). I mean, totally move into the computer, as a dynamic pattern in it. And not just ourselves, but everyone and our civilization... living in a virtual world, having anything we want happen (virtually, of course, but we wouldn't see any difference), and being immortal (as long as the computer wasn't hit by a meteor, etc.). Now wouldn't that be wonderful? Think about it. Anything you wanted, any life, any environment, any physical laws, no risk, no death... as long as you want.
Now, if I were an alien civilization faced with that possibility, vs. living in the cold, hard, limited real universe, hey, why not? So the second theory is that we can't contact them because when a civilization gets advanced to that stage, they just all move into their computer(s) and live happily ever after, in a virtual heaven of their own design, with the computer protected behind layers of armor and powered by something reasonably perpetual. Sounds good to me, anyway. So that's my second theory as to why we haven't and won't contact them. They're out there, zillions of them. They're just living luxuriously in the basement, so to speak, hoping to go unnoticed for as long as possible.
Or it could be a combination of the two above, with extremely advanced virtual civilizations communicating with each other by means unavailable (and incomprehensible) to us, until we get to that point.
The first thing to say is that if the alien succeeded in making it understood that it wanted to know 'what it meant for human beings to have a mind', then you would presume that it had a mind. Of course, there's always the initial possibility that you are listening to a tape recording, but if you manage to continue an intelligent conversation, that can be ruled out. Then there's the possibility that your 'alien' is merely a mechanical probe responding to instructions from real aliens in their orbiting space ship or back on Mars, and relaying their questions to you. In that case, you are dealing with real minds, at one remove.
However, that misses the real point of the question. With an alien being, we lack all sorts of basic evidential cues. We can't tell the difference between a 'smile' and a 'frown', or between different tones of voice. There's little to empathize with. Or we might be faced with the more extreme Star Trek scenario of a being made of pulses of incandescent energy. Does that pose an insuperable problem?
The mathematician Alan Turing proposed a famous test which could be used to determine whether an individual at the other end of a computer terminal had a mind. The test is to see whether you can keep up an intelligent conversation. In other words, there's sufficient evidence going by speech alone to make a decision. Going by that test, it is irrelevant how physically different the alien is from us.
For anyone who has doubts about the sufficiency of the Turing test — as I have — the question remains open. Suppose that someone suggested that the aliens were intelligent, but unfeeling machines. So it was morally acceptable to use the aliens as tools, enslave them, put them to whatever purpose we liked. The question is whether there is a philosophical argument to show why that attitude would be wrong.
Source:
http://www.123infinity.com/extraterrestrial_life.html
