Does intelligent life exist elsewhere in the universe? Probably. There are an estimated 210 sextillion planets in the universe, so the likelihood of a planet existing that's very similar to ours seems really, really high. The part I cannot believe, however, is that this other intelligent life has visited our little planet here. With 210 sextillion planets, it seems unlikely that they would find our specific little planet in our specific little solar system in our specific little galaxy. The odds of THAT are astronomically low, I'm sure. Even if there was 1 intelligent planet per galaxy, meaning approximately 125 billion intelligent planets, we still have about a 1 in 6 x 10^13 shot (60 trillion) of being discovered by one of these 125 billion intelligent races. So, basically, if the government is disclosing stuff, my guess is they'll say "Nope, haven't seen any."
Perhaps, but this may not be the case. Certainly, if there is intelligent life on a planet in a galaxy that's in the far sides of the universe, the odds of them finding us are nearly infinitesimal. But as you get closer to Earth, I would think the odds would increase. For example, the odds of people on that planet finding us would not be as great as the odds of people on a planet in Alpha Centauri finding us. In fact, if there was intelligence in Alpha Centauri, our solar system would probably be one of the first ones they'd look at because Alpha Centauri is the closest solar system to ours.
But the likelihood of two planets supporting intelligent life in adjacent solar systems is very, very low. Supporting life at all takes a delicate balance with distance from the sun and various atmospheric conditions. Or, maybe supporting Earth life... perhaps there are things that can like in extreme high/low-pressure environments with Earth-toxic atmosphere. Still, I find it difficult to believe that it exists in an adjacent solar system. It's a bit more believable within our galaxy, but the galaxy is still huge (a trillion planets, is it?) and the likelihood is still infinitesimal.
... and to agree with you, I think we've already determined that Alpha Centauri isn't capable of having an inhabitable Earth-like planet... ...however... That doesn't mean that there are infinitesimal odds against us finding such a planet. Look at the Kepler mission. We've launched this telescope into space. It's sole purpose is to find terrestrial planets that are in inhabitable zones near their stars. Over the next 5 years, it's going to watch over 100,000 stars and estimates are that it will discover hundreds of earth-size or smaller planets in or near the habitable zone. When you start thinking about that, those "odds against" start to lose their bite. And human kind is only in its infant stages of extra-solar exploration!
But again, I'm not talking about odds against there being life elsewhere in the galaxy. I'm talking about odds against that life finding us. It's like a double-whammy of unlikeliness.
UFO != Alien, watch it be a whack announcement. Be super cool if it an actual announcement that shakes the world though!
True, but if we can find them, logic would indicate that, if their intelligence equals or surpasses our own, they could certainly find us. The way I see it... the biggest barrier which we need to learn to get past is light speed. Even if we find one of those planets, and it's full of people, what then? In order to travel or even communicate with them, we are going to need to figure out how to send a communication signal that can travel faster than the speed of light. And we certainly would need to know how to make a ship travel faster than light speed if we intend to visit them. Hell... a one-way ticket to Mars takes three years with current technology. If we intend to visit another planet in another solar system, we're gonna have to do a lot better than that.
But we haven't, thus, my disbelief that someone's visited us. Agreed. You'd think constant acceleration could get you there given that there's little to no resistance in the vacuum of space, but then you'd have the question: how do you stop? Also, where do you get the energy to constantly accelerate? To suddenly accelerate to beyond light speed is another conundrum. Anything like that would immediately crush/kill us. How do you dampen intertia? This science fiction stuff is so cool when meshed with reality, and you really realize how far off we are from any sort of decent space exploration.
Accelerating at 1g (9.8 m/s^2), it would take us 58.2 years to reach the speed of light (299,792,458 m/s). In order to get there is some feasible amount of time, we'd definitely need a way to dampen the force of acceleration.
